123/NotesListAdapter.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.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;

/*
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（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（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
*/
    @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
*/
    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（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
*/
    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
    }
/*
建立选择项的下标列表
*/
    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) {
                    Log.d(TAG, "Wrong item id, should not happen");//原文件不需要添加
                } else {
                    itemSet.add(id);
                }
//则将id下标加入选项集合中
            }
        }

        return itemSet;
    }
/*
函数功能：建立桌面widget的选项表
*/
    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
                if (c != null) {//若光标位置可用就建立新的widget属性并编辑下表和类型，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
*/
    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
*/
    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（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
*/
    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
        }
    }
}