Notes/src/ui/NoteEditActivity.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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 {
    private class HeadViewHolder {//头视图持有者类？？？
        public TextView tvModified;//文本修改

        public ImageView ivAlertIcon;//图像提醒按钮？

        public TextView tvAlertDate;//文本提醒日期？

        public ImageView ibSetBgColor;//设置背景颜色图像视图
    }

    private static final Map<Integer, Integer> sBgSelectorBtnsMap = new HashMap<Integer, Integer>();//背景颜色选择按钮映射
    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);
    }
    //上下是反的为啥？构建双向印射关系，方便根据颜色值获取对应的选择按钮ID（比如当前背景是红的，红的按钮就是按下去的），或者根据选择按钮ID获取对应的颜色值
    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);
    }

    private static final Map<Integer, Integer> sFontSizeBtnsMap = new HashMap<Integer, Integer>();//字体大小选择按钮映射
    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);
    }
//同颜色的映射关系
    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);
    }

    private static final String TAG = "NoteEditActivity";

    private HeadViewHolder mNoteHeaderHolder;

    private View mHeadViewPanel;

    private View mNoteBgColorSelector;

    private View mFontSizeSelector;

    private EditText mNoteEditor;

    private View mNoteEditorPanel;

    private WorkingNote mWorkingNote;

    private SharedPreferences mSharedPrefs;
    private int mFontSizeId;

    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;

    private String mUserQuery;
    private Pattern mPattern;

    @Override
    protected void onCreate(Bundle savedInstanceState) {//创建活动时调用
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.note_edit);

        if (savedInstanceState == null && !initActivityState(getIntent())) {
            finish();
            return;
        }
        initResources();//初始化资源
    }

    /**
     * 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) {//存储uid便于恢复活动状态时调用
        super.onRestoreInstanceState(savedInstanceState);               //使用 Intent Extra 在组件之间传递uid
        if (savedInstanceState != null && savedInstanceState.containsKey(Intent.EXTRA_UID)) {
            Intent intent = new Intent(Intent.ACTION_VIEW); //创建一个意图，用于显示笔记详情,大小是（action_view显示数据功能）
            intent.putExtra(Intent.EXTRA_UID, savedInstanceState.getLong(Intent.EXTRA_UID));//将uid添加到意图中，用于之后再调出来
            if (!initActivityState(intent)) {
                finish();
                return;
            }
            Log.d(TAG, "Restoring from killed activity");
        }
    }

    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())) {//如果意图是查看操作
            long noteId = intent.getLongExtra(Intent.EXTRA_UID, 0);//获取uid
            mUserQuery = "";//初始化用户查询，用于后续搜索

            /**
             * Starting from the searched result
             */
            if (intent.hasExtra(SearchManager.EXTRA_DATA_KEY)) {//如果意图包含搜索数据键
                noteId = Long.parseLong(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY));//解析出笔记id
                mUserQuery = intent.getStringExtra(SearchManager.USER_QUERY);//解析出用户查询
            }

            if (!DataUtils.visibleInNoteDatabase(getContentResolver(), noteId, Notes.TYPE_NOTE)) {//如果笔记数据库中不存在该笔记
                Intent jump = new Intent(this, NotesListActivity.class);
                startActivity(jump);//执行跳转
                showToast(R.string.error_note_not_exist);//显示笔记不存在的提示
                finish();
                return false;
            } else {
                mWorkingNote = WorkingNote.load(this, noteId);//加载笔记
                if (mWorkingNote == null) {
                    Log.e(TAG, "load note failed with note id" + noteId);
                    finish();
                    return false;
                }
            }
            getWindow().setSoftInputMode( //控制软键盘的操作？
                    WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN //隐藏
                            | WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);//调整布局
        } else if(TextUtils.equals(Intent.ACTION_INSERT_OR_EDIT, intent.getAction())) {//如果意图是插入或编辑操作
            // New note
            long folderId = intent.getLongExtra(Notes.INTENT_EXTRA_FOLDER_ID, 0);//获取文件夹id
            int widgetId = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);//获取小部件id
            int widgetType = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_TYPE,
                    Notes.TYPE_WIDGET_INVALIDE);//获取小部件类型
            int bgResId = intent.getIntExtra(Notes.INTENT_EXTRA_BACKGROUND_ID,
                    ResourceParser.getDefaultBgId(this));//获取背景资源id

