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      1 /*
      2  * Copyright (C) 2009 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.camera;
     18 
     19 import android.content.Context;
     20 import android.content.res.Configuration;
     21 import android.util.AttributeSet;
     22 import android.view.View;
     23 import android.widget.RelativeLayout;
     24 
     25 /**
     26  * A layout which handles the preview aspect ratio.
     27  */
     28 public class PreviewFrameLayout extends RelativeLayout {
     29     /** A callback to be invoked when the preview frame's size changes. */
     30     public interface OnSizeChangedListener {
     31         public void onSizeChanged(int width, int height);
     32     }
     33 
     34     private double mAspectRatio;
     35     private View mBorder;
     36     private OnSizeChangedListener mListener;
     37 
     38     public PreviewFrameLayout(Context context, AttributeSet attrs) {
     39         super(context, attrs);
     40         setAspectRatio(4.0 / 3.0);
     41     }
     42 
     43     @Override
     44     protected void onFinishInflate() {
     45         mBorder = findViewById(R.id.preview_border);
     46     }
     47 
     48     public void setAspectRatio(double ratio) {
     49         if (ratio <= 0.0) throw new IllegalArgumentException();
     50 
     51         if (getResources().getConfiguration().orientation
     52                 == Configuration.ORIENTATION_PORTRAIT) {
     53             ratio = 1 / ratio;
     54         }
     55 
     56         if (mAspectRatio != ratio) {
     57             mAspectRatio = ratio;
     58             requestLayout();
     59         }
     60     }
     61 
     62     public void showBorder(boolean enabled) {
     63         mBorder.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);
     64     }
     65 
     66     public void fadeOutBorder() {
     67         Util.fadeOut(mBorder);
     68     }
     69 
     70     @Override
     71     protected void onMeasure(int widthSpec, int heightSpec) {
     72         int previewWidth = MeasureSpec.getSize(widthSpec);
     73         int previewHeight = MeasureSpec.getSize(heightSpec);
     74 
     75         // Get the padding of the border background.
     76         int hPadding = getPaddingLeft() + getPaddingRight();
     77         int vPadding = getPaddingTop() + getPaddingBottom();
     78 
     79         // Resize the preview frame with correct aspect ratio.
     80         previewWidth -= hPadding;
     81         previewHeight -= vPadding;
     82         if (previewWidth > previewHeight * mAspectRatio) {
     83             previewWidth = (int) (previewHeight * mAspectRatio + .5);
     84         } else {
     85             previewHeight = (int) (previewWidth / mAspectRatio + .5);
     86         }
     87 
     88         // Add the padding of the border.
     89         previewWidth += hPadding;
     90         previewHeight += vPadding;
     91 
     92         // Ask children to follow the new preview dimension.
     93         super.onMeasure(MeasureSpec.makeMeasureSpec(previewWidth, MeasureSpec.EXACTLY),
     94                 MeasureSpec.makeMeasureSpec(previewHeight, MeasureSpec.EXACTLY));
     95     }
     96 
     97     public void setOnSizeChangedListener(OnSizeChangedListener listener) {
     98         mListener = listener;
     99     }
    100 
    101     @Override
    102     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    103         if (mListener != null) mListener.onSizeChanged(w, h);
    104     }
    105 }
    106