ExpandCollapseAnimation.java

package tk.djcrazy.MyCC98.animation;

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

/**
 * Animation that either expands or collapses a view by sliding it down to make it visible.
 * Or by sliding it up so it will hide. It will look like it slides behind the view above.
 *
 * @auther tjerk
 * @date 6/9/12 4:58 PM
 */
public class ExpandCollapseAnimation extends Animation {
	private View mAnimatedView;
	private int mEndHeight;
	private int mType;
	public final static int COLLAPSE = 1;
	public final static int EXPAND = 0;
	private LinearLayout.LayoutParams mLayoutParams;

	/**
	 * 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 == EXPAND) {
			mAnimatedView.setPadding(0, 0, 0, mEndHeight);
 		} else {

 		}
//		Log.d("ExpandCollapseAnimation", ""+mLayoutParams.bottomMargin);
//		mAnimatedView.setLayoutParams(mLayoutParams);
		view.setVisibility(View.VISIBLE);
	}

	@Override
	protected void applyTransformation(float interpolatedTime, Transformation t) {

		super.applyTransformation(interpolatedTime, t);
		if (interpolatedTime < 1.0f) {
			if(mType == EXPAND) {
				mAnimatedView.setPadding(0, 0, 0, -mEndHeight + (int) (mEndHeight * interpolatedTime)) ;
			} else {
//				mLayoutParams.bottomMargin = - (int) (mEndHeight * interpolatedTime);
			}
//			Log.d("ExpandCollapseAnimation", "anim height " + mLayoutParams.bottomMargin);
			mAnimatedView.requestLayout();
		} else {
			if(mType == EXPAND) {
				mAnimatedView.setPadding(0, 0, 0, 0);
				mAnimatedView.requestLayout();
			} else {
//				mLayoutParams.bottomMargin = -mEndHeight;
				mAnimatedView.setVisibility(View.GONE);
				mAnimatedView.requestLayout();
			}
		}
	}
}