            // Parse call-record note
            String phoneNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);//获取电话号码
            long callDate = intent.getLongExtra(Notes.INTENT_EXTRA_CALL_DATE, 0);//获取调用日期
            if (callDate != 0 && phoneNumber != null) {//如果调用日期和电话号码都不为空
                if (TextUtils.isEmpty(phoneNumber)) {
                    Log.w(TAG, "The call record number is null");
                }
                long noteId = 0;//初始化笔记id
                if ((noteId = DataUtils.getNoteIdByPhoneNumberAndCallDate(getContentResolver(),
                        phoneNumber, callDate)) > 0) {//如果记录中根据电话号码和调用日期查询到笔记id
                    mWorkingNote = WorkingNote.load(this, noteId);//加载笔记
                    if (mWorkingNote == null) {
                        Log.e(TAG, "load call note failed with note id" + noteId);
                        finish();
                        return false;
                    }
                } else {
                    mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                            widgetType, bgResId);//新建笔记
                    mWorkingNote.convertToCallNote(phoneNumber, callDate);//将笔记转换为call笔记
                }
            } else {
                mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId, widgetType,
                        bgResId);//新建笔记
            }

            getWindow().setSoftInputMode(//设置软键盘操作
                    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);//设置笔记设置状态改变监听器
        return true;
    }

    @Override
    protected void onResume() {//已经oncreate后切出，再次调用时，初始化笔记界面
        super.onResume();
        initNoteScreen();
    }

    private void initNoteScreen() {
        mNoteEditor.setTextAppearance(this, TextAppearanceResources
                .getTexAppearanceResource(mFontSizeId));//设置文本字体外观资源
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {//根据笔记模式（ 清单模式 或 普通模式 ）初始化编辑器内容
            switchToListMode(mWorkingNote.getContent());//切换到列表清单模式
        } else {
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));//设置文本内容为高亮查询结果
            mNoteEditor.setSelection(mNoteEditor.getText().length());//将光标定位到文本末尾，方便用户继续编辑
        }
        for (Integer id : sBgSelectorSelectionMap.keySet()) {//隐藏所有背景色选择器的 选中状态指示器
            findViewById(sBgSelectorSelectionMap.get(id)).setVisibility(View.GONE);
        }
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());//设置笔记标题界面的 背景资源
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());设置笔记编辑区界面的 背景资源

        mNoteHeaderHolder.tvModified.setText(DateUtils.formatDateTime(this,   //显示笔记的 最后修改日期 ，并格式化显示
                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();
    }

    private void showAlertHeader() {//显示笔记的 闹钟提醒 信息
        if (mWorkingNote.hasClockAlert()) {
            long time = System.currentTimeMillis();
            if (time > mWorkingNote.getAlertDate()) {
                mNoteHeaderHolder.tvAlertDate.setText(R.string.note_alert_expired);//显示已过期信息
            } else {
                mNoteHeaderHolder.tvAlertDate.setText(DateUtils.getRelativeTimeSpanString(
                        mWorkingNote.getAlertDate(), time, DateUtils.MINUTE_IN_MILLIS));//显示剩余时间信息
            }
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.VISIBLE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.VISIBLE);
        } else {
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.GONE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.GONE);
        };
    }

