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 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;
  20
  21 import android.content.Context;
  22 import android.graphics.Canvas;
  23 import android.util.AttributeSet;
  24 import android.widget.ListView;
  25
  26 /**
  27  * ListView allowing to specify the position of an item that should be centered in the visible area, if possible.
  28  *
  29  * The cleanest way I found to overcome the problem due to getHeight() returns 0 until the view is really drawn.
  30  *
  31  * @author David A. Velasco
  32  */
  33 public class ExtendedListView extends ListView {
  34
  35     private int mPositionToSetAndCenter;
  36
  37     public ExtendedListView(Context context) {
  38         super(context);
  39     }
  40
  41     public ExtendedListView(Context context, AttributeSet attrs) {
  42         super(context, attrs);
  43     }
  44
  45     public ExtendedListView(Context context, AttributeSet attrs, int defStyle) {
  46         super(context, attrs, defStyle);
  47     }
  48
  49     /**
  50      * {@inheritDoc}
  51      *
  52      *
  53      */
  54     @Override
  55     protected void onDraw (Canvas canvas) {
  56         super.onDraw(canvas);
  57         if (mPositionToSetAndCenter > 0) {
  58             this.setSelectionFromTop(mPositionToSetAndCenter, getHeight() / 2);
  59             mPositionToSetAndCenter = 0;
  60         }
  61     }
  62
  63     /**
  64      * Public method to set the position of the item that should be centered in the visible area of the view.
  65      *
  66      * The position is saved here and checked in onDraw().
  67      *
  68      * @param position         Position (in the list of items) of the item to center in the visible area.
  69      */
  70     public void setAndCenterSelection(int position) {
  71         mPositionToSetAndCenter = position;
  72     }
  73 }