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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 com.android.camera.R;
     20 
     21 import android.app.Activity;
     22 import android.content.Context;
     23 import android.content.pm.ActivityInfo;
     24 import android.view.View;
     25 import android.util.AttributeSet;
     26 import android.widget.RelativeLayout;
     27 /**
     28  * A layout which handles the preview aspect ratio.
     29  */
     30 public class PreviewFrameLayout extends RelativeLayout {
     31     /** A callback to be invoked when the preview frame's size changes. */
     32     public interface OnSizeChangedListener {
     33         public void onSizeChanged();
     34     }
     35 
     36     private double mAspectRatio;
     37 
     38     public PreviewFrameLayout(Context context, AttributeSet attrs) {
     39         super(context, attrs);
     40         setAspectRatio(4.0 / 3.0);
     41     }
     42 
     43     public void setAspectRatio(double ratio) {
     44         if (ratio <= 0.0) throw new IllegalArgumentException();
     45 
     46         if (((Activity) getContext()).getRequestedOrientation()
     47                 == ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) {
     48             ratio = 1 / ratio;
     49         }
     50 
     51         if (mAspectRatio != ratio) {
     52             mAspectRatio = ratio;
     53             requestLayout();
     54         }
     55     }
     56 
     57     public void showBorder(boolean enabled) {
     58         findViewById(R.id.preview_border).setVisibility(
     59                 enabled ? View.VISIBLE : View.INVISIBLE);
     60     }
     61 
     62     @Override
     63     protected void onMeasure(int widthSpec, int heightSpec) {
     64         int previewWidth = MeasureSpec.getSize(widthSpec);
     65         int previewHeight = MeasureSpec.getSize(heightSpec);
     66 
     67         // Get the padding of the border background.
     68         int hPadding = mPaddingLeft + mPaddingRight;
     69         int vPadding = mPaddingTop + mPaddingBottom;
     70 
     71         // Resize the preview frame with correct aspect ratio.
     72         previewWidth -= hPadding;
     73         previewHeight -= vPadding;
     74         if (previewWidth > previewHeight * mAspectRatio) {
     75             previewWidth = (int) (previewHeight * mAspectRatio + .5);
     76         } else {
     77             previewHeight = (int) (previewWidth / mAspectRatio + .5);
     78         }
     79 
     80         // Add the padding of the border.
     81         previewWidth += hPadding;
     82         previewHeight += vPadding;
     83 
     84         // Ask children to follow the new preview dimension.
     85         super.onMeasure(MeasureSpec.makeMeasureSpec(previewWidth, MeasureSpec.EXACTLY),
     86                 MeasureSpec.makeMeasureSpec(previewHeight, MeasureSpec.EXACTLY));
     87     }
     88 }
     89