    @Override
    protected void onNewIntent(Intent intent) {//处理新的intent
        super.onNewIntent(intent);
        initActivityState(intent);
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {//保存活动状态
        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();
        }
        outState.putLong(Intent.EXTRA_UID, mWorkingNote.getNoteId());
        Log.d(TAG, "Save working note id: " + mWorkingNote.getNoteId() + " onSaveInstanceState");
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {//处理触摸事件
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mNoteBgColorSelector, ev)) {//如果背景色选择器可见，且触摸事件不在范围内？
            mNoteBgColorSelector.setVisibility(View.GONE);//隐藏背景色选择器
            return true;
        }

        if (mFontSizeSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mFontSizeSelector, ev)) {//如果字体大小选择器可见，且触摸事件不在范围内？
            mFontSizeSelector.setVisibility(View.GONE);//隐藏字体大小选择器
            return true;
        }
        return super.dispatchTouchEvent(ev);//将事件传递给父类处理
    }

    private boolean inRangeOfView(View view, MotionEvent ev) {//判断触摸事件是否在视图范围内
        int []location = new int[2];//获取视图在屏幕上的坐标，长度为2的整数数组
        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())) {
                    return false;
                }
        return true;
    }

    private void initResources() {//初始化资源
        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);
        }

        mFontSizeSelector = findViewById(R.id.font_size_selector);
        for (int id : sFontSizeBtnsMap.keySet()) {
            View view = findViewById(id);
            view.setOnClickListener(this);
        };
        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() {//在活动暂停时调用（切出去了）
        super.onPause();//调用父类的onPause方法
        if(saveNote()) {
            Log.d(TAG, "Note data was saved with length:" + mWorkingNote.getContent().length());
        }
        clearSettingState();//清除设置状态
    }

    private void updateWidget() {//更新应用小部件
        Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);//接受意图
        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[] {//添加应用小部件id
            mWorkingNote.getWidgetId()
        });

        sendBroadcast(intent);//发送广播更新应用小部件
        setResult(RESULT_OK, intent);//设置结果为成功，返回意图
    }

    public void onClick(View v) {//点击事件处理，语法细节没看
        int id = v.getId();
        if (id == R.id.btn_set_bg_color) {//如果点击的是设置背景颜色按钮
            mNoteBgColorSelector.setVisibility(View.VISIBLE);
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    -                    View.VISIBLE);
        } else if (sBgSelectorBtnsMap.containsKey(id)) {//如果点击的是背景颜色选择按钮
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    View.GONE);
            mWorkingNote.setBgColorId(sBgSelectorBtnsMap.get(id));
            mNoteBgColorSelector.setVisibility(View.GONE);
        } else if (sFontSizeBtnsMap.containsKey(id)) {//如果点击的是字体大小选择按钮
            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);
            //区分两种模式，列表模式和普通模式
            if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
                getWorkingText();
                switchToListMode(mWorkingNote.getContent());
            } else {
                mNoteEditor.setTextAppearance(this,
                        TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
            }
            mFontSizeSelector.setVisibility(View.GONE);
        }
    }

    @Override
    public void onBackPressed() {//返回键处理
        if(clearSettingState()) {
            return;
        }

