项目结构

软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
主要部分有java文件夹和res文件夹,其中java文件夹内为程序代码部分,res中为资源文件。
泛读代码后可以得到各个类的主要作用及其包结构。
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
体系结构图如下:
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
image.png

代码分析

整体分析

先用SonarLint整体扫一遍,发现35个文件中有385个问题。
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
但这其中有很多问题是因时代原因和重复的。所以需要人工复审一下。复审就很容易知道,其中一大半都是命名规范,或是因时代导致当时的函数如今被废弃了。总而言之,小米便签的源代码质量还是不错的。
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
在SonarQube中,代码缺陷分为以下五个级别:
(1)Blocker: 极有可能影响应用程序表现的错误;
(2)Critical: 可能影响应用程序表现的错误和表示安全缺陷的问题;
(3)Major:严重影响开发者效率的质量缺陷:.
(4)Minor:轻微影响开发者效率的质量缺陷;.
(5)Info:不是错误或者质量缺陷。
所以下面就分析代码中缺陷等级为Blocker、Critical、Major的部分

Blocker部分

BackupUtils.java
  • 资源未关闭 出错位置:288行
private PrintStream getExportToTextPrintStream() {  
    File file = generateFileMountedOnSDcard(mContext, R.string.file_path,  
            R.string.file_name_txt_format);  
    if (file == null) {  
        Log.e(TAG, "create file to exported failed");  
        return null;    }  
    mFileName = file.getName();  
    mFileDirectory = mContext.getString(R.string.file_path);  
    PrintStream ps = null;  
    try {  
        FileOutputStream fos = new FileOutputStream(file);  
        ps = new PrintStream(fos);  
    } catch (FileNotFoundException e) {  
        e.printStackTrace();  
        return null;    } catch (NullPointerException e) {  
        e.printStackTrace();  
        return null;    }  
    return ps;  
}

上述代码中的文件输出流未关闭,可能会发生内存泄漏的问题。解决方案就是在使用资源类时配合try-with-resources的方式,最终在finally块中写入close方法即可。

NoteEditActivity.java
  • Refactor this method to not always return the same value.
    当一个方法被设计为返回一个不变值时,它可能是一个糟糕的设计,但它不应该对程序的结果产生不利影响。然而,当它发生在逻辑的所有路径上时,它肯定是一个错误。
    当一个方法包含多个返回相同值的返回语句时,此规则会引发问题。
public boolean onPrepareOptionsMenu(Menu menu) {  
    if (isFinishing()) {  
        return true;  
    }  
    clearSettingState();  
    menu.clear();  
    if (mWorkingNote.getFolderId() == Notes.ID_CALL_RECORD_FOLDER) {  
        getMenuInflater().inflate(R.menu.call_note_edit, menu);  
    } else {  
        getMenuInflater().inflate(R.menu.note_edit, menu);  
    }  
    if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {  
        menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_normal_mode);  
    } else {  
        menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_list_mode);  
    }  
    if (mWorkingNote.hasClockAlert()) {  
        menu.findItem(R.id.menu_alert).setVisible(false);  
    } else {  
        menu.findItem(R.id.menu_delete_remind).setVisible(false);  
    }  
    return true;  
}

Critical部分

BackupUtils.java
  • Refactor this method to reduce its Cognitive Complexity from 27 to the 15 allowed.
    某方法的复杂度太高了,每个方法最高的认知复杂度就是15。所谓认知复杂度就是你方法的复杂高低,比如你方法里套了一堆if,每个if的判断条件还又特别复杂,那这样方法的认知复杂度就会很高。
    这个规范其实我自己写代码的时候也经常遇到,说实话,我还是挺烦这个的,虽然我们都知道在OOP里,要时刻有着把重复代码抽出来成方法、复杂代码里的关键逻辑抽出来成方法的意识,但是sonarlint里这个规范实际上很不合理。比如有时候我就写了18行,他就非要让我改成15行,因为这还是个Blocker级别的区别,很严重了。
private void exportNoteToText(String noteId, PrintStream ps) {  
    Cursor dataCursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI,  
            DATA_PROJECTION, DataColumns.NOTE_ID + "=?", new String[] {  
                noteId  
            }, null);  
  
    if (dataCursor != null) {  
        if (dataCursor.moveToFirst()) {  
            do {  
                String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);  
                if (DataConstants.CALL_NOTE.equals(mimeType)) {  
                    // Print phone number  
                    String phoneNumber = dataCursor.getString(DATA_COLUMN_PHONE_NUMBER);  
                    long callDate = dataCursor.getLong(DATA_COLUMN_CALL_DATE);  
                    String location = dataCursor.getString(DATA_COLUMN_CONTENT);  
  
                    if (!TextUtils.isEmpty(phoneNumber)) {  
                        ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),  
                                phoneNumber));  
                    }  
                    // Print call date  
                    ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT), DateFormat  
                            .format(mContext.getString(R.string.format_datetime_mdhm),  
                                    callDate)));  
                    // Print call attachment location  
                    if (!TextUtils.isEmpty(location)) {  
                        ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),  
                                location));  
                    }  
                } else if (DataConstants.NOTE.equals(mimeType)) {  
                    String content = dataCursor.getString(DATA_COLUMN_CONTENT);  
                    if (!TextUtils.isEmpty(content)) {  
                        ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),  
                                content));  
                    }  
                }  
            } while (dataCursor.moveToNext());  
        }  
        dataCursor.close();  
    }  
    // print a line separator between note  
    try {  
        ps.write(new byte[] {  
                Character.LINE_SEPARATOR, Character.LETTER_NUMBER  
        });  
    } catch (IOException e) {  
        Log.e(TAG, e.toString());  
    }  
}

上述代码的解决方案也很简单,无非就是把这个方法按逻辑抽成几个小方法,最后拼在一起。

Contact.java
  • Use static access with "android.provider.ContactsContract$DataColumns" for "MIMETYPE".
    为了代码清晰,基类的静态成员不应使用派生类型的名称进行访问。
    举个十分简单的例子:
//错误版本
class Parent {
  public static int counter;
}

class Child extends Parent {
  public Child() {
    Child.counter++;  // Noncompliant
  }
}

//正确版本
class Parent {
  public static int counter;
}

class Child extends Parent {
  public Child() {
    Parent.counter++;
  }
}

因为static变量无论在哪里使用,都是共享同一块内存空间。所以最好是使用定义了这个静态变量的类名进行属性的引用。

private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER  
+ ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"  
+ " AND " + Data.RAW_CONTACT_ID + " IN "  
        + "(SELECT raw_contact_id "  
        + " FROM phone_lookup"  
        + " WHERE min_match = '+')";

上述小米便签中的错误出在了这条SQL语句中,本人猜测是当时没有很合适的ORM框架,流行的是把SQL语句和代码捆绑写在同一个类中。不过这个扯远了,并不是这个问题的描述。
上面代码出现的问题是,Data.MINETYPE这个常量,其实是Data实现的ContactCounts这个接口中定义的一个静态变量。所以将Data改为接口名就可以了。

  • Add a private constructor to hide the implicit public one.
    添加私有构造函数以隐藏隐式公共构造函数。
    实用程序类是静态成员的集合,并不意味着要实例化。即使可以扩展的抽象实用程序类也不应该有公共构造函数。
    Java为每个类添加了一个隐式公共构造函数,该类至少没有显式定义一个。因此,应至少定义一个非公共构造函数。
    解决方法也很简单,给Contact类加个private构造方法就行。
DataUtils.java
  • Define a constant instead of duplicating this literal "%s: %s" 4 times.
    字符串不应该被复制。这个问题很显而易见了。如果我们采用复制字符串编写代码的方式,在代码重构的过程中,如果需要修改部分,首先麻烦,其次如果部分换部分不换,还会造成一致性错误。
    解决方法:抽出来为一个常量即可。
GTaskSyncService.java
  • Make the enclosing method "static" or remove this set.
    从非静态方法正确更新静态字段很难,如果存在多个类实例和/或多个线程,则很容易导致错误。理想情况下,静态字段仅从同步的静态方法更新。
    每次从非静态方法更新静态字段时,此规则都会引发一个问题。
    说白了就是静态变量共用同一块内存空间,但是现在代码里修改静态变量的部分不是上锁的,就导致多线程环境下的潜在危险。那解决方案就很简单,加个合适的锁。
private void startSync() {  
    if (mSyncTask == null) {  
        mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {  
            public void onComplete() {  
                mSyncTask = null;  
                sendBroadcast("");  
                stopSelf();  
            }  
        });  
        sendBroadcast("");  
        mSyncTask.execute();  
    }  
}
//可修改为如下
private synchronized void startSync() {  
    if (mSyncTask == null) {  
        mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {  
            public void onComplete() {  
                mSyncTask = null;  
                sendBroadcast("");  
                stopSelf();  
            }  
        });  
        sendBroadcast("");  
        mSyncTask.execute();  
    }  
}
NoteEditText.java
  • Add a default case to this switch.
@Override  
public boolean onTouchEvent(MotionEvent event) {  
    switch (event.getAction()) {  
        case MotionEvent.ACTION_DOWN:  
  
            int x = (int) event.getX();  
            int y = (int) event.getY();  
            x -= getTotalPaddingLeft();  
            y -= getTotalPaddingTop();  
            x += getScrollX();  
            y += getScrollY();  
  
            Layout layout = getLayout();  
            int line = layout.getLineForVertical(y);  
            int off = layout.getOffsetForHorizontal(line, x);  
            Selection.setSelection(getText(), off);  
            break;    }  
    return super.onTouchEvent(event);  
}

switch没有default语句,并且default要加着在最后一个。

NoteItemData.java
  • Update this method so that its implementation is not identical to "getParentId" on line 185.
public long getFolderId () {  
    return mParentId;  
}

public long getParentId() {  
    return mParentId;  
}

小米便签里有两个部分,代码相同,但方法名不同。只能说,也有说法能解释,但是肯定是统一成一个更好。

Notes.java
  • Move constants defined in this interfaces to another class or enum.
    常量接口模式是对接口的一种不良使用。
    一个类在内部使用一些常量是一个实现细节。
    实现一个常量接口会导致这个实现细节泄露到该类的输出API中。对于一个类的用户来说,该类实现了一个常量接口是没有任何意义的。事实上,这甚至会使他们感到困惑。更糟糕的是,它代表了一种承诺:如果在未来的版本中,类被修改得不再需要使用常量,它仍然必须实现这个接口以确保二进制的兼容性。如果一个非最终版本的类实现了一个常量接口。
    它的所有子类都会被接口中的常量污染它们的名字空间。
    解决方式:把接口中的常量搞个常量类或者枚举类就行了

Major部分

DataUtils.java
  • 移除永远为false的判断条件
    这个没啥好说的
  • Merge this if statement with the enclosing one.
    将此if语句与封闭语句合并。
if(cursor != null) {  
    if(cursor.moveToFirst()) {  
        try {  
            count = cursor.getInt(0);  
        } catch (IndexOutOfBoundsException e) {  
            Log.e(TAG, "get folder count failed:" + e.toString());  
        } finally {  
            cursor.close();  
        }  
    }  
}

修改为如下:

if (cursor != null && cursor.moveToFirst()) {  
    try {  
        count = cursor.getInt(0);  
    } catch (IndexOutOfBoundsException e) {  
        Log.e(TAG, "get folder count failed:" + e.toString());  
    } finally {  
        cursor.close();  
    }  
}
DataTimePicker.java
  • Make this anonymous inner class a lambda
    将此匿名内部类设置为lambda
    这个说实话,猜不出原因,因为当年应该有JDK8才对,那时候已经有lambda表达式了。也许是因为当时这个特性太新了,小米公司那会也没有函数式编程人才,所以没有这个意识。
    将匿名内部类变为lambda表达式会大大增加可读性和代码优雅,但是修改起来确实不舒服。
private NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() {  
    @Override  
    public void onValueChange(NumberPicker picker, int oldVal, int newVal) {  
        mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal);  
        updateDateControl();  
        onDateTimeChanged();  
    }  
};
  • This conditional operation returns the same value whether the condition is "true" or "false".
    无论条件是“true”还是“false”,此条件操作都返回相同的值。
    这个挺逗的,不知道当时他们咋想的。
private void updateTitle(long date) {  
    int flag =  
        DateUtils.FORMAT_SHOW_YEAR |  
        DateUtils.FORMAT_SHOW_DATE |  
        DateUtils.FORMAT_SHOW_TIME;  
    flag |= mIs24HourView ? DateUtils.FORMAT_24HOUR : DateUtils.FORMAT_24HOUR;  
    setTitle(DateUtils.formatDateTime(this.getContext(), date, flag));  
}

把三元运算符改了就行。

GTaskManager.java
  • Constructors for String, BigInteger, BigDecimal and the objects used to wrap primitives should never be used. Doing so is less clear and uses more memory than simply using the desired value in the case of strings, and using valueOf for everything else.
Long parentId = (node instanceof Task) ? mGidToNid.get(((Task) node).getParent().getGid())  
        : new Long(Notes.ID_ROOT_FOLDER);
//改成下面这样即可
Long parentId = (node instanceof Task) ? mGidToNid.get(((Task) node).getParent().getGid())  
        : Long.valueOf(Notes.ID_ROOT_FOLDER);
GTaskSyncService.java
  • Make this anonymous inner class a lambda
    匿名类改lambda表达式,不再赘述
private synchronized void startSync() {  
    if (mSyncTask == null) {  
        mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {  
            public void onComplete() {  
                mSyncTask = null;  
                sendBroadcast("");  
                stopSelf();  
            }  
        });  
        sendBroadcast("");  
        mSyncTask.execute();  
    }  
}
//修改如下
private synchronized void startSync() {  
    if (mSyncTask == null) {  
        mSyncTask = new GTaskASyncTask(this, () -> {  
            mSyncTask = null;  
            sendBroadcast("");  
            stopSelf();  
        });  
        sendBroadcast("");  
        mSyncTask.execute();  
    }  
}
Node.java
  • Change the visibility of this constructor to "protected".
    抽象类不应有公共构造函数。抽象类的构造函数只能在其子类的构造函数中调用。因此,将其公开是没有意义的。受保护的修饰符应该足够了。
NoteEditActivity.java
  • Iterate over the "entrySet" instead of the "keySet"
    当循环中只需要map中的关键点时,迭代keySet是有意义的。但是,当同时需要键和值时,迭代entrySet会更有效,这样可以同时访问键和值。
private void initNoteScreen() {  
    mNoteEditor.setTextAppearance(this, TextAppearanceResources  
            .getTexAppearanceResource(mFontSizeId));  
    if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {  
        switchToListMode(mWorkingNote.getContent());  
    } else {  
        mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));  
        mNoteEditor.setSelection(mNoteEditor.getText().length());  
    }  
    for (Integer id : sBgSelectorSelectionMap.keySet()) {  
        findViewById(sBgSelectorSelectionMap.get(id)).setVisibility(View.GONE);  
    }  
    mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());  
    mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());  
  
    mNoteHeaderHolder.tvModified.setText(DateUtils.formatDateTime(this,  
            mWorkingNote.getModifiedDate(), DateUtils.FORMAT_SHOW_DATE  
                    | DateUtils.FORMAT_NUMERIC_DATE | DateUtils.FORMAT_SHOW_TIME  
                    | DateUtils.FORMAT_SHOW_YEAR));  
  
