ExpandCollapseAnimation.java

package com.lesgens.blindr.utils;

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

/**
 * Class for handling collapse and expand animations.
 * @author Esben Gaarsmand
 *
 */
public class ExpandCollapseAnimation extends Animation {
    private View mAnimatedView;
    private int mEndHeight;
    private int mType;

    /**
     * Initializes expand collapse animation, has two types, collapse (1) and expand (0).
     * @param view The view to animate
     * @param duration
     * @param type The type of animation: 0 will expand from gone and 0 size to visible and layout size defined in xml. 
     * 1 will collapse view and set to gone
     */
    public ExpandCollapseAnimation(View view, int duration, int type) {
        setDuration(duration);
        mAnimatedView = view;
        mEndHeight = mAnimatedView.getLayoutParams().height;
        mType = type;
        if(mType == 0) {
            mAnimatedView.getLayoutParams().height = 0;
            mAnimatedView.setVisibility(View.VISIBLE);
        }
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        if (interpolatedTime < 1.0f) {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = (int) (mEndHeight * interpolatedTime);
            } else {
                mAnimatedView.getLayoutParams().height = mEndHeight - (int) (mEndHeight * interpolatedTime);
            }
            mAnimatedView.requestLayout();
        } else {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = mEndHeight;
                mAnimatedView.requestLayout();
            } else {
                mAnimatedView.getLayoutParams().height = 0;
                mAnimatedView.setVisibility(View.GONE);
                mAnimatedView.requestLayout();
                mAnimatedView.getLayoutParams().height = mEndHeight;
            }
        }
    }
}