src/com/owncloud/android/ui/fragment/ExtendedListFragment.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012 Bartek Przybylski
   3  *   Copyright (C) 2012-2013 ownCloud Inc.
   4  *
   5  *   This program is free software: you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License version 2,
   7  *   as published by the Free Software Foundation.
   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
  19 package com.owncloud.android.ui.fragment;
  20
  21 import java.util.ArrayList;
  22
  23 import android.os.Bundle;
  24 import android.support.v4.widget.SwipeRefreshLayout;
  25 import android.view.LayoutInflater;
  26 import android.view.View;
  27 import android.view.ViewGroup;
  28 import android.widget.AdapterView;
  29 import android.widget.AdapterView.OnItemClickListener;
  30 import android.widget.ListAdapter;
  31 import android.widget.ListView;
  32 import android.widget.TextView;
  33
  34 import com.actionbarsherlock.app.SherlockFragment;
  35 import com.owncloud.android.R;
  36 import com.owncloud.android.ui.ExtendedListView;
  37 import com.owncloud.android.utils.Log_OC;
  38
  39 /**
  40  *  TODO extending SherlockListFragment instead of SherlockFragment
  41  */
  42 public class ExtendedListFragment extends SherlockFragment implements OnItemClickListener, SwipeRefreshLayout.OnRefreshListener{
  43
  44     private static final String TAG = ExtendedListFragment.class.getSimpleName();
  45
  46     private static final String KEY_SAVED_LIST_POSITION = "SAVED_LIST_POSITION";
  47     private static final String KEY_INDEXES = "INDEXES";
  48     private static final String KEY_FIRST_POSITIONS= "FIRST_POSITIONS";
  49     private static final String KEY_TOPS = "TOPS";
  50     private static final String KEY_HEIGHT_CELL = "HEIGHT_CELL";
  51     private static final String KEY_EMPTY_LIST_MESSAGE = "EMPTY_LIST_MESSAGE";
  52
  53     protected ExtendedListView mList;
  54
  55     private SwipeRefreshLayout mRefreshLayout;
  56     private SwipeRefreshLayout mRefreshEmptyLayout;
  57     private TextView mEmptyListMessage;
  58
  59     // Save the state of the scroll in browsing
  60     private ArrayList<Integer> mIndexes;
  61     private ArrayList<Integer> mFirstPositions;
  62     private ArrayList<Integer> mTops;
  63     private int mHeightCell = 0;
  64
  65
  66     public void setListAdapter(ListAdapter listAdapter) {
  67         mList.setAdapter(listAdapter);
  68         mList.invalidate();
  69     }
  70
  71     public ListView getListView() {
  72         return mList;
  73     }
  74
  75
  76     @Override
  77     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
  78         Log_OC.e(TAG, "onCreateView");
  79
  80         View v = inflater.inflate(R.layout.list_fragment, null);
  81         mEmptyListMessage = (TextView) v.findViewById(R.id.empty_list_view);
  82         mList = (ExtendedListView)(v.findViewById(R.id.list_root));
  83         mList.setOnItemClickListener(this);
  84
  85         mList.setDivider(getResources().getDrawable(R.drawable.uploader_list_separator));
  86         mList.setDividerHeight(1);
  87
  88         if (savedInstanceState != null) {
  89             int referencePosition = savedInstanceState.getInt(KEY_SAVED_LIST_POSITION);
  90             setReferencePosition(referencePosition);
  91         }
  92
  93         // Pull down refresh
  94         mRefreshLayout = (SwipeRefreshLayout) v.findViewById(R.id.swipe_refresh_files);
  95         mRefreshEmptyLayout = (SwipeRefreshLayout) v.findViewById(R.id.swipe_refresh_files_emptyView);
  96
  97         onCreateSwipeToRefresh(mRefreshLayout);
  98         onCreateSwipeToRefresh(mRefreshEmptyLayout);
  99
 100         mList.setEmptyView(mRefreshEmptyLayout);
 101
 102         return v;
 103     }
 104
 105
 106     /**
 107      * {@inheritDoc}
 108      */
 109     @Override
 110     public void onActivityCreated(Bundle savedInstanceState) {
 111         super.onActivityCreated(savedInstanceState);
 112
 113         if (savedInstanceState != null) {
 114             mIndexes = savedInstanceState.getIntegerArrayList(KEY_INDEXES);
 115             mFirstPositions = savedInstanceState.getIntegerArrayList(KEY_FIRST_POSITIONS);
 116             mTops = savedInstanceState.getIntegerArrayList(KEY_TOPS);
 117             mHeightCell = savedInstanceState.getInt(KEY_HEIGHT_CELL);
 118             setMessageForEmptyList(savedInstanceState.getString(KEY_EMPTY_LIST_MESSAGE));
 119
 120         } else {
 121             mIndexes = new ArrayList<Integer>();
 122             mFirstPositions = new ArrayList<Integer>();
 123             mTops = new ArrayList<Integer>();
 124             mHeightCell = 0;
 125         }
 126     }
 127
 128
 129     @Override
 130     public void onSaveInstanceState(Bundle savedInstanceState) {
 131         super.onSaveInstanceState(savedInstanceState);
 132         Log_OC.e(TAG, "onSaveInstanceState()");
 133         savedInstanceState.putInt(KEY_SAVED_LIST_POSITION, getReferencePosition());
 134         savedInstanceState.putIntegerArrayList(KEY_INDEXES, mIndexes);
 135         savedInstanceState.putIntegerArrayList(KEY_FIRST_POSITIONS, mFirstPositions);
 136         savedInstanceState.putIntegerArrayList(KEY_TOPS, mTops);
 137         savedInstanceState.putInt(KEY_HEIGHT_CELL, mHeightCell);
 138         savedInstanceState.putString(KEY_EMPTY_LIST_MESSAGE, getEmptyViewText());
 139     }
 140
 141
 142     /**
 143      * Calculates the position of the item that will be used as a reference to reposition the visible items in the list when
 144      * the device is turned to other position.
