AnimatedVectorDrawable/ObjectAnimator startoffset bug?

Question

I want to animated a VectorDrawable.

Here is my VectorDrawable (converted from SVG, simplified for this example):

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="888dp"
        android:height="600dp"
        android:viewportHeight="600"
        android:viewportWidth="888">

    <group
        android:name="wheel"
        android:pivotX="498.0"
        android:pivotY="385.0"
        android:rotation="0.0">
        <path
            android:fillColor="#BDEDFF"
            android:pathData="M547.4,363.9l-23.7,6.7c-1.1-1.8-2.5-3.5-4-5l12-21.5c2.2-3.9,0.8-8.9-3.1-11.1c-3.9-2.2-8.9-0.8-11.1,3.1
l-12,21.5c-2-0.5-4.2-0.7-6.4-0.8l-6.7-23.7c-1.2-4.3-5.7-6.8-10-5.6c-4.3,1.2-6.8,5.7-5.6,10l6.7,23.7c-1.8,1.1-3.5,2.5-5,4
l-21.5-12c-3.9-2.2-8.9-0.8-11.1,3.1c-2.2,3.9-0.8,8.9,3.1,11.1l21.5,12c-0.5,2-0.7,4.2-0.8,6.4l-23.7,6.7c-4.3,1.2-6.8,5.7-5.6,10
c1,3.6,4.3,5.9,7.8,5.9c0.7,0,1.5-0.1,2.2-0.3l23.7-6.7c1.1,1.8,2.5,3.5,4,5l-12,21.5c-2.2,3.9-0.8,8.9,3.1,11.1c1.3,0.7,2.6,1,4,1
c2.9,0,5.6-1.5,7.1-4.2l12-21.5c2,0.5,4.2,0.7,6.4,0.8l6.7,23.7c1,3.6,4.3,5.9,7.8,5.9c0.7,0,1.5-0.1,2.2-0.3
c4.3-1.2,6.8-5.7,5.6-10l-6.7-23.7c1.8-1.1,3.5-2.5,5-4l21.5,12c1.3,0.7,2.6,1,4,1c2.8,0,5.6-1.5,7.1-4.2c2.2-3.9,0.8-8.9-3.1-11.1
l-21.5-12c0.5-2,0.7-4.2,0.8-6.4l23.7-6.7c4.3-1.2,6.8-5.7,5.6-10C556.2,365.1,551.7,362.6,547.4,363.9z"/>
    </group>
</vector>

My AnimatedVectorDrawable:

<?xml version="1.0" encoding="utf-8"?>
<animated-vector
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/image_vect">
    <target
        android:name="wheel"
        android:animation="@anim/wheel"/>
</animated-vector>

My animation:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <objectAnimator
        android:duration="1000"
        android:propertyName="rotation"
        android:startOffset="1000"
        android:valueFrom="0"
        android:valueTo="180"
        android:valueType="floatType"/>
</set>

My issue is with startOffset:

• if android:startOffset is 100, the animation is playing on both 4.4 and 6.0. Perfect.

• if android:startOffset is 300, the animation is not playing on 4.4 and it's playing on 6.0

• if android:startOffset is 500, the animation is not playing on 4.4 neither on 6.0

Am I doing something wrong?

Thanks for your help!

Ps: my final vector contains more elements and my animation contains more steps (turn right, then turn left after a delay, then …). But this simplify version is enough to show the error I'm facing.

Answer 1

I've found startOffset to be generally problematic with AnimatedVectorDrawables, enough so that I just avoid using it.

The alternative approach being to include an ObjectAnimator of the required length keeping the property at the next starting value. In this case:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="sequentially">
    <objectAnimator
        android:duration="1000"
        android:propertyName="rotation"
        android:valueFrom="0"
        android:valueTo="0"
        android:valueType="floatType"/>
    <objectAnimator
        android:duration="1000"
        android:propertyName="rotation"
        android:valueFrom="0"
        android:valueTo="180"
        android:valueType="floatType"/>
</set>