RotateImageView.java revision 5332b201e37ae0bb8854636fac9e0dbee3bb37df 
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 TwoStateImageView 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    protected int getDegree() {
60        return mTargetDegree;
61    }
62
63    // Rotate the view counter-clockwise
64    @Override
65    public void setOrientation(int degree, boolean animation) {
66        mEnableAnimation = animation;
67        // make sure in the range of [0, 359]
68        degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
69        if (degree == mTargetDegree) return;
70
71        mTargetDegree = degree;
72        if (mEnableAnimation) {
73            mStartDegree = mCurrentDegree;
74            mAnimationStartTime = AnimationUtils.currentAnimationTimeMillis();
75
76            int diff = mTargetDegree - mCurrentDegree;
77            diff = diff >= 0 ? diff : 360 + diff; // make it in range [0, 359]
78
79            // Make it in range [-179, 180]. That's the shorted distance between the
80            // two angles
81            diff = diff > 180 ? diff - 360 : diff;
82
83            mClockwise = diff >= 0;
84            mAnimationEndTime = mAnimationStartTime
85                    + Math.abs(diff) * 1000 / ANIMATION_SPEED;
86        } else {
87            mCurrentDegree = mTargetDegree;
88        }
89
90        invalidate();
91    }
92
93    @Override
94    protected void onDraw(Canvas canvas) {
95        Drawable drawable = getDrawable();
96        if (drawable == null) return;
97
98        Rect bounds = drawable.getBounds();
99        int w = bounds.right - bounds.left;
100        int h = bounds.bottom - bounds.top;
101
102        if (w == 0 || h == 0) return; // nothing to draw
103
104        if (mCurrentDegree != mTargetDegree) {
105            long time = AnimationUtils.currentAnimationTimeMillis();
106            if (time < mAnimationEndTime) {
107                int deltaTime = (int)(time - mAnimationStartTime);
108                int degree = mStartDegree + ANIMATION_SPEED
109                        * (mClockwise ? deltaTime : -deltaTime) / 1000;
110                degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
111                mCurrentDegree = degree;
112                invalidate();
113            } else {
114                mCurrentDegree = mTargetDegree;
115            }
116        }
117
118        int left = getPaddingLeft();
119        int top = getPaddingTop();
120        int right = getPaddingRight();
121        int bottom = getPaddingBottom();
122        int width = getWidth() - left - right;
123        int height = getHeight() - top - bottom;
124
125        int saveCount = canvas.getSaveCount();
126
127        // Scale down the image first if required.
128        if ((getScaleType() == ImageView.ScaleType.FIT_CENTER) &&
129                ((width < w) || (height < h))) {
130            float ratio = Math.min((float) width / w, (float) height / h);
131            canvas.scale(ratio, ratio, width / 2.0f, height / 2.0f);
132        }
133        canvas.translate(left + width / 2, top + height / 2);
134        canvas.rotate(-mCurrentDegree);
135        canvas.translate(-w / 2, -h / 2);
136        drawable.draw(canvas);
137        canvas.restoreToCount(saveCount);
138    }
139
140    private Bitmap mThumb;
141    private Drawable[] mThumbs;
142    private TransitionDrawable mThumbTransition;
143
144    public void setBitmap(Bitmap bitmap) {
145        // Make sure uri and original are consistently both null or both
146        // non-null.
147        if (bitmap == null) {
148            mThumb = null;
149            mThumbs = null;
150            setImageDrawable(null);
151            setVisibility(GONE);
152            return;
153        }
154
155        LayoutParams param = getLayoutParams();
156        final int miniThumbWidth = param.width
157                - getPaddingLeft() - getPaddingRight();
158        final int miniThumbHeight = param.height
159                - getPaddingTop() - getPaddingBottom();
160        mThumb = ThumbnailUtils.extractThumbnail(
161                bitmap, miniThumbWidth, miniThumbHeight);
162        Drawable drawable;
163        if (mThumbs == null || !mEnableAnimation) {
164            mThumbs = new Drawable[2];
165            mThumbs[1] = new BitmapDrawable(getContext().getResources(), mThumb);
166            setImageDrawable(mThumbs[1]);
167        } else {
168            mThumbs[0] = mThumbs[1];
169            mThumbs[1] = new BitmapDrawable(getContext().getResources(), mThumb);
170            mThumbTransition = new TransitionDrawable(mThumbs);
171            setImageDrawable(mThumbTransition);
172            mThumbTransition.startTransition(500);
173        }
174        setVisibility(VISIBLE);
175    }
176}
177