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.FileDownloadFragment;
  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 DataStorageManager mStorageManager;
  55
  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     /**
  65      * Constructor.
  66      *
  67      * @param fragmentManager   {@link FragmentManager} instance that will handle the {@link Fragment}s provided by the adapter.
  68      * @param parentFolder      Folder where images will be searched for.
  69      * @param storageManager    Bridge to database.
  70      */
  71     public PreviewImagePagerAdapter(FragmentManager fragmentManager, OCFile parentFolder, Account account, DataStorageManager storageManager) {
  72         super(fragmentManager);
  73
  74         if (fragmentManager == null) {
  75             throw new IllegalArgumentException("NULL FragmentManager instance");
  76         }
  77         if (parentFolder == null) {
  78             throw new IllegalArgumentException("NULL parent folder");
  79         }
  80         if (storageManager == null) {
  81             throw new IllegalArgumentException("NULL storage manager");
  82         }
  83
  84         mAccount = account;
  85         mStorageManager = storageManager;
  86         mImageFiles = mStorageManager.getDirectoryImages(parentFolder);
  87         mObsoleteFragments = new HashSet<Object>();
  88     }
  89
  90
  91     /**
  92      * Returns the image files handled by the adapter.
  93      *
  94      * @return  A vector with the image files handled by the adapter.
  95      */
  96     protected OCFile getFileAt(int position) {
  97         return mImageFiles.get(position);
  98     }
  99
 100
 101     public Fragment getItem(int i) {
 102         Log.e(TAG, "GETTING PAGE " + i);
 103         OCFile file = mImageFiles.get(i);
 104         Fragment fragment = null;
 105         if (file.isDown()) {
 106             fragment = new PreviewImageFragment(file, mAccount);
 107         } else {
 108             fragment = new FileDownloadFragment(file, mAccount);
 109         }
 110         return fragment;
 111     }
 112
 113     @Override
 114     public int getCount() {
 115         return mImageFiles.size();
 116     }
 117
 118     @Override
 119     public CharSequence getPageTitle(int position) {
 120         return mImageFiles.get(position).getFileName();
 121     }
 122
 123     public void updateFile(int position, OCFile file) {
 124         mImageFiles.set(position, file);
 125         mObsoleteFragments.add(instantiateItem(null, position));
 126     }
 127
 128     @Override
 129     public int getItemPosition(Object object) {
 130         Log.e(TAG, "getItemPosition ");
 131         if (mObsoleteFragments.contains(object)) {
 132             return POSITION_NONE;
 133         }
 134         return super.getItemPosition(object);
 135     }
 136
 137     /* *
 138      * Called when a change in the shown pages is going to start being made.
 139      *
 140      * @param   container   The containing View which is displaying this adapter's page views.
 141      * -/
 142     @Override
 143     public void startUpdate(ViewGroup container) {
 144         Log.e(TAG, "** startUpdate");
 145     }
 146
 147     @Override
 148     public Object instantiateItem(ViewGroup container, int position) {
 149         Log.e(TAG, "** instantiateItem " + position);
 150
 151         if (mFragments.size() > position) {
 152             Fragment fragment = mFragments.get(position);
 153             if (fragment != null) {
 154                 Log.e(TAG, "** \t returning cached item");
 155                 return fragment;
 156             }
 157         }
 158
 159         if (mCurTransaction == null) {
 160             mCurTransaction = mFragmentManager.beginTransaction();
 161         }
 162
 163         Fragment fragment = getItem(position);
 164         if (mSavedState.size() > position) {
 165             Fragment.SavedState savedState = mSavedState.get(position);
 166             if (savedState != null) {
 167                 // TODO WATCH OUT:
 168                 // * The Fragment must currently be attached to the FragmentManager.
 169                 // * A new Fragment created using this saved state must be the same class type as the Fragment it was created from.
