1 /*
2  * Copyright (C) 2023 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.car.portraitlauncher.panel;
18 
19 import android.content.Context;
20 import android.content.res.Resources;
21 import android.graphics.Canvas;
22 import android.graphics.Paint;
23 import android.util.AttributeSet;
24 import android.view.SurfaceHolder;
25 import android.view.SurfaceView;
26 
27 import androidx.annotation.NonNull;
28 import androidx.annotation.Nullable;
29 
30 import com.android.car.portraitlauncher.R;
31 
32 /**
33  * A {@link SurfaceView} that acts as a solid black background of {@link TaskViewPanel}. It
34  * avoids user to see the background app when an activity in RootTaskView fades out.
35  * TODO(b/336858361): improve the UI for this surfaceview.
36  */
37 public class BackgroundSurfaceView extends SurfaceView {
38 
39     // Whether the panel should use a fixed color.
40     private boolean mUseFixedColor;
41 
42     // The color used in the surface view.
43     private int mColor;
44     private int mTextColor;
45 
46     // The Text at the center of the surface view.
47     private String mText;
48 
BackgroundSurfaceView(Context context)49     public BackgroundSurfaceView(Context context) {
50         this(context, null);
51     }
52 
BackgroundSurfaceView(Context context, AttributeSet attrs)53     public BackgroundSurfaceView(Context context, AttributeSet attrs) {
54         this(context, attrs, 0);
55     }
56 
BackgroundSurfaceView(Context context, AttributeSet attrs, int defStyleAttr)57     public BackgroundSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
58         this(context, attrs, defStyleAttr, 0);
59     }
60 
BackgroundSurfaceView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)61     public BackgroundSurfaceView(Context context, AttributeSet attrs, int defStyleAttr,
62             int defStyleRes) {
63         this(context, attrs, defStyleAttr, defStyleRes, false);
64     }
65 
BackgroundSurfaceView(@onNull Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes, boolean disableBackgroundLayer)66     public BackgroundSurfaceView(@NonNull Context context,
67             @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes,
68             boolean disableBackgroundLayer) {
69         super(context, attrs, defStyleAttr, defStyleRes, disableBackgroundLayer);
70         setZOrderMediaOverlay(true);
71         setupSurfaceView();
72     }
73 
setupSurfaceView()74     private void setupSurfaceView() {
75         mColor = getResources().getColor(R.color.car_background, getContext().getTheme());
76         mTextColor = getResources().getColor(R.color.car_on_background, getContext().getTheme());
77 
78         getHolder().addCallback(new SurfaceHolder.Callback() {
79             @Override
80             public void surfaceCreated(@NonNull SurfaceHolder holder) {
81                 drawSurface(holder);
82             }
83 
84             @Override
85             public void surfaceChanged(@NonNull SurfaceHolder holder, int format, int width,
86                     int height) {
87                 drawSurface(holder);
88             }
89 
90             @Override
91             public void surfaceDestroyed(@NonNull SurfaceHolder holder) {
92 
93             }
94         });
95     }
96 
drawSurface(SurfaceHolder holder)97     private void drawSurface(SurfaceHolder holder) {
98         Canvas canvas = holder.lockCanvas();
99         if (canvas == null) {
100             return;
101         }
102         canvas.drawColor(mColor);
103 
104         if (mText != null) {
105             Paint paint = new Paint();
106             paint.setColor(mTextColor);
107             paint.setTextSize(20);
108             paint.setTextAlign(Paint.Align.CENTER);
109             float xPos = (canvas.getWidth() / 2f);
110             float yPos = (canvas.getHeight() / 2f - ((paint.descent() + paint.ascent()) / 2));
111             canvas.drawText(mText, xPos, yPos, paint);
112         }
113 
114         holder.unlockCanvasAndPost(canvas);
115     }
116 
117     /** Sets the fixed color on the surface view */
setFixedColor(int color)118     public void setFixedColor(int color) {
119         mColor = color;
120         mUseFixedColor = true;
121         drawSurface(getHolder());
122     }
123 
124     /** Sets the text that shows on the surface view */
setText(String text)125     public void setText(String text) {
126         mText = text;
127         drawSurface(getHolder());
128     }
129 
130     /** Sets the fixed color and centered text on the surface view */
setFixedColorAndText(int color, String text)131     public void setFixedColorAndText(int color, String text) {
132         mText = text;
133         setFixedColor(color);
134     }
135 
136     /** refreshes the color of the surface view if needed. */
refresh(Resources.Theme theme)137     public void refresh(Resources.Theme theme) {
138         if (!mUseFixedColor) {
139             mColor = getResources().getColor(R.color.car_background, theme);
140             mTextColor = getResources().getColor(R.color.car_on_background,
141                     getContext().getTheme());
142             drawSurface(getHolder());
143         }
144     }
145 }
146