    /**  
     * TODO: Add the menu for setting alert. Currently disable it because the DateTimePicker  
     * is not ready     */    showAlertHeader();  
}

代码注解

AlarmAlertActivity.java

package net.micode.notes.ui;
 
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.DialogInterface.OnDismissListener;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.PowerManager;
import android.provider.Settings;
import android.view.Window;
import android.view.WindowManager;
 
import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.tool.DataUtils;
 
import java.io.IOException;
 
public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
    private long mNoteId;      //文本在数据库存储中的ID号 
    private String mSnippet;   //闹钟提示时出现的文本片段
    private static final int SNIPPET_PREW_MAX_LEN = 60;
    MediaPlayer mPlayer;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {    
        super.onCreate(savedInstanceState);
        //Bundle类型的数据与Map类型的数据相似,都是以key-value的形式存储数据的
        //onsaveInstanceState方法是用来保存Activity的状态的
        //能从onCreate的参数savedInsanceState中获得状态数据
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        //界面显示——无标题
 
        final Window win = getWindow();
        win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
 
        if (!isScreenOn()) {
            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
            		//保持窗体点亮
                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
                    //将窗体点亮
                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
                    //允许窗体点亮时锁屏
                    | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR);
        }//在手机锁屏后如果到了闹钟提示时间,点亮屏幕
 
        Intent intent = getIntent();
 
        try {
            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
            //根据ID从数据库中获取标签的内容;
            //getContentResolver()是实现数据共享,实例存储。
            mSnippet = mSnippet.length() > SNIPPET_PREW_MAX_LEN ? mSnippet.substring(0,
                    SNIPPET_PREW_MAX_LEN) + getResources().getString(R.string.notelist_string_info)
                    : mSnippet;
            //判断标签片段是否达到符合长度
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
            return;
        }
        /*
        try
        {
        	// 代码区
        }
        catch(Exception e)
        {
        	// 异常处理
        }
                     代码区如果有错误,就会返回所写异常的处理。*/
        mPlayer = new MediaPlayer();
        if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
            showActionDialog();
            //弹出对话框
            playAlarmSound();
            //闹钟提示音激发
        } else {
            finish();
            //完成闹钟动作
        }
    }
 
    private boolean isScreenOn() {
    	//判断屏幕是否锁屏,调用系统函数判断,最后返回值是布尔类型
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        return pm.isScreenOn();
    }
 
    private void playAlarmSound() {
    	//闹钟提示音激发
        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);
        //调用系统的铃声管理URI,得到闹钟提示音
        int silentModeStreams = Settings.System.getInt(getContentResolver(),
                Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);
 
        if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
            mPlayer.setAudioStreamType(silentModeStreams);
        } else {
            mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
        }
        try {
            mPlayer.setDataSource(this, url);
            //方法:setDataSource(Context context, Uri uri) 
            //解释:无返回值,设置多媒体数据来源【根据 Uri】
            mPlayer.prepare();
            //准备同步
            mPlayer.setLooping(true);
            //设置是否循环播放
            mPlayer.start();
            //开始播放
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            //e.printStackTrace()函数功能是抛出异常, 还将显示出更深的调用信息
            //System.out.println(e),这个方法打印出异常,并且输出在哪里出现的异常
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
 
    private void showActionDialog() {
        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        //AlertDialog的构造方法全部是Protected的
        //所以不能直接通过new一个AlertDialog来创建出一个AlertDialog。
        //要创建一个AlertDialog,就要用到AlertDialog.Builder中的create()方法
        //如这里的dialog就是新建了一个AlertDialog
        dialog.setTitle(R.string.app_name);
        //为对话框设置标题
        dialog.setMessage(mSnippet);
        //为对话框设置内容
        dialog.setPositiveButton(R.string.notealert_ok, this);
        //给对话框添加"Yes"按钮
        if (isScreenOn()) {
            dialog.setNegativeButton(R.string.notealert_enter, this);
        }//对话框添加"No"按钮
        dialog.show().setOnDismissListener(this);
    }
 
    public void onClick(DialogInterface dialog, int which) {
        switch (which) {
        //用which来选择click后下一步的操作
            case DialogInterface.BUTTON_NEGATIVE:
            	//这是取消操作
                Intent intent = new Intent(this, NoteEditActivity.class);
                //实现两个类间的数据传输
                intent.setAction(Intent.ACTION_VIEW);
                //设置动作属性
                intent.putExtra(Intent.EXTRA_UID, mNoteId);
                //实现key-value对
                //EXTRA_UID为key;mNoteId为键
                startActivity(intent);
                //开始动作
                break;
            default:
            	//这是确定操作
                break;
        }
    }
 
    public void onDismiss(DialogInterface dialog) {
    	//忽略
        stopAlarmSound();
        //停止闹钟声音
        finish();
        //完成该动作
    }
 
    private void stopAlarmSound() {
        if (mPlayer != null) {
            mPlayer.stop();
            //停止播放
            mPlayer.release();
            //释放MediaPlayer对象
            mPlayer = null;
        }
    }
}

AlarmInitReceiver.java

package net.micode.notes.ui;
 
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ContentUris;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
 
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;
 
 
public class AlarmInitReceiver extends BroadcastReceiver {
 
    private static final String [] PROJECTION = new String [] {
        NoteColumns.ID,
        NoteColumns.ALERTED_DATE
    };
    //对数据库的操作,调用标签ID和闹钟时间
    private static final int COLUMN_ID                = 0;
    private static final int COLUMN_ALERTED_DATE      = 1;
 
    @Override
    public void onReceive(Context context, Intent intent) {
        long currentDate = System.currentTimeMillis();
        //System.currentTimeMillis()产生一个当前的毫秒
        //这个毫秒其实就是自1970年1月1日0时起的毫秒数
        Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                PROJECTION,
                NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,
                new String[] { String.valueOf(currentDate) },
                //将long变量currentDate转化为字符串
                null);
        //Cursor在这里的作用是通过查找数据库中的标签内容,找到和当前系统时间相等的标签
 
        if (c != null) {
            if (c.moveToFirst()) {
                do {
                    long alertDate = c.getLong(COLUMN_ALERTED_DATE);
                    Intent sender = new Intent(context, AlarmReceiver.class);
                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
                    AlarmManager alermManager = (AlarmManager) context
                            .getSystemService(Context.ALARM_SERVICE);
                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
                } while (c.moveToNext());
            }
            c.close();
        }
        //然而通过网上查找资料发现,对于闹钟机制的启动,通常需要上面的几个步骤
        //如新建Intent、PendingIntent以及AlarmManager等
        //这里就是根据数据库里的闹钟时间创建一个闹钟机制
    }
}

AlarmReceiver.java

package net.micode.notes.ui;
 
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
 
public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        intent.setClass(context, AlarmAlertActivity.class);  
        //启动AlarmAlertActivity
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        //activity要存在于activity的栈中,而非activity的途径启动activity时必然不存在一个activity的栈
        //所以要新起一个栈装入启动的activity
        context.startActivity(intent);
    }
}
//这是实现alarm这个功能最接近用户层的包,基于上面的两个包,
//作用还需要深究但是对于setClass和addFlags的

DateTimePicker.java

package net.micode.notes.ui;
 
import java.text.DateFormatSymbols;
import java.util.Calendar;
 
import net.micode.notes.R;
 
 
import android.content.Context;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.NumberPicker;
 
public class DateTimePicker extends FrameLayout {
	//FrameLayout是布局模板之一
	//所有的子元素全部在屏幕的右上方
    private static final boolean DEFAULT_ENABLE_STATE = true;
 
    private static final int HOURS_IN_HALF_DAY = 12;
    private static final int HOURS_IN_ALL_DAY = 24;
    private static final int DAYS_IN_ALL_WEEK = 7;
    private static final int DATE_SPINNER_MIN_VAL = 0;
    private static final int DATE_SPINNER_MAX_VAL = DAYS_IN_ALL_WEEK - 1;
    private static final int HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW = 0;
    private static final int HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW = 23;
    private static final int HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW = 1;
    private static final int HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW = 12;
    private static final int MINUT_SPINNER_MIN_VAL = 0;
    private static final int MINUT_SPINNER_MAX_VAL = 59;
    private static final int AMPM_SPINNER_MIN_VAL = 0;
    private static final int AMPM_SPINNER_MAX_VAL = 1;
    //初始化控件
    private final NumberPicker mDateSpinner;
    private final NumberPicker mHourSpinner;
    private final NumberPicker mMinuteSpinner;
    private final NumberPicker mAmPmSpinner;
    //NumberPicker是数字选择器
    //这里定义的四个变量全部是在设置闹钟时需要选择的变量(如日期、时、分、上午或者下午)
    private Calendar mDate;
    //定义了Calendar类型的变量mDate,用于操作时间
    private String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK];
 
    private boolean mIsAm;
 
    private boolean mIs24HourView;
 
    private boolean mIsEnabled = DEFAULT_ENABLE_STATE;
 
    private boolean mInitialising;
 
    private OnDateTimeChangedListener mOnDateTimeChangedListener;
 
    private NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
            mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal);
            updateDateControl();
            onDateTimeChanged();
        }
    };//OnValueChangeListener,这是时间改变监听器,这里主要是对日期的监听
    //将现在日期的值传递给mDate;updateDateControl是同步操作
 
    private NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() {
        //这里是对 小时(Hour) 的监听
    	@Override
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
            boolean isDateChanged = false;
            Calendar cal = Calendar.getInstance();
            //声明一个Calendar的变量cal,便于后续的操作
            if (!mIs24HourView) {
                if (!mIsAm && oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY) {
                    cal.setTimeInMillis(mDate.getTimeInMillis());
                    cal.add(Calendar.DAY_OF_YEAR, 1);
                    isDateChanged = true;
                    //这里是对于12小时制时,晚上11点和12点交替时对日期的更改
                } else if (mIsAm && oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
                    cal.setTimeInMillis(mDate.getTimeInMillis());
                    cal.add(Calendar.DAY_OF_YEAR, -1);
                    isDateChanged = true;
                } 
                //这里是对于12小时制时,凌晨11点和12点交替时对日期的更改
                if (oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY ||
                        oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
                    mIsAm = !mIsAm;
                    updateAmPmControl();
                }//这里是对于12小时制时,中午11点和12点交替时对AM和PM的更改
            } else {
                if (oldVal == HOURS_IN_ALL_DAY - 1 && newVal == 0) {
                    cal.setTimeInMillis(mDate.getTimeInMillis());
                    cal.add(Calendar.DAY_OF_YEAR, 1);
                    isDateChanged = true;
                    //这里是对于24小时制时,晚上11点和12点交替时对日期的更改
                } else if (oldVal == 0 && newVal == HOURS_IN_ALL_DAY - 1) {
                    cal.setTimeInMillis(mDate.getTimeInMillis());
                    cal.add(Calendar.DAY_OF_YEAR, -1);
                    isDateChanged = true;
                }
            } //这里是对于12小时制时,凌晨11点和12点交替时对日期的更改
            int newHour = mHourSpinner.getValue() % HOURS_IN_HALF_DAY + (mIsAm ? 0 : HOURS_IN_HALF_DAY);
            //通过数字选择器对newHour的赋值
            mDate.set(Calendar.HOUR_OF_DAY, newHour);
            //通过set函数将新的Hour值传给mDate
            onDateTimeChanged();
            if (isDateChanged) {
                setCurrentYear(cal.get(Calendar.YEAR));
                setCurrentMonth(cal.get(Calendar.MONTH));
                setCurrentDay(cal.get(Calendar.DAY_OF_MONTH));
            }
        }
    };
 
    private NumberPicker.OnValueChangeListener mOnMinuteChangedListener = new NumberPicker.OnValueChangeListener() {
        @Override
        //这里是对 分钟(Minute)改变的监听
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
            int minValue = mMinuteSpinner.getMinValue();
            int maxValue = mMinuteSpinner.getMaxValue();
            int offset = 0;
            //设置offset,作为小时改变的一个记录数据
            if (oldVal == maxValue && newVal == minValue) {
                offset += 1;
            } else if (oldVal == minValue && newVal == maxValue) {
                offset -= 1;
            }
            //如果原值为59,新值为0,则offset加1
            //如果原值为0,新值为59,则offset减1
            if (offset != 0) {
                mDate.add(Calendar.HOUR_OF_DAY, offset);
                mHourSpinner.setValue(getCurrentHour());
                updateDateControl();
                int newHour = getCurrentHourOfDay();
                if (newHour >= HOURS_IN_HALF_DAY) {
                    mIsAm = false;
                    updateAmPmControl();
                } else {
                    mIsAm = true;
                    updateAmPmControl();
                }
            }
            mDate.set(Calendar.MINUTE, newVal);
            onDateTimeChanged();
        }
    };
 
    private NumberPicker.OnValueChangeListener mOnAmPmChangedListener = new NumberPicker.OnValueChangeListener() {
        //对AM和PM的监听
    	@Override
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
            mIsAm = !mIsAm;
            if (mIsAm) {
                mDate.add(Calendar.HOUR_OF_DAY, -HOURS_IN_HALF_DAY);
            } else {
                mDate.add(Calendar.HOUR_OF_DAY, HOURS_IN_HALF_DAY);
            }
            updateAmPmControl();
            onDateTimeChanged();
        }
    };
 
    public interface OnDateTimeChangedListener {
        void onDateTimeChanged(DateTimePicker view, int year, int month,
                int dayOfMonth, int hourOfDay, int minute);
    }
 
    public DateTimePicker(Context context) {
        this(context, System.currentTimeMillis());
    }//通过对数据库的访问,获取当前的系统时间
 
    public DateTimePicker(Context context, long date) {
        this(context, date, DateFormat.is24HourFormat(context));
    }//上面函数的得到的是一个天文数字(1970至今的秒数),需要DateFormat将其变得有意义
 
    public DateTimePicker(Context context, long date, boolean is24HourView) {
        super(context);
        //获取系统时间
        mDate = Calendar.getInstance();
        mInitialising = true;
        mIsAm = getCurrentHourOfDay() >= HOURS_IN_HALF_DAY;
        inflate(context, R.layout.datetime_picker, this);
        //如果当前Activity里用到别的layout,比如对话框layout
        //还要设置这个layout上的其他组件的内容,就必须用inflate()方法先将对话框的layout找出来
        //然后再用findViewById()找到它上面的其它组件
        mDateSpinner = (NumberPicker) findViewById(R.id.date);
        mDateSpinner.setMinValue(DATE_SPINNER_MIN_VAL);
        mDateSpinner.setMaxValue(DATE_SPINNER_MAX_VAL);
        mDateSpinner.setOnValueChangedListener(mOnDateChangedListener);
 
        mHourSpinner = (NumberPicker) findViewById(R.id.hour);
        mHourSpinner.setOnValueChangedListener(mOnHourChangedListener);
        mMinuteSpinner = (NumberPicker) findViewById(R.id.minute);
        mMinuteSpinner.setMinValue(MINUT_SPINNER_MIN_VAL);  
        mMinuteSpinner.setMaxValue(MINUT_SPINNER_MAX_VAL);
        mMinuteSpinner.setOnLongPressUpdateInterval(100);
        mMinuteSpinner.setOnValueChangedListener(mOnMinuteChangedListener);
 
