1f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein/* 2f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * Copyright (C) 2011 Google Inc. 3f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * Licensed to The Android Open Source Project. 4f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * 5f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * Licensed under the Apache License, Version 2.0 (the "License"); 6f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * you may not use this file except in compliance with the License. 7f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * You may obtain a copy of the License at 8f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * 9f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * http://www.apache.org/licenses/LICENSE-2.0 10f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * 11f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * Unless required by applicable law or agreed to in writing, software 12f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * distributed under the License is distributed on an "AS IS" BASIS, 13f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * See the License for the specific language governing permissions and 15f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * limitations under the License. 16f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein */ 17f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 18f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinpackage com.android.ex.photo.adapters; 19f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 20f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinimport android.os.Parcelable; 218746927a945358bb9e515985a37cac7807261026Martin Hibdonimport android.support.v4.app.Fragment; 228746927a945358bb9e515985a37cac7807261026Martin Hibdonimport android.support.v4.app.FragmentManager; 238746927a945358bb9e515985a37cac7807261026Martin Hibdonimport android.support.v4.app.FragmentTransaction; 24f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinimport android.support.v4.view.PagerAdapter; 25f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinimport android.util.Log; 26f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinimport android.util.LruCache; 27f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinimport android.view.View; 28f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 29f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein/** 30f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * NOTE: This is a direct copy of {@link FragmentPagerAdapter} with four very important 31f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * modifications. 32f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * <p> 33f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * <ol> 34f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * <li>The method {@link #makeFragmentName(int, int)} is declared "protected" 35f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * in our class. We need to be able to re-define the fragment's name according to data 36f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * only available to sub-classes.</li> 37f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * <li>The method {@link #isViewFromObject(View, Object)} has been reimplemented to search 38f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * the entire view hierarchy for the given view.</li> 39f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * <li>In method {@link #destroyItem(View, int, Object)}, the fragment is detached and 40f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * added to a cache. If the fragment is evicted from the cache, it will be deleted. 41f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * An album may contain thousands of photos and we want to avoid having thousands of 42f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * fragments.</li> 43f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * </ol> 44f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein */ 45f77a7eb196d16110c7b1087352b423913821ff61Andrew Sappersteinpublic abstract class BaseFragmentPagerAdapter extends PagerAdapter { 46f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein /** The default size of {@link #mFragmentCache} */ 47f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private static final int DEFAULT_CACHE_SIZE = 5; 48f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private static final String TAG = "FragmentPagerAdapter"; 49f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private static final boolean DEBUG = false; 50f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 51f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private final FragmentManager mFragmentManager; 52f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private FragmentTransaction mCurTransaction = null; 53f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private Fragment mCurrentPrimaryItem = null; 54f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein /** A cache to store detached fragments before they are removed */ 55f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private LruCache<String, Fragment> mFragmentCache = new FragmentCache(DEFAULT_CACHE_SIZE); 56f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 578746927a945358bb9e515985a37cac7807261026Martin Hibdon public BaseFragmentPagerAdapter(android.support.v4.app.FragmentManager fm) { 58f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mFragmentManager = fm; 59f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 60f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 61f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein /** 62f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * Return the Fragment associated with a specified position. 63f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein */ 64f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public abstract Fragment getItem(int position); 65f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 66f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 67f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public void startUpdate(View container) { 68f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 69f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 70f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 71f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public Object instantiateItem(View container, int position) { 72f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (mCurTransaction == null) { 73f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction = mFragmentManager.beginTransaction(); 74f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 75f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 76f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // Do we already have this fragment? 77f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein String name = makeFragmentName(container.getId(), position); 78f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 79f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // Remove item from the cache 80f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mFragmentCache.remove(name); 81f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 82f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein Fragment fragment = mFragmentManager.findFragmentByTag(name); 83f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (fragment != null) { 84f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (DEBUG) Log.v(TAG, "Attaching item #" + position + ": f=" + fragment); 85f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction.attach(fragment); 86f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } else { 87f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein fragment = getItem(position); 880ab3e0cf9cbb5751a276e4c2555640a0e8173b5fAdam Copp if(fragment == null) { 890ab3e0cf9cbb5751a276e4c2555640a0e8173b5fAdam Copp if (DEBUG) Log.e(TAG, "NPE workaround for getItem(). See b/7103023"); 900ab3e0cf9cbb5751a276e4c2555640a0e8173b5fAdam Copp return null; 910ab3e0cf9cbb5751a276e4c2555640a0e8173b5fAdam Copp } 