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.Rect;
26 import android.graphics.RectF;
27 import android.graphics.drawable.BitmapDrawable;
28 import android.graphics.drawable.Drawable;
29 import android.view.View;
30 import android.view.ViewGroup;
31 import android.widget.ImageView;
32 
33 /**
34  * Static utility methods for Transitions.
35  *
36  * @hide
37  */
38 public class TransitionUtils {
39     private static int MAX_IMAGE_SIZE = (1024 * 1024);
40 
mergeAnimators(Animator animator1, Animator animator2)41     static Animator mergeAnimators(Animator animator1, Animator animator2) {
42         if (animator1 == null) {
43             return animator2;
44         } else if (animator2 == null) {
45             return animator1;
46         } else {
47             AnimatorSet animatorSet = new AnimatorSet();
48             animatorSet.playTogether(animator1, animator2);
49             return animatorSet;
50         }
51     }
52 
mergeTransitions(Transition... transitions)53     public static Transition mergeTransitions(Transition... transitions) {
54         int count = 0;
55         int nonNullIndex = -1;
56         for (int i = 0; i < transitions.length; i++) {
57             if (transitions[i] != null) {
58                 count++;
59                 nonNullIndex = i;
60             }
61         }
62 
63         if (count == 0) {
64             return null;
65         }
66 
67         if (count == 1) {
68             return transitions[nonNullIndex];
69         }
70 
71         TransitionSet transitionSet = new TransitionSet();
72         for (int i = 0; i < transitions.length; i++) {
73             if (transitions[i] != null) {
74                 transitionSet.addTransition(transitions[i]);
75             }
76         }
77         return transitionSet;
78     }
79 
80     /**
81      * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
82      * the copy will use a scaled bitmap of the given view.
83      *
84      * @param sceneRoot The ViewGroup in which the view copy will be displayed.
85      * @param view The view to create a copy of.
86      * @param parent The parent of view.
87      */
copyViewImage(ViewGroup sceneRoot, View view, View parent)88     public static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
89         Matrix matrix = new Matrix();
90         matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
91         view.transformMatrixToGlobal(matrix);
92         sceneRoot.transformMatrixToLocal(matrix);
93         RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
94         matrix.mapRect(bounds);
95         int left = Math.round(bounds.left);
96         int top = Math.round(bounds.top);
97         int right = Math.round(bounds.right);
98         int bottom = Math.round(bounds.bottom);
99 
100         ImageView copy = new ImageView(view.getContext());
101         copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
102         Bitmap bitmap = createViewBitmap(view, matrix, bounds);
103         if (bitmap != null) {
104             copy.setImageBitmap(bitmap);
105         }
106         int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
107         int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
108         copy.measure(widthSpec, heightSpec);
109         copy.layout(left, top, right, bottom);
110         return copy;
111     }
112 
113     /**
114      * Get a copy of bitmap of given drawable, return null if intrinsic size is zero
115      */
createDrawableBitmap(Drawable drawable)116     public static Bitmap createDrawableBitmap(Drawable drawable) {
117         int width = drawable.getIntrinsicWidth();
118         int height = drawable.getIntrinsicHeight();
119         if (width <= 0 || height <= 0) {
120             return null;
121         }
122         float scale = Math.min(1f, ((float)MAX_IMAGE_SIZE) / (width * height));
123         if (drawable instanceof BitmapDrawable && scale == 1f) {
124             // return same bitmap if scale down not needed
125             return ((BitmapDrawable) drawable).getBitmap();
126         }
127         int bitmapWidth = (int) (width * scale);
128         int bitmapHeight = (int) (height * scale);
129         Bitmap bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
130         Canvas canvas = new Canvas(bitmap);
131         Rect existingBounds = drawable.getBounds();
132         int left = existingBounds.left;
133         int top = existingBounds.top;
134         int right = existingBounds.right;
135         int bottom = existingBounds.bottom;
136         drawable.setBounds(0, 0, bitmapWidth, bitmapHeight);
137         drawable.draw(canvas);
138         drawable.setBounds(left, top, right, bottom);
139         return bitmap;
140     }
141 
142     /**
143      * Creates a Bitmap of the given view, using the Matrix matrix to transform to the local
144      * coordinates. <code>matrix</code> will be modified during the bitmap creation.
145      *
146      * <p>If the bitmap is large, it will be scaled uniformly down to at most 1MB size.</p>
147      * @param view The view to create a bitmap for.
148      * @param matrix The matrix converting the view local coordinates to the coordinates that
149      *               the bitmap will be displayed in. <code>matrix</code> will be modified before
150      *               returning.
151      * @param bounds The bounds of the bitmap in the destination coordinate system (where the
152      *               view should be presented. Typically, this is matrix.mapRect(viewBounds);
153      * @return A bitmap of the given view or null if bounds has no width or height.
154      */
createViewBitmap(View view, Matrix matrix, RectF bounds)155     public static Bitmap createViewBitmap(View view, Matrix matrix, RectF bounds) {
156         Bitmap bitmap = null;
157         int bitmapWidth = Math.round(bounds.width());
158         int bitmapHeight = Math.round(bounds.height());
159         if (bitmapWidth > 0 && bitmapHeight > 0) {
160             float scale = Math.min(1f, ((float)MAX_IMAGE_SIZE) / (bitmapWidth * bitmapHeight));
161             bitmapWidth *= scale;
162             bitmapHeight *= scale;
163             matrix.postTranslate(-bounds.left, -bounds.top);
164             matrix.postScale(scale, scale);
165             bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
166             Canvas canvas = new Canvas(bitmap);
167             canvas.concat(matrix);
168             view.draw(canvas);
169         }
170         return bitmap;
171     }
172 
173     public static class MatrixEvaluator implements TypeEvaluator<Matrix> {
174 
175         float[] mTempStartValues = new float[9];
176 
177         float[] mTempEndValues = new float[9];
178 
179         Matrix mTempMatrix = new Matrix();
180 
181         @Override
evaluate(float fraction, Matrix startValue, Matrix endValue)182         public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
183             startValue.getValues(mTempStartValues);
184             endValue.getValues(mTempEndValues);
185             for (int i = 0; i < 9; i++) {
186                 float diff = mTempEndValues[i] - mTempStartValues[i];
187                 mTempEndValues[i] = mTempStartValues[i] + (fraction * diff);
188             }
189             mTempMatrix.setValues(mTempEndValues);
190             return mTempMatrix;
191         }
192     }
193 }
194