        String[] stringsForAmPm = new DateFormatSymbols().getAmPmStrings();
        mAmPmSpinner = (NumberPicker) findViewById(R.id.amPm);
        mAmPmSpinner.setMinValue(AMPM_SPINNER_MIN_VAL);
        mAmPmSpinner.setMaxValue(AMPM_SPINNER_MAX_VAL);
        mAmPmSpinner.setDisplayedValues(stringsForAmPm);
        mAmPmSpinner.setOnValueChangedListener(mOnAmPmChangedListener);
 
        // update controls to initial state
        updateDateControl();
        updateHourControl();
        updateAmPmControl();
 
        set24HourView(is24HourView);
 
        // set to current time
        setCurrentDate(date);
 
        setEnabled(isEnabled());
 
        // set the content descriptions
        mInitialising = false;
    }
 
    @Override
    public void setEnabled(boolean enabled) {
        if (mIsEnabled == enabled) {
            return;
        }
        super.setEnabled(enabled);
        mDateSpinner.setEnabled(enabled);
        mMinuteSpinner.setEnabled(enabled);
        mHourSpinner.setEnabled(enabled);
        mAmPmSpinner.setEnabled(enabled);
        mIsEnabled = enabled;
    }
    //存在疑问!!!!!!!!!!!!!setEnabled的作用
    //下面的代码通过原程序的注释已经比较清晰,另外可以通过函数名来判断
    //下面的各函数主要是对上面代码引用到的各函数功能的实现
    @Override
    public boolean isEnabled() {
        return mIsEnabled;
    }
 
    /**
     * Get the current date in millis
     *
     * @return the current date in millis
     */
    public long getCurrentDateInTimeMillis() {
        return mDate.getTimeInMillis();
    }//实现函数——得到当前的秒数
 
    /**
     * Set the current date
     *
     * @param date The current date in millis
     */
    public void setCurrentDate(long date) {
        Calendar cal = Calendar.getInstance();
        cal.setTimeInMillis(date);
        setCurrentDate(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH),
                cal.get(Calendar.HOUR_OF_DAY), cal.get(Calendar.MINUTE));
    }//实现函数功能——设置当前的时间,参数是date
 
    /**
     * Set the current date
     *
     * @param year The current year
     * @param month The current month
     * @param dayOfMonth The current dayOfMonth
     * @param hourOfDay The current hourOfDay
     * @param minute The current minute
     */
    public void setCurrentDate(int year, int month,
            int dayOfMonth, int hourOfDay, int minute) {
        setCurrentYear(year);
        setCurrentMonth(month);
        setCurrentDay(dayOfMonth);
        setCurrentHour(hourOfDay);
        setCurrentMinute(minute);
    }//实现函数功能——设置当前的时间,参数是各详细的变量
 
    /**
     * Get current year
     *
     * @return The current year
     */
    //下面是得到year、month、day等值
    public int getCurrentYear() {
        return mDate.get(Calendar.YEAR);
    }
 
    /**
     * Set current year
     *
     * @param year The current year
     */
    public void setCurrentYear(int year) {
        if (!mInitialising && year == getCurrentYear()) {
            return;
        }
        mDate.set(Calendar.YEAR, year);
        updateDateControl();
        onDateTimeChanged();
    }
 
    /**
     * Get current month in the year
     *
     * @return The current month in the year
     */
    public int getCurrentMonth() {
        return mDate.get(Calendar.MONTH);
    }
 
    /**
     * Set current month in the year
     *
     * @param month The month in the year
     */
    public void setCurrentMonth(int month) {
        if (!mInitialising && month == getCurrentMonth()) {
            return;
        }
        mDate.set(Calendar.MONTH, month);
        updateDateControl();
        onDateTimeChanged();
    }
 
    /**
     * Get current day of the month
     *
     * @return The day of the month
     */
    public int getCurrentDay() {
        return mDate.get(Calendar.DAY_OF_MONTH);
    }
 
    /**
     * Set current day of the month
     *
     * @param dayOfMonth The day of the month
     */
    public void setCurrentDay(int dayOfMonth) {
        if (!mInitialising && dayOfMonth == getCurrentDay()) {
            return;
        }
        mDate.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        updateDateControl();
        onDateTimeChanged();
    }
 
    /**
     * Get current hour in 24 hour mode, in the range (0~23)
     * @return The current hour in 24 hour mode
     */
    public int getCurrentHourOfDay() {
        return mDate.get(Calendar.HOUR_OF_DAY);
    }
 
    private int getCurrentHour() {
        if (mIs24HourView){
            return getCurrentHourOfDay();
        } else {
            int hour = getCurrentHourOfDay();
            if (hour > HOURS_IN_HALF_DAY) {
                return hour - HOURS_IN_HALF_DAY;
            } else {
                return hour == 0 ? HOURS_IN_HALF_DAY : hour;
            }
        }
    }
 
    /**
     * Set current hour in 24 hour mode, in the range (0~23)
     *
     * @param hourOfDay
     */
    public void setCurrentHour(int hourOfDay) {
        if (!mInitialising && hourOfDay == getCurrentHourOfDay()) {
            return;
        }
        mDate.set(Calendar.HOUR_OF_DAY, hourOfDay);
        if (!mIs24HourView) {
            if (hourOfDay >= HOURS_IN_HALF_DAY) {
                mIsAm = false;
                if (hourOfDay > HOURS_IN_HALF_DAY) {
                    hourOfDay -= HOURS_IN_HALF_DAY;
                }
            } else {
                mIsAm = true;
                if (hourOfDay == 0) {
                    hourOfDay = HOURS_IN_HALF_DAY;
                }
            }
            updateAmPmControl();
        }
        mHourSpinner.setValue(hourOfDay);
        onDateTimeChanged();
    }
 
    /**
     * Get currentMinute
     *
     * @return The Current Minute
     */
    public int getCurrentMinute() {
        return mDate.get(Calendar.MINUTE);
    }
 
    /**
     * Set current minute
     */
    public void setCurrentMinute(int minute) {
        if (!mInitialising && minute == getCurrentMinute()) {
            return;
        }
        mMinuteSpinner.setValue(minute);
        mDate.set(Calendar.MINUTE, minute);
        onDateTimeChanged();
    }
 
    /**
     * @return true if this is in 24 hour view else false.
     */
    public boolean is24HourView () {
        return mIs24HourView;
    }
 
    /**
     * Set whether in 24 hour or AM/PM mode.
     *
     * @param is24HourView True for 24 hour mode. False for AM/PM mode.
     */
    public void set24HourView(boolean is24HourView) {
        if (mIs24HourView == is24HourView) {
            return;
        }
        mIs24HourView = is24HourView;
        mAmPmSpinner.setVisibility(is24HourView ? View.GONE : View.VISIBLE);
        int hour = getCurrentHourOfDay();
        updateHourControl();
        setCurrentHour(hour);
        updateAmPmControl();
    }
 
    private void updateDateControl() {
        Calendar cal = Calendar.getInstance();
        cal.setTimeInMillis(mDate.getTimeInMillis());
        cal.add(Calendar.DAY_OF_YEAR, -DAYS_IN_ALL_WEEK / 2 - 1);
        mDateSpinner.setDisplayedValues(null);
        for (int i = 0; i < DAYS_IN_ALL_WEEK; ++i) {
            cal.add(Calendar.DAY_OF_YEAR, 1);
            mDateDisplayValues[i] = (String) DateFormat.format("MM.dd EEEE", cal);
        }
        mDateSpinner.setDisplayedValues(mDateDisplayValues);
        mDateSpinner.setValue(DAYS_IN_ALL_WEEK / 2);
        mDateSpinner.invalidate();
    }// 对于星期几的算法
 
    private void updateAmPmControl() {
        if (mIs24HourView) {
            mAmPmSpinner.setVisibility(View.GONE);
        } else {
            int index = mIsAm ? Calendar.AM : Calendar.PM;
            mAmPmSpinner.setValue(index);
            mAmPmSpinner.setVisibility(View.VISIBLE);
        }// 对于上下午操作的算法
    }
 
    private void updateHourControl() {
        if (mIs24HourView) {
            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW);
            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW);
        } else {
            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW);
            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW);
        }// 对与小时的算法
    }
 
    /**
     * Set the callback that indicates the 'Set' button has been pressed.
     * @param callback the callback, if null will do nothing
     */
    public void setOnDateTimeChangedListener(OnDateTimeChangedListener callback) {
        mOnDateTimeChangedListener = callback;
    }
 
    private void onDateTimeChanged() {
        if (mOnDateTimeChangedListener != null) {
            mOnDateTimeChangedListener.onDateTimeChanged(this, getCurrentYear(),
                    getCurrentMonth(), getCurrentDay(), getCurrentHourOfDay(), getCurrentMinute());
        }  
    }
}

DateTimePickerDialog.java

package net.micode.notes.ui;
 
import java.util.Calendar;
 
import net.micode.notes.R;
import net.micode.notes.ui.DateTimePicker;
import net.micode.notes.ui.DateTimePicker.OnDateTimeChangedListener;
 
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.text.format.DateFormat;
import android.text.format.DateUtils;
 
public class DateTimePickerDialog extends AlertDialog implements OnClickListener {
 
    private Calendar mDate = Calendar.getInstance();
    //创建一个Calendar类型的变量 mDate,方便时间的操作
    private boolean mIs24HourView;
    private OnDateTimeSetListener mOnDateTimeSetListener;
    //声明一个时间日期滚动选择控件 mOnDateTimeSetListener
    private DateTimePicker mDateTimePicker;
    //DateTimePicker控件,控件一般用于让用户可以从日期列表中选择单个值。
    //运行时,单击控件边上的下拉箭头,会显示为两个部分:一个下拉列表,一个用于选择日期的
 
    public interface OnDateTimeSetListener {
        void OnDateTimeSet(AlertDialog dialog, long date);
    }
 
    public DateTimePickerDialog(Context context, long date) {
    	//对该界面对话框的实例化
        super(context);
        //对数据库的操作
        mDateTimePicker = new DateTimePicker(context);
        setView(mDateTimePicker);
        //添加一个子视图
        mDateTimePicker.setOnDateTimeChangedListener(new OnDateTimeChangedListener() {
            public void onDateTimeChanged(DateTimePicker view, int year, int month,
                    int dayOfMonth, int hourOfDay, int minute) {
                mDate.set(Calendar.YEAR, year);
                mDate.set(Calendar.MONTH, month);
                mDate.set(Calendar.DAY_OF_MONTH, dayOfMonth);
                mDate.set(Calendar.HOUR_OF_DAY, hourOfDay);
                mDate.set(Calendar.MINUTE, minute);
                //将视图中的各选项设置为系统当前时间
                updateTitle(mDate.getTimeInMillis());
            }
        });
        mDate.setTimeInMillis(date);
        //得到系统时间
        mDate.set(Calendar.SECOND, 0);
        //将秒数设置为0
        mDateTimePicker.setCurrentDate(mDate.getTimeInMillis());
        setButton(context.getString(R.string.datetime_dialog_ok), this);
        setButton2(context.getString(R.string.datetime_dialog_cancel), (OnClickListener)null);
        //设置按钮
        set24HourView(DateFormat.is24HourFormat(this.getContext()));
        //时间标准化打印
        updateTitle(mDate.getTimeInMillis());
    }
 
    public void set24HourView(boolean is24HourView) {
        mIs24HourView = is24HourView;
    }
 
    public void setOnDateTimeSetListener(OnDateTimeSetListener callBack) {
        mOnDateTimeSetListener = callBack;
    }//将时间日期滚动选择控件实例化
 
    private void updateTitle(long date) {
        int flag =
            DateUtils.FORMAT_SHOW_YEAR |
            DateUtils.FORMAT_SHOW_DATE |
            DateUtils.FORMAT_SHOW_TIME;
        flag |= mIs24HourView ? DateUtils.FORMAT_24HOUR : DateUtils.FORMAT_24HOUR;
        setTitle(DateUtils.formatDateTime(this.getContext(), date, flag));
    }//android开发中常见日期管理工具类(API)——DateUtils:按照上下午显示时间
 
    public void onClick(DialogInterface arg0, int arg1) {
        if (mOnDateTimeSetListener != null) {
            mOnDateTimeSetListener.OnDateTimeSet(this, mDate.getTimeInMillis());
        }
    }//第一个参数arg0是接收到点击事件的对话框
    //第二个参数arg1是该对话框上的按钮
 
}
package net.micode.notes.ui;
 
import android.content.Context;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.PopupMenu;
import android.widget.PopupMenu.OnMenuItemClickListener;
 
import net.micode.notes.R;
 
public class DropdownMenu {
    private Button mButton;
    private PopupMenu mPopupMenu;
    //声明一个下拉菜单
    private Menu mMenu;
 
    public DropdownMenu(Context context, Button button, int menuId) {
        mButton = button;
        mButton.setBackgroundResource(R.drawable.dropdown_icon);
        //设置这个view的背景
        mPopupMenu = new PopupMenu(context, mButton);
        mMenu = mPopupMenu.getMenu();
        mPopupMenu.getMenuInflater().inflate(menuId, mMenu);
        //MenuInflater是用来实例化Menu目录下的Menu布局文件
        //根据ID来确认menu的内容选项
        mButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mPopupMenu.show();
            }
        });
    }
 
    public void setOnDropdownMenuItemClickListener(OnMenuItemClickListener listener) {
        if (mPopupMenu != null) {
            mPopupMenu.setOnMenuItemClickListener(listener);
        }//设置菜单的监听
    }
 
    public MenuItem findItem(int id) {
        return mMenu.findItem(id);
    }//对于菜单选项的初始化,根据索引搜索菜单需要的选项
 
    public void setTitle(CharSequence title) {
        mButton.setText(title);
    }//布局文件,设置标题
}

