src/com/owncloud/android/ui/preview/PreviewImagePagerAdapter.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012-2013  ownCloud Inc.
   3  *
   4  *   This program is free software: you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License as published by
   6  *   the Free Software Foundation, either version 2 of the License, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *   GNU General Public License for more details.
  13  *
  14  *   You should have received a copy of the GNU General Public License
  15  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  *
  17  */
  18 package com.owncloud.android.ui.preview;
  19
  20 import java.util.ArrayList;
  21 import java.util.HashSet;
  22 import java.util.Set;
  23 import java.util.Vector;
  24
  25 import android.accounts.Account;
  26 import android.os.Bundle;
  27 import android.os.Parcelable;
  28 import android.support.v4.app.Fragment;
  29 import android.support.v4.app.FragmentManager;
  30 import android.support.v4.app.FragmentStatePagerAdapter;
  31 import android.support.v4.app.FragmentTransaction;
  32 import android.support.v4.view.PagerAdapter;
  33 import android.util.Log;
  34 import android.view.View;
  35 import android.view.ViewGroup;
  36
  37 import com.owncloud.android.datamodel.DataStorageManager;
  38 import com.owncloud.android.datamodel.OCFile;
  39 import com.owncloud.android.ui.fragment.FileFragment;
  40
  41 /**
  42  * Adapter class that provides Fragment instances
  43  *
  44  * @author David A. Velasco
  45  */
  46 public class PreviewImagePagerAdapter extends PagerAdapter {
  47 //public class PreviewImagePagerAdapter extends FragmentStatePagerAdapter {
  48
  49     private static final String TAG = PreviewImagePagerAdapter.class.getSimpleName();
  50
  51     private Vector<OCFile> mImageFiles;
  52     private Account mAccount;
  53     private Set<Object> mObsoleteFragments;
  54     private Set<Integer> mObsoletePositions;
  55     private DataStorageManager mStorageManager;
  56
  57     private final FragmentManager mFragmentManager;
  58     private FragmentTransaction mCurTransaction = null;
  59     private ArrayList<Fragment.SavedState> mSavedState = new ArrayList<Fragment.SavedState>();
  60     private ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
  61     private Fragment mCurrentPrimaryItem = null;
  62
  63     /**
  64      * Constructor.
  65      *
  66      * @param fragmentManager   {@link FragmentManager} instance that will handle the {@link Fragment}s provided by the adapter.
  67      * @param parentFolder      Folder where images will be searched for.
  68      * @param storageManager    Bridge to database.
  69      */
  70     public PreviewImagePagerAdapter(FragmentManager fragmentManager, OCFile parentFolder, Account account, DataStorageManager storageManager) {
  71         //super(fragmentManager);
  72
  73         if (fragmentManager == null) {
  74             throw new IllegalArgumentException("NULL FragmentManager instance");
  75         }
  76         if (parentFolder == null) {
  77             throw new IllegalArgumentException("NULL parent folder");
  78         }
  79         if (storageManager == null) {
  80             throw new IllegalArgumentException("NULL storage manager");
  81         }
  82
  83         mAccount = account;
  84         mStorageManager = storageManager;
  85         mImageFiles = mStorageManager.getDirectoryImages(parentFolder);
  86         mObsoleteFragments = new HashSet<Object>();
  87         mObsoletePositions = new HashSet<Integer>();
  88         mFragmentManager = fragmentManager;
  89     }
  90
  91
  92     /**
  93      * Returns the image files handled by the adapter.
  94      *
  95      * @return  A vector with the image files handled by the adapter.
  96      */
  97     protected OCFile getFileAt(int position) {
  98         return mImageFiles.get(position);
  99     }
 100
 101
 102     public Fragment getItem(int i) {
 103         Log.e(TAG, "GETTING PAGE " + i);
 104         OCFile file = mImageFiles.get(i);
 105         Fragment fragment = null;
 106         if (file.isDown()) {
 107             fragment = new PreviewImageFragment(file, mAccount, mObsoletePositions.contains(Integer.valueOf(i)));
 108         } else {
 109             fragment = new FileDownloadFragment(file, mAccount, mObsoletePositions.contains(Integer.valueOf(i)));
 110         }
 111         return fragment;
 112     }
 113
 114     public int getFilePosition(OCFile file) {
 115         return mImageFiles.indexOf(file);
 116     }
 117
 118     @Override
 119     public int getCount() {
 120         return mImageFiles.size();
 121     }
 122
 123     @Override
 124     public CharSequence getPageTitle(int position) {
 125         return mImageFiles.get(position).getFileName();
 126     }
 127
 128     public void updateFile(int position, OCFile file) {
 129         mObsoleteFragments.add(instantiateItem(null, position));
 130         mObsoletePositions.add(Integer.valueOf(position));
 131         mImageFiles.set(position, file);
 132     }
 133
 134     @Override
 135     public int getItemPosition(Object object) {
 136         Log.e(TAG, "getItemPosition ");
 137         if (mObsoleteFragments.contains(object)) {
 138             mObsoleteFragments.remove(object);
 139             return POSITION_NONE;
 140         }
 141         return super.getItemPosition(object);
 142     }
 143
 144
 145     /**
 146      * Should not be used for not already started fragments...
 147      *
 148      * @return
 149      */
 150     protected FileFragment getFragmentAt(int position) {
 151         try {
 152             return (FileFragment) instantiateItem(null, position);
 153
 154         } catch (Exception e) {
 155             Log.e(TAG, "Wrong access to fragment in gallery ", e);
 156             return null;
 157         }
 158     }
 159
 160
 161     /**
 162      * Called when a change in the shown pages is going to start being made.
