1/*
2 * Copyright (C) 2012 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 */
16package com.example.android.apis.app;
17
18//BEGIN_INCLUDE(complete)
19import android.app.ActionBar;
20import android.app.ActionBar.Tab;
21import android.app.Activity;
22import android.app.Fragment;
23import android.app.FragmentManager;
24import android.app.FragmentTransaction;
25import android.os.Bundle;
26import android.widget.Toast;
27
28/**
29 * This demonstrates the use of action bar tabs and how they interact
30 * with other action bar features.
31 */
32public class FragmentNestingTabs extends Activity {
33    @Override
34    protected void onCreate(Bundle savedInstanceState) {
35        FragmentManager.enableDebugLogging(true);
36        super.onCreate(savedInstanceState);
37
38        final ActionBar bar = getActionBar();
39        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
40        bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);
41
42        bar.addTab(bar.newTab()
43                .setText("Menus")
44                .setTabListener(new TabListener<FragmentMenuFragment>(
45                        this, "menus", FragmentMenuFragment.class)));
46        bar.addTab(bar.newTab()
47                .setText("Args")
48                .setTabListener(new TabListener<FragmentArgumentsFragment>(
49                        this, "args", FragmentArgumentsFragment.class)));
50        bar.addTab(bar.newTab()
51                .setText("Stack")
52                .setTabListener(new TabListener<FragmentStackFragment>(
53                        this, "stack", FragmentStackFragment.class)));
54        bar.addTab(bar.newTab()
55                .setText("Tabs")
56                .setTabListener(new TabListener<FragmentTabsFragment>(
57                        this, "tabs", FragmentTabsFragment.class)));
58
59        if (savedInstanceState != null) {
60            bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
61        }
62    }
63
64    @Override
65    protected void onSaveInstanceState(Bundle outState) {
66        super.onSaveInstanceState(outState);
67        outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
68    }
69
70    public static class TabListener<T extends Fragment> implements ActionBar.TabListener {
71        private final Activity mActivity;
72        private final String mTag;
73        private final Class<T> mClass;
74        private final Bundle mArgs;
75        private Fragment mFragment;
76
77        public TabListener(Activity activity, String tag, Class<T> clz) {
78            this(activity, tag, clz, null);
79        }
80
81        public TabListener(Activity activity, String tag, Class<T> clz, Bundle args) {
82            mActivity = activity;
83            mTag = tag;
84            mClass = clz;
85            mArgs = args;
86
87            // Check to see if we already have a fragment for this tab, probably
88            // from a previously saved state.  If so, deactivate it, because our
89            // initial state is that a tab isn't shown.
90            mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
91            if (mFragment != null && !mFragment.isDetached()) {
92                FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
93                ft.detach(mFragment);
94                ft.commit();
95            }
96        }
97
98        public void onTabSelected(Tab tab, FragmentTransaction ft) {
99            if (mFragment == null) {
100                mFragment = Fragment.instantiate(mActivity, mClass.getName(), mArgs);
101                ft.add(android.R.id.content, mFragment, mTag);
102            } else {
103                ft.attach(mFragment);
104            }
105        }
106
107        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
108            if (mFragment != null) {
109                ft.detach(mFragment);
110            }
111        }
112
113        public void onTabReselected(Tab tab, FragmentTransaction ft) {
114            Toast.makeText(mActivity, "Reselected!", Toast.LENGTH_SHORT).show();
115        }
116    }
117}
118//END_INCLUDE(complete)
119