FoldersListAdapter.java

package net.micode.notes.ui;
 
import android.content.Context;
import android.database.Cursor;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;
 
import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;
 
 
public class FoldersListAdapter extends CursorAdapter {
	//CursorAdapter是Cursor和ListView的接口
	//FoldersListAdapter继承了CursorAdapter的类
	//主要作用是便签数据库和用户的交互
	//这里就是用folder(文件夹)的形式展现给用户
    public static final String [] PROJECTION = {
        NoteColumns.ID,
        NoteColumns.SNIPPET
    };//调用数据库中便签的ID和片段
 
    public static final int ID_COLUMN   = 0;
    public static final int NAME_COLUMN = 1;
 
    public FoldersListAdapter(Context context, Cursor c) {
        super(context, c);
        // TODO Auto-generated constructor stub
    }//数据库操作
 
    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        //ViewGroup是容器
    	return new FolderListItem(context);
    }//创建一个文件夹,对于各文件夹中子标签的初始化
 
    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        if (view instanceof FolderListItem) {
            String folderName = (cursor.getLong(ID_COLUMN) == Notes.ID_ROOT_FOLDER) ? context
                    .getString(R.string.menu_move_parent_folder) : cursor.getString(NAME_COLUMN);
            ((FolderListItem) view).bind(folderName);
        }
    }//将各个布局文件绑定起来
 
    public String getFolderName(Context context, int position) {
        Cursor cursor = (Cursor) getItem(position);
        return (cursor.getLong(ID_COLUMN) == Notes.ID_ROOT_FOLDER) ? context
                .getString(R.string.menu_move_parent_folder) : cursor.getString(NAME_COLUMN);
    }//根据数据库中标签的ID得到标签的各项内容
 
    private class FolderListItem extends LinearLayout {
        private TextView mName;
 
        public FolderListItem(Context context) {
            super(context);
            //操作数据库
            inflate(context, R.layout.folder_list_item, this);
            //根据布局文件的名字等信息将其找出来
            mName = (TextView) findViewById(R.id.tv_folder_name);
        }
 
        public void bind(String name) {
            mName.setText(name);
        }
    }
 
}

NoteEditActivity.java

package net.micode.notes.ui;
 
import android.app.Activity;
import android.app.AlarmManager;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.app.SearchManager;
import android.appwidget.AppWidgetManager;
import android.content.ContentUris;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Paint;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.TextUtils;
import android.text.format.DateUtils;
import android.text.style.BackgroundColorSpan;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
 
import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.TextNote;
import net.micode.notes.model.WorkingNote;
import net.micode.notes.model.WorkingNote.NoteSettingChangedListener;
import net.micode.notes.tool.DataUtils;
import net.micode.notes.tool.ResourceParser;
import net.micode.notes.tool.ResourceParser.TextAppearanceResources;
import net.micode.notes.ui.DateTimePickerDialog.OnDateTimeSetListener;
import net.micode.notes.ui.NoteEditText.OnTextViewChangeListener;
import net.micode.notes.widget.NoteWidgetProvider_2x;
import net.micode.notes.widget.NoteWidgetProvider_4x;
 
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
 
public class NoteEditActivity extends Activity implements OnClickListener,
        NoteSettingChangedListener, OnTextViewChangeListener {
	//该类主要是针对标签的编辑
	//继承了系统内部许多和监听有关的类
    private class HeadViewHolder {
        public TextView tvModified;
 
        public ImageView ivAlertIcon;
 
        public TextView tvAlertDate;
 
        public ImageView ibSetBgColor;
    }
    //使用Map实现数据存储
    private static final Map<Integer, Integer> sBgSelectorBtnsMap = new HashMap<Integer, Integer>();
    static {
        sBgSelectorBtnsMap.put(R.id.iv_bg_yellow, ResourceParser.YELLOW);
        sBgSelectorBtnsMap.put(R.id.iv_bg_red, ResourceParser.RED);
        sBgSelectorBtnsMap.put(R.id.iv_bg_blue, ResourceParser.BLUE);
        sBgSelectorBtnsMap.put(R.id.iv_bg_green, ResourceParser.GREEN);
        sBgSelectorBtnsMap.put(R.id.iv_bg_white, ResourceParser.WHITE);
        //put函数是将指定值和指定键相连
    }
 
    private static final Map<Integer, Integer> sBgSelectorSelectionMap = new HashMap<Integer, Integer>();
    static {
        sBgSelectorSelectionMap.put(ResourceParser.YELLOW, R.id.iv_bg_yellow_select);
        sBgSelectorSelectionMap.put(ResourceParser.RED, R.id.iv_bg_red_select);
        sBgSelectorSelectionMap.put(ResourceParser.BLUE, R.id.iv_bg_blue_select);
        sBgSelectorSelectionMap.put(ResourceParser.GREEN, R.id.iv_bg_green_select);
        sBgSelectorSelectionMap.put(ResourceParser.WHITE, R.id.iv_bg_white_select);
        //put函数是将指定值和指定键相连
    }
 
    private static final Map<Integer, Integer> sFontSizeBtnsMap = new HashMap<Integer, Integer>();
    static {
        sFontSizeBtnsMap.put(R.id.ll_font_large, ResourceParser.TEXT_LARGE);
        sFontSizeBtnsMap.put(R.id.ll_font_small, ResourceParser.TEXT_SMALL);
        sFontSizeBtnsMap.put(R.id.ll_font_normal, ResourceParser.TEXT_MEDIUM);
        sFontSizeBtnsMap.put(R.id.ll_font_super, ResourceParser.TEXT_SUPER);
        //put函数是将指定值和指定键相连
    }
 
    private static final Map<Integer, Integer> sFontSelectorSelectionMap = new HashMap<Integer, Integer>();
    static {
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_LARGE, R.id.iv_large_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_SMALL, R.id.iv_small_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_MEDIUM, R.id.iv_medium_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_SUPER, R.id.iv_super_select);
        //put函数是将指定值和指定键相连
    }
 
    private static final String TAG = "NoteEditActivity";
 
    private HeadViewHolder mNoteHeaderHolder;
 
    private View mHeadViewPanel;
    //私有化一个界面操作mHeadViewPanel,对表头的操作
    private View mNoteBgColorSelector;
    //私有化一个界面操作mNoteBgColorSelector,对背景颜色的操作
    private View mFontSizeSelector;
    //私有化一个界面操作mFontSizeSelector,对标签字体的操作
    private EditText mNoteEditor;
    //声明编辑控件,对文本操作
    private View mNoteEditorPanel;
    //私有化一个界面操作mNoteEditorPanel,文本编辑的控制板
    //private WorkingNote mWorkingNote;
    public WorkingNote mWorkingNote;
    //对模板WorkingNote的初始化
    private SharedPreferences mSharedPrefs;
    //私有化SharedPreferences的数据存储方式
    //它的本质是基于XML文件存储key-value键值对数据
    private int mFontSizeId;
    //用于操作字体的大小
    private static final String PREFERENCE_FONT_SIZE = "pref_font_size";
 
    private static final int SHORTCUT_ICON_TITLE_MAX_LEN = 10;
 
    public static final String TAG_CHECKED = String.valueOf('\u221A');
    public static final String TAG_UNCHECKED = String.valueOf('\u25A1');
 
    private LinearLayout mEditTextList;
    //线性布局
    private String mUserQuery;
    private Pattern mPattern;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.note_edit);
        //对数据库的访问操作
        if (savedInstanceState == null && !initActivityState(getIntent())) {
            finish();
            return;
        }
        initResources();
    }
 
    /**
     * Current activity may be killed when the memory is low. Once it is killed, for another time
     * user load this activity, we should restore the former state
     */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        if (savedInstanceState != null && savedInstanceState.containsKey(Intent.EXTRA_UID)) {
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.putExtra(Intent.EXTRA_UID, savedInstanceState.getLong(Intent.EXTRA_UID));
            if (!initActivityState(intent)) {
                finish();
                return;
            }
            Log.d(TAG, "Restoring from killed activity");
        }//为防止内存不足时程序的终止,在这里有一个保存现场的函数
    }
 
    private boolean initActivityState(Intent intent) {
        /**
         * If the user specified the {@link Intent#ACTION_VIEW} but not provided with id,
         * then jump to the NotesListActivity
         */
        mWorkingNote = null;
        if (TextUtils.equals(Intent.ACTION_VIEW, intent.getAction())) {
            long noteId = intent.getLongExtra(Intent.EXTRA_UID, 0);
            mUserQuery = "";
            //如果用户实例化标签时,系统并未给出标签ID
            /**
             * Starting from the searched result
             */
            //根据键值查找ID
            if (intent.hasExtra(SearchManager.EXTRA_DATA_KEY)) {
                noteId = Long.parseLong(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY));
                mUserQuery = intent.getStringExtra(SearchManager.USER_QUERY);
            }
            //如果ID在数据库中未找到
            if (!DataUtils.visibleInNoteDatabase(getContentResolver(), noteId, Notes.TYPE_NOTE)) {
                Intent jump = new Intent(this, NotesListActivity.class);
                startActivity(jump);
                //程序将跳转到上面声明的intent——jump
                showToast(R.string.error_note_not_exist);
                finish();
                return false;
            } 
            //ID在数据库中找到
            else {
                mWorkingNote = WorkingNote.load(this, noteId);
                if (mWorkingNote == null) {
                    Log.e(TAG, "load note failed with note id" + noteId);
                    //打印出红色的错误信息
                    finish();
                    return false;
                }
            }
            //setSoftInputMode——软键盘输入模式
            getWindow().setSoftInputMode(
                    WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN
                            | WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
        } else if(TextUtils.equals(Intent.ACTION_INSERT_OR_EDIT, intent.getAction())) {
            // intent.getAction()
        	// 大多用于broadcast发送广播时给机制(intent)设置一个action,就是一个字符串 
        	// 用户可以通过receive(接受)intent,通过 getAction得到的字符串,来决定做什么
            long folderId = intent.getLongExtra(Notes.INTENT_EXTRA_FOLDER_ID, 0);
            int widgetId = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);
            int widgetType = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_TYPE,
                    Notes.TYPE_WIDGET_INVALIDE);
            int bgResId = intent.getIntExtra(Notes.INTENT_EXTRA_BACKGROUND_ID,
                    ResourceParser.getDefaultBgId(this));
            // intent.getInt(Long、String)Extra是对各变量的语法分析
            // Parse call-record note
            String phoneNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
            long callDate = intent.getLongExtra(Notes.INTENT_EXTRA_CALL_DATE, 0);
            if (callDate != 0 && phoneNumber != null) {
                if (TextUtils.isEmpty(phoneNumber)) {
                    Log.w(TAG, "The call record number is null");
                }
                long noteId = 0;
                if ((noteId = DataUtils.getNoteIdByPhoneNumberAndCallDate(getContentResolver(),
                        phoneNumber, callDate)) > 0) {
                    mWorkingNote = WorkingNote.load(this, noteId);
                    if (mWorkingNote == null) {
                        Log.e(TAG, "load call note failed with note id" + noteId);
                        finish();
                        return false;
                    }
                    //将电话号码与手机的号码簿相关
                } else {
                    mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                            widgetType, bgResId);
                    mWorkingNote.convertToCallNote(phoneNumber, callDate);
                    //
                }
            } else {
                mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId, widgetType,
                        bgResId);
            }//创建一个新的WorkingNote
 
            getWindow().setSoftInputMode(
                    WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE
                            | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
        } else {
            Log.e(TAG, "Intent not specified action, should not support");
            finish();
            return false;
        }
        mWorkingNote.setOnSettingStatusChangedListener(this);
        return true;
    }
 
    @Override
    protected void onResume() {
        super.onResume();
        initNoteScreen();
    }
 
    private void initNoteScreen() {
    	//对界面的初始化操作
        mNoteEditor.setTextAppearance(this, TextAppearanceResources
                .getTexAppearanceResource(mFontSizeId));
        //设置外观
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            switchToListMode(mWorkingNote.getContent());
        } else {
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            mNoteEditor.setSelection(mNoteEditor.getText().length());
        }
        for (Integer id : sBgSelectorSelectionMap.keySet()) {
            findViewById(sBgSelectorSelectionMap.get(id)).setVisibility(View.GONE);
        }
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());
 
        mNoteHeaderHolder.tvModified.setText(DateUtils.formatDateTime(this,
                mWorkingNote.getModifiedDate(), DateUtils.FORMAT_SHOW_DATE
                        | DateUtils.FORMAT_NUMERIC_DATE | DateUtils.FORMAT_SHOW_TIME
                        | DateUtils.FORMAT_SHOW_YEAR));
 
        /**
         * TODO: Add the menu for setting alert. Currently disable it because the DateTimePicker
         * is not ready
         */
        showAlertHeader();
    }
    //设置闹钟的显示
    private void showAlertHeader() {
        if (mWorkingNote.hasClockAlert()) {
            long time = System.currentTimeMillis();
            if (time > mWorkingNote.getAlertDate()) {
                mNoteHeaderHolder.tvAlertDate.setText(R.string.note_alert_expired);
            } 
            //如果系统时间大于了闹钟设置的时间,那么闹钟失效
            else {
                mNoteHeaderHolder.tvAlertDate.setText(DateUtils.getRelativeTimeSpanString(
                        mWorkingNote.getAlertDate(), time, DateUtils.MINUTE_IN_MILLIS));
            }
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.VISIBLE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.VISIBLE);
            //显示闹钟开启的图标
        } else {
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.GONE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.GONE);
        };
    }
 
    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        initActivityState(intent);
    }
 
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        /**
         * For new note without note id, we should firstly save it to
         * generate a id. If the editing note is not worth saving, there
         * is no id which is equivalent to create new note
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }
        //在创建一个新的标签时,先在数据库中匹配
        //如果不存在,那么先在数据库中存储
        outState.putLong(Intent.EXTRA_UID, mWorkingNote.getNoteId());
        Log.d(TAG, "Save working note id: " + mWorkingNote.getNoteId() + " onSaveInstanceState");
    }
 
