FragmentPagerAdapter.java revision 7dc96cc2410f551eefaa973ddc144146ad72d1ec
1ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn/* 2ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Copyright (C) 2011 The Android Open Source Project 3ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * 4ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Licensed under the Apache License, Version 2.0 (the "License"); 5ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * you may not use this file except in compliance with the License. 6ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * You may obtain a copy of the License at 7ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * 8ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * http://www.apache.org/licenses/LICENSE-2.0 9ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * 10ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Unless required by applicable law or agreed to in writing, software 11ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * distributed under the License is distributed on an "AS IS" BASIS, 12ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * See the License for the specific language governing permissions and 14ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * limitations under the License. 15ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn */ 16ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 17ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornpackage android.support.v13.app; 18ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 19ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.app.Fragment; 20ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.app.FragmentManager; 21ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.app.FragmentTransaction; 22ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.os.Parcelable; 237dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackbornimport android.support.v4.app.FragmentStatePagerAdapter; 245c1637087453de15e31861f073eae5133c4e9f7bDianne Hackbornimport android.support.v4.view.PagerAdapter; 25ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.util.Log; 26ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.view.View; 27583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powellimport android.view.ViewGroup; 28ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 295c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn/** 305c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * Implementation of {@link android.support.v4.view.PagerAdapter} that 315c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * represents each page as a {@link android.app.Fragment} that is persistently 325c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * kept in the fragment manager as long as the user can return to the page. 337dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 347dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>This version of the pager is best for use when there are a handful of 357dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * typically more static fragments to be paged through, such as a set of tabs. 367dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * The fragment of each page the user visits will be kept in memory, though its 377dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * view hierarchy may be destroyed when not visible. This can result in using 387dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * a significant amount of memory since fragment instances can hold on to an 397dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * arbitrary amount of state. For larger sets of pages, consider 407dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * {@link FragmentStatePagerAdapter}. 417dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 427dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>When using FragmentPagerAdapter the host ViewPager must have a 437dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * valid ID set.</p> 447dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 457dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>Subclasses only need to implement {@link #getItem(int)} 467dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * and {@link #getCount()} to have a working adapter. 477dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 487dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>Here is an example implementation of a pager containing fragments of 497dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * lists: 507dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 517dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * {@sample development/samples/Support13Demos/src/com/example/android/supportv13/app/FragmentPagerSupport.java 527dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * complete} 537dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 547dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>The <code>R.layout.fragment_pager</code> resource of the top-level fragment is: 557dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 567dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * {@sample development/samples/Support13Demos/res/layout/fragment_pager.xml 577dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * complete} 587dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 597dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * <p>The <code>R.layout.fragment_pager_list</code> resource containing each 607dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * individual fragment's layout is: 617dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * 627dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * {@sample development/samples/Support13Demos/res/layout/fragment_pager_list.xml 637dc96cc2410f551eefaa973ddc144146ad72d1ecDianne Hackborn * complete} 645c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn */ 655c1637087453de15e31861f073eae5133c4e9f7bDianne Hackbornpublic abstract class FragmentPagerAdapter extends PagerAdapter { 66ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final String TAG = "FragmentPagerAdapter"; 67ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final boolean DEBUG = false; 68ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 69ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private final FragmentManager mFragmentManager; 70ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private FragmentTransaction mCurTransaction = null; 712a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn private Fragment mCurrentPrimaryItem = null; 72ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 73ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public FragmentPagerAdapter(FragmentManager fm) { 74ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager = fm; 75ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 76ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 77ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn /** 78ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Return the Fragment associated with a specified position. 79ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn */ 80ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public abstract Fragment getItem(int position); 81ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 82ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 83583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powell public void startUpdate(ViewGroup container) { 84ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 85ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 86ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 87583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powell public Object instantiateItem(ViewGroup container, int position) { 88ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 89ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 90ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 91ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 92ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn // Do we already have this fragment? 935c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn String name = makeFragmentName(container.getId(), position); 94ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn Fragment fragment = mFragmentManager.findFragmentByTag(name); 95ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (fragment != null) { 96ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Attaching item #" + position + ": f=" + fragment); 97ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.attach(fragment); 98ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } else { 99ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn fragment = getItem(position); 100ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment); 1015c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn mCurTransaction.add(container.getId(), fragment, 1025c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn makeFragmentName(container.getId(), position)); 103ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 1042a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn if (fragment != mCurrentPrimaryItem) { 1052a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn FragmentCompat.setMenuVisibility(fragment, false); 10679398eaefea45e61d839cf4e0534f0eafee70a09Adam Powell FragmentCompat.setUserVisibleHint(fragment, false); 1072a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn } 108ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 109ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return fragment; 110ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 111ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 112ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 113583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powell public void destroyItem(ViewGroup container, int position, Object object) { 114ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 115ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 116ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 117ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Detaching item #" + position + ": f=" + object 118ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn + " v=" + ((Fragment)object).getView()); 119ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.detach((Fragment)object); 120ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 121ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 122ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 123583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powell public void setPrimaryItem(ViewGroup container, int position, Object object) { 1242a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn Fragment fragment = (Fragment)object; 1252a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn if (fragment != mCurrentPrimaryItem) { 1262a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn if (mCurrentPrimaryItem != null) { 1272a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn FragmentCompat.setMenuVisibility(mCurrentPrimaryItem, false); 12879398eaefea45e61d839cf4e0534f0eafee70a09Adam Powell FragmentCompat.setUserVisibleHint(mCurrentPrimaryItem, false); 1292a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn } 1302a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn if (fragment != null) { 1312a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn FragmentCompat.setMenuVisibility(fragment, true); 13279398eaefea45e61d839cf4e0534f0eafee70a09Adam Powell FragmentCompat.setUserVisibleHint(fragment, true); 1332a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn } 1342a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn mCurrentPrimaryItem = fragment; 1352a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn } 1362a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn } 1372a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn 1382a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn @Override 139583d8a1ff64c7c59dd4e11759f3d8e994ce878d9Adam Powell public void finishUpdate(ViewGroup container) { 140ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction != null) { 1412a4d8518f36346ea25a22a736453ff28f2954165Dianne Hackborn mCurTransaction.commitAllowingStateLoss(); 142ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = null; 143ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager.executePendingTransactions(); 144ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 145ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 146ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 147ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 148ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public boolean isViewFromObject(View view, Object object) { 149ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return ((Fragment)object).getView() == view; 150ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 151ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 152ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 153ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public Parcelable saveState() { 154ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return null; 155ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 156ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 157ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 1585c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public void restoreState(Parcelable state, ClassLoader loader) { 159ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 160ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 161ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static String makeFragmentName(int viewId, int index) { 162ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return "android:switcher:" + viewId + ":" + index; 163ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 164ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn}