1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file 5 * except in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the 10 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 11 * KIND, either express or implied. See the License for the specific language governing 12 * permissions and limitations under the License. 13 */ 14 15 package com.android.settings.widget; 16 17 import android.content.Context; 18 import android.content.res.TypedArray; 19 import android.support.annotation.VisibleForTesting; 20 import android.util.AttributeSet; 21 import android.widget.FrameLayout; 22 23 import com.android.settings.R; 24 25 /** 26 * A {@link FrameLayout} with customizable aspect ratio. 27 * This is used to avoid dynamically calculating the height for the frame. Default aspect 28 * ratio will be 1 if none is set in layout attribute. 29 */ 30 public final class AspectRatioFrameLayout extends FrameLayout { 31 32 private static final float ASPECT_RATIO_CHANGE_THREASHOLD = 0.01f; 33 34 @VisibleForTesting 35 float mAspectRatio = 1.0f; 36 AspectRatioFrameLayout(Context context)37 public AspectRatioFrameLayout(Context context) { 38 this(context, null); 39 } 40 AspectRatioFrameLayout(Context context, AttributeSet attrs)41 public AspectRatioFrameLayout(Context context, AttributeSet attrs) { 42 this(context, attrs, 0); 43 } 44 AspectRatioFrameLayout(Context context, AttributeSet attrs, int defStyle)45 public AspectRatioFrameLayout(Context context, AttributeSet attrs, int defStyle) { 46 super(context, attrs, defStyle); 47 if (attrs != null) { 48 TypedArray array = 49 context.obtainStyledAttributes(attrs, R.styleable.AspectRatioFrameLayout); 50 mAspectRatio = array.getFloat( 51 R.styleable.AspectRatioFrameLayout_aspectRatio, 1.0f); 52 array.recycle(); 53 } 54 } 55 setAspectRatio(float aspectRadio)56 public void setAspectRatio(float aspectRadio) { 57 mAspectRatio = aspectRadio; 58 } 59 60 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)61 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 62 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 63 int width = getMeasuredWidth(); 64 int height = getMeasuredHeight(); 65 if (width == 0 || height == 0) { 66 return; 67 } 68 final float viewAspectRatio = (float) width / height; 69 final float aspectRatioDiff = mAspectRatio - viewAspectRatio; 70 if (Math.abs(aspectRatioDiff) <= ASPECT_RATIO_CHANGE_THREASHOLD) { 71 // Close enough, skip. 72 return; 73 } 74 75 width = (int) (height * mAspectRatio); 76 77 super.onMeasure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY), 78 MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY)); 79 } 80 81 } 82