FragmentMenuSupport.java revision 109979ea9794aa98665d125ebe6a90448ff65f1f 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.example.android.supportv4.app;
18
19import com.example.android.supportv4.R;
20
21import android.support.v4.app.Fragment;
22import android.support.v4.app.FragmentActivity;
23import android.support.v4.app.FragmentManager;
24import android.support.v4.app.FragmentTransaction;
25import android.support.v4.view.MenuItemCompat;
26
27import android.os.Bundle;
28import android.view.Menu;
29import android.view.MenuInflater;
30import android.view.MenuItem;
31import android.view.View;
32import android.view.View.OnClickListener;
33import android.widget.CheckBox;
34
35/**
36 * Demonstrates how fragments can participate in the options menu.
37 */
38public class FragmentMenuSupport extends FragmentActivity {
39    Fragment mFragment1;
40    Fragment mFragment2;
41    CheckBox mCheckBox1;
42    CheckBox mCheckBox2;
43
44    // Update fragment visibility when check boxes are changed.
45    final OnClickListener mClickListener = new OnClickListener() {
46        public void onClick(View v) {
47            updateFragmentVisibility();
48        }
49    };
50
51    @Override
52    protected void onCreate(Bundle savedInstanceState) {
53        super.onCreate(savedInstanceState);
54        setContentView(R.layout.fragment_menu);
55
56        // Make sure the two menu fragments are created.
57        FragmentManager fm = getSupportFragmentManager();
58        FragmentTransaction ft = fm.beginTransaction();
59        mFragment1 = fm.findFragmentByTag("f1");
60        if (mFragment1 == null) {
61            mFragment1 = new MenuFragment();
62            ft.add(mFragment1, "f1");
63        }
64        mFragment2 = fm.findFragmentByTag("f2");
65        if (mFragment2 == null) {
66            mFragment2 = new Menu2Fragment();
67            ft.add(mFragment2, "f2");
68        }
69        ft.commit();
70
71        // Watch check box clicks.
72        mCheckBox1 = (CheckBox)findViewById(R.id.menu1);
73        mCheckBox1.setOnClickListener(mClickListener);
74        mCheckBox2 = (CheckBox)findViewById(R.id.menu2);
75        mCheckBox2.setOnClickListener(mClickListener);
76
77        // Make sure fragments start out with correct visibility.
78        updateFragmentVisibility();
79    }
80
81    @Override
82    protected void onRestoreInstanceState(Bundle savedInstanceState) {
83        super.onRestoreInstanceState(savedInstanceState);
84        // Make sure fragments are updated after check box view state is restored.
85        updateFragmentVisibility();
86    }
87
88    // Update fragment visibility based on current check box state.
89    void updateFragmentVisibility() {
90        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
91        if (mCheckBox1.isChecked()) ft.show(mFragment1);
92        else ft.hide(mFragment1);
93        if (mCheckBox2.isChecked()) ft.show(mFragment2);
94        else ft.hide(mFragment2);
95        ft.commit();
96    }
97
98    /**
99     * A fragment that displays a menu.  This fragment happens to not
100     * have a UI (it does not implement onCreateView), but it could also
101     * have one if it wanted.
102     */
103    public static class MenuFragment extends Fragment {
104
105        @Override
106        public void onCreate(Bundle savedInstanceState) {
107            super.onCreate(savedInstanceState);
108            setHasOptionsMenu(true);
109        }
110
111        @Override
112        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
113            MenuItem item;
114            item = menu.add("Menu 1a");
115            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
116            item = menu.add("Menu 1b");
117            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
118        }
119    }
120
121    /**
122     * Second fragment with a menu.
123     */
124    public static class Menu2Fragment extends Fragment {
125
126        @Override
127        public void onCreate(Bundle savedInstanceState) {
128            super.onCreate(savedInstanceState);
129            setHasOptionsMenu(true);
130        }
131
132        @Override
133        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
134            MenuItem item;
135            item = menu.add("Menu 2");
136            MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
137        }
138    }
139}
140