1 /* 2 * Copyright (C) 2011 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 17 package androidx.legacy.app; 18 19 import android.app.Fragment; 20 import android.app.FragmentManager; 21 import android.app.FragmentTransaction; 22 import android.os.Parcelable; 23 import android.util.Log; 24 import android.view.View; 25 import android.view.ViewGroup; 26 27 import androidx.fragment.app.FragmentStatePagerAdapter; 28 import androidx.viewpager.widget.PagerAdapter; 29 30 /** 31 * Implementation of {@link PagerAdapter} that 32 * represents each page as a {@link android.app.Fragment} that is persistently 33 * kept in the fragment manager as long as the user can return to the page. 34 * 35 * <p>This version of the pager is best for use when there are a handful of 36 * typically more static fragments to be paged through, such as a set of tabs. 37 * The fragment of each page the user visits will be kept in memory, though its 38 * view hierarchy may be destroyed when not visible. This can result in using 39 * a significant amount of memory since fragment instances can hold on to an 40 * arbitrary amount of state. For larger sets of pages, consider 41 * {@link FragmentStatePagerAdapter}. 42 * 43 * <p>When using FragmentPagerAdapter the host ViewPager must have a 44 * valid ID set.</p> 45 * 46 * <p>Subclasses only need to implement {@link #getItem(int)} 47 * and {@link #getCount()} to have a working adapter. 48 * 49 * <p>Here is an example implementation of a pager containing fragments of 50 * lists: 51 * 52 * {@sample frameworks/support/samples/Support13Demos/src/main/java/com/example/android/supportv13/app/FragmentPagerSupport.java 53 * complete} 54 * 55 * <p>The <code>R.layout.fragment_pager</code> resource of the top-level fragment is: 56 * 57 * {@sample frameworks/support/samples/Support13Demos/src/main/res/layout/fragment_pager.xml 58 * complete} 59 * 60 * <p>The <code>R.layout.fragment_pager_list</code> resource containing each 61 * individual fragment's layout is: 62 * 63 * {@sample frameworks/support/samples/Support13Demos/src/main/res/layout/fragment_pager_list.xml 64 * complete} 65 * 66 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 67 */ 68 @Deprecated 69 public abstract class FragmentPagerAdapter extends PagerAdapter { 70 private static final String TAG = "FragmentPagerAdapter"; 71 private static final boolean DEBUG = false; 72 73 private final FragmentManager mFragmentManager; 74 private FragmentTransaction mCurTransaction = null; 75 private Fragment mCurrentPrimaryItem = null; 76 77 /** 78 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 79 */ 80 @Deprecated 81 public FragmentPagerAdapter(FragmentManager fm) { 82 mFragmentManager = fm; 83 } 84 85 /** 86 * Return the Fragment associated with a specified position. 87 * 88 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 89 */ 90 @Deprecated 91 public abstract Fragment getItem(int position); 92 93 /** 94 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 95 */ 96 @Deprecated 97 @Override 98 public void startUpdate(ViewGroup container) { 99 if (container.getId() == View.NO_ID) { 100 throw new IllegalStateException("ViewPager with adapter " + this 101 + " requires a view id"); 102 } 103 } 104 105 /** 106 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 107 */ 108 @Deprecated 109 @SuppressWarnings("ReferenceEquality") 110 @Override 111 public Object instantiateItem(ViewGroup container, int position) { 112 if (mCurTransaction == null) { 113 mCurTransaction = mFragmentManager.beginTransaction(); 114 } 115 116 final long itemId = getItemId(position); 117 118 // Do we already have this fragment? 119 String name = makeFragmentName(container.getId(), itemId); 120 Fragment fragment = mFragmentManager.findFragmentByTag(name); 121 if (fragment != null) { 122 if (DEBUG) Log.v(TAG, "Attaching item #" + itemId + ": f=" + fragment); 123 mCurTransaction.attach(fragment); 124 } else { 125 fragment = getItem(position); 126 if (DEBUG) Log.v(TAG, "Adding item #" + itemId + ": f=" + fragment); 127 mCurTransaction.add(container.getId(), fragment, 128 makeFragmentName(container.getId(), itemId)); 129 } 130 if (fragment != mCurrentPrimaryItem) { 131 fragment.setMenuVisibility(false); 132 FragmentCompat.setUserVisibleHint(fragment, false); 133 } 134 135 return fragment; 136 } 137 138 /** 139 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 140 */ 141 @Deprecated 142 @Override 143 public void destroyItem(ViewGroup container, int position, Object object) { 144 if (mCurTransaction == null) { 145 mCurTransaction = mFragmentManager.beginTransaction(); 146 } 147 if (DEBUG) Log.v(TAG, "Detaching item #" + getItemId(position) + ": f=" + object 148 + " v=" + ((Fragment)object).getView()); 149 mCurTransaction.detach((Fragment)object); 150 } 151 152 /** 153 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 154 */ 155 @Deprecated 156 @SuppressWarnings("ReferenceEquality") 157 @Override 158 public void setPrimaryItem(ViewGroup container, int position, Object object) { 159 Fragment fragment = (Fragment)object; 160 if (fragment != mCurrentPrimaryItem) { 161 if (mCurrentPrimaryItem != null) { 162 mCurrentPrimaryItem.setMenuVisibility(false); 163 FragmentCompat.setUserVisibleHint(mCurrentPrimaryItem, false); 164 } 165 if (fragment != null) { 166 fragment.setMenuVisibility(true); 167 FragmentCompat.setUserVisibleHint(fragment, true); 168 } 169 mCurrentPrimaryItem = fragment; 170 } 171 } 172 173 /** 174 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 175 */ 176 @Deprecated 177 @Override 178 public void finishUpdate(ViewGroup container) { 179 if (mCurTransaction != null) { 180 mCurTransaction.commitAllowingStateLoss(); 181 mCurTransaction = null; 182 mFragmentManager.executePendingTransactions(); 183 } 184 } 185 186 /** 187 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 188 */ 189 @Deprecated 190 @Override 191 public boolean isViewFromObject(View view, Object object) { 192 return ((Fragment)object).getView() == view; 193 } 194 195 /** 196 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 197 */ 198 @Deprecated 199 @Override 200 public Parcelable saveState() { 201 return null; 202 } 203 204 /** 205 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 206 */ 207 @Deprecated 208 @Override 209 public void restoreState(Parcelable state, ClassLoader loader) { 210 } 211 212 /** 213 * Return a unique identifier for the item at the given position. 214 * 215 * <p>The default implementation returns the given position. 216 * Subclasses should override this method if the positions of items can change.</p> 217 * 218 * @param position Position within this adapter 219 * @return Unique identifier for the item at position 220 * 221 * @deprecated Use {@link androidx.fragment.app.FragmentPagerAdapter} instead. 222 */ 223 @Deprecated 224 public long getItemId(int position) { 225 return position; 226 } 227 228 private static String makeFragmentName(int viewId, long id) { 229 return "android:switcher:" + viewId + ":" + id; 230 } 231 }