Animated Vector Drawable for on click rotation of arrow
All you need is just one line of code -
view.animate().rotationBy(degree_of_rotation).setDuration(duration_in_milliseconds).start();
1. Add vector images
We also need to wrap path
in group
because group
is the part of vector resource that will be animated. You can set any name for a group.
res/drawable/ic_arrow_down.xml
<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:viewportWidth="306"
android:viewportHeight="306"
android:width="306dp"
android:height="306dp">
<group
android:name="arrow"
android:pivotX="153"
android:pivotY="153">
<path
android:pathData="M153 247.35L306 94.35 270.3 58.65 153 175.95 35.7 58.65 0 94.35Z"
android:fillColor="#000000" />
</group>
</vector>
res/drawable/ic_arrow_top.xml
<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:viewportWidth="306"
android:viewportHeight="306"
android:width="306dp"
android:height="306dp">
<group
android:name="arrow"
android:pivotX="153"
android:pivotY="153">
<path
android:pathData="M270.3 247.35L306 211.65 153 58.65 0 211.65 35.7 247.35 153 130.05Z"
android:fillColor="#000000" />
</group>
</vector>
2. Add animator
res/animator/animation_arrow_rotation.xml
<?xml version="1.0" encoding="utf-8"?>
<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="@android:integer/config_shortAnimTime"
android:propertyName="rotation"
android:valueFrom="0"
android:valueTo="180" />
3. Add animated vector drawables
<target>
references to the group
's name.
res/drawable/ic_animated_arrow_down.xml
<?xml version="1.0" encoding="utf-8"?>
<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
android:drawable="@drawable/ic_arrow_down">
<target
android:name="arrow"
android:animation="@animator/animation_arrow_rotation" />
</animated-vector>
res/drawable/ic_animated_arrow_up.xml
<?xml version="1.0" encoding="utf-8"?>
<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"
android:drawable="@drawable/ic_arrow_up">
<target
android:name="arrow"
android:animation="@animator/animation_arrow_rotation" />
</animated-vector>
4. Add some code to Adapter
Init ImageView in ParentViewHolder's inheritor:
void bind(UiModel uiModel) {
arrowImageView.setImageResource(isExpanded() ? R.drawable.ic_animated_arrow_down :
R.drawable.ic_animated_arrow_up);
// some other code
}
and override onExpansionToggled
:
@Override
public void onExpansionToggled(boolean expanded) {
super.onExpansionToggled(expanded);
arrowImageView.setImageResource(expanded ? R.drawable.ic_animated_arrow_down :
R.drawable.ic_animated_arrow_up);
AnimatedVectorDrawableCompat drawable = (AnimatedVectorDrawableCompat) arrowImageView.getDrawable();
drawable.registerAnimationCallback(new Animatable2Compat.AnimationCallback() {
@Override
public void onAnimationEnd(Drawable ignored) {
drawable.clearAnimationCallbacks();
arrowImageView.setImageResource(expanded ? R.drawable.ic_animated_arrow_up :
R.drawable.ic_animated_arrow_down);
}
});
drawable.start();
}
By the way, you can define AnimatedVectorDrawable XML resources in one XML file. Details here.