    @Override
    //MotionEvent是对屏幕触控的传递机制
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mNoteBgColorSelector, ev)) {
            mNoteBgColorSelector.setVisibility(View.GONE);
            return true;
        }//颜色选择器在屏幕上可见
 
        if (mFontSizeSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mFontSizeSelector, ev)) {
            mFontSizeSelector.setVisibility(View.GONE);
            return true;
        }//字体大小选择器在屏幕上可见
        return super.dispatchTouchEvent(ev);
    }
    //对屏幕触控的坐标进行操作
    private boolean inRangeOfView(View view, MotionEvent ev) {
        int []location = new int[2];
        view.getLocationOnScreen(location);
        int x = location[0];
        int y = location[1];
        if (ev.getX() < x
                || ev.getX() > (x + view.getWidth())
                || ev.getY() < y
                || ev.getY() > (y + view.getHeight()))
        //如果触控的位置超出了给定的范围,返回false
        {
                    return false;
                }
        return true;
    }
 
    private void initResources() {
        mHeadViewPanel = findViewById(R.id.note_title);
        mNoteHeaderHolder = new HeadViewHolder();
        mNoteHeaderHolder.tvModified = (TextView) findViewById(R.id.tv_modified_date);
        mNoteHeaderHolder.ivAlertIcon = (ImageView) findViewById(R.id.iv_alert_icon);
        mNoteHeaderHolder.tvAlertDate = (TextView) findViewById(R.id.tv_alert_date);
        mNoteHeaderHolder.ibSetBgColor = (ImageView) findViewById(R.id.btn_set_bg_color);
        mNoteHeaderHolder.ibSetBgColor.setOnClickListener(this);
        mNoteEditor = (EditText) findViewById(R.id.note_edit_view);
        mNoteEditorPanel = findViewById(R.id.sv_note_edit);
        mNoteBgColorSelector = findViewById(R.id.note_bg_color_selector);
        for (int id : sBgSelectorBtnsMap.keySet()) {
            ImageView iv = (ImageView) findViewById(id);
            iv.setOnClickListener(this);
        }//对标签各项属性内容的初始化
 
        mFontSizeSelector = findViewById(R.id.font_size_selector);
        for (int id : sFontSizeBtnsMap.keySet()) {
            View view = findViewById(id);
            view.setOnClickListener(this);
        };//对字体大小的选择
        mSharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
        mFontSizeId = mSharedPrefs.getInt(PREFERENCE_FONT_SIZE, ResourceParser.BG_DEFAULT_FONT_SIZE);
        /**
         * HACKME: Fix bug of store the resource id in shared preference.
         * The id may larger than the length of resources, in this case,
         * return the {@link ResourceParser#BG_DEFAULT_FONT_SIZE}
         */
        if(mFontSizeId >= TextAppearanceResources.getResourcesSize()) {
            mFontSizeId = ResourceParser.BG_DEFAULT_FONT_SIZE;
        }
        mEditTextList = (LinearLayout) findViewById(R.id.note_edit_list);
    }
 
    @Override
    protected void onPause() {
        super.onPause();
        if(saveNote()) {
            Log.d(TAG, "Note data was saved with length:" + mWorkingNote.getContent().length());
        }
        clearSettingState();
    }
    //和桌面小工具的同步
    private void updateWidget() {
        Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
        if (mWorkingNote.getWidgetType() == Notes.TYPE_WIDGET_2X) {
            intent.setClass(this, NoteWidgetProvider_2x.class);
        } else if (mWorkingNote.getWidgetType() == Notes.TYPE_WIDGET_4X) {
            intent.setClass(this, NoteWidgetProvider_4x.class);
        } else {
            Log.e(TAG, "Unspported widget type");
            return;
        }
 
        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, new int[] {
            mWorkingNote.getWidgetId()
        });
 
        sendBroadcast(intent);
        setResult(RESULT_OK, intent);
    }
 
    public void onClick(View v) {
        int id = v.getId();
        if (id == R.id.btn_set_bg_color) {
            mNoteBgColorSelector.setVisibility(View.VISIBLE);
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    -                    View.VISIBLE);
        } else if (sBgSelectorBtnsMap.containsKey(id)) {
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    View.GONE);
            mWorkingNote.setBgColorId(sBgSelectorBtnsMap.get(id));
            mNoteBgColorSelector.setVisibility(View.GONE);
        } else if (sFontSizeBtnsMap.containsKey(id)) {
            findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.GONE);
            mFontSizeId = sFontSizeBtnsMap.get(id);
            mSharedPrefs.edit().putInt(PREFERENCE_FONT_SIZE, mFontSizeId).commit();
            findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
            if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
                getWorkingText();
                switchToListMode(mWorkingNote.getContent());
            } else {
                mNoteEditor.setTextAppearance(this,
                        TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
            }
            mFontSizeSelector.setVisibility(View.GONE);
        }
    }//************************存在问题
 
    @Override
    public void onBackPressed() {
        if(clearSettingState()) {
            return;
        }
 
        saveNote();
        super.onBackPressed();
    }
 
    private boolean clearSettingState() {
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE) {
            mNoteBgColorSelector.setVisibility(View.GONE);
            return true;
        } else if (mFontSizeSelector.getVisibility() == View.VISIBLE) {
            mFontSizeSelector.setVisibility(View.GONE);
            return true;
        }
        return false;
    }
 
    public void onBackgroundColorChanged() {
        findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                View.VISIBLE);
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
    }
 
    @Override
    //对选择菜单的准备
    public boolean onPrepareOptionsMenu(Menu menu) {
        if (isFinishing()) {
            return true;
        }
        clearSettingState();
        menu.clear();
        if (mWorkingNote.getFolderId() == Notes.ID_CALL_RECORD_FOLDER) {
            getMenuInflater().inflate(R.menu.call_note_edit, menu);
            // MenuInflater是用来实例化Menu目录下的Menu布局文件的
        } else {
            getMenuInflater().inflate(R.menu.note_edit, menu);
        }
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_normal_mode);
        } else {
            menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_list_mode);
        }
        if (mWorkingNote.hasClockAlert()) {
            menu.findItem(R.id.menu_alert).setVisible(false);
        } else {
            menu.findItem(R.id.menu_delete_remind).setVisible(false);
        }
        return true;
    }
 
    @Override
    /*
     * 函数功能:动态改变菜单选项内容
     * 函数实现:如下注释
     */
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        //根据菜单的id来编剧相关项目
            case R.id.menu_new_note:
            	//创建一个新的便签
                createNewNote();
                break;
            case R.id.menu_delete:
            	//删除便签
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                //创建关于删除操作的对话框
                builder.setTitle(getString(R.string.alert_title_delete));
                // 设置标签的标题为alert_title_delete
                builder.setIcon(android.R.drawable.ic_dialog_alert);
                //设置对话框图标
                builder.setMessage(getString(R.string.alert_message_delete_note));
                //设置对话框内容
                builder.setPositiveButton(android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                	//建立按键监听器
                            public void onClick(DialogInterface dialog, int which) {
                            	//点击所触发事件
                                deleteCurrentNote();
                                //  删除单签便签
                                finish();
                            }
                        });
                //添加“YES”按钮
                builder.setNegativeButton(android.R.string.cancel, null);
                //添加“NO”的按钮
                builder.show();
                //显示对话框
                break;
            case R.id.menu_font_size:
            //字体大小的编辑
                mFontSizeSelector.setVisibility(View.VISIBLE);
            // 将字体选择器置为可见
                findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
            // 通过id找到相应的大小
                break;
            case R.id.menu_list_mode:
            	//选择列表模式
                mWorkingNote.setCheckListMode(mWorkingNote.getCheckListMode() == 0 ?
                        TextNote.MODE_CHECK_LIST : 0);
                break;
            case R.id.menu_share:
            	//菜单共享
                getWorkingText();
                sendTo(this, mWorkingNote.getContent());
                // 用sendto函数将运行文本发送到遍历的本文内
                break;
            case R.id.menu_send_to_desktop:
            	//发送到桌面
                sendToDesktop();
                break;
            case R.id.menu_alert:
            	//创建提醒器
                setReminder();
                break;
            case R.id.menu_delete_remind:
            	//删除日期提醒
                mWorkingNote.setAlertDate(0, false);
                break;
            default:
                break;
        }
        return true;
    }
 
    /*
     * 函数功能:建立事件提醒器
     * 函数实现:如下注释
     */
    private void setReminder() {
        DateTimePickerDialog d = new DateTimePickerDialog(this, System.currentTimeMillis());
        // 建立修改时间日期的对话框
        d.setOnDateTimeSetListener(new OnDateTimeSetListener() {
            public void OnDateTimeSet(AlertDialog dialog, long date) {
                mWorkingNote.setAlertDate(date	, true);
                //选择提醒的日期
            }
        }); 
        //建立时间日期的监听器
        d.show();
        //显示对话框
    }
 
    /**
     * Share note to apps that support {@link Intent#ACTION_SEND} action
     * and {@text/plain} type
     */
    /*
     * 函数功能:共享便签
     * 函数实现:如下注释
     */
    private void sendTo(Context context, String info) {
        Intent intent = new Intent(Intent.ACTION_SEND);
        //建立intent链接选项
        intent.putExtra(Intent.EXTRA_TEXT, info);
        //将需要传递的便签信息放入text文件中
        intent.setType("text/plain");
        //编辑连接器的类型
        context.startActivity(intent);
        //在acti中进行链接
    }
 
    /*
     * 函数功能:创建一个新的便签
     * 函数实现:如下注释
     */
    private void createNewNote() {
        // Firstly, save current editing notes
    	//保存当前便签
        saveNote();
 
        // For safety, start a new NoteEditActivity
        finish();
        Intent intent = new Intent(this, NoteEditActivity.class);
        //设置链接器
        intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
        //该活动定义为创建或编辑
        intent.putExtra(Notes.INTENT_EXTRA_FOLDER_ID, mWorkingNote.getFolderId());
        //将运行便签的id添加到INTENT_EXTRA_FOLDER_ID标记中
        startActivity(intent);
        //开始activity并链接
    }
 
    /*
     * 函数功能:删除当前便签
     * 函数实现:如下注释
     */
    private void deleteCurrentNote() {
        if (mWorkingNote.existInDatabase()) {
        	//假如当前运行的便签内存有数据
            HashSet<Long> ids = new HashSet<Long>();
            long id = mWorkingNote.getNoteId();
            if (id != Notes.ID_ROOT_FOLDER) {
                ids.add(id);
            //如果不是头文件夹建立一个hash表把便签id存起来
            } else {
                Log.d(TAG, "Wrong note id, should not happen");
                //否则报错
            }
            if (!isSyncMode()) {
            	//在非同步模式情况下
            	//删除操作
                if (!DataUtils.batchDeleteNotes(getContentResolver(), ids)) {
                    Log.e(TAG, "Delete Note error");
                }
            } else {
            	 //同步模式
            	//移动至垃圾文件夹的操作
                if (!DataUtils.batchMoveToFolder(getContentResolver(), ids, Notes.ID_TRASH_FOLER)) {
                    Log.e(TAG, "Move notes to trash folder error, should not happens");
                }
            }
        }
        mWorkingNote.markDeleted(true);
        //将这些标签的删除标记置为true
    }
 
    /*
     * 函数功能:判断是否为同步模式
     * 函数实现:直接看NotesPreferenceActivity中同步名称是否为空
     */
    private boolean isSyncMode() {
        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
    }
 
    /*
     * 函数功能:设置提醒时间
     * 函数实现:如下注释
     */
    public void onClockAlertChanged(long date, boolean set) {
        /**
         * User could set clock to an unsaved note, so before setting the
         * alert clock, we should save the note first
         */
        if (!mWorkingNote.existInDatabase()) {
        	//首先保存已有的便签
            saveNote();
        }
        if (mWorkingNote.getNoteId() > 0) {
            Intent intent = new Intent(this, AlarmReceiver.class);
            intent.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mWorkingNote.getNoteId()));
            //若有有运行的便签就是建立一个链接器将标签id都存在uri中
            PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
            AlarmManager alarmManager = ((AlarmManager) getSystemService(ALARM_SERVICE));
            //设置提醒管理器
            showAlertHeader();
            if(!set) {
                alarmManager.cancel(pendingIntent);
            } else {
                alarmManager.set(AlarmManager.RTC_WAKEUP, date, pendingIntent);
            }
            //如果用户设置了时间,就通过提醒管理器设置一个监听事项
        } else {
            /**
             * There is the condition that user has input nothing (the note is
             * not worthy saving), we have no note id, remind the user that he
             * should input something
             */ 
        	//没有运行的便签就报错
            Log.e(TAG, "Clock alert setting error");
            showToast(R.string.error_note_empty_for_clock);
        }
    }
 
    /*
     * 函数功能:Widget发生改变的所触发的事件
     */
    public void onWidgetChanged() {
        updateWidget();//更新Widget
    }
 
    /*
     * 函数功能: 删除编辑文本框所触发的事件
     * 函数实现:如下注释
     */
    public void onEditTextDelete(int index, String text) {
        int childCount = mEditTextList.getChildCount();
        if (childCount == 1) {
            return;
        }
        //没有编辑框的话直接返回
        for (int i = index + 1; i < childCount; i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i - 1);
            //通过id把编辑框存在便签编辑框中
        }
 
        mEditTextList.removeViewAt(index);
        //删除特定位置的视图
        NoteEditText edit = null;
        if(index == 0) {
            edit = (NoteEditText) mEditTextList.getChildAt(0).findViewById(
                    R.id.et_edit_text);
        } else {
            edit = (NoteEditText) mEditTextList.getChildAt(index - 1).findViewById(
                    R.id.et_edit_text);
        }
        //通过id把编辑框存在空的NoteEditText中
        int length = edit.length();
        edit.append(text);
        edit.requestFocus();//请求优先完成该此 编辑
        edit.setSelection(length);//定位到length位置处的条目
    }
 
    /*
     * 函数功能:进入编辑文本框所触发的事件
     * 函数实现:如下注释
     */
    public void onEditTextEnter(int index, String text) {
        /**
         * Should not happen, check for debug
         */
        if(index > mEditTextList.getChildCount()) {
            Log.e(TAG, "Index out of mEditTextList boundrary, should not happen");
            //越界把偶偶
        }
 
        View view = getListItem(text, index);
        mEditTextList.addView(view, index);
        //建立一个新的视图并添加到编辑文本框内
        NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        edit.requestFocus();//请求优先操作
        edit.setSelection(0);//定位到起始位置
        for (int i = index + 1; i < mEditTextList.getChildCount(); i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i);
            //遍历子文本框并设置对应对下标
        }
    }
 
    /*
     * 函数功能:切换至列表模式
     * 函数实现:如下注释
     */
    private void switchToListMode(String text) {
        mEditTextList.removeAllViews();
        String[] items = text.split("\n");
        int index = 0;
        //清空所有视图,初始化下标
        for (String item : items) {
            if(!TextUtils.isEmpty(item)) {
                mEditTextList.addView(getListItem(item, index));
                index++;
                //遍历所有文本单元并添加到文本框中
            }
        }
        mEditTextList.addView(getListItem("", index));
        mEditTextList.getChildAt(index).findViewById(R.id.et_edit_text).requestFocus();
        //优先请求此操作
 
        mNoteEditor.setVisibility(View.GONE);
        //便签编辑器不可见
        mEditTextList.setVisibility(View.VISIBLE);
        //将文本编辑框置为可见
    }
 
    /*
     * 函数功能:获取高亮效果的反馈情况
     * 函数实现:如下注释
     */
    private Spannable getHighlightQueryResult(String fullText, String userQuery) {
        SpannableString spannable = new SpannableString(fullText == null ? "" : fullText);
        //新建一个效果选项
        if (!TextUtils.isEmpty(userQuery)) {
            mPattern = Pattern.compile(userQuery);
            //将用户的询问进行解析
            Matcher m = mPattern.matcher(fullText);
            //建立一个状态机检查Pattern并进行匹配
            int start = 0;
            while (m.find(start)) {
                spannable.setSpan(
                        new BackgroundColorSpan(this.getResources().getColor(
                                R.color.user_query_highlight)), m.start(), m.end(),
                        Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
                //设置背景颜色
                start = m.end();
                //跟新起始位置
            }
        }
        return spannable;
    }
 