        saveNote();//保存笔记
        super.onBackPressed();
    }

    private boolean clearSettingState() {//清除设置状态
        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);//显示选中的背景颜色
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());//设置笔记编辑面板的背景颜色
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());//设置标题栏的背景颜色
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {//准备选项菜单
        if (isFinishing()) {
            return true;
        }
        clearSettingState();
        menu.clear();
        if (mWorkingNote.getFolderId() == Notes.ID_CALL_RECORD_FOLDER) {//判断类型
            getMenuInflater().inflate(R.menu.call_note_edit, menu);//如果是通话记录文件夹， 通话记录转化为菜单
        } 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);//如果是列表模式， 菜单标题为普通模式
        } else {
            menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_list_mode);//如果不是列表模式， 菜单标题为列表模式
        }
        if (mWorkingNote.hasClockAlert()) {
            menu.findItem(R.id.menu_alert).setVisible(false);
        } else {
            menu.findItem(R.id.menu_delete_remind).setVisible(false);
        }
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {//处理选项菜单点击事件
        switch (item.getItemId()) {
            case R.id.menu_new_note://新建笔记
                createNewNote();
                break;
            case R.id.menu_delete://删除笔记
                AlertDialog.Builder builder = new AlertDialog.Builder(this);//创建删除确认对话框
                builder.setTitle(getString(R.string.alert_title_delete));
                builder.setIcon(android.R.drawable.ic_dialog_alert);
                builder.setMessage(getString(R.string.alert_message_delete_note));
                builder.setPositiveButton(android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                deleteCurrentNote();
                                finish();
                            }
                        });
                builder.setNegativeButton(android.R.string.cancel, null);
                builder.show();
                break;
            case R.id.menu_font_size://字体大小选择
                mFontSizeSelector.setVisibility(View.VISIBLE);
                findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
                break;
            case R.id.menu_list_mode://列表模式切换
                mWorkingNote.setCheckListMode(mWorkingNote.getCheckListMode() == 0 ?
                        TextNote.MODE_CHECK_LIST : 0);
                break;
            case R.id.menu_share://分享笔记
                getWorkingText();
                sendTo(this, mWorkingNote.getContent());
                break;
            case R.id.menu_send_to_desktop://发送到桌面
                sendToDesktop();
                break;
            case R.id.menu_alert://设置提醒
                setReminder();
                break;
            case R.id.menu_delete_remind://删除提醒
                mWorkingNote.setAlertDate(0, false);
                break;
            default:
                break;
        }
        return true;
    }
//下面是上文相关函数的具体实现
    private void setReminder() {
        DateTimePickerDialog d = new DateTimePickerDialog(this, System.currentTimeMillis());
        d.setOnDateTimeSetListener(new OnDateTimeSetListener() {
            public void OnDateTimeSet(AlertDialog dialog, long date) {
                mWorkingNote.setAlertDate(date	, true);
            }
        });
        d.show();
    }

    /**
     * Share note to apps that support {@link Intent#ACTION_SEND} action
     * and {@text/plain} type
     */
    private void sendTo(Context context, String info) {
        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.putExtra(Intent.EXTRA_TEXT, info);//再intetn中添加标签为EXTRA_TEXT， 值为info
        intent.setType("text/plain");
        context.startActivity(intent);
    }

    private void createNewNote() {
        // Firstly, save current editing notes
        saveNote();

        // For safety, start a new NoteEditActivity
        finish();
        Intent intent = new Intent(this, NoteEditActivity.class);
        intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
        intent.putExtra(Notes.INTENT_EXTRA_FOLDER_ID, mWorkingNote.getFolderId());
        startActivity(intent);
    }

    private void deleteCurrentNote() {
        if (mWorkingNote.existInDatabase()) {
            HashSet<Long> ids = new HashSet<Long>();
            long id = mWorkingNote.getNoteId();
            if (id != Notes.ID_ROOT_FOLDER) {//如果不是根文件夹
                ids.add(id);//将笔记id添加到集合中
            } else {
                Log.d(TAG, "Wrong note id, should not happen");
            }
            if (!isSyncMode()) {//如果不是同步模式
                if (!DataUtils.batchDeleteNotes(getContentResolver(), ids)) {//批量删除笔记
                    Log.e(TAG, "Delete Note error");
                }
            } else {
                if (!DataUtils.batchMoveToFolder(getContentResolver(), ids, Notes.ID_TRASH_FOLER)) {//将笔记移动到回收站文件夹
                    Log.e(TAG, "Move notes to trash folder error, should not happens");
                }
            }
        }
        mWorkingNote.markDeleted(true);
    }

    private boolean isSyncMode() {
        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
    }

    public void onClockAlertChanged(long date, boolean set) {//设置提醒时间
        /**
         * User could set clock to an unsaved note, so before setting the
         * alert clock, we should save the note first
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }
        if (mWorkingNote.getNoteId() > 0) {
            Intent intent = new Intent(this, AlarmReceiver.class);
            intent.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mWorkingNote.getNoteId()));
            PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
            AlarmManager alarmManager = ((AlarmManager) getSystemService(ALARM_SERVICE));
            showAlertHeader();
            if(!set) {
                alarmManager.cancel(pendingIntent);
            } else {
                alarmManager.set(AlarmManager.RTC_WAKEUP, date, pendingIntent);
            }
        } 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, "Clock alert setting error");
            showToast(R.string.error_note_empty_for_clock);
        }
    }

