Android example source code file (MenuDialogHelper.java)

This example Android source code file (MenuDialogHelper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

alertdialog, android, app, application, content, keyevent, listadapter, menubuilder, menudialoghelper, os, ui, view, window

The MenuDialogHelper.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * 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 com.android.internal.view.menu;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.IBinder;
import android.view.KeyEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ListAdapter;

/**
 * Helper for menus that appear as Dialogs (context and submenus).
 * 
 * @hide
 */
public class MenuDialogHelper implements DialogInterface.OnKeyListener, DialogInterface.OnClickListener {
    private MenuBuilder mMenu;
    private ListAdapter mAdapter;
    private AlertDialog mDialog;
    
    public MenuDialogHelper(MenuBuilder menu) {
        mMenu = menu;
    }

    /**
     * Shows menu as a dialog. 
     * 
     * @param windowToken Optional token to assign to the window.
     */
    public void show(IBinder windowToken) {
        // Many references to mMenu, create local reference
        final MenuBuilder menu = mMenu;
        
        // Get an adapter for the menu item views
        mAdapter = menu.getMenuAdapter(MenuBuilder.TYPE_DIALOG);
        
        // Get the builder for the dialog
        final AlertDialog.Builder builder = new AlertDialog.Builder(menu.getContext())
                .setAdapter(mAdapter, this); 

        // Set the title
        final View headerView = menu.getHeaderView();
        if (headerView != null) {
            // Menu's client has given a custom header view, use it
            builder.setCustomTitle(headerView);
        } else {
            // Otherwise use the (text) title and icon
            builder.setIcon(menu.getHeaderIcon()).setTitle(menu.getHeaderTitle());
        }
        
        // Set the key listener
        builder.setOnKeyListener(this);

        // Since this is for a menu, disable the recycling of views
        // This is done by the menu framework anyway
        builder.setRecycleOnMeasureEnabled(false);
        
        // Show the menu
        mDialog = builder.create();
        
        WindowManager.LayoutParams lp = mDialog.getWindow().getAttributes();
        lp.type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
        if (windowToken != null) {
            lp.token = windowToken;
        }
        lp.flags |= WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM;
        
        mDialog.show();
    }
    
    public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_MENU || keyCode == KeyEvent.KEYCODE_BACK) {
            if (event.getAction() == KeyEvent.ACTION_DOWN
                    && event.getRepeatCount() == 0) {
                Window win = mDialog.getWindow();
                if (win != null) {
                    View decor = win.getDecorView();
                    if (decor != null) {
                        KeyEvent.DispatcherState ds = decor.getKeyDispatcherState();
                        if (ds != null) {
                            ds.startTracking(event, this);
                            return true;
                        }
                    }
                }
            } else if (event.getAction() == KeyEvent.ACTION_UP && !event.isCanceled()) {
                Window win = mDialog.getWindow();
                if (win != null) {
                    View decor = win.getDecorView();
                    if (decor != null) {
                        KeyEvent.DispatcherState ds = decor.getKeyDispatcherState();
                        if (ds != null && ds.isTracking(event)) {
                            mMenu.close(true);
                            dialog.dismiss();
                            return true;
                        }
                    }
                }
            }
        }

        // Menu shortcut matching
        return mMenu.performShortcut(keyCode, event, 0);

    }

    /**
     * Dismisses the menu's dialog.
     * 
     * @see Dialog#dismiss()
     */
    public void dismiss() {
        if (mDialog != null) {
            mDialog.dismiss();
        }
    }
    
    public void onClick(DialogInterface dialog, int which) {
        mMenu.performItemAction((MenuItemImpl) mAdapter.getItem(which), 0);
    }
    
}