    /*
     * 函数功能:获取列表项
     * 函数实现:如下注释
     */
    private View getListItem(String item, int index) {
        View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
        //创建一个视图
        final NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        edit.setTextAppearance(this, TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
        //创建一个文本编辑框并设置可见性
        CheckBox cb = ((CheckBox) view.findViewById(R.id.cb_edit_item));
        cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
                } else {
                    edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
                }
            }
        });
        //建立一个打钩框并设置监听器
 
        if (item.startsWith(TAG_CHECKED)) {
        	//选择勾选
            cb.setChecked(true);
            edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
            item = item.substring(TAG_CHECKED.length(), item.length()).trim();
        } else if (item.startsWith(TAG_UNCHECKED)) {
        	//选择不勾选
            cb.setChecked(false);
            edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
            item = item.substring(TAG_UNCHECKED.length(), item.length()).trim();
        }
 
        edit.setOnTextViewChangeListener(this);
        edit.setIndex(index);
        edit.setText(getHighlightQueryResult(item, mUserQuery));
        //运行编辑框的监听器对该行为作出反应,并设置下标及文本内容
        return view;
    }
 
    /*
     * 函数功能:便签内容发生改变所 触发的事件
     * 函数实现:如下注释
     */
    public void onTextChange(int index, boolean hasText) {
        if (index >= mEditTextList.getChildCount()) {
            Log.e(TAG, "Wrong index, should not happen");
            return;
            //越界报错
        }
        if(hasText) {
            mEditTextList.getChildAt(index).findViewById(R.id.cb_edit_item).setVisibility(View.VISIBLE);
        } else {
            mEditTextList.getChildAt(index).findViewById(R.id.cb_edit_item).setVisibility(View.GONE);
        }
        //如果内容不为空则将其子编辑框可见性置为可见,否则不可见
    }
 
    /*
     * 函数功能:检查模式和列表模式的切换
     * 函数实现:如下注释
     */
    public void onCheckListModeChanged(int oldMode, int newMode) {
        if (newMode == TextNote.MODE_CHECK_LIST) {
            switchToListMode(mNoteEditor.getText().toString());
            //检查模式切换到列表模式
        } else {
            if (!getWorkingText()) {
                mWorkingNote.setWorkingText(mWorkingNote.getContent().replace(TAG_UNCHECKED + " ",
                        ""));
            }
            //若是获取到文本就改变其检查标记
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            mEditTextList.setVisibility(View.GONE);
            mNoteEditor.setVisibility(View.VISIBLE);
            //修改文本编辑器的内容和可见性
        }
    }
 
    /*
     * 函数功能:设置勾选选项表并返回是否勾选的标记
     * 函数实现:如下注释
     */
    private boolean getWorkingText() {
        boolean hasChecked = false;
        //初始化check标记
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
        	// 若模式为CHECK_LIST
            StringBuilder sb = new StringBuilder();
            //创建可变字符串
            for (int i = 0; i < mEditTextList.getChildCount(); i++) {
                View view = mEditTextList.getChildAt(i);
                //遍历所有子编辑框的视图 
                NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
                if (!TextUtils.isEmpty(edit.getText())) {
                	//若文本不为空
                    if (((CheckBox) view.findViewById(R.id.cb_edit_item)).isChecked()) {
                    	//该选项框已打钩
                        sb.append(TAG_CHECKED).append(" ").append(edit.getText()).append("\n");
                        hasChecked = true;
                        //扩展字符串为已打钩并把标记置true
                    } else {
                        sb.append(TAG_UNCHECKED).append(" ").append(edit.getText()).append("\n");
                        //扩展字符串添加未打钩
                    }
                }
            }
            mWorkingNote.setWorkingText(sb.toString());
            //利用编辑好的字符串设置运行便签的内容
        } else {
            mWorkingNote.setWorkingText(mNoteEditor.getText().toString());
            // 若不是该模式直接用编辑器中的内容设置运行中标签的内容
        }
        return hasChecked;
    }
 
    /*
     * 函数功能:保存便签
     * 函数实现:如下注释 
     */
    private boolean saveNote() {
        getWorkingText();
        boolean saved = mWorkingNote.saveNote();
        //运行 getWorkingText()之后保存
        if (saved) {
            /**
             * There are two modes from List view to edit view, open one note,
             * create/edit a node. Opening node requires to the original
             * position in the list when back from edit view, while creating a
             * new node requires to the top of the list. This code
             * {@link #RESULT_OK} is used to identify the create/edit state
             */
        	//如英文注释所说链接RESULT_OK是为了识别保存的2种情况,一是创建后保存,二是修改后保存
            setResult(RESULT_OK);
        }
        return saved;
    }
 
    /*
     * 函数功能:将便签发送至桌面
     * 函数实现:如下注释 
     */
    private void sendToDesktop() {
        /**
         * Before send message to home, we should make sure that current
         * editing note is exists in databases. So, for new note, firstly
         * save it
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
            //若不存在数据也就是新的标签就保存起来先
        }
 
        if (mWorkingNote.getNoteId() > 0) {
        	//若是有内容
            Intent sender = new Intent();
            Intent shortcutIntent = new Intent(this, NoteEditActivity.class);
            //建立发送到桌面的连接器
            shortcutIntent.setAction(Intent.ACTION_VIEW);
            //链接为一个视图
            shortcutIntent.putExtra(Intent.EXTRA_UID, mWorkingNote.getNoteId());
            sender.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);
            sender.putExtra(Intent.EXTRA_SHORTCUT_NAME,
                    makeShortcutIconTitle(mWorkingNote.getContent()));
            sender.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
                    Intent.ShortcutIconResource.fromContext(this, R.drawable.icon_app));
            sender.putExtra("duplicate", true);
            //将便签的相关信息都添加到要发送的文件里
            sender.setAction("com.android.launcher.action.INSTALL_SHORTCUT");
            //设置sneder的行为是发送
            showToast(R.string.info_note_enter_desktop);
            sendBroadcast(sender);
            //显示到桌面
        } else {
            /**
             * There is the condition that user has input nothing (the note is
             * not worthy saving), we have no note id, remind the user that he
             * should input something
             */
            Log.e(TAG, "Send to desktop error");
            showToast(R.string.error_note_empty_for_send_to_desktop);
            //空便签直接报错
        }
    }
 
    /*
     * 函数功能:编辑小图标的标题
     * 函数实现:如下注释 
     */
    private String makeShortcutIconTitle(String content) {
        content = content.replace(TAG_CHECKED, "");
        content = content.replace(TAG_UNCHECKED, "");
        return content.length() > SHORTCUT_ICON_TITLE_MAX_LEN ? content.substring(0,
                SHORTCUT_ICON_TITLE_MAX_LEN) : content;
        //直接设置为content中的内容并返回,有勾选和未勾选2种
    } 
 
    /*
     * 函数功能:显示提示的视图
     * 函数实现:根据下标显示对应的提示
     */
    private void showToast(int resId) {
        showToast(resId, Toast.LENGTH_SHORT);
    }
 
    /*
     * 函数功能:持续显示提示的视图
     * 函数实现:根据下标和持续的时间(duration)编辑提示视图并显示
     */
    private void showToast(int resId, int duration) {
        Toast.makeText(this, resId, duration).show();
    }
}

NotesPreferenceActivity.java

package net.micode.notes.ui;
 
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.ActionBar;
import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.ContentValues;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.Preference;
import android.preference.Preference.OnPreferenceClickListener;
import android.preference.PreferenceActivity;
import android.preference.PreferenceCategory;
import android.text.TextUtils;
import android.text.format.DateFormat;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
 
import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;
import net.micode.notes.gtask.remote.GTaskSyncService;
 
/*
 *该类功能:NotesPreferenceActivity,在小米便签中主要实现的是对背景颜色和字体大小的数据储存。
 *       继承了PreferenceActivity主要功能为对系统信息和配置进行自动保存的Activity
 */
public class NotesPreferenceActivity extends PreferenceActivity {
    public static final String PREFERENCE_NAME = "notes_preferences";
                              //优先名 
    public static final String PREFERENCE_SYNC_ACCOUNT_NAME = "pref_key_account_name";
                              //同步账号
    public static final String PREFERENCE_LAST_SYNC_TIME = "pref_last_sync_time";
                               //同步时间
    public static final String PREFERENCE_SET_BG_COLOR_KEY = "pref_key_bg_random_appear";
 
    private static final String PREFERENCE_SYNC_ACCOUNT_KEY = "pref_sync_account_key";
                               //同步密码
    private static final String AUTHORITIES_FILTER_KEY = "authorities";
                               //本地密码
    private PreferenceCategory mAccountCategory;
                                 //账户分组
    private GTaskReceiver mReceiver;
                              //同步任务接收器
    private Account[] mOriAccounts;
                              //账户
    private boolean mHasAddedAccount;
                             //账户的hash标记
 
    @Override
    /*
     *函数功能:创建一个activity,在函数里要完成所有的正常静态设置
     *参数:Bundle icicle:存放了 activity 当前的状态
     *函数实现:如下注释
     */
    protected void onCreate(Bundle icicle) {
    	//先执行父类的创建函数
        super.onCreate(icicle);
        
        /* using the app icon for navigation */
        getActionBar().setDisplayHomeAsUpEnabled(true);
        //给左上角图标的左边加上一个返回的图标 
 
        addPreferencesFromResource(R.xml.preferences);
        //添加xml来源并显示 xml
        mAccountCategory = (PreferenceCategory) findPreference(PREFERENCE_SYNC_ACCOUNT_KEY);
        //根据同步账户关键码来初始化分组
        mReceiver = new GTaskReceiver();
        IntentFilter filter = new IntentFilter();
        filter.addAction(GTaskSyncService.GTASK_SERVICE_BROADCAST_NAME);
        registerReceiver(mReceiver, filter);
        //初始化同步组件
 
        mOriAccounts = null;
        View header = LayoutInflater.from(this).inflate(R.layout.settings_header, null);
        //获取listvivew,ListView的作用:用于列出所有选择 
        getListView().addHeaderView(header, null, true);
        //在listview组件上方添加其他组件
    }
 
    @Override
    /*
     * 函数功能:activity交互功能的实现,用于接受用户的输入
     * 函数实现:如下注释
     */
    protected void onResume() {
    	//先执行父类 的交互实现
        super.onResume();
 
        // need to set sync account automatically if user has added a new
        // account
        if (mHasAddedAccount) {
        	//若用户新加了账户则自动设置同步账户
            Account[] accounts = getGoogleAccounts();
            //获取google同步账户
            if (mOriAccounts != null && accounts.length > mOriAccounts.length) {
                //若原账户不为空且当前账户有增加
            	for (Account accountNew : accounts) {
                    boolean found = false;
                    for (Account accountOld : mOriAccounts) {
                        if (TextUtils.equals(accountOld.name, accountNew.name)) {
                        	//更新账户
                            found = true;
                            break;
                        }
                    }
                    if (!found) {
                        setSyncAccount(accountNew.name);
                        //若是没有找到旧的账户,那么同步账号中就只添加新账户
                        break;
                    }
                }
            }
        }
 
        refreshUI();
        //刷新标签界面
    }
 
    @Override
    /*
     * 函数功能:销毁一个activity
     * 函数实现:如下注释
     */
    protected void onDestroy() {
        if (mReceiver != null) {
            unregisterReceiver(mReceiver);
            //注销接收器
        }
        super.onDestroy();
        //执行父类的销毁动作
    }
 
    /*
     * 函数功能:重新设置账户信息
     * 函数实现:如下注释
     */
    private void loadAccountPreference() {
        mAccountCategory.removeAll();
        //销毁所有的分组
        Preference accountPref = new Preference(this);
        //建立首选项
        final String defaultAccount = getSyncAccountName(this);
        accountPref.setTitle(getString(R.string.preferences_account_title));
        accountPref.setSummary(getString(R.string.preferences_account_summary));
        //设置首选项的大标题和小标题
        accountPref.setOnPreferenceClickListener(new OnPreferenceClickListener() {
            public boolean onPreferenceClick(Preference preference) {
            	//建立监听器
                if (!GTaskSyncService.isSyncing()) {
                    if (TextUtils.isEmpty(defaultAccount)) {
                        // the first time to set account
                    	//若是第一次建立账户显示选择账户提示对话框
                        showSelectAccountAlertDialog();
                    } else {
                        // if the account has already been set, we need to promp
                        // user about the risk
                    	//若是已经建立则显示修改对话框并进行修改操作
                        showChangeAccountConfirmAlertDialog();
                    }
                } else {
                	//若在没有同步的情况下,则在toast中显示不能修改
                    Toast.makeText(NotesPreferenceActivity.this,
                            R.string.preferences_toast_cannot_change_account, Toast.LENGTH_SHORT)
                            .show();
                }
                return true;
            }
        });
 
        //根据新建首选项编辑新的账户分组
        mAccountCategory.addPreference(accountPref);
    }
 
    /*
     *函数功能:设置按键的状态和最后同步的时间
     *函数实现:如下注释 
     */
    private void loadSyncButton() {
        Button syncButton = (Button) findViewById(R.id.preference_sync_button);
        TextView lastSyncTimeView = (TextView) findViewById(R.id.prefenerece_sync_status_textview);
        //获取同步按钮控件和最终同步时间的的窗口
        // set button state
        //设置按钮的状态
        if (GTaskSyncService.isSyncing()) {
        	//若是在同步状态下
            syncButton.setText(getString(R.string.preferences_button_sync_cancel));
            syncButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    GTaskSyncService.cancelSync(NotesPreferenceActivity.this);
                }
            });
            //设置按钮显示的文本为“取消同步”以及监听器
        } else {
            syncButton.setText(getString(R.string.preferences_button_sync_immediately));
            syncButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    GTaskSyncService.startSync(NotesPreferenceActivity.this);
                }
            });
          //若是不同步则设置按钮显示的文本为“立即同步”以及对应监听器
        }
        syncButton.setEnabled(!TextUtils.isEmpty(getSyncAccountName(this)));
        //设置按键可用还是不可用
 
        // set last sync time
        // 设置最终同步时间
        if (GTaskSyncService.isSyncing()) {
        	//若是在同步的情况下
            lastSyncTimeView.setText(GTaskSyncService.getProgressString());
            lastSyncTimeView.setVisibility(View.VISIBLE);
            // 根据当前同步服务器设置时间显示框的文本以及可见性
        } else {
        	//若是非同步情况
            long lastSyncTime = getLastSyncTime(this);
            if (lastSyncTime != 0) {
                lastSyncTimeView.setText(getString(R.string.preferences_last_sync_time,
                        DateFormat.format(getString(R.string.preferences_last_sync_time_format),
                                lastSyncTime)));
                lastSyncTimeView.setVisibility(View.VISIBLE);
                //则根据最后同步时间的信息来编辑时间显示框的文本内容和可见性
            } else {
            	 //若时间为空直接设置为不可见状态
                lastSyncTimeView.setVisibility(View.GONE);
            }
        }
    }
     /*
      *函数功能:刷新标签界面
      *函数实现:调用上文设置账号和设置按键两个函数来实现 
      */
    private void refreshUI() {
        loadAccountPreference();
        loadSyncButton();
    }
 
