1<!--
2  Copyright 2012 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<!--
18    This object animator is used as a custom fragment transition. See
19    FragmentTransaction.setCustomAnimation for more details.
20
21    The overall effect of this animator is to rotate the front of the card
22    into view. The order of operations is described below:
23
24    1. The front is immediately set to transparent.
25    2. The invisible front rotates 90 degrees, from being fully flipped
26       to being zero-width, fully perpendicular to the viewer, facing left.
27       It is still invisible.
28    3. The front is then made visible (this is half-way through the
29       animation).
30    4. The front rotates another 90 degrees, from zero-width, to
31       100% of its normal width, facing the user.
32
33    This is accomplished using the 3 child animators below, executed in
34    parallel. Note that the last animator starts half-way into the animation.
35-->
36
37<set xmlns:android="http://schemas.android.com/apk/res/android">
38    <!-- Before rotating, immediately set the alpha to 0. -->
39    <objectAnimator
40        android:valueFrom="1.0"
41        android:valueTo="0.0"
42        android:propertyName="alpha"
43        android:duration="0" />
44
45    <!-- Rotate. -->
46    <objectAnimator
47        android:valueFrom="180"
48        android:valueTo="0"
49        android:propertyName="rotationY"
50        android:interpolator="@android:interpolator/accelerate_decelerate"
51        android:duration="@integer/card_flip_time_full" />
52
53    <!-- Half-way through the rotation (see startOffset), set the alpha to 1. -->
54    <objectAnimator
55        android:valueFrom="0.0"
56        android:valueTo="1.0"
57        android:propertyName="alpha"
58        android:startOffset="@integer/card_flip_time_half"
59        android:duration="1" />
60</set>
61