package com.github.takahirom.materialelement.animation.transition;
import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.transition.Transition;
import android.transition.TransitionValues;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import com.github.takahirom.materialelement.R;
/**
* A transition that animates the elevation of a View from a given value down to zero.
* <p>
* Useful for creating parent↔child navigation transitions
* (https://www.google.com/design/spec/patterns/navigational-transitions.html#navigational-transitions-parent-to-child)
* when combined with a {@link android.transition.ChangeBounds} on a shared element.
*/
public class LiftOff extends Transition {
private static final String PROPNAME_ELEVATION = "plaid:liftoff:elevation";
private static final String[] transitionProperties = {
PROPNAME_ELEVATION
};
private final float initialElevation;
private final float finalElevation;
public LiftOff(Context context, AttributeSet attrs) {
super(context, attrs);
final TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.LiftOff);
initialElevation = ta.getDimension(R.styleable.LiftOff_initialElevation, 0f);
finalElevation = ta.getDimension(R.styleable.LiftOff_finalElevation, 0f);
ta.recycle();
}
@Override
public String[] getTransitionProperties() {
return transitionProperties;
}
@Override
public void captureStartValues(TransitionValues transitionValues) {
transitionValues.values.put(PROPNAME_ELEVATION, initialElevation);
}
@Override
public void captureEndValues(TransitionValues transitionValues) {
transitionValues.values.put(PROPNAME_ELEVATION, finalElevation);
}
@Override
public Animator createAnimator(ViewGroup sceneRoot, TransitionValues startValues,
TransitionValues endValues) {
return ObjectAnimator.ofFloat(endValues.view, View.TRANSLATION_Z,
initialElevation, finalElevation);
}
}