FragmentPagerAdapter.java revision ea2c91b0198855073983b4a8437aa71cbd83872f
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; 23ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.support.v13.view.PagerAdapter; 24ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.util.Log; 25ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornimport android.view.View; 26ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 27ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackbornpublic abstract class FragmentPagerAdapter implements PagerAdapter { 28ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final String TAG = "FragmentPagerAdapter"; 29ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static final boolean DEBUG = false; 30ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 31ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private final FragmentManager mFragmentManager; 32ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private FragmentTransaction mCurTransaction = null; 33ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 34ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public FragmentPagerAdapter(FragmentManager fm) { 35ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager = fm; 36ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 37ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 38ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn /** 39ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn * Return the Fragment associated with a specified position. 40ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn */ 41ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public abstract Fragment getItem(int position); 42ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 43ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 44ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public void startUpdate() { 45ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 46ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 47ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 48ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public Object instantiateItem(int viewId, int position) { 49ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 50ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 51ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 52ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 53ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn // Do we already have this fragment? 54ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn String name = makeFragmentName(viewId, position); 55ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn Fragment fragment = mFragmentManager.findFragmentByTag(name); 56ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (fragment != null) { 57ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Attaching item #" + position + ": f=" + fragment); 58ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.attach(fragment); 59ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } else { 60ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn fragment = getItem(position); 61ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment); 62ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.add(viewId, fragment, makeFragmentName(viewId, position)); 63ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 64ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 65ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return fragment; 66ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 67ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 68ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 69ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public void destroyItem(int position, Object object) { 70ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction == null) { 71ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = mFragmentManager.beginTransaction(); 72ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 73ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (DEBUG) Log.v(TAG, "Detaching item #" + position + ": f=" + object 74ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn + " v=" + ((Fragment)object).getView()); 75ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.detach((Fragment)object); 76ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 77ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 78ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 79ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public void finishUpdate() { 80ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn if (mCurTransaction != null) { 81ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction.commit(); 82ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mCurTransaction = null; 83ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn mFragmentManager.executePendingTransactions(); 84ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 85ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 86ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 87ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 88ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public boolean isViewFromObject(View view, Object object) { 89ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return ((Fragment)object).getView() == view; 90ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 91ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 92ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 93ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public Parcelable saveState() { 94ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return null; 95ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 96ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 97ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn @Override 98ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn public void restoreState(Parcelable state) { 99ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 100ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn 101ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn private static String makeFragmentName(int viewId, int index) { 102ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn return "android:switcher:" + viewId + ":" + index; 103ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn } 104ea2c91b0198855073983b4a8437aa71cbd83872fDianne Hackborn}