FragmentPagerAdapter.java revision 5c1637087453de15e31861f073eae5133c4e9f7b
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; 235c1637087453de15e31861f073eae5133c4e9f7bDianne Hackbornimport android.support.v4.view.PagerAdapter; 24ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.util.Log; 25ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.view.View; 26ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 275c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn/** 285c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * Implementation of {@link android.support.v4.view.PagerAdapter} that 295c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * represents each page as a {@link android.app.Fragment} that is persistently 305c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn * kept in the fragment manager as long as the user can return to the page. 315c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn */ 325c1637087453de15e31861f073eae5133c4e9f7bDianne Hackbornpublic abstract class FragmentPagerAdapter extends PagerAdapter { 33ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final String TAG = "FragmentPagerAdapter"; 34ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final boolean DEBUG = false; 35ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 36ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private final FragmentManager mFragmentManager; 37ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private FragmentTransaction mCurTransaction = null; 38ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 39ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public FragmentPagerAdapter(FragmentManager fm) { 40ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager = fm; 41ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 42ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 43ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn /** 44ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Return the Fragment associated with a specified position. 45ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn */ 46ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public abstract Fragment getItem(int position); 47ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 48ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 495c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public void startUpdate(View container) { 50ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 51ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 52ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 535c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public Object instantiateItem(View container, int position) { 54ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 55ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 56ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 57ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 58ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn // Do we already have this fragment? 595c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn String name = makeFragmentName(container.getId(), position); 60ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn Fragment fragment = mFragmentManager.findFragmentByTag(name); 61ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (fragment != null) { 62ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Attaching item #" + position + ": f=" + fragment); 63ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.attach(fragment); 64ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } else { 65ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn fragment = getItem(position); 66ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment); 675c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn mCurTransaction.add(container.getId(), fragment, 685c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn makeFragmentName(container.getId(), position)); 69ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 70ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 71ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return fragment; 72ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 73ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 74ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 755c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public void destroyItem(View container, int position, Object object) { 76ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 77ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 78ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 79ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Detaching item #" + position + ": f=" + object 80ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn + " v=" + ((Fragment)object).getView()); 81ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.detach((Fragment)object); 82ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 83ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 84ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 855c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public void finishUpdate(View container) { 86ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction != null) { 87ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.commit(); 88ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = null; 89ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager.executePendingTransactions(); 90ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 91ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 92ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 93ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 94ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public boolean isViewFromObject(View view, Object object) { 95ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return ((Fragment)object).getView() == view; 96ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 97ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 98ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 99ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public Parcelable saveState() { 100ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return null; 101ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 102ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 103ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 1045c1637087453de15e31861f073eae5133c4e9f7bDianne Hackborn public void restoreState(Parcelable state, ClassLoader loader) { 105ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 106ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 107ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static String makeFragmentName(int viewId, int index) { 108ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return "android:switcher:" + viewId + ":" + index; 109ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 110ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn}