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 */ 16 package com.example.android.supportv13.app; 17 18 import java.util.ArrayList; 19 20 import com.example.android.supportv13.R; 21 22 import android.app.ActionBar; 23 import android.app.ActionBar.Tab; 24 import android.app.Activity; 25 import android.app.Fragment; 26 import android.app.FragmentTransaction; 27 import android.content.Context; 28 import android.os.Bundle; 29 import android.support.v13.app.FragmentPagerAdapter; 30 import android.support.v4.view.ViewPager; 31 32 //BEGIN_INCLUDE(complete) 33 public class FragmentNestingPagerSupport extends Activity { 34 ViewPager mViewPager; 35 TabsAdapter mTabsAdapter; 36 37 @Override 38 protected void onCreate(Bundle savedInstanceState) { 39 super.onCreate(savedInstanceState); 40 41 mViewPager = new ViewPager(this); 42 mViewPager.setId(R.id.pager); 43 setContentView(mViewPager); 44 45 final ActionBar bar = getActionBar(); 46 bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 47 bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE); 48 49 mTabsAdapter = new TabsAdapter(this, mViewPager); 50 mTabsAdapter.addTab(bar.newTab().setText("Simple"), 51 CountingFragment.class, null); 52 mTabsAdapter.addTab(bar.newTab().setText("List"), 53 FragmentPagerSupport.ArrayListFragment.class, null); 54 mTabsAdapter.addTab(bar.newTab().setText("Cursor"), 55 CursorFragment.class, null); 56 mTabsAdapter.addTab(bar.newTab().setText("Tabs"), 57 FragmentTabsFragment.class, null); 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 /** 71 * This is a helper class that implements the management of tabs and all 72 * details of connecting a ViewPager with associated TabHost. It relies on a 73 * trick. Normally a tab host has a simple API for supplying a View or 74 * Intent that each tab will show. This is not sufficient for switching 75 * between pages. So instead we make the content part of the tab host 76 * 0dp high (it is not shown) and the TabsAdapter supplies its own dummy 77 * view to show as the tab content. It listens to changes in tabs, and takes 78 * care of switch to the correct paged in the ViewPager whenever the selected 79 * tab changes. 80 */ 81 public static class TabsAdapter extends FragmentPagerAdapter 82 implements ActionBar.TabListener, ViewPager.OnPageChangeListener { 83 private final Context mContext; 84 private final ActionBar mActionBar; 85 private final ViewPager mViewPager; 86 private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>(); 87 88 static final class TabInfo { 89 private final Class<?> clss; 90 private final Bundle args; 91 92 TabInfo(Class<?> _class, Bundle _args) { 93 clss = _class; 94 args = _args; 95 } 96 } 97 98 public TabsAdapter(Activity activity, ViewPager pager) { 99 super(activity.getFragmentManager()); 100 mContext = activity; 101 mActionBar = activity.getActionBar(); 102 mViewPager = pager; 103 mViewPager.setAdapter(this); 104 mViewPager.addOnPageChangeListener(this); 105 } 106 107 public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) { 108 TabInfo info = new TabInfo(clss, args); 109 tab.setTag(info); 110 tab.setTabListener(this); 111 mTabs.add(info); 112 mActionBar.addTab(tab); 113 notifyDataSetChanged(); 114 } 115 116 @Override 117 public int getCount() { 118 return mTabs.size(); 119 } 120 121 @Override 122 public Fragment getItem(int position) { 123 TabInfo info = mTabs.get(position); 124 return Fragment.instantiate(mContext, info.clss.getName(), info.args); 125 } 126 127 @Override 128 public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { 129 } 130 131 @Override 132 public void onPageSelected(int position) { 133 mActionBar.setSelectedNavigationItem(position); 134 } 135 136 @Override 137 public void onPageScrollStateChanged(int state) { 138 } 139 140 @Override 141 public void onTabSelected(Tab tab, FragmentTransaction ft) { 142 Object tag = tab.getTag(); 143 for (int i=0; i<mTabs.size(); i++) { 144 if (mTabs.get(i) == tag) { 145 mViewPager.setCurrentItem(i); 146 } 147 } 148 } 149 150 @Override 151 public void onTabUnselected(Tab tab, FragmentTransaction ft) { 152 } 153 154 @Override 155 public void onTabReselected(Tab tab, FragmentTransaction ft) { 156 } 157 } 158 } 159 //END_INCLUDE(complete) 160