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.app.Activity; 20 import android.content.Context; 21 import android.util.AttributeSet; 22 import android.util.DisplayMetrics; 23 import android.view.ViewGroup; 24 import android.widget.FrameLayout; 25 26 /** 27 * A layout which handles the preview aspect ratio and the position of 28 * the gripper. 29 */ 30 public class PreviewFrameLayout extends ViewGroup { 31 private static final int MIN_HORIZONTAL_MARGIN = 10; // 10dp 32 33 /** A callback to be invoked when the preview frame's size changes. */ 34 public interface OnSizeChangedListener { onSizeChanged()35 public void onSizeChanged(); 36 } 37 38 private double mAspectRatio = 4.0 / 3.0; 39 private FrameLayout mFrame; 40 private OnSizeChangedListener mSizeListener; 41 private final DisplayMetrics mMetrics = new DisplayMetrics(); 42 PreviewFrameLayout(Context context, AttributeSet attrs)43 public PreviewFrameLayout(Context context, AttributeSet attrs) { 44 super(context, attrs); 45 ((Activity) context).getWindowManager() 46 .getDefaultDisplay().getMetrics(mMetrics); 47 } 48 setOnSizeChangedListener(OnSizeChangedListener listener)49 public void setOnSizeChangedListener(OnSizeChangedListener listener) { 50 mSizeListener = listener; 51 } 52 53 @Override onFinishInflate()54 protected void onFinishInflate() { 55 mFrame = (FrameLayout) findViewById(R.id.frame); 56 if (mFrame == null) { 57 throw new IllegalStateException( 58 "must provide child with id as \"frame\""); 59 } 60 } 61 setAspectRatio(double ratio)62 public void setAspectRatio(double ratio) { 63 if (ratio <= 0.0) throw new IllegalArgumentException(); 64 65 if (mAspectRatio != ratio) { 66 mAspectRatio = ratio; 67 requestLayout(); 68 } 69 } 70 71 @Override onLayout(boolean changed, int l, int t, int r, int b)72 protected void onLayout(boolean changed, int l, int t, int r, int b) { 73 int frameWidth = getWidth(); 74 int frameHeight = getHeight(); 75 76 FrameLayout f = mFrame; 77 int horizontalPadding = f.getPaddingLeft() + f.getPaddingRight(); 78 int verticalPadding = f.getPaddingBottom() + f.getPaddingTop(); 79 int previewHeight = frameHeight - verticalPadding; 80 int previewWidth = frameWidth - horizontalPadding; 81 82 // resize frame and preview for aspect ratio 83 if (previewWidth > previewHeight * mAspectRatio) { 84 previewWidth = (int) (previewHeight * mAspectRatio + .5); 85 } else { 86 previewHeight = (int) (previewWidth / mAspectRatio + .5); 87 } 88 89 frameWidth = previewWidth + horizontalPadding; 90 frameHeight = previewHeight + verticalPadding; 91 92 int hSpace = ((r - l) - frameWidth) / 2; 93 int vSpace = ((b - t) - frameHeight) / 2; 94 mFrame.measure( 95 MeasureSpec.makeMeasureSpec(frameWidth, MeasureSpec.EXACTLY), 96 MeasureSpec.makeMeasureSpec(frameHeight, MeasureSpec.EXACTLY)); 97 mFrame.layout(l + hSpace, t + vSpace, r - hSpace, b - vSpace); 98 if (mSizeListener != null) { 99 mSizeListener.onSizeChanged(); 100 } 101 } 102 } 103 104