RotateImageView.java revision 3ebe49d8f1b4defb7cfd4850a14e795aada2ebd1 
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.ui;
18
19import android.content.Context;
20import android.graphics.Bitmap;
21import android.graphics.Canvas;
22import android.graphics.Rect;
23import android.graphics.drawable.BitmapDrawable;
24import android.graphics.drawable.Drawable;
25import android.graphics.drawable.TransitionDrawable;
26import android.media.ThumbnailUtils;
27import android.util.AttributeSet;
28import android.view.ViewGroup.LayoutParams;
29import android.view.animation.AnimationUtils;
30import android.widget.ImageView;
31
32/**
33 * A @{code ImageView} which can rotate it's content.
34 */
35public class RotateImageView extends ColorFilterImageView implements Rotatable {
36
37    @SuppressWarnings("unused")
38    private static final String TAG = "RotateImageView";
39
40    private static final int ANIMATION_SPEED = 270; // 270 deg/sec
41
42    private int mCurrentDegree = 0; // [0, 359]
43    private int mStartDegree = 0;
44    private int mTargetDegree = 0;
45
46    private boolean mClockwise = false, mEnableAnimation = true;
47
48    private long mAnimationStartTime = 0;
49    private long mAnimationEndTime = 0;
50
51    public RotateImageView(Context context, AttributeSet attrs) {
52        super(context, attrs);
53    }
54
55    public RotateImageView(Context context) {
56        super(context);
57    }
58
59    public void enableAnimation(boolean enable) {
60        mEnableAnimation = enable;
61    }
62
63    protected int getDegree() {
64        return mTargetDegree;
65    }
66
67    // Rotate the view counter-clockwise
68    public void setOrientation(int degree) {
69        // make sure in the range of [0, 359]
70        degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
71        if (degree == mTargetDegree) return;
72
73        mTargetDegree = degree;
74        mStartDegree = mCurrentDegree;
75        mAnimationStartTime = AnimationUtils.currentAnimationTimeMillis();
76
77        int diff = mTargetDegree - mCurrentDegree;
78        diff = diff >= 0 ? diff : 360 + diff; // make it in range [0, 359]
79
80        // Make it in range [-179, 180]. That's the shorted distance between the
81        // two angles
82        diff = diff > 180 ? diff - 360 : diff;
83
84        mClockwise = diff >= 0;
85        mAnimationEndTime = mAnimationStartTime
86                + Math.abs(diff) * 1000 / ANIMATION_SPEED;
87
88        invalidate();
89    }
90
91    @Override
92    protected void onDraw(Canvas canvas) {
93        Drawable drawable = getDrawable();
94        if (drawable == null) return;
95
96        Rect bounds = drawable.getBounds();
97        int w = bounds.right - bounds.left;
98        int h = bounds.bottom - bounds.top;
99
100        if (w == 0 || h == 0) return; // nothing to draw
101
102        if (mCurrentDegree != mTargetDegree) {
103            long time = AnimationUtils.currentAnimationTimeMillis();
104            if (time < mAnimationEndTime) {
105                int deltaTime = (int)(time - mAnimationStartTime);
106                int degree = mStartDegree + ANIMATION_SPEED
107                        * (mClockwise ? deltaTime : -deltaTime) / 1000;
108                degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
109                mCurrentDegree = degree;
110                invalidate();
111            } else {
112                mCurrentDegree = mTargetDegree;
113            }
114        }
115
116        int left = getPaddingLeft();
117        int top = getPaddingTop();
118        int right = getPaddingRight();
119        int bottom = getPaddingBottom();
120        int width = getWidth() - left - right;
121        int height = getHeight() - top - bottom;
122
123        int saveCount = canvas.getSaveCount();
124
125        // Scale down the image first if required.
126        if ((getScaleType() == ImageView.ScaleType.FIT_CENTER) &&
127                ((width < w) || (height < h))) {
128            float ratio = Math.min((float) width / w, (float) height / h);
129            canvas.scale(ratio, ratio, width / 2.0f, height / 2.0f);
130        }
131        canvas.translate(left + width / 2, top + height / 2);
132        canvas.rotate(-mCurrentDegree);
133        canvas.translate(-w / 2, -h / 2);
134        drawable.draw(canvas);
135        canvas.restoreToCount(saveCount);
136    }
137
138    private Bitmap mThumb;
139    private Drawable[] mThumbs;
140    private TransitionDrawable mThumbTransition;
141
142    public void setBitmap(Bitmap bitmap) {
143        // Make sure uri and original are consistently both null or both
144        // non-null.
145        if (bitmap == null) {
146            mThumb = null;
147            mThumbs = null;
148            setImageDrawable(null);
149            setVisibility(GONE);
150            return;
151        }
152
153        LayoutParams param = getLayoutParams();
154        final int miniThumbWidth = param.width
155                - getPaddingLeft() - getPaddingRight();
156        final int miniThumbHeight = param.height
157                - getPaddingTop() - getPaddingBottom();
158        mThumb = ThumbnailUtils.extractThumbnail(
159                bitmap, miniThumbWidth, miniThumbHeight);
160        Drawable drawable;
161        if (mThumbs == null || !mEnableAnimation) {
162            mThumbs = new Drawable[2];
163            mThumbs[1] = new BitmapDrawable(getContext().getResources(), mThumb);
164            setImageDrawable(mThumbs[1]);
165        } else {
166            mThumbs[0] = mThumbs[1];
167            mThumbs[1] = new BitmapDrawable(getContext().getResources(), mThumb);
168            mThumbTransition = new TransitionDrawable(mThumbs);
169            setImageDrawable(mThumbTransition);
170            mThumbTransition.startTransition(500);
171        }
172        setVisibility(VISIBLE);
173    }
174}
175