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

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012 Bartek Przybylski
   3  *   Copyright (C) 2012-2015 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 import com.owncloud.android.lib.common.utils.Log_OC;
  27
  28 /**
  29  * ListView allowing to specify the position of an item that should be centered in the visible area, if possible.
  30  *
  31  * The cleanest way I found to overcome the problem due to getHeight() returns 0 until the view is really drawn.
  32  *
  33  * @author David A. Velasco
  34  */
  35 public class ExtendedListView extends ListView {
  36
  37     private static final String TAG = ExtendedListView.class.getSimpleName();
  38
  39     private int mPositionToSetAndCenter = 0;
  40
  41     public ExtendedListView(Context context) {
  42         super(context);
  43     }
  44
  45     public ExtendedListView(Context context, AttributeSet attrs) {
  46         super(context, attrs);
  47     }
  48
  49     public ExtendedListView(Context context, AttributeSet attrs, int defStyle) {
  50         super(context, attrs, defStyle);
  51     }
  52
  53     /**
  54      * {@inheritDoc}
  55      *
  56      *
  57      */
  58     @Override
  59     protected void onDraw (Canvas canvas) {
  60         super.onDraw(canvas);
  61         if (mPositionToSetAndCenter > 0) {
  62             Log_OC.v(TAG, "Centering around position " + mPositionToSetAndCenter);
  63             this.setSelectionFromTop(mPositionToSetAndCenter, getHeight() / 2);
  64             mPositionToSetAndCenter = 0;
  65         }
  66     }
  67
  68     /**
  69      * Public method to set the position of the item that should be centered in the visible area of the view.
  70      *
  71      * The position is saved here and checked in onDraw().
  72      *
  73      * @param position         Position (in the list of items) of the item to center in the visible area.
  74      */
  75     public void setAndCenterSelection(int position) {
  76         mPositionToSetAndCenter = position;
  77     }
  78
  79 }