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