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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 android.content.Context;
     20 import android.graphics.Canvas;
     21 import android.graphics.Rect;
     22 import android.graphics.drawable.Drawable;
     23 import android.util.AttributeSet;
     24 import android.view.animation.AnimationUtils;
     25 import android.widget.ImageView;
     26 
     27 /**
     28  * A @{code ImageView} which can rotate it's content.
     29  */
     30 public class RotateImageView extends ImageView {
     31 
     32     @SuppressWarnings("unused")
     33     private static final String TAG = "RotateImageView";
     34 
     35     private static final int ANIMATION_SPEED = 180; // 180 deg/sec
     36 
     37     private int mCurrentDegree = 0; // [0, 359]
     38     private int mStartDegree = 0;
     39     private int mTargetDegree = 0;
     40 
     41     private boolean mClockwise = false;
     42 
     43     private long mAnimationStartTime = 0;
     44     private long mAnimationEndTime = 0;
     45 
     46     public RotateImageView(Context context, AttributeSet attrs) {
     47         super(context, attrs);
     48     }
     49 
     50     public void setDegree(int degree) {
     51         // make sure in the range of [0, 359]
     52         degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
     53         if (degree == mTargetDegree) return;
     54 
     55         mTargetDegree = degree;
     56         mStartDegree = mCurrentDegree;
     57         mAnimationStartTime = AnimationUtils.currentAnimationTimeMillis();
     58 
     59         int diff = mTargetDegree - mCurrentDegree;
     60         diff = diff >= 0 ? diff : 360 + diff; // make it in range [0, 359]
     61 
     62         // Make it in range [-179, 180]. That's the shorted distance between the
     63         // two angles
     64         diff = diff > 180 ? diff - 360 : diff;
     65 
     66         mClockwise = diff >= 0;
     67         mAnimationEndTime = mAnimationStartTime
     68                 + Math.abs(diff) * 1000 / ANIMATION_SPEED;
     69 
     70         invalidate();
     71     }
     72 
     73     @Override
     74     protected void onDraw(Canvas canvas) {
     75 
     76         Drawable drawable = getDrawable();
     77         if (drawable == null) return;
     78 
     79         Rect bounds = drawable.getBounds();
     80         int w = bounds.right - bounds.left;
     81         int h = bounds.bottom - bounds.top;
     82 
     83         if (w == 0 || h == 0) return; // nothing to draw
     84 
     85         if (mCurrentDegree != mTargetDegree) {
     86             long time = AnimationUtils.currentAnimationTimeMillis();
     87             if (time < mAnimationEndTime) {
     88                 int deltaTime = (int)(time - mAnimationStartTime);
     89                 int degree = mStartDegree + ANIMATION_SPEED
     90                         * (mClockwise ? deltaTime : -deltaTime) / 1000;
     91                 degree = degree >= 0 ? degree % 360 : degree % 360 + 360;
     92                 mCurrentDegree = degree;
     93                 invalidate();
     94             } else {
     95                 mCurrentDegree = mTargetDegree;
     96             }
     97         }
     98 
     99         int left = getPaddingLeft();
    100         int top = getPaddingTop();
    101         int right = getPaddingRight();
    102         int bottom = getPaddingBottom();
    103         int width = getWidth() - left - right;
    104         int height = getHeight() - top - bottom;
    105 
    106         int saveCount = canvas.getSaveCount();
    107         canvas.translate(left + width / 2, top + height / 2);
    108         canvas.rotate(-mCurrentDegree);
    109         canvas.translate(-w / 2, -h / 2);
    110         drawable.draw(canvas);
    111         canvas.restoreToCount(saveCount);
    112     }
    113 }
    114