Home | History | Annotate | Download | only in packageinstaller 
      1 /*
      2 **
      3 ** Copyright 2012, The Android Open Source Project
      4 **
      5 ** Licensed under the Apache License, Version 2.0 (the "License");
      6 ** you may not use this file except in compliance with the License.
      7 ** You may obtain a copy of the License at
      8 **
      9 **     http://www.apache.org/licenses/LICENSE-2.0
     10 **
     11 ** Unless required by applicable law or agreed to in writing, software
     12 ** distributed under the License is distributed on an "AS IS" BASIS,
     13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 ** See the License for the specific language governing permissions and
     15 ** limitations under the License.
     16 */
     17 
     18 package com.android.packageinstaller;
     19 
     20 import android.content.Context;
     21 import android.graphics.Canvas;
     22 import android.util.AttributeSet;
     23 import android.widget.ScrollView;
     24 
     25 /**
     26  * It's a ScrollView that knows how to stay awake.
     27  */
     28 class CaffeinatedScrollView extends ScrollView {
     29     private Runnable mFullScrollAction;
     30     private int mBottomSlop;
     31 
     32     public CaffeinatedScrollView(Context context) {
     33         super(context);
     34     }
     35 
     36     public CaffeinatedScrollView(Context context, AttributeSet attrs) {
     37         super(context, attrs);
     38     }
     39 
     40     /**
     41      * Make this visible so we can call it
     42      */
     43     @Override
     44     public boolean awakenScrollBars() {
     45         return super.awakenScrollBars();
     46     }
     47 
     48     public void setFullScrollAction(Runnable action) {
     49         mFullScrollAction = action;
     50         mBottomSlop = (int)(4 * getResources().getDisplayMetrics().density);
     51     }
     52 
     53     @Override
     54     protected void onDraw(Canvas canvas) {
     55         super.onDraw(canvas);
     56         checkFullScrollAction();
     57     }
     58 
     59     @Override
     60     protected void onScrollChanged(int l, int t, int oldl, int oldt) {
     61         super.onScrollChanged(l, t, oldl, oldt);
     62         checkFullScrollAction();
     63     }
     64 
     65     private void checkFullScrollAction() {
     66         if (mFullScrollAction != null) {
     67             int daBottom = getChildAt(0).getBottom();
     68             int screenBottom = getScrollY() + getHeight() - getPaddingBottom();
     69             if ((daBottom - screenBottom) < mBottomSlop) {
     70                 mFullScrollAction.run();
     71                 mFullScrollAction = null;
     72             }
     73         }
     74     }
     75 }
     76