1 /* 2 * Copyright (C) 2021 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.example.android.apis.view; 18 19 import android.content.Context; 20 import android.content.res.TypedArray; 21 import android.util.AttributeSet; 22 import android.util.Rational; 23 import android.widget.ImageView; 24 25 import com.example.android.apis.R; 26 27 /** 28 * Extended {@link ImageView} that keeps fixed aspect ratio (specified in layout file) when 29 * one of the dimension is in exact while the other one in wrap_content size mode. 30 */ 31 public class FixedAspectRatioImageView extends ImageView { 32 private final Rational mAspectRatio; 33 FixedAspectRatioImageView(Context context, AttributeSet attrs)34 public FixedAspectRatioImageView(Context context, AttributeSet attrs) { 35 super(context, attrs); 36 final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, 37 R.styleable.FixedAspectRatioImageView, 0, 0); 38 try { 39 mAspectRatio = Rational.parseRational( 40 a.getString(R.styleable.FixedAspectRatioImageView_aspectRatio)); 41 } finally { 42 a.recycle(); 43 } 44 } 45 46 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)47 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 48 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 49 final int width, height; 50 if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY 51 && MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY) { 52 width = MeasureSpec.getSize(widthMeasureSpec); 53 height = MeasureSpec.getSize(heightMeasureSpec); 54 } else if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY) { 55 width = MeasureSpec.getSize(widthMeasureSpec); 56 height = (int) (width / mAspectRatio.floatValue()); 57 } else { 58 height = MeasureSpec.getSize(heightMeasureSpec); 59 width = (int) (height * mAspectRatio.floatValue()); 60 } 61 android.util.Log.d("DebugMe", "onMeasure w=" + width + " h=" + height); 62 setMeasuredDimension(width, height); 63 } 64 }