92f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment); 93f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction.add(container.getId(), fragment, 94f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein makeFragmentName(container.getId(), position)); 95f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 96f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (fragment != mCurrentPrimaryItem) { 97f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein fragment.setMenuVisibility(false); 98f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 99f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 100f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein return fragment; 101f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 102f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 103f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 104f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public void destroyItem(View container, int position, Object object) { 105f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (mCurTransaction == null) { 106f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction = mFragmentManager.beginTransaction(); 107f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 108f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (DEBUG) Log.v(TAG, "Detaching item #" + position + ": f=" + object 109f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein + " v=" + ((Fragment)object).getView()); 110f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 111f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein Fragment fragment = (Fragment) object; 112f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein String name = fragment.getTag(); 113f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (name == null) { 114f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // We prefer to get the name directly from the fragment, but, if the fragment is 115f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // detached before the add transaction is committed, this could be 'null'. In 116f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // that case, generate a name so we can still cache the fragment. 117f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein name = makeFragmentName(container.getId(), position); 118f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 119f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 120f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mFragmentCache.put(name, fragment); 121f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction.detach(fragment); 122f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 123f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 124f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 125f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public void setPrimaryItem(View container, int position, Object object) { 126f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein Fragment fragment = (Fragment) object; 127f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (fragment != mCurrentPrimaryItem) { 128f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (mCurrentPrimaryItem != null) { 129f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurrentPrimaryItem.setMenuVisibility(false); 130f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 131f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (fragment != null) { 132f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein fragment.setMenuVisibility(true); 133f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 134f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurrentPrimaryItem = fragment; 135f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 136f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 137f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 138f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 139f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 140f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public void finishUpdate(View container) { 141f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (mCurTransaction != null) { 142f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction.commitAllowingStateLoss(); 143f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction = null; 144f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mFragmentManager.executePendingTransactions(); 145f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 146f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 147f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 148f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 149f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public boolean isViewFromObject(View view, Object object) { 150f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // Ascend the tree to determine if the view is a child of the fragment 151f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein View root = ((Fragment) object).getView(); 152f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein for (Object v = view; v instanceof View; v = ((View) v).getParent()) { 153f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (v == root) { 154f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein return true; 155f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 156f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 157f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein return false; 158f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 159f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 160f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 161f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public Parcelable saveState() { 162f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein return null; 163f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 164f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 165f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 166f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public void restoreState(Parcelable state, ClassLoader loader) { 167f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 168f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 169f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein /** Creates a name for the fragment */ 170f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein protected String makeFragmentName(int viewId, int index) { 171f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein return "android:switcher:" + viewId + ":" + index; 172f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 173f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 174f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein /** 175f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein * A cache of detached fragments. 176f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein */ 177f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein private class FragmentCache extends LruCache<String, Fragment> { 178f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein public FragmentCache(int size) { 179f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein super(size); 180f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 181f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein 182f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein @Override 183f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein protected void entryRemoved(boolean evicted, String key, 184f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein Fragment oldValue, Fragment newValue) { 185f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein // remove the fragment if it's evicted OR it's replaced by a new fragment 186f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein if (evicted || (newValue != null && oldValue != newValue)) { 187f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein mCurTransaction.remove(oldValue); 188f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 189f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 190f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein } 191f77a7eb196d16110c7b1087352b423913821ff61Andrew Sapperstein} 192