<!--
  Copyright 2012 The Android Open Source Project

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  -->

<!--
    This object animator is used as a custom fragment transition. See
    FragmentTransaction.setCustomAnimation for more details.

    The overall effect of this animator is to rotate the front of the card
    into view. The order of operations is described below:

    1. The front is immediately set to transparent.
    2. The invisible front rotates 90 degrees, from being fully flipped
       to being zero-width, fully perpendicular to the viewer, facing left.
       It is still invisible.
    3. The front is then made visible (this is half-way through the
       animation).
    4. The front rotates another 90 degrees, from zero-width, to
       100% of its normal width, facing the user.

    This is accomplished using the 3 child animators below, executed in
    parallel. Note that the last animator starts half-way into the animation.
-->

<set xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Before rotating, immediately set the alpha to 0. -->
    <objectAnimator
        android:valueFrom="1.0"
        android:valueTo="0.0"
        android:propertyName="alpha"
        android:duration="0" />

    <!-- Rotate. -->
    <objectAnimator
        android:valueFrom="180"
        android:valueTo="0"
        android:propertyName="rotationY"
        android:interpolator="@android:interpolator/accelerate_decelerate"
        android:duration="@integer/card_flip_time_full" />

    <!-- Half-way through the rotation (see startOffset), set the alpha to 1. -->
    <objectAnimator
        android:valueFrom="0.0"
        android:valueTo="1.0"
        android:propertyName="alpha"
        android:startOffset="@integer/card_flip_time_half"
        android:duration="1" />
</set>