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      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 
     37     public AspectRatioFrameLayout(Context context) {
     38         this(context, null);
     39     }
     40 
     41     public AspectRatioFrameLayout(Context context, AttributeSet attrs) {
     42         this(context, attrs, 0);
     43     }
     44 
     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 
     56     public void setAspectRatio(float aspectRadio) {
     57         mAspectRatio = aspectRadio;
     58     }
     59 
     60     @Override
     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