ActionBarSettingsActionProviderActivity.java

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The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...

/*
 * Copyright (C) 2011 The Android开源工程
 *
 * 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.example.android.apis.app;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.provider.Settings;
import android.view.ActionProvider;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;

import com.example.android.apis.R;

/**
 * This activity demonstrates how to implement an {@link android.view.ActionProvider}
 * for adding functionality to the Action Bar. In particular this demo creates an
 * ActionProvider for launching the system settings and adds a menu item with that
 * provider.
 */
public class ActionBarSettingsActionProviderActivity extends Activity {

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.action_bar_settings_action_provider, menu);
        return true;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // If this callback does not handle the item click, onPerformDefaultAction
        // of the ActionProvider is invoked. Hence, the provider encapsulates the
        // complete functionality of the menu item.
        Toast.makeText(this, R.string.action_bar_settings_action_provider_no_handling,
                Toast.LENGTH_SHORT).show();
        return false;
    }

    public static class SettingsActionProvider extends ActionProvider {

        /** An intent for launching the system settings. */
        private static final Intent sSettingsIntent = new Intent(Settings.ACTION_SETTINGS);

        /** Context for accessing resources. */
        private final Context mContext;

        /**
         * Creates a new instance.
         *
         * @param context Context for accessing resources.
         */
        public SettingsActionProvider(Context context) {
            super(context);
            mContext = context;
        }

        /**
         * {@inheritDoc}
         */
        @Override
        public View onCreateActionView() {
            // Inflate the action view to be shown on the action bar.
            LayoutInflater layoutInflater = LayoutInflater.from(mContext);
            View view = layoutInflater.inflate(R.layout.action_bar_settings_action_provider, null);
            ImageButton button = (ImageButton) view.findViewById(R.id.button);
            // Attach a click listener for launching the system settings.
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mContext.startActivity(sSettingsIntent);
                }
            });
            return view;
        }

        /**
         * {@inheritDoc}
         */
        @Override
        public boolean onPerformDefaultAction() {
            // This is called if the host menu item placed in the overflow menu of the
            // action bar is clicked and the host activity did not handle the click.
            mContext.startActivity(sSettingsIntent);
            return true;
        }
    }
}