    /*
     * 函数功能:显示账户选择的对话框并进行账户的设置
     * 函数实现:如下注释
     */
    private void showSelectAccountAlertDialog() {
        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
        //创建一个新的对话框
 
        View titleView = LayoutInflater.from(this).inflate(R.layout.account_dialog_title, null);
        TextView titleTextView = (TextView) titleView.findViewById(R.id.account_dialog_title);
        titleTextView.setText(getString(R.string.preferences_dialog_select_account_title));
        TextView subtitleTextView = (TextView) titleView.findViewById(R.id.account_dialog_subtitle);
        subtitleTextView.setText(getString(R.string.preferences_dialog_select_account_tips));
        //设置标题以及子标题的内容
        dialogBuilder.setCustomTitle(titleView);
        dialogBuilder.setPositiveButton(null, null);
        //设置对话框的自定义标题,建立一个YES的按钮
        Account[] accounts = getGoogleAccounts();
        String defAccount = getSyncAccountName(this);
        //获取同步账户信息
        mOriAccounts = accounts;
        mHasAddedAccount = false;
 
        if (accounts.length > 0) {
        	//若账户不为空
            CharSequence[] items = new CharSequence[accounts.length];
            final CharSequence[] itemMapping = items;
            int checkedItem = -1;
            int index = 0;
            for (Account account : accounts) {
                if (TextUtils.equals(account.name, defAccount)) {
                    checkedItem = index;
                    //在账户列表中查询到所需账户
                }
                items[index++] = account.name;
            }
            dialogBuilder.setSingleChoiceItems(items, checkedItem,
            		//在对话框建立一个单选的复选框
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            setSyncAccount(itemMapping[which].toString());
                            dialog.dismiss();
                            //取消对话框
                            refreshUI();
                        }
                        //设置点击后执行的事件,包括检录新同步账户和刷新标签界面
                    });
            //建立对话框网络版的监听器
        }
 
        View addAccountView = LayoutInflater.from(this).inflate(R.layout.add_account_text, null);
        dialogBuilder.setView(addAccountView);
        //给新加账户对话框设置自定义样式
 
        final AlertDialog dialog = dialogBuilder.show();
        //显示对话框
        addAccountView.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                mHasAddedAccount = true;
                //将新加账户的hash置true
                Intent intent = new Intent("android.settings.ADD_ACCOUNT_SETTINGS");
                //建立网络建立组件
                intent.putExtra(AUTHORITIES_FILTER_KEY, new String[] {
                    "gmail-ls"
                });
                startActivityForResult(intent, -1);
                //跳回上一个选项
                dialog.dismiss();
            }
        });
        //建立新加账户对话框的监听器
    }
 
    /*
     * 函数功能:显示账户选择对话框和相关账户操作
     * 函数实现:如下注释
     */
    private void showChangeAccountConfirmAlertDialog() {
        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
        //创建一个新的对话框
        View titleView = LayoutInflater.from(this).inflate(R.layout.account_dialog_title, null);
        TextView titleTextView = (TextView) titleView.findViewById(R.id.account_dialog_title);
        titleTextView.setText(getString(R.string.preferences_dialog_change_account_title,
                getSyncAccountName(this)));
        TextView subtitleTextView = (TextView) titleView.findViewById(R.id.account_dialog_subtitle);
        subtitleTextView.setText(getString(R.string.preferences_dialog_change_account_warn_msg));
        //根据同步修改的账户信息设置标题以及子标题的内容
        dialogBuilder.setCustomTitle(titleView);
      //设置对话框的自定义标题
        CharSequence[] menuItemArray = new CharSequence[] {
                getString(R.string.preferences_menu_change_account),
                getString(R.string.preferences_menu_remove_account),
                getString(R.string.preferences_menu_cancel)
        };
        //定义一些标记字符串
        dialogBuilder.setItems(menuItemArray, new DialogInterface.OnClickListener() {
        	//设置对话框要显示的一个list,用于显示几个命令时,即change,remove,cancel
            public void onClick(DialogInterface dialog, int which) {
            	//按键功能,由which来决定
                if (which == 0) {
                	//进入账户选择对话框
                    showSelectAccountAlertDialog();
                } else if (which == 1) {
                	//删除账户并且跟新便签界面
                    removeSyncAccount();
                    refreshUI();
                }
            }
        });
        dialogBuilder.show();
        //显示对话框
    }
 
    /*
     *函数功能:获取谷歌账户
     *函数实现:通过账户管理器直接获取
     */
    private Account[] getGoogleAccounts() {
        AccountManager accountManager = AccountManager.get(this);
        return accountManager.getAccountsByType("com.google");
    }
 
    /*
     * 函数功能:设置同步账户
     * 函数实现:如下注释:
     */
    private void setSyncAccount(String account) {
        if (!getSyncAccountName(this).equals(account)) {
        	//假如该账号不在同步账号列表中
            SharedPreferences settings = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = settings.edit();
            //编辑共享的首选项
            if (account != null) {
                editor.putString(PREFERENCE_SYNC_ACCOUNT_NAME, account);
            } else {
                editor.putString(PREFERENCE_SYNC_ACCOUNT_NAME, "");
            }
            //将该账号加入到首选项中
            
            editor.commit();
            //提交修改的数据
 
            
            setLastSyncTime(this, 0);
          //将最后同步时间清零
 
            // clean up local gtask related info
            new Thread(new Runnable() {
                public void run() {
                    ContentValues values = new ContentValues();
                    values.put(NoteColumns.GTASK_ID, "");
                    values.put(NoteColumns.SYNC_ID, 0);
                    getContentResolver().update(Notes.CONTENT_NOTE_URI, values, null, null);
                }
            }).start();
            //重置当地同步任务的信息
 
            Toast.makeText(NotesPreferenceActivity.this,
                    getString(R.string.preferences_toast_success_set_accout, account),
                    Toast.LENGTH_SHORT).show();
            //将toast的文本信息置为“设置账户成功”并显示出来
        }
    }
    /*
     * 函数功能:删除同步账户
     * 函数实现:如下注释:
     */
    private void removeSyncAccount() {
        SharedPreferences settings = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = settings.edit();
        //设置共享首选项
        
        if (settings.contains(PREFERENCE_SYNC_ACCOUNT_NAME)) {
            editor.remove(PREFERENCE_SYNC_ACCOUNT_NAME);
            //假如当前首选项中有账户就删除
        }
        if (settings.contains(PREFERENCE_LAST_SYNC_TIME)) {
            editor.remove(PREFERENCE_LAST_SYNC_TIME);
            //删除当前首选项中有账户时间
        }
        editor.commit();
        //提交更新后的数据
        
        // clean up local gtask related info
        new Thread(new Runnable() {
            public void run() {
                ContentValues values = new ContentValues();
                values.put(NoteColumns.GTASK_ID, "");
                values.put(NoteColumns.SYNC_ID, 0);
                getContentResolver().update(Notes.CONTENT_NOTE_URI, values, null, null);
            }
        }).start();
      //重置当地同步任务的信息
    }
    
    /*
     * 函数功能:获取同步账户名称
     * 函数实现:通过共享的首选项里的信息直接获取
     */
    public static String getSyncAccountName(Context context) {
        SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                Context.MODE_PRIVATE);
        return settings.getString(PREFERENCE_SYNC_ACCOUNT_NAME, "");
    }
 
    /*
     * 函数功能:设置最终同步的时间
     * 函数实现:如下注释
     */
    public static void setLastSyncTime(Context context, long time) {
        SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = settings.edit();
        // 从共享首选项中找到相关账户并获取其编辑器
        editor.putLong(PREFERENCE_LAST_SYNC_TIME, time);
        editor.commit();
        //编辑最终同步时间并提交更新
    }
    /*
     * 函数功能:获取最终同步时间
     * 函数实现:通过共享的首选项里的信息直接获取
     */
    public static long getLastSyncTime(Context context) {
        SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME,
                Context.MODE_PRIVATE);
        return settings.getLong(PREFERENCE_LAST_SYNC_TIME, 0);
    }
 
    /*
     * 函数功能:接受同步信息
     * 函数实现:继承BroadcastReceiver
     */
    private class GTaskReceiver extends BroadcastReceiver {
 
        @Override
        public void onReceive(Context context, Intent intent) {
            refreshUI();
            if (intent.getBooleanExtra(GTaskSyncService.GTASK_SERVICE_BROADCAST_IS_SYNCING, false)) {
                //获取随广播而来的Intent中的同步服务的数据
            	TextView syncStatus = (TextView) findViewById(R.id.prefenerece_sync_status_textview);
                syncStatus.setText(intent
                        .getStringExtra(GTaskSyncService.GTASK_SERVICE_BROADCAST_PROGRESS_MSG));
                //通过获取的数据在设置系统的状态
            }
 
        }
    }
 
    /*
     * 函数功能:处理菜单的选项
     * 函数实现:如下注释
     * 参数:MenuItem菜单选项
     */
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        //根据选项的id选择,这里只有一个主页
            case android.R.id.home:
                Intent intent = new Intent(this, NotesListActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(intent);
                return true;
                //在主页情况下在创建连接组件intent,发出清空的信号并开始一个相应的activity
            default:
                return false;
        }
    }
}
 

NoteItemData.java

package net.micode.notes.ui;
 
import android.content.Context;
import android.database.Cursor;
import android.text.TextUtils;
 
import net.micode.notes.data.Contact;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;
import net.micode.notes.tool.DataUtils;
 
 
public class NoteItemData {
    static final String [] PROJECTION = new String [] {
        NoteColumns.ID,
        NoteColumns.ALERTED_DATE,
        NoteColumns.BG_COLOR_ID,
        NoteColumns.CREATED_DATE,
        NoteColumns.HAS_ATTACHMENT,
        NoteColumns.MODIFIED_DATE,
        NoteColumns.NOTES_COUNT,
        NoteColumns.PARENT_ID,
        NoteColumns.SNIPPET,
        NoteColumns.TYPE,
        NoteColumns.WIDGET_ID,
        NoteColumns.WIDGET_TYPE,
    };
    //常量标记和数据就不一一标记了,意义翻译基本就知道
    private static final int ID_COLUMN                    = 0;
    private static final int ALERTED_DATE_COLUMN          = 1;
    private static final int BG_COLOR_ID_COLUMN           = 2;
    private static final int CREATED_DATE_COLUMN          = 3;
    private static final int HAS_ATTACHMENT_COLUMN        = 4;
    private static final int MODIFIED_DATE_COLUMN         = 5;
    private static final int NOTES_COUNT_COLUMN           = 6;
    private static final int PARENT_ID_COLUMN             = 7;
    private static final int SNIPPET_COLUMN               = 8;
    private static final int TYPE_COLUMN                  = 9;
    private static final int WIDGET_ID_COLUMN             = 10;
    private static final int WIDGET_TYPE_COLUMN           = 11;
 
    private long mId;
    private long mAlertDate;
    private int mBgColorId;
    private long mCreatedDate;
    private boolean mHasAttachment;
    private long mModifiedDate;
    private int mNotesCount;
    private long mParentId;
    private String mSnippet;
    private int mType;
    private int mWidgetId;
    private int mWidgetType;
    private String mName;
    private String mPhoneNumber;
 
    private boolean mIsLastItem;
    private boolean mIsFirstItem;
    private boolean mIsOnlyOneItem;
    private boolean mIsOneNoteFollowingFolder;
    private boolean mIsMultiNotesFollowingFolder;
    //初始化NoteItemData,主要利用光标cursor获取的东西
    public NoteItemData(Context context, Cursor  cursor) {
    	//getxxx为转换格式
        mId = cursor.getLong(ID_COLUMN);
        mAlertDate = cursor.getLong(ALERTED_DATE_COLUMN);
        mBgColorId = cursor.getInt(BG_COLOR_ID_COLUMN);
        mCreatedDate = cursor.getLong(CREATED_DATE_COLUMN);
        mHasAttachment = (cursor.getInt(HAS_ATTACHMENT_COLUMN) > 0) ? true : false;
        mModifiedDate = cursor.getLong(MODIFIED_DATE_COLUMN);
        mNotesCount = cursor.getInt(NOTES_COUNT_COLUMN);
        mParentId = cursor.getLong(PARENT_ID_COLUMN);
        mSnippet = cursor.getString(SNIPPET_COLUMN);
        mSnippet = mSnippet.replace(NoteEditActivity.TAG_CHECKED, "").replace(
                NoteEditActivity.TAG_UNCHECKED, "");
        mType = cursor.getInt(TYPE_COLUMN);
        mWidgetId = cursor.getInt(WIDGET_ID_COLUMN);
        mWidgetType = cursor.getInt(WIDGET_TYPE_COLUMN);
 
        //初始化电话号码的信息
        mPhoneNumber = "";
        if (mParentId == Notes.ID_CALL_RECORD_FOLDER) {
            mPhoneNumber = DataUtils.getCallNumberByNoteId(context.getContentResolver(), mId);
            if (!TextUtils.isEmpty(mPhoneNumber)) {//mphonenumber里有符合字符串,则用contart功能连接
                mName = Contact.getContact(context, mPhoneNumber);
                if (mName == null) {
                    mName = mPhoneNumber;
                }
            }
        }
 
        if (mName == null) {
            mName = "";
        }
        checkPostion(cursor);
    }
    ///根据鼠标的位置设置标记,和位置
    private void checkPostion(Cursor cursor) {
    	//初始化几个标记,cursor具体功能笔记中已提到,不一一叙述
        mIsLastItem = cursor.isLast() ? true : false;
        mIsFirstItem = cursor.isFirst() ? true : false;
        mIsOnlyOneItem = (cursor.getCount() == 1);
        //初始化“多重子文件”“单一子文件”2个标记
        mIsMultiNotesFollowingFolder = false;
        mIsOneNoteFollowingFolder = false;
 
