/*
 * 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.
 */

// 定义一个名为DropdownMenu的公开类
public class DropdownMenu {
    // 声明一个Button类型的私有成员变量mButton，用于存储下拉按钮
    private Button mButton;
    // 声明一个PopupMenu类型的私有成员变量mPopupMenu，用于存储弹出的菜单
    private PopupMenu mPopupMenu;
    // 声明一个Menu类型的私有成员变量mMenu，用于存储菜单项
    private Menu mMenu;

    // 构造方法，初始化DropdownMenu对象
    public DropdownMenu(Context context, Button button, int menuId) {
        mButton = button; // 将传入的Button对象赋值给mButton
        mButton.setBackgroundResource(R.drawable.dropdown_icon); // 设置按钮的背景资源为dropdown_icon
        mPopupMenu = new PopupMenu(context, mButton); // 创建一个新的PopupMenu对象，并将其与mButton绑定
        mMenu = mPopupMenu.getMenu(); // 获取PopupMenu中的Menu对象
        mPopupMenu.getMenuInflater().inflate(menuId, mMenu); // 使用menuId指定的XML布局文件来填充Menu对象
        mButton.setOnClickListener(new OnClickListener() { // 为mButton设置点击监听器
            public void onClick(View v) {
                mPopupMenu.show(); // 当按钮被点击时，显示PopupMenu
            }
        });
    }

    // 设置PopupMenu的菜单项点击监听器
    public void setOnDropdownMenuItemClickListener(OnMenuItemClickListener listener) {
        if (mPopupMenu != null) {
            mPopupMenu.setOnMenuItemClickListener(listener); // 为PopupMenu设置菜单项点击监听器
        }
    }

    // 根据ID查找菜单项
    public MenuItem findItem(int id) {
        return mMenu.findItem(id); // 在Menu对象中查找具有指定ID的菜单项，并返回它
    }

    // 设置按钮的标题
    public void setTitle(CharSequence title) {
        mButton.setText(title); // 将传入的CharSequence对象设置为按钮的标题
    }
}