 170                 // * The saved state can not contain dependencies on other fragments -- that is it can't use putFragment(Bundle, String, Fragment)
 171                 //   to store a fragment reference
 172                 fragment.setInitialSavedState(savedState);
 173             }
 174         }
 175         while (mFragments.size() <= position) {
 176             mFragments.add(null);
 177         }
 178         fragment.setMenuVisibility(false);
 179         mFragments.set(position, fragment);
 180         Log.e(TAG, "** \t adding fragment at position " + position + ", containerId " + container.getId());
 181         mCurTransaction.add(container.getId(), fragment);
 182
 183         return fragment;
 184     }
 185
 186     @Override
 187     public void destroyItem(ViewGroup container, int position, Object object) {
 188         Log.e(TAG, "** destroyItem " + position);
 189         Fragment fragment = (Fragment)object;
 190
 191         if (mCurTransaction == null) {
 192             mCurTransaction = mFragmentManager.beginTransaction();
 193         }
 194         Log.e(TAG, "** \t removing fragment at position " + position);
 195         while (mSavedState.size() <= position) {
 196             mSavedState.add(null);
 197         }
 198         mSavedState.set(position, mFragmentManager.saveFragmentInstanceState(fragment));
 199         mFragments.set(position, null);
 200
 201         mCurTransaction.remove(fragment);
 202     }
 203
 204     @Override
 205     public void setPrimaryItem(ViewGroup container, int position, Object object) {
 206         Fragment fragment = (Fragment)object;
 207         if (fragment != mCurrentPrimaryItem) {
 208             if (mCurrentPrimaryItem != null) {
 209                 mCurrentPrimaryItem.setMenuVisibility(false);
 210             }
 211             if (fragment != null) {
 212                 fragment.setMenuVisibility(true);
 213             }
 214             mCurrentPrimaryItem = fragment;
 215         }
 216     }
 217
 218     @Override
 219     public void finishUpdate(ViewGroup container) {
 220         Log.e(TAG, "** finishUpdate (start)");
 221         if (mCurTransaction != null) {
 222             mCurTransaction.commitAllowingStateLoss();
 223             mCurTransaction = null;
 224             mFragmentManager.executePendingTransactions();
 225         }
 226         Log.e(TAG, "** finishUpdate (end)");
 227     }
 228
 229     @Override
 230     public boolean isViewFromObject(View view, Object object) {
 231         return ((Fragment)object).getView() == view;
 232     }
 233
 234     @Override
 235     public Parcelable saveState() {
 236         Bundle state = null;
 237         if (mSavedState.size() > 0) {
 238             state = new Bundle();
 239             Fragment.SavedState[] savedStates = new Fragment.SavedState[mSavedState.size()];
 240             mSavedState.toArray(savedStates);
 241             state.putParcelableArray("states", savedStates);
 242         }
 243         for (int i=0; i<mFragments.size(); i++) {
 244             Fragment fragment = mFragments.get(i);
 245             if (fragment != null) {
 246                 if (state == null) {
 247                     state = new Bundle();
 248                 }
 249                 String key = "f" + i;
 250                 mFragmentManager.putFragment(state, key, fragment);
 251             }
 252         }
 253         return state;
 254     }
 255
 256     @Override
 257     public void restoreState(Parcelable state, ClassLoader loader) {
 258         if (state != null) {
 259             Bundle bundle = (Bundle)state;
 260             bundle.setClassLoader(loader);
 261             Parcelable[] states = bundle.getParcelableArray("states");
 262             mSavedState.clear();
 263             mFragments.clear();
 264             if (states != null) {
 265                 for (int i=0; i<states.length; i++) {
 266                     mSavedState.add((Fragment.SavedState)states[i]);
 267                 }
 268             }
 269             Iterable<String> keys = bundle.keySet();
 270             for (String key: keys) {
 271                 if (key.startsWith("f")) {
 272                     int index = Integer.parseInt(key.substring(1));
 273                     Fragment f = mFragmentManager.getFragment(bundle, key);
 274                     if (f != null) {
 275                         while (mFragments.size() <= index) {
 276                             mFragments.add(null);
 277                         }
 278                         f.setMenuVisibility(false);
 279                         mFragments.set(index, f);
 280                     } else {
 281                         Log.w(TAG, "Bad fragment at key " + key);
 282                     }
 283                 }
 284             }
 285         }
 286     } */
 287
 288 }