src/com/owncloud/android/ui/ExtendedListView.java

   1 /**
   2  *   ownCloud Android client application
   3  *
   4  *   @author David A. Velasco
   5  *   Copyright (C) 2012 Bartek Przybylski
   6  *   Copyright (C) 2012-2015 ownCloud Inc.
   7  *
   8  *   This program is free software: you can redistribute it and/or modify
   9  *   it under the terms of the GNU General Public License version 2,
  10  *   as published by the Free Software Foundation.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 package com.owncloud.android.ui;
  23
  24 import android.content.Context;
  25 import android.graphics.Canvas;
  26 import android.util.AttributeSet;
  27 import android.widget.ListView;
  28
  29 import com.owncloud.android.lib.common.utils.Log_OC;
  30
  31 /**
  32  * ListView allowing to specify the position of an item that should be centered in the visible area, if possible.
  33  *
  34  * The cleanest way I found to overcome the problem due to getHeight() returns 0 until the view is really drawn.
  35  */
  36 public class ExtendedListView extends ListView {
  37
  38     private static final String TAG = ExtendedListView.class.getSimpleName();
  39
  40     private int mPositionToSetAndCenter = 0;
  41
  42     public ExtendedListView(Context context) {
  43         super(context);
  44     }
  45
  46     public ExtendedListView(Context context, AttributeSet attrs) {
  47         super(context, attrs);
  48     }
  49
  50     public ExtendedListView(Context context, AttributeSet attrs, int defStyle) {
  51         super(context, attrs, defStyle);
  52     }
  53
  54     /**
  55      * {@inheritDoc}
  56      *
  57      *
  58      */
  59     @Override
  60     protected void onDraw (Canvas canvas) {
  61         super.onDraw(canvas);
  62         if (mPositionToSetAndCenter > 0) {
  63             Log_OC.v(TAG, "Centering around position " + mPositionToSetAndCenter);
  64             this.setSelectionFromTop(mPositionToSetAndCenter, getHeight() / 2);
  65             mPositionToSetAndCenter = 0;
  66         }
  67     }
  68
  69     /**
  70      * Public method to set the position of the item that should be centered in the visible area of the view.
  71      *
  72      * The position is saved here and checked in onDraw().
  73      *
  74      * @param position         Position (in the list of items) of the item to center in the visible area.
  75      */
  76     public void setAndCenterSelection(int position) {
  77         mPositionToSetAndCenter = position;
  78     }
  79
  80 }