1 /*
<lambda>null2  * Copyright (C) 2022 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 
18 package com.android.wallpaper.picker
19 
20 import android.content.Context
21 import android.util.AttributeSet
22 import android.widget.FrameLayout
23 import androidx.core.view.children
24 import com.android.wallpaper.config.BaseFlags
25 import com.android.wallpaper.util.ScreenSizeCalculator
26 import kotlin.math.max
27 
28 /**
29  * [FrameLayout] that sizes its children using a fixed aspect ratio that is the same as that of the
30  * display.
31  *
32  * Uses the initial height to calculate width based on the display ratio, then use the new width to
33  * get the new height, this will wrap the child view inside like wrap content for both width and
34  * height, for this to work the width must be wrap_content or 0dp and the height cannot be 0dp.
35  */
36 class DisplayAspectRatioFrameLayout(context: Context, attrs: AttributeSet?) :
37     FrameLayout(context, attrs) {
38 
39     override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
40         super.onMeasure(widthMeasureSpec, heightMeasureSpec)
41         val screenAspectRatio = ScreenSizeCalculator.getInstance().getScreenAspectRatio(context)
42         // We're always forcing the width based on the height. This will only work if the
43         // DisplayAspectRatioFrameLayout is allowed to stretch to fill its parent (for example if
44         // the parent is a vertical LinearLayout and the DisplayAspectRatioFrameLayout has a height
45         // if 0 and a weight of 1.
46         // However we make sure that the width of the children never exceeds the width of the parent
47         //
48         // If you need to use this class to force the height dimension based on the width instead,
49         // you will need to flip the logic below.
50         var maxWidth = 0
51         children.forEach { child ->
52             // Calculate child width from height based on display ratio, max at parent width.
53             val childWidth =
54                 (child.measuredHeight / screenAspectRatio).toInt().coerceAtMost(measuredWidth)
55             child.measure(
56                 MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY),
57                 MeasureSpec.makeMeasureSpec(
58                     if (childWidth < measuredWidth) {
59                         // Child width not capped, height is the same.
60                         child.measuredHeight
61                     } else {
62                         // Child width capped at parent width, recalculates height based on ratio.
63                         (childWidth * screenAspectRatio).toInt()
64                     },
65                     MeasureSpec.EXACTLY,
66                 ),
67             )
68             // Find max width among all children.
69             maxWidth = max(maxWidth, child.measuredWidth)
70         }
71 
72         if (BaseFlags.get().isNewPickerUi()) {
73             // New height based on the new width
74             val newHeight = (maxWidth * screenAspectRatio).toInt()
75 
76             // Makes width wrap content
77             setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), newHeight)
78         }
79     }
80 }
81