 163      *
 164      * @param   container   The containing View which is displaying this adapter's page views.
 165      */
 166     @Override
 167     public void startUpdate(ViewGroup container) {
 168         Log.e(TAG, "** startUpdate");
 169     }
 170
 171     @Override
 172     public Object instantiateItem(ViewGroup container, int position) {
 173         Log.e(TAG, "** instantiateItem " + position);
 174
 175         if (mFragments.size() > position) {
 176             Fragment fragment = mFragments.get(position);
 177             if (fragment != null) {
 178                 Log.e(TAG, "** \t returning cached item");
 179                 return fragment;
 180             }
 181         }
 182
 183         if (mCurTransaction == null) {
 184             mCurTransaction = mFragmentManager.beginTransaction();
 185         }
 186
 187         Fragment fragment = getItem(position);
 188         if (mSavedState.size() > position) {
 189             Fragment.SavedState savedState = mSavedState.get(position);
 190             if (savedState != null) {
 191                 // TODO WATCH OUT:
 192                 // * The Fragment must currently be attached to the FragmentManager.
 193                 // * A new Fragment created using this saved state must be the same class type as the Fragment it was created from.
 194                 // * The saved state can not contain dependencies on other fragments -- that is it can't use putFragment(Bundle, String, Fragment)
 195                 //   to store a fragment reference
 196                 fragment.setInitialSavedState(savedState);
 197             }
 198         }
 199         while (mFragments.size() <= position) {
 200             mFragments.add(null);
 201         }
 202         fragment.setMenuVisibility(false);
 203         mFragments.set(position, fragment);
 204         //Log.e(TAG, "** \t adding fragment at position " + position + ", containerId " + container.getId());
 205         mCurTransaction.add(container.getId(), fragment);
 206
 207         return fragment;
 208     }
 209
 210     @Override
 211     public void destroyItem(ViewGroup container, int position, Object object) {
 212         Log.e(TAG, "** destroyItem " + position);
 213         Fragment fragment = (Fragment)object;
 214
 215         if (mCurTransaction == null) {
 216             mCurTransaction = mFragmentManager.beginTransaction();
 217         }
 218         Log.e(TAG, "** \t removing fragment at position " + position);
 219         while (mSavedState.size() <= position) {
 220             mSavedState.add(null);
 221         }
 222         mSavedState.set(position, mFragmentManager.saveFragmentInstanceState(fragment));
 223         mFragments.set(position, null);
 224
 225         mCurTransaction.remove(fragment);
 226     }
 227
 228     @Override
 229     public void setPrimaryItem(ViewGroup container, int position, Object object) {
 230         Fragment fragment = (Fragment)object;
 231         if (fragment != mCurrentPrimaryItem) {
 232             if (mCurrentPrimaryItem != null) {
 233                 mCurrentPrimaryItem.setMenuVisibility(false);
 234             }
 235             if (fragment != null) {
 236                 fragment.setMenuVisibility(true);
 237             }
 238             mCurrentPrimaryItem = fragment;
 239         }
 240     }
 241
 242     @Override
 243     public void finishUpdate(ViewGroup container) {
 244         Log.e(TAG, "** finishUpdate (start)");
 245         if (mCurTransaction != null) {
 246             mCurTransaction.commitAllowingStateLoss();
 247             mCurTransaction = null;
 248             mFragmentManager.executePendingTransactions();
 249         }
 250         Log.e(TAG, "** finishUpdate (end)");
 251     }
 252
 253     @Override
 254     public boolean isViewFromObject(View view, Object object) {
 255         return ((Fragment)object).getView() == view;
 256     }
 257
 258     @Override
 259     public Parcelable saveState() {
 260         Bundle state = null;
 261         if (mSavedState.size() > 0) {
 262             state = new Bundle();
 263             Fragment.SavedState[] savedStates = new Fragment.SavedState[mSavedState.size()];
 264             mSavedState.toArray(savedStates);
 265             state.putParcelableArray("states", savedStates);
 266         }
 267         for (int i=0; i<mFragments.size(); i++) {
 268             Fragment fragment = mFragments.get(i);
 269             if (fragment != null) {
 270                 if (state == null) {
 271                     state = new Bundle();
 272                 }
 273                 String key = "f" + i;
 274                 mFragmentManager.putFragment(state, key, fragment);
 275             }
 276         }
 277         return state;
 278     }
 279
 280     @Override
 281     public void restoreState(Parcelable state, ClassLoader loader) {
 282         if (state != null) {
 283             Bundle bundle = (Bundle)state;
 284             bundle.setClassLoader(loader);
 285             Parcelable[] states = bundle.getParcelableArray("states");
 286             mSavedState.clear();
 287             mFragments.clear();
 288             if (states != null) {
 289                 for (int i=0; i<states.length; i++) {
 290                     mSavedState.add((Fragment.SavedState)states[i]);
 291                 }
 292             }
 293             Iterable<String> keys = bundle.keySet();
 294             for (String key: keys) {
 295                 if (key.startsWith("f")) {
 296                     int index = Integer.parseInt(key.substring(1));
 297                     Fragment f = mFragmentManager.getFragment(bundle, key);
 298                     if (f != null) {
 299                         while (mFragments.size() <= index) {
 300                             mFragments.add(null);
 301                         }
 302                         f.setMenuVisibility(false);
 303                         mFragments.set(index, f);
 304                     } else {
 305                         Log.w(TAG, "Bad fragment at key " + key);
 306                     }
 307                 }
 308             }
 309         }
 310     }
 311
 312 }