1/*
2 * Copyright (C) 2017 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 android.support.transition;
18
19import android.animation.Animator;
20import android.animation.AnimatorSet;
21import android.animation.TypeEvaluator;
22import android.graphics.Bitmap;
23import android.graphics.Canvas;
24import android.graphics.Matrix;
25import android.graphics.RectF;
26import android.view.View;
27import android.view.ViewGroup;
28import android.widget.ImageView;
29
30class TransitionUtils {
31
32    private static final int MAX_IMAGE_SIZE = 1024 * 1024;
33
34    /**
35     * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
36     * the copy will use a scaled bitmap of the given view.
37     *
38     * @param sceneRoot The ViewGroup in which the view copy will be displayed.
39     * @param view      The view to create a copy of.
40     * @param parent    The parent of view.
41     */
42    static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
43        Matrix matrix = new Matrix();
44        matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
45        ViewUtils.transformMatrixToGlobal(view, matrix);
46        ViewUtils.transformMatrixToLocal(sceneRoot, matrix);
47        RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
48        matrix.mapRect(bounds);
49        int left = Math.round(bounds.left);
50        int top = Math.round(bounds.top);
51        int right = Math.round(bounds.right);
52        int bottom = Math.round(bounds.bottom);
53
54        ImageView copy = new ImageView(view.getContext());
55        copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
56        Bitmap bitmap = createViewBitmap(view, matrix, bounds);
57        if (bitmap != null) {
58            copy.setImageBitmap(bitmap);
59        }
60        int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
61        int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
62        copy.measure(widthSpec, heightSpec);
63        copy.layout(left, top, right, bottom);
64        return copy;
65    }
66
67    /**
68     * Creates a Bitmap of the given view, using the Matrix matrix to transform to the local
69     * coordinates. <code>matrix</code> will be modified during the bitmap creation.
70     *
71     * <p>If the bitmap is large, it will be scaled uniformly down to at most 1MB size.</p>
72     *
73     * @param view   The view to create a bitmap for.
74     * @param matrix The matrix converting the view local coordinates to the coordinates that
75     *               the bitmap will be displayed in. <code>matrix</code> will be modified before
76     *               returning.
77     * @param bounds The bounds of the bitmap in the destination coordinate system (where the
78     *               view should be presented. Typically, this is matrix.mapRect(viewBounds);
79     * @return A bitmap of the given view or null if bounds has no width or height.
80     */
81    private static Bitmap createViewBitmap(View view, Matrix matrix, RectF bounds) {
82        Bitmap bitmap = null;
83        int bitmapWidth = Math.round(bounds.width());
84        int bitmapHeight = Math.round(bounds.height());
85        if (bitmapWidth > 0 && bitmapHeight > 0) {
86            float scale = Math.min(1f, ((float) MAX_IMAGE_SIZE) / (bitmapWidth * bitmapHeight));
87            bitmapWidth = (int) (bitmapWidth * scale);
88            bitmapHeight = (int) (bitmapHeight * scale);
89            matrix.postTranslate(-bounds.left, -bounds.top);
90            matrix.postScale(scale, scale);
91            bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
92            Canvas canvas = new Canvas(bitmap);
93            canvas.concat(matrix);
94            view.draw(canvas);
95        }
96        return bitmap;
97    }
98
99    static Animator mergeAnimators(Animator animator1, Animator animator2) {
100        if (animator1 == null) {
101            return animator2;
102        } else if (animator2 == null) {
103            return animator1;
104        } else {
105            AnimatorSet animatorSet = new AnimatorSet();
106            animatorSet.playTogether(animator1, animator2);
107            return animatorSet;
108        }
109    }
110
111    static class MatrixEvaluator implements TypeEvaluator<Matrix> {
112
113        final float[] mTempStartValues = new float[9];
114
115        final float[] mTempEndValues = new float[9];
116
117        final Matrix mTempMatrix = new Matrix();
118
119        @Override
120        public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
121            startValue.getValues(mTempStartValues);
122            endValue.getValues(mTempEndValues);
123            for (int i = 0; i < 9; i++) {
124                float diff = mTempEndValues[i] - mTempStartValues[i];
125                mTempEndValues[i] = mTempStartValues[i] + (fraction * diff);
126            }
127            mTempMatrix.setValues(mTempEndValues);
128            return mTempMatrix;
129        }
130
131    }
132
133}
134