 145      *
 146      * THe current policy is take as a reference the visible item in the center of the screen.
 147      *
 148      * @return      The position in the list of the visible item in the center of the screen.
 149      */
 150     protected int getReferencePosition() {
 151         if (mList != null) {
 152             return (mList.getFirstVisiblePosition() + mList.getLastVisiblePosition()) / 2;
 153         } else {
 154             return 0;
 155         }
 156     }
 157
 158
 159     /**
 160      * Sets the visible part of the list from the reference position.
 161      *
 162      * @param   position    Reference position previously returned by {@link LocalFileListFragment#getReferencePosition()}
 163      */
 164     protected void setReferencePosition(int position) {
 165         if (mList != null) {
 166             mList.setAndCenterSelection(position);
 167         }
 168     }
 169
 170
 171     /*
 172      * Restore index and position
 173      */
 174     protected void restoreIndexAndTopPosition() {
 175         if (mIndexes.size() > 0) {
 176             // needs to be checked; not every browse-up had a browse-down before
 177
 178             int index = mIndexes.remove(mIndexes.size() - 1);
 179
 180             int firstPosition = mFirstPositions.remove(mFirstPositions.size() -1);
 181
 182             int top = mTops.remove(mTops.size() - 1);
 183
 184             mList.setSelectionFromTop(firstPosition, top);
 185
 186             // Move the scroll if the selection is not visible
 187             int indexPosition = mHeightCell*index;
 188             int height = mList.getHeight();
 189
 190             if (indexPosition > height) {
 191                 if (android.os.Build.VERSION.SDK_INT >= 11)
 192                 {
 193                     mList.smoothScrollToPosition(index);
 194                 }
 195                 else if (android.os.Build.VERSION.SDK_INT >= 8)
 196                 {
 197                     mList.setSelectionFromTop(index, 0);
 198                 }
 199
 200             }
 201         }
 202     }
 203
 204     /*
 205      * Save index and top position
 206      */
 207     protected void saveIndexAndTopPosition(int index) {
 208
 209         mIndexes.add(index);
 210
 211         int firstPosition = mList.getFirstVisiblePosition();
 212         mFirstPositions.add(firstPosition);
 213
 214         View view = mList.getChildAt(0);
 215         int top = (view == null) ? 0 : view.getTop() ;
 216
 217         mTops.add(top);
 218
 219         // Save the height of a cell
 220         mHeightCell = (view == null || mHeightCell != 0) ? mHeightCell : view.getHeight();
 221     }
 222
 223
 224     @Override
 225     public void onItemClick (AdapterView<?> parent, View view, int position, long id) {
 226         // to be @overriden
 227     }
 228
 229     @Override
 230     public void onRefresh() {
 231         // to be @overriden
 232         mRefreshLayout.setRefreshing(false);
 233         mRefreshEmptyLayout.setRefreshing(false);
 234     }
 235
 236     /**
 237      * Enables swipe gesture
 238      */
 239     public void enableSwipe() {
 240         mRefreshLayout.setEnabled(true);
 241     }
 242
 243     /**
 244      * Disables swipe gesture. It prevents manual gestures but keeps the option you show
 245      * refreshing programmatically.
 246      */
 247     public void disableSwipe() {
 248         mRefreshLayout.setEnabled(false);
 249     }
 250
 251     /**
 252      * It shows the SwipeRefreshLayout progress
 253      */
 254     public void showSwipeProgress() {
 255         mRefreshLayout.setRefreshing(true);
 256     }
 257
 258     /**
 259      * It shows the SwipeRefreshLayout progress
 260      */
 261     public void hideSwipeProgress() {
 262         mRefreshLayout.setRefreshing(false);
 263     }
 264
 265     /**
 266      * Set message for empty list view
 267      */
 268     public void setMessageForEmptyList(String message) {
 269         if (mEmptyListMessage != null) {
 270             mEmptyListMessage.setText(message);
 271         }
 272     }
 273
 274     /**
 275      * Get the text of EmptyListMessage TextView
 276      *
 277      * @return String
 278      */
 279     public String getEmptyViewText() {
 280         return (mEmptyListMessage != null) ? mEmptyListMessage.getText().toString() : "";
 281     }
 282
 283     private void onCreateSwipeToRefresh(SwipeRefreshLayout refreshLayout) {
 284         // Colors in animations: background
 285         refreshLayout.setColorScheme(R.color.background_color, R.color.background_color, R.color.background_color,
 286                 R.color.background_color);
 287
 288         refreshLayout.setOnRefreshListener(this);
 289     }
 290
 291 }