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      1 /*
      2  * Copyright (C) 2014 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 android.transition;
     18 
     19 import android.animation.Animator;
     20 import android.animation.AnimatorSet;
     21 import android.animation.TypeEvaluator;
     22 import android.graphics.Bitmap;
     23 import android.graphics.Canvas;
     24 import android.graphics.Matrix;
     25 import android.graphics.RectF;
     26 import android.graphics.drawable.BitmapDrawable;
     27 import android.view.View;
     28 import android.view.ViewGroup;
     29 import android.widget.ImageView;
     30 
     31 /**
     32  * Static utility methods for Transitions.
     33  *
     34  * @hide
     35  */
     36 public class TransitionUtils {
     37     private static int MAX_IMAGE_SIZE = (1024 * 1024);
     38 
     39     static Animator mergeAnimators(Animator animator1, Animator animator2) {
     40         if (animator1 == null) {
     41             return animator2;
     42         } else if (animator2 == null) {
     43             return animator1;
     44         } else {
     45             AnimatorSet animatorSet = new AnimatorSet();
     46             animatorSet.playTogether(animator1, animator2);
     47             return animatorSet;
     48         }
     49     }
     50 
     51     public static Transition mergeTransitions(Transition... transitions) {
     52         int count = 0;
     53         int nonNullIndex = -1;
     54         for (int i = 0; i < transitions.length; i++) {
     55             if (transitions[i] != null) {
     56                 count++;
     57                 nonNullIndex = i;
     58             }
     59         }
     60 
     61         if (count == 0) {
     62             return null;
     63         }
     64 
     65         if (count == 1) {
     66             return transitions[nonNullIndex];
     67         }
     68 
     69         TransitionSet transitionSet = new TransitionSet();
     70         for (int i = 0; i < transitions.length; i++) {
     71             if (transitions[i] != null) {
     72                 transitionSet.addTransition(transitions[i]);
     73             }
     74         }
     75         return transitionSet;
     76     }
     77 
     78     /**
     79      * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
     80      * the copy will use a scaled bitmap of the given view.
     81      *
     82      * @param sceneRoot The ViewGroup in which the view copy will be displayed.
     83      * @param view The view to create a copy of.
     84      * @param parent The parent of view.
     85      */
     86     public static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
     87         Matrix matrix = new Matrix();
     88         matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
     89         view.transformMatrixToGlobal(matrix);
     90         sceneRoot.transformMatrixToLocal(matrix);
     91         RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
     92         matrix.mapRect(bounds);
     93         int left = Math.round(bounds.left);
     94         int top = Math.round(bounds.top);
     95         int right = Math.round(bounds.right);
     96         int bottom = Math.round(bounds.bottom);
     97 
     98         ImageView copy = new ImageView(view.getContext());
     99         copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
    100         Bitmap bitmap = createViewBitmap(view, matrix, bounds);
    101         if (bitmap != null) {
    102             copy.setImageBitmap(bitmap);
    103         }
    104         int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
    105         int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
    106         copy.measure(widthSpec, heightSpec);
    107         copy.layout(left, top, right, bottom);
    108         return copy;
    109     }
    110 
    111     /**
    112      * Creates a Bitmap of the given view, using the Matrix matrix to transform to the local
    113      * coordinates. <code>matrix</code> will be modified during the bitmap creation.
    114      *
    115      * <p>If the bitmap is large, it will be scaled uniformly down to at most 1MB size.</p>
    116      * @param view The view to create a bitmap for.
    117      * @param matrix The matrix converting the view local coordinates to the coordinates that
    118      *               the bitmap will be displayed in. <code>matrix</code> will be modified before
    119      *               returning.
    120      * @param bounds The bounds of the bitmap in the destination coordinate system (where the
    121      *               view should be presented. Typically, this is matrix.mapRect(viewBounds);
    122      * @return A bitmap of the given view or null if bounds has no width or height.
    123      */
    124     public static Bitmap createViewBitmap(View view, Matrix matrix, RectF bounds) {
    125         Bitmap bitmap = null;
    126         int bitmapWidth = Math.round(bounds.width());
    127         int bitmapHeight = Math.round(bounds.height());
    128         if (bitmapWidth > 0 && bitmapHeight > 0) {
    129             float scale = Math.min(1f, ((float)MAX_IMAGE_SIZE) / (bitmapWidth * bitmapHeight));
    130             bitmapWidth *= scale;
    131             bitmapHeight *= scale;
    132             matrix.postTranslate(-bounds.left, -bounds.top);
    133             matrix.postScale(scale, scale);
    134             bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
    135             Canvas canvas = new Canvas(bitmap);
    136             canvas.concat(matrix);
    137             view.draw(canvas);
    138         }
    139         return bitmap;
    140     }
    141 
    142     public static class MatrixEvaluator implements TypeEvaluator<Matrix> {
    143 
    144         float[] mTempStartValues = new float[9];
    145 
    146         float[] mTempEndValues = new float[9];
    147 
    148         Matrix mTempMatrix = new Matrix();
    149 
    150         @Override
    151         public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
    152             startValue.getValues(mTempStartValues);
    153             endValue.getValues(mTempEndValues);
    154             for (int i = 0; i < 9; i++) {
    155                 float diff = mTempEndValues[i] - mTempStartValues[i];
    156                 mTempEndValues[i] = mTempStartValues[i] + (fraction * diff);
    157             }
    158             mTempMatrix.setValues(mTempEndValues);
    159             return mTempMatrix;
    160         }
    161     }
    162 }
    163