ResizeAnimation.java

package sulca.pe.expandenditem;

import android.view.View;
import android.view.animation.Animation;
import android.view.animation.Transformation;

/**
 * Created by William_ST on 30/08/16.
 */
public class ResizeAnimation extends Animation {

    private final String TAG = ResizeAnimation.class.getSimpleName();
    private final int targetHeight;
    private View view;
    private int startHeight;

    public ResizeAnimation(View view, int startHeight, int targetHeight) {
        this.view = view;
        this.targetHeight = targetHeight;
        this.startHeight = startHeight;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        if(startHeight < targetHeight){
            int newHeight = (int) ((startHeight + targetHeight) * interpolatedTime);
            view.getLayoutParams().height = newHeight;
            view.requestLayout();
        } else {
            int newHeight = (int) ((startHeight + targetHeight) * (1-interpolatedTime));
            view.getLayoutParams().height = newHeight;
            view.requestLayout();
        }
    }

    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
    }

    @Override
    public boolean willChangeBounds() {
        return true;
    }
}