CanvasTransformerBuilder.java

package com.slidingmenu.lib;

import android.graphics.Canvas;
import android.view.animation.Interpolator;

import com.slidingmenu.lib.SlidingMenu.CanvasTransformer;

public class CanvasTransformerBuilder {

	private CanvasTransformer mTrans;

	private static Interpolator lin = new Interpolator() {
		public float getInterpolation(float t) {
			return t;
		}
	};

	private void initTransformer() {
		if (mTrans == null)
			mTrans = new CanvasTransformer() {
			public void transformCanvas(Canvas canvas, float percentOpen) {	}
		};
	}

	public CanvasTransformer zoom(final int openedX, final int closedX, 
			final int openedY, final int closedY, 
			final int px, final int py) {
		return zoom(openedX, closedX, openedY, closedY, px, py, lin);
	}

	public CanvasTransformer zoom(final int openedX, final int closedX, 
			final int openedY, final int closedY,
			final int px, final int py, final Interpolator interp) {
		initTransformer();
		mTrans = new CanvasTransformer() {
			public void transformCanvas(Canvas canvas, float percentOpen) {
				mTrans.transformCanvas(canvas, percentOpen);
				float f = interp.getInterpolation(percentOpen);
				canvas.scale((openedX - closedX) * f + closedX,
						(openedY - closedY) * f + closedY, px, py);
			}			
		};
		return mTrans;
	}

	public CanvasTransformer rotate(final int openedDeg, final int closedDeg, 
			final int px, final int py) {
		return rotate(openedDeg, closedDeg, px, py, lin);
	}

	public CanvasTransformer rotate(final int openedDeg, final int closedDeg, 
			final int px, final int py, final Interpolator interp) {
		initTransformer();
		mTrans = new CanvasTransformer() {
			public void transformCanvas(Canvas canvas, float percentOpen) {
				mTrans.transformCanvas(canvas, percentOpen);
				float f = interp.getInterpolation(percentOpen);
				canvas.rotate((openedDeg - closedDeg) * f + closedDeg, 
						px, py);
			}			
		};
		return mTrans;
	}

	public CanvasTransformer translate(final int openedX, final int closedX, 
			final int openedY, final int closedY) {
		return translate(openedX, closedX, openedY, closedY, lin);
	}

	public CanvasTransformer translate(final int openedX, final int closedX, 
			final int openedY, final int closedY, final Interpolator interp) {
		initTransformer();
		mTrans = new CanvasTransformer() {
			public void transformCanvas(Canvas canvas, float percentOpen) {
				mTrans.transformCanvas(canvas, percentOpen);
				float f = interp.getInterpolation(percentOpen);
				canvas.translate((openedX - closedX) * f + closedX,
						(openedY - closedY) * f + closedY);
			}			
		};
		return mTrans;
	}

	public CanvasTransformer concatTransformer(final CanvasTransformer t) {
		initTransformer();
		mTrans = new CanvasTransformer() {
			public void transformCanvas(Canvas canvas, float percentOpen) {
				mTrans.transformCanvas(canvas, percentOpen);
				t.transformCanvas(canvas, percentOpen);
			}			
		};
		return mTrans;
	}

}