Scale.java revision 0fff85d7f9dee67ec5116f3cba4e8b3961f805a7 
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 */
16package android.support.v17.leanback.transition;
17
18import android.animation.Animator;
19import android.animation.ValueAnimator;
20import android.view.View;
21import android.view.ViewGroup;
22import android.transition.Transition;
23import android.transition.TransitionValues;
24
25class Scale extends Transition {
26    private static final String PROPNAME_SCALE = "android:leanback:scale";
27
28    public Scale() {
29    }
30
31    private void captureValues(TransitionValues values) {
32        View view = values.view;
33        values.values.put(PROPNAME_SCALE, view.getScaleX());
34    }
35
36    @Override
37    public void captureStartValues(TransitionValues transitionValues) {
38        captureValues(transitionValues);
39    }
40
41    @Override
42    public void captureEndValues(TransitionValues transitionValues) {
43        captureValues(transitionValues);
44    }
45
46    @Override
47    public Animator createAnimator(final ViewGroup sceneRoot, TransitionValues startValues,
48            TransitionValues endValues) {
49        if (startValues == null || endValues == null) {
50            return null;
51        }
52
53        final float startScale = (Float) startValues.values.get(PROPNAME_SCALE);
54        final float endScale = (Float) endValues.values.get(PROPNAME_SCALE);
55
56        final View view = startValues.view;
57        view.setScaleX(startScale);
58        view.setScaleY(startScale);
59
60        ValueAnimator animator = ValueAnimator.ofFloat(startScale, endScale);
61        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
62            @Override
63            public void onAnimationUpdate(ValueAnimator animation) {
64                final float scale = (Float) animation.getAnimatedValue();
65                view.setScaleX(scale);
66                view.setScaleY(scale);
67            }
68        });
69        return animator;
70    }
71}
72