PreviewFrameLayout.java revision ec38f8b0e662f945738ce31c7f70eb67300f960e 
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
17package com.android.camera;
18
19import com.android.camera.R;
20
21import android.app.Activity;
22import android.content.Context;
23import android.content.pm.ActivityInfo;
24import android.view.View;
25import android.util.AttributeSet;
26import android.widget.RelativeLayout;
27
28/**
29 * A layout which handles the preview aspect ratio.
30 */
31public class PreviewFrameLayout extends RelativeLayout {
32    /** A callback to be invoked when the preview frame's size changes. */
33    public interface OnSizeChangedListener {
34        public void onSizeChanged();
35    }
36
37    private double mAspectRatio;
38    private View mBorder;
39
40    public PreviewFrameLayout(Context context, AttributeSet attrs) {
41        super(context, attrs);
42        setAspectRatio(4.0 / 3.0);
43    }
44
45    protected void onFinishInflate() {
46        mBorder = findViewById(R.id.preview_border);
47    }
48
49    public void setAspectRatio(double ratio) {
50        if (ratio <= 0.0) throw new IllegalArgumentException();
51
52        if (((Activity) getContext()).getRequestedOrientation()
53                == ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) {
54            ratio = 1 / ratio;
55        }
56
57        if (mAspectRatio != ratio) {
58            mAspectRatio = ratio;
59            requestLayout();
60        }
61    }
62
63    public void showBorder(boolean enabled) {
64        mBorder.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);
65    }
66
67    public void fadeOutBorder() {
68        Util.fadeOut(mBorder);
69    }
70
71    @Override
72    protected void onMeasure(int widthSpec, int heightSpec) {
73        int previewWidth = MeasureSpec.getSize(widthSpec);
74        int previewHeight = MeasureSpec.getSize(heightSpec);
75
76        // Get the padding of the border background.
77        int hPadding = mPaddingLeft + mPaddingRight;
78        int vPadding = mPaddingTop + mPaddingBottom;
79
80        // Resize the preview frame with correct aspect ratio.
81        previewWidth -= hPadding;
82        previewHeight -= vPadding;
83        if (previewWidth > previewHeight * mAspectRatio) {
84            previewWidth = (int) (previewHeight * mAspectRatio + .5);
85        } else {
86            previewHeight = (int) (previewWidth / mAspectRatio + .5);
87        }
88
89        // Add the padding of the border.
90        previewWidth += hPadding;
91        previewHeight += vPadding;
92
93        // Ask children to follow the new preview dimension.
94        super.onMeasure(MeasureSpec.makeMeasureSpec(previewWidth, MeasureSpec.EXACTLY),
95                MeasureSpec.makeMeasureSpec(previewHeight, MeasureSpec.EXACTLY));
96    }
97}
98