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
17package android.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.Picture;
26import android.graphics.Rect;
27import android.graphics.RectF;
28import android.graphics.drawable.BitmapDrawable;
29import android.graphics.drawable.Drawable;
30import android.view.View;
31import android.view.ViewGroup;
32import android.widget.ImageView;
33
34/**
35 * Static utility methods for Transitions.
36 *
37 * @hide
38 */
39public class TransitionUtils {
40    private static int MAX_IMAGE_SIZE = (1024 * 1024);
41
42    static Animator mergeAnimators(Animator animator1, Animator animator2) {
43        if (animator1 == null) {
44            return animator2;
45        } else if (animator2 == null) {
46            return animator1;
47        } else {
48            AnimatorSet animatorSet = new AnimatorSet();
49            animatorSet.playTogether(animator1, animator2);
50            return animatorSet;
51        }
52    }
53
54    public static Transition mergeTransitions(Transition... transitions) {
55        int count = 0;
56        int nonNullIndex = -1;
57        for (int i = 0; i < transitions.length; i++) {
58            if (transitions[i] != null) {
59                count++;
60                nonNullIndex = i;
61            }
62        }
63
64        if (count == 0) {
65            return null;
66        }
67
68        if (count == 1) {
69            return transitions[nonNullIndex];
70        }
71
72        TransitionSet transitionSet = new TransitionSet();
73        for (int i = 0; i < transitions.length; i++) {
74            if (transitions[i] != null) {
75                transitionSet.addTransition(transitions[i]);
76            }
77        }
78        return transitionSet;
79    }
80
81    /**
82     * Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
83     * the copy will use a scaled bitmap of the given view.
84     *
85     * @param sceneRoot The ViewGroup in which the view copy will be displayed.
86     * @param view The view to create a copy of.
87     * @param parent The parent of view.
88     */
89    public static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
90        Matrix matrix = new Matrix();
91        matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
92        view.transformMatrixToGlobal(matrix);
93        sceneRoot.transformMatrixToLocal(matrix);
94        RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
95        matrix.mapRect(bounds);
96        int left = Math.round(bounds.left);
97        int top = Math.round(bounds.top);
98        int right = Math.round(bounds.right);
99        int bottom = Math.round(bounds.bottom);
100
101        ImageView copy = new ImageView(view.getContext());
102        copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
103        Bitmap bitmap = createViewBitmap(view, matrix, bounds, sceneRoot);
104        if (bitmap != null) {
105            copy.setImageBitmap(bitmap);
106        }
107        int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
108        int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
109        copy.measure(widthSpec, heightSpec);
110        copy.layout(left, top, right, bottom);
111        return copy;
112    }
113
114    /**
115     * Get a copy of bitmap of given drawable, return null if intrinsic size is zero
116     */
117    public static Bitmap createDrawableBitmap(Drawable drawable, View hostView) {
118        int width = drawable.getIntrinsicWidth();
119        int height = drawable.getIntrinsicHeight();
120        if (width <= 0 || height <= 0) {
121            return null;
122        }
123        float scale = Math.min(1f, ((float)MAX_IMAGE_SIZE) / (width * height));
124        if (drawable instanceof BitmapDrawable && scale == 1f) {
125            // return same bitmap if scale down not needed
126            return ((BitmapDrawable) drawable).getBitmap();
127        }
128        int bitmapWidth = (int) (width * scale);
129        int bitmapHeight = (int) (height * scale);
130        final Picture picture = new Picture();
131        final Canvas canvas = picture.beginRecording(width, height);
132        // Do stuff with the canvas
133        Rect existingBounds = drawable.getBounds();
134        int left = existingBounds.left;
135        int top = existingBounds.top;
136        int right = existingBounds.right;
137        int bottom = existingBounds.bottom;
138        drawable.setBounds(0, 0, bitmapWidth, bitmapHeight);
139        drawable.draw(canvas);
140        drawable.setBounds(left, top, right, bottom);
141        picture.endRecording();
142        return Bitmap.createBitmap(picture);
143    }
144
145    /**
146     * Creates a Bitmap of the given view, using the Matrix matrix to transform to the local
147     * coordinates. <code>matrix</code> will be modified during the bitmap creation.
148     *
149     * <p>If the bitmap is large, it will be scaled uniformly down to at most 1MB size.</p>
150     * @param view The view to create a bitmap for.
151     * @param matrix The matrix converting the view local coordinates to the coordinates that
152     *               the bitmap will be displayed in. <code>matrix</code> will be modified before
153     *               returning.
154     * @param bounds The bounds of the bitmap in the destination coordinate system (where the
155     *               view should be presented. Typically, this is matrix.mapRect(viewBounds);
156     * @param sceneRoot A ViewGroup that is attached to the window to temporarily contain the view
157     *                  if it isn't attached to the window.
158     * @return A bitmap of the given view or null if bounds has no width or height.
159     */
160    public static Bitmap createViewBitmap(View view, Matrix matrix, RectF bounds,
161            ViewGroup sceneRoot) {
162        final boolean addToOverlay = !view.isAttachedToWindow();
163        ViewGroup parent = null;
164        int indexInParent = 0;
165        if (addToOverlay) {
166            if (sceneRoot == null || !sceneRoot.isAttachedToWindow()) {
167                return null;
168            }
169            parent = (ViewGroup) view.getParent();
170            indexInParent = parent.indexOfChild(view);
171            sceneRoot.getOverlay().add(view);
172        }
173        Bitmap bitmap = null;
174        int bitmapWidth = Math.round(bounds.width());
175        int bitmapHeight = Math.round(bounds.height());
176        if (bitmapWidth > 0 && bitmapHeight > 0) {
177            float scale = Math.min(1f, ((float) MAX_IMAGE_SIZE) / (bitmapWidth * bitmapHeight));
178            bitmapWidth *= scale;
179            bitmapHeight *= scale;
180            matrix.postTranslate(-bounds.left, -bounds.top);
181            matrix.postScale(scale, scale);
182
183            final Picture picture = new Picture();
184            final Canvas canvas = picture.beginRecording(bitmapWidth, bitmapHeight);
185            canvas.concat(matrix);
186            view.draw(canvas);
187            picture.endRecording();
188            bitmap = Bitmap.createBitmap(picture);
189        }
190        if (addToOverlay) {
191            sceneRoot.getOverlay().remove(view);
192            parent.addView(view, indexInParent);
193        }
194        return bitmap;
195    }
196
197    public static class MatrixEvaluator implements TypeEvaluator<Matrix> {
198
199        float[] mTempStartValues = new float[9];
200
201        float[] mTempEndValues = new float[9];
202
203        Matrix mTempMatrix = new Matrix();
204
205        @Override
206        public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
207            startValue.getValues(mTempStartValues);
208            endValue.getValues(mTempEndValues);
209            for (int i = 0; i < 9; i++) {
210                float diff = mTempEndValues[i] - mTempStartValues[i];
211                mTempEndValues[i] = mTempStartValues[i] + (fraction * diff);
212            }
213            mTempMatrix.setValues(mTempEndValues);
214            return mTempMatrix;
215        }
216    }
217}
218