    public void onWidgetChanged() {
        updateWidget();
    }

    public void onEditTextDelete(int index, String text) {//处理清单模式下删除列表项 的操作
        int childCount = mEditTextList.getChildCount();//获取编辑框的子视图数量
        if (childCount == 1) {
            return;
        }

        for (int i = index + 1; i < childCount; i++) {//遍历删除项（index处）之后的所有列表项 ，将它们的索引减1，不会影响到后续的列表项的索引，从而避免了索引错乱的问题
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i - 1);
        }

        mEditTextList.removeViewAt(index);//删除index处的子图
        //亮点：小米笔记清单模式下的特殊设计 ，属于防误删的安全机制 ，主要为了保护用户内容，这是啥意思？
        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);//
        }
        int length = edit.length();//获取删除项（index处）之前的列表项的文本长度
        edit.append(text);//将被删除项的文本追加到目标项末尾
        edit.requestFocus();//将焦点自动切换到目标项
        edit.setSelection(length);//将光标定位到合并前的文本末尾
    }

    public void onEditTextEnter(int index, String text) {//处理清单模式下添加列表项的操作
        /**
         * Should not happen, check for debug
         */
        if(index > mEditTextList.getChildCount()) {
            Log.e(TAG, "Index out of mEditTextList boundrary, should not happen");
        }

        View view = getListItem(text, index);
        mEditTextList.addView(view, index);//将新的列表项视图添加到编辑框中，位置为index
        NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);//获取新添加的列表项的编辑框
        edit.requestFocus();
        edit.setSelection(0);//将光标定位到新添加的列表项的文本开头
        for (int i = index + 1; i < mEditTextList.getChildCount(); i++) {//索引加一
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i);
        }
    }

    private void switchToListMode(String text) {//将编辑框切换到清单模式
        mEditTextList.removeAllViews();
        String[] items = text.split("\n");
        int index = 0;
        for (String item : items) {
            if(!TextUtils.isEmpty(item)) {
                mEditTextList.addView(getListItem(item, index));//将新的列表项视图添加到编辑框中，位置为index
                index++;
            }
        }
        mEditTextList.addView(getListItem("", index));//添加一个空列表项
        mEditTextList.getChildAt(index).findViewById(R.id.et_edit_text).requestFocus();//将焦点自动切换到新添加的空列表项的编辑框

        mNoteEditor.setVisibility(View.GONE);//隐藏编辑框
        mEditTextList.setVisibility(View.VISIBLE);
    }

    private Spannable getHighlightQueryResult(String fullText, String userQuery) {//高亮显示用户查询的文本，这里用了spannable，是比较好的视图管理器
        SpannableString spannable = new SpannableString(fullText == null ? "" : fullText);//存储高亮显示的文本
        if (!TextUtils.isEmpty(userQuery)) { 
            mPattern = Pattern.compile(userQuery, Pattern.CASE_INSENSITIVE);//编译正则表达式
            Matcher m = mPattern.matcher(fullText);//创建一个 Matcher 对象，用于对输入字符串进行匹配操作
            int start = 0;
            while (m.find(start)) {  //构建span字符串
                spannable.setSpan(
                        new BackgroundColorSpan(this.getResources().getColor(
                                R.color.user_query_highlight)), m.start(), m.end(),
                        Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
                start = m.end();
            }
        }
        return spannable;
    }

    private View getListItem(String item, int index) { //获取清单模式下的列表项视图
        View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
        final NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);//获取列表项的编辑框
        edit.setTextAppearance(this, TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
        CheckBox cb = ((CheckBox) view.findViewById(R.id.cb_edit_item)); //复选框用于让用户从有限数量的选项中选择一个或多个选项。
        cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {//复选框变化监听
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {//
                if (isChecked) {//PaintFlags是Android中用于控制文本绘制样式的位掩码 ，通过位运算组合多个绘制标志
                    edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);//添加删除线效果
                } else {
                    edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);//清除删除线效果
                }
            }
        });