        //主要是设置上诉2标记
        if (mType == Notes.TYPE_NOTE && !mIsFirstItem) {//若是note格式并且不是第一个元素
            int position = cursor.getPosition();
            if (cursor.moveToPrevious()) {//获取光标位置后看上一行
                if (cursor.getInt(TYPE_COLUMN) == Notes.TYPE_FOLDER
                        || cursor.getInt(TYPE_COLUMN) == Notes.TYPE_SYSTEM) {//若光标满足系统或note格式
                    if (cursor.getCount() > (position + 1)) {
                        mIsMultiNotesFollowingFolder = true;//若是数据行数大于但前位置+1则设置成正确
                    } else {
                        mIsOneNoteFollowingFolder = true;//否则单一文件夹标记为true
                    }
                }
                if (!cursor.moveToNext()) {//若不能再往下走则报错
                    throw new IllegalStateException("cursor move to previous but can't move back");
                }
            }
        }
    }
///以下都是获取标记没什么好说的,不过倒数第二个需要说明下,很具体看下面
    public boolean isOneFollowingFolder() {
        return mIsOneNoteFollowingFolder;
    }
 
    public boolean isMultiFollowingFolder() {
        return mIsMultiNotesFollowingFolder;
    }
 
    public boolean isLast() {
        return mIsLastItem;
    }
 
    public String getCallName() {
        return mName;
    }
 
    public boolean isFirst() {
        return mIsFirstItem;
    }
 
    public boolean isSingle() {
        return mIsOnlyOneItem;
    }
 
    public long getId() {
        return mId;
    }
 
    public long getAlertDate() {
        return mAlertDate;
    }
 
    public long getCreatedDate() {
        return mCreatedDate;
    }
 
    public boolean hasAttachment() {
        return mHasAttachment;
    }
 
    public long getModifiedDate() {
        return mModifiedDate;
    }
 
    public int getBgColorId() {
        return mBgColorId;
    }
 
    public long getParentId() {
        return mParentId;
    }
 
    public int getNotesCount() {
        return mNotesCount;
    }
 
    public long getFolderId () {
        return mParentId;
    }
 
    public int getType() {
        return mType;
    }
 
    public int getWidgetType() {
        return mWidgetType;
    }
 
    public int getWidgetId() {
        return mWidgetId;
    }
 
    public String getSnippet() {
        return mSnippet;
    }
 
    public boolean hasAlert() {
        return (mAlertDate > 0);
    }
 
    //若数据父id为保存至文件夹模式的id且满足电话号码单元不为空,则isCallRecord为true
    public boolean isCallRecord() {
        return (mParentId == Notes.ID_CALL_RECORD_FOLDER && !TextUtils.isEmpty(mPhoneNumber));
    }
 
    public static int getNoteType(Cursor cursor) {
        return cursor.getInt(TYPE_COLUMN);
    }
}

NotesListAdapter.java

package net.micode.notes.ui;
 
import android.content.Context;
import android.database.Cursor;
import android.util.Log;
import android.view.View; 
import android.view.ViewGroup;
import android.widget.CursorAdapter;
 
 
import net.micode.notes.data.Notes;
 
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
 
 
/*
 * 功能:直译为便签表连接器,继承了CursorAdapter,它为cursor和ListView提供了连接的桥梁。
 *     所以NotesListAdapter实现的是鼠标和编辑便签链接的桥梁
 */
public class NotesListAdapter extends CursorAdapter {
    private static final String TAG = "NotesListAdapter";
    private Context mContext;
    private HashMap<Integer, Boolean> mSelectedIndex;
    private int mNotesCount;    //便签数
    private boolean mChoiceMode;   //选择模式标记
 
    /*
     * 桌面widget的属性,包括编号和类型
     */
    public static class AppWidgetAttribute {
        public int widgetId;
        public int widgetType;
    };
 
    /*
     * 函数功能:初始化便签链接器
     * 函数实现:根据传进来的内容设置相关变量
     */
    public NotesListAdapter(Context context) {
        super(context, null);  //父类对象置空
        mSelectedIndex = new HashMap<Integer, Boolean>();  //新建选项下标的hash表
        mContext = context;
        mNotesCount = 0;
    }
 
    @Override
    /*
     * 函数功能:新建一个视图来存储光标所指向的数据
     * 函数实现:使用兄弟类NotesListItem新建一个项目选项
     */
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        return new NotesListItem(context);
    }
 
    /*
     * 函数功能:将已经存在的视图和鼠标指向的数据进行捆绑
     * 函数实现:如下注释
     */
    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        if (view instanceof NotesListItem) {
        	//若view是NotesListItem的一个实例
            NoteItemData itemData = new NoteItemData(context, cursor);
            ((NotesListItem) view).bind(context, itemData, mChoiceMode,
                    isSelectedItem(cursor.getPosition()));
           //则新建一个项目选项并且用bind跟将view和鼠标,内容,便签数据捆绑在一起
        }
    }
 
    /*
     * 函数功能:设置勾选框
     * 函数实现:如下注释
     */
    public void setCheckedItem(final int position, final boolean checked) {
        mSelectedIndex.put(position, checked);
        //根据定位和是否勾选设置下标
        notifyDataSetChanged();
        //在修改后刷新activity
    }
 
    /*
     * 函数功能:判断单选按钮是否勾选
     */
    public boolean isInChoiceMode() {
        return mChoiceMode;
    }
 
    /*
     * 函数功能:设置单项选项框
     * 函数实现:重置下标并且根据参数mode设置选项
     */
    public void setChoiceMode(boolean mode) {
        mSelectedIndex.clear();
        mChoiceMode = mode;
    }
 
    /*
     * 函数功能:选择全部选项
     * 函数实现:如下注释
     */
    public void selectAll(boolean checked) {
        Cursor cursor = getCursor();
        //获取光标位置
        for (int i = 0; i < getCount(); i++) {
            if (cursor.moveToPosition(i)) {
                if (NoteItemData.getNoteType(cursor) == Notes.TYPE_NOTE) {
                    setCheckedItem(i, checked);
                }
            }
        }
        //遍历所有光标可用的位置在判断为便签类型之后勾选单项框
    }
 
    /*
     * 函数功能:建立选择项的下标列表
     * 函数实现:如下注释
     */
    public HashSet<Long> getSelectedItemIds() {
        HashSet<Long> itemSet = new HashSet<Long>();
        //建立hash表
        for (Integer position : mSelectedIndex.keySet()) {
        	//遍历所有的关键
            if (mSelectedIndex.get(position) == true) {
            	//若光标位置可用
                Long id = getItemId(position);
                if (id == Notes.ID_ROOT_FOLDER) {
                	//原文件不需要添加
                    Log.d(TAG, "Wrong item id, should not happen");
                } else {
                    itemSet.add(id);
                }
                //则将id该下标假如选项集合中
                
            }
        }
 
        return itemSet;
    }
 
    /*
     * 函数功能:建立桌面Widget的选项表
     * 函数实现:如下注释
     */
    public HashSet<AppWidgetAttribute> getSelectedWidget() {
        HashSet<AppWidgetAttribute> itemSet = new HashSet<AppWidgetAttribute>();
        for (Integer position : mSelectedIndex.keySet()) {
            if (mSelectedIndex.get(position) == true) {
                Cursor c = (Cursor) getItem(position);
                //以上4句和getSelectedItemIds一样,不再重复
                if (c != null) {
                	//光标位置可用的话就建立新的Widget属性并编辑下标和类型,最后添加到选项集中
                    AppWidgetAttribute widget = new AppWidgetAttribute();
                    NoteItemData item = new NoteItemData(mContext, c);
                    widget.widgetId = item.getWidgetId();
                    widget.widgetType = item.getWidgetType();
                    itemSet.add(widget);
                    /**
                     * Don't close cursor here, only the adapter could close it
                     */
                } else {
                    Log.e(TAG, "Invalid cursor");
                    return null;
                }
            }
        }
        return itemSet;
    }
 
    /*
     * 函数功能:获取选项个数
     * 函数实现:如下注释
     */
    public int getSelectedCount() {
        Collection<Boolean> values = mSelectedIndex.values();
        //首先获取选项下标的值
        if (null == values) {
            return 0;
        }
        Iterator<Boolean> iter = values.iterator();
        //初始化叠加器
        int count = 0;
        while (iter.hasNext()) {
            if (true == iter.next()) {
            	//若value值为真计数+1
                count++;
            }
        }
        return count;
    }
 
    /*
     * 函数功能:判断是否全部选中
     * 函数实现:如下注释
     */
    public boolean isAllSelected() {
        int checkedCount = getSelectedCount();
        return (checkedCount != 0 && checkedCount == mNotesCount);
        //获取选项数看是否等于便签的个数
    }
 
    /*
     * 函数功能:判断是否为选项表
     * 函数实现:通过传递的下标来确定
     */
    public boolean isSelectedItem(final int position) {
        if (null == mSelectedIndex.get(position)) {
            return false;
        }
        return mSelectedIndex.get(position);
    }
 
    @Override
    /*
     * 函数功能:在activity内容发生局部变动的时候回调该函数计算便签的数量
     * 函数实现:如下注释
     */
    protected void onContentChanged() {
        super.onContentChanged();
        //执行基类函数
        calcNotesCount();
    }
 
    @Override
    /*
     * 函数功能:在activity光标发生局部变动的时候回调该函数计算便签的数量
     */
    public void changeCursor(Cursor cursor) {
        super.changeCursor(cursor);
      //执行基类函数
        calcNotesCount();
    }
 
    /*
     * 函数功能:计算便签数量
     * 
     */
    private void calcNotesCount() {
        mNotesCount = 0;
        for (int i = 0; i < getCount(); i++) {
        	//获取总数同时遍历
            Cursor c = (Cursor) getItem(i);
            if (c != null) {
                if (NoteItemData.getNoteType(c) == Notes.TYPE_NOTE) {
                    mNotesCount++;
                   //若该位置不为空并且文本类型为便签就+1
                }
            } else {
                Log.e(TAG, "Invalid cursor");
                return;
            }
            //否则报错
        }
    } 
}

NotesListItem.java

package net.micode.notes.ui;
 
import android.content.Context;
import android.text.format.DateUtils;
import android.view.View;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
 
import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.tool.DataUtils;
import net.micode.notes.tool.ResourceParser.NoteItemBgResources;
 
 
//创建便签列表项目选项
public class NotesListItem extends LinearLayout {
    private ImageView mAlert;//闹钟图片
    private TextView mTitle;  //标题
    private TextView mTime;   //时间
    private TextView mCallName;    //
    private NoteItemData mItemData; //标签数据
    private CheckBox mCheckBox;    //打钩框
 
    /*初始化基本信息*/
    public NotesListItem(Context context) {
        super(context);   //super()它的主要作用是调整调用父类构造函数的顺序
        inflate(context, R.layout.note_item, this);//Inflate可用于将一个xml中定义的布局控件找出来,这里的xml是r。layout
        //findViewById用于从contentView中查找指定ID的View,转换出来的形式根据需要而定;
        mAlert = (ImageView) findViewById(R.id.iv_alert_icon);
        mTitle = (TextView) findViewById(R.id.tv_title);
        mTime = (TextView) findViewById(R.id.tv_time);
        mCallName = (TextView) findViewById(R.id.tv_name);
        mCheckBox = (CheckBox) findViewById(android.R.id.checkbox);
    }
  ///根据data的属性对各个控件的属性的控制,主要是可见性Visibility,内容setText,格式setTextAppearance
    public void bind(Context context, NoteItemData data, boolean choiceMode, boolean checked) {
        if (choiceMode && data.getType() == Notes.TYPE_NOTE) {
            mCheckBox.setVisibility(View.VISIBLE);  ///设置可见行为可见
            mCheckBox.setChecked(checked);         ///格子打钩
        } else {
            mCheckBox.setVisibility(View.GONE);
        }
 
        mItemData = data;
        ///设置控件属性,一共三种情况,由data的id和父id是否与保存到文件夹的id一致来决定
        if (data.getId() == Notes.ID_CALL_RECORD_FOLDER) {
            mCallName.setVisibility(View.GONE);
            mAlert.setVisibility(View.VISIBLE);
            //设置该textview的style
            mTitle.setTextAppearance(context, R.style.TextAppearancePrimaryItem);
            //settext为设置内容
            mTitle.setText(context.getString(R.string.call_record_folder_name)
                    + context.getString(R.string.format_folder_files_count, data.getNotesCount()));
            mAlert.setImageResource(R.drawable.call_record);
        } else if (data.getParentId() == Notes.ID_CALL_RECORD_FOLDER) {
            mCallName.setVisibility(View.VISIBLE);
            mCallName.setText(data.getCallName());
            mTitle.setTextAppearance(context,R.style.TextAppearanceSecondaryItem);
            mTitle.setText(DataUtils.getFormattedSnippet(data.getSnippet()));
            ///关于闹钟的设置
            if (data.hasAlert()) {
                mAlert.setImageResource(R.drawable.clock);//图片来源的设置
                mAlert.setVisibility(View.VISIBLE);
            } else {
                mAlert.setVisibility(View.GONE);
            }
        } else {
            mCallName.setVisibility(View.GONE);
            mTitle.setTextAppearance(context, R.style.TextAppearancePrimaryItem);
            ///设置title格式
            if (data.getType() == Notes.TYPE_FOLDER) {
                mTitle.setText(data.getSnippet()
                        + context.getString(R.string.format_folder_files_count,
                                data.getNotesCount()));
                mAlert.setVisibility(View.GONE);
            } else {
                mTitle.setText(DataUtils.getFormattedSnippet(data.getSnippet()));
                if (data.hasAlert()) {
                    mAlert.setImageResource(R.drawable.clock);///设置图片来源
                    mAlert.setVisibility(View.VISIBLE);
                } else {
                    mAlert.setVisibility(View.GONE);
                }
            }
        }
        ///设置内容,获取相关时间,从data里编辑的日期中获取
        mTime. setText(DateUtils.getRelativeTimeSpanString(data.getModifiedDate()));
       
        setBackground(data);
    }
    //根据data的文件属性来设置背景
    private void setBackground(NoteItemData data) {
        int id = data.getBgColorId();
        //,若是note型文件,则4种情况,对于4种不同情况的背景来源
        if (data.getType() == Notes.TYPE_NOTE) {
        	//单个数据并且只有一个子文件夹
            if (data.isSingle() || data.isOneFollowingFolder()) {
                setBackgroundResource(NoteItemBgResources.getNoteBgSingleRes(id));
            } else if (data.isLast()) {//是最后一个数据
                setBackgroundResource(NoteItemBgResources.getNoteBgLastRes(id));
            } else if (data.isFirst() || data.isMultiFollowingFolder()) {//是一个数据并有多个子文件夹
                setBackgroundResource(NoteItemBgResources.getNoteBgFirstRes(id));
            } else {
                setBackgroundResource(NoteItemBgResources.getNoteBgNormalRes(id));
            }
        } else {
        	//若不是note直接调用文件夹的背景来源
            setBackgroundResource(NoteItemBgResources.getFolderBgRes());
        }
    }
    public NoteItemData getItemData() {
        return mItemData;
    }
}

添加功能

UI变化

image.png

便签功能

新建一个文件夹
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
创建文件夹完毕后效果如下图所示
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
便签记录
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
在记录便签页,可以有如下操作。例如设置字体大小、分享给他人、定时提醒功能。
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
任务清单效果
软件体系结构作业-小米便签源码阅读分析及新增功能二次开发-小白菜博客
image.png