1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.server.policy;
18 
19 import android.content.Context;
20 import android.graphics.Canvas;
21 import android.graphics.Rect;
22 import android.graphics.drawable.Drawable;
23 import android.util.AttributeSet;
24 import android.view.Gravity;
25 import android.view.View;
26 import android.widget.LinearLayout;
27 
28 /**
29  * A vertical linear layout.  However, instead of drawing the background
30  * behnd the items, it draws the background outside the items based on the
31  * padding.  If there isn't enough room to draw both, it clips the background
32  * instead of the contents.
33  */
34 public class RecentApplicationsBackground extends LinearLayout {
35     private static final String TAG = "RecentApplicationsBackground";
36 
37     private boolean mBackgroundSizeChanged;
38     private Drawable mBackground;
39     private Rect mTmp0 = new Rect();
40     private Rect mTmp1 = new Rect();
41 
RecentApplicationsBackground(Context context)42     public RecentApplicationsBackground(Context context) {
43         this(context, null);
44         init();
45     }
46 
RecentApplicationsBackground(Context context, AttributeSet attrs)47     public RecentApplicationsBackground(Context context, AttributeSet attrs) {
48         super(context, attrs);
49         init();
50     }
51 
init()52     private void init() {
53         mBackground = getBackground();
54         setBackgroundDrawable(null);
55         setPadding(0, 0, 0, 0);
56         setGravity(Gravity.CENTER);
57     }
58 
59     @Override
setFrame(int left, int top, int right, int bottom)60     protected boolean setFrame(int left, int top, int right, int bottom) {
61         setWillNotDraw(false);
62         if (mLeft != left || mRight != right || mTop != top || mBottom != bottom) {
63             mBackgroundSizeChanged = true;
64         }
65         return super.setFrame(left, top, right, bottom);
66     }
67 
68     @Override
verifyDrawable(Drawable who)69     protected boolean verifyDrawable(Drawable who) {
70         return who == mBackground || super.verifyDrawable(who);
71     }
72 
73     @Override
jumpDrawablesToCurrentState()74     public void jumpDrawablesToCurrentState() {
75         super.jumpDrawablesToCurrentState();
76         if (mBackground != null) mBackground.jumpToCurrentState();
77     }
78 
79     @Override
drawableStateChanged()80     protected void drawableStateChanged() {
81         Drawable d = mBackground;
82         if (d != null && d.isStateful()) {
83             d.setState(getDrawableState());
84         }
85         super.drawableStateChanged();
86     }
87 
88     @Override
draw(Canvas canvas)89     public void draw(Canvas canvas) {
90         final Drawable background = mBackground;
91         if (background != null) {
92             if (mBackgroundSizeChanged) {
93                 mBackgroundSizeChanged = false;
94                 Rect chld = mTmp0;
95                 Rect bkg = mTmp1;
96                 mBackground.getPadding(bkg);
97                 getChildBounds(chld);
98                 // This doesn't clamp to this view's bounds, which is what we want,
99                 // so that the drawing is clipped.
100                 final int top = chld.top - bkg.top;
101                 final int bottom = chld.bottom + bkg.bottom;
102                 // The background here is a gradient that wants to
103                 // extend the full width of the screen (whatever that
104                 // may be).
105                 int left, right;
106                 if (false) {
107                     // This limits the width of the drawable.
108                     left = chld.left - bkg.left;
109                     right = chld.right + bkg.right;
110                 } else {
111                     // This expands it to full width.
112                     left = 0;
113                     right = getRight();
114                 }
115                 background.setBounds(left, top, right, bottom);
116             }
117         }
118         mBackground.draw(canvas);
119 
120         if (false) {
121             android.graphics.Paint p = new android.graphics.Paint();
122             p.setColor(0x88ffff00);
123             canvas.drawRect(background.getBounds(), p);
124         }
125         canvas.drawARGB((int)(0.75*0xff), 0, 0, 0);
126 
127         super.draw(canvas);
128     }
129 
130     @Override
onAttachedToWindow()131     protected void onAttachedToWindow() {
132         super.onAttachedToWindow();
133         mBackground.setCallback(this);
134         setWillNotDraw(false);
135     }
136 
137     @Override
onDetachedFromWindow()138     protected void onDetachedFromWindow() {
139         super.onDetachedFromWindow();
140         mBackground.setCallback(null);
141     }
142 
getChildBounds(Rect r)143     private void getChildBounds(Rect r) {
144         r.left = r.top = Integer.MAX_VALUE;
145         r.bottom = r.right = Integer.MIN_VALUE;
146         final int N = getChildCount();
147         for (int i=0; i<N; i++) {
148             View v = getChildAt(i);
149             if (v.getVisibility() == View.VISIBLE) {
150                 r.left = Math.min(r.left, v.getLeft());
151                 r.top = Math.min(r.top, v.getTop());
152                 r.right = Math.max(r.right, v.getRight());
153                 r.bottom = Math.max(r.bottom, v.getBottom());
154             }
155         }
156     }
157 }
158