        if (item.startsWith(TAG_CHECKED)) {//如果列表项以(TAG_CHECKED)开头，则将复选框设置为选中状态
            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)) {
            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));
        return view;
    }

    public void onTextChange(int index, boolean hasText) {// 列表项文本变化事件
        if (index >= mEditTextList.getChildCount()) {//检查索引是否超出范围
            Log.e(TAG, "Wrong index, should not happen");
            return;
        }
        if(hasText) {//如果列表项有文本
            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);
        }
    }

    public void onCheckListModeChanged(int oldMode, int newMode) {// 检查列表模式变化事件
        if (newMode == TextNote.MODE_CHECK_LIST) {//如果切换到检查列表模式
            switchToListMode(mNoteEditor.getText().toString());
        } else {
            if (!getWorkingText()) {
                mWorkingNote.setWorkingText(mWorkingNote.getContent().replace(TAG_UNCHECKED + " ",
                        ""));//如果没有选中项，则将所有未选中项的文本删除
            }
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            mEditTextList.setVisibility(View.GONE);
            mNoteEditor.setVisibility(View.VISIBLE);
        }
    }

    private boolean getWorkingText() {//获取选中项的文本
        boolean hasChecked = false;
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {//如果是检查列表模式
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < mEditTextList.getChildCount(); i++) {//遍历所有列表项
                View view = mEditTextList.getChildAt(i);
                NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
                if (!TextUtils.isEmpty(edit.getText())) {
                    if (((CheckBox) view.findViewById(R.id.cb_edit_item)).isChecked()) {
                        sb.append(TAG_CHECKED).append(" ").append(edit.getText()).append("\n");//如果列表项选中，则将其文本添加到 StringBuilder 中
                        hasChecked = true;
                    } else {
                        sb.append(TAG_UNCHECKED).append(" ").append(edit.getText()).append("\n");//如果列表项未选中，则将其文本添加到 StringBuilder 中
                    }
                }
            }
            mWorkingNote.setWorkingText(sb.toString());
        } else {
            mWorkingNote.setWorkingText(mNoteEditor.getText().toString());
        }
        return hasChecked;
    }

    private boolean saveNote() {//保存笔记
        getWorkingText();
        boolean saved = mWorkingNote.saveNote();
        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
             */
            setResult(RESULT_OK);
        }
        return saved;
    }

    private void sendToDesktop() {//将笔记发送到桌面
        /**
         * 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()) {//如果笔记不存在于数据库中
            saveNote();
        }

        if (mWorkingNote.getNoteId() > 0) {//如果笔记存在于数据库中
            Intent sender = new Intent();
            Intent shortcutIntent = new Intent(this, NoteEditActivity.class);
            shortcutIntent.setAction(Intent.ACTION_VIEW);//设置意图操作行为为查看
            shortcutIntent.putExtra(Intent.EXTRA_UID, mWorkingNote.getNoteId());
            sender.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);//将意图添加到发送者意图中
            sender.putExtra(Intent.EXTRA_SHORTCUT_NAME,
                    makeShortcutIconTitle(mWorkingNote.getContent()));//将快捷图标标题添加到发送者意图中
            sender.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
                    Intent.ShortcutIconResource.fromContext(this, R.drawable.icon_app));
            sender.putExtra("duplicate", true);//将重复项添加到发送者意图中
            sender.setAction("com.android.launcher.action.INSTALL_SHORTCUT");//设置意图操作行为为安装快捷图标
            showToast(R.string.info_note_enter_desktop);//显示提示消息（成功）
            sendBroadcast(sender);
        } 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);
        }
    }

    private String makeShortcutIconTitle(String content) {//创建快捷图标标题
        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;
    }

    private void showToast(int resId) {//显示短时间的提示消息
        showToast(resId, Toast.LENGTH_SHORT);//
    }

    private void showToast(int resId, int duration) {//显示自定义时间长度的 Toast 消息
        Toast.makeText(this, resId, duration).show();
    }
}