ClingDrawerImpl.java

package com.espian.showcaseview.drawing;

import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.Log;

import com.github.espiandev.showcaseview.R;

/**
 * Created by curraa01 on 13/10/2013.
 */
public class ClingDrawerImpl implements ClingDrawer {

	private Paint mEraser;
	private Drawable mShowcaseDrawable;
	private Rect mShowcaseRect;

	public ClingDrawerImpl(Resources resources, int showcaseColor) {
		PorterDuffXfermode mBlender = new PorterDuffXfermode(PorterDuff.Mode.CLEAR);
		mEraser = new Paint();
		mEraser.setColor(0xFFFFFF);
		mEraser.setAlpha(0);
		mEraser.setXfermode(mBlender);
		mEraser.setAntiAlias(true);

		mShowcaseDrawable = resources.getDrawable(R.drawable.cling_bleached);
		mShowcaseDrawable.setColorFilter(showcaseColor, PorterDuff.Mode.MULTIPLY);
	}

	@Override
	public void drawShowcase(Canvas canvas, float x, float y, float scaleMultiplier, float radius) {
		Matrix mm = new Matrix();
		mm.postScale(scaleMultiplier, scaleMultiplier, x, y);
		canvas.setMatrix(mm);

		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
			canvas.drawCircle(x, y, radius, mEraser);
		}

		mShowcaseDrawable.setBounds(mShowcaseRect);
		mShowcaseDrawable.draw(canvas);

		canvas.setMatrix(new Matrix());
	}

	@Override
	public int getShowcaseWidth() {
		return mShowcaseDrawable.getIntrinsicWidth();
	}

	@Override
	public int getShowcaseHeight() {
		return mShowcaseDrawable.getIntrinsicHeight();
	}

	/**
	 * Creates a {@link android.graphics.Rect} which represents the area the showcase covers. Used
	 * to calculate where best to place the text
	 *
	 * @return true if voidedArea has changed, false otherwise.
	 */
	@Override
	public boolean calculateShowcaseRect(float x, float y) {

		if (mShowcaseRect == null) {
			mShowcaseRect = new Rect();
		}

		int cx = (int) x, cy = (int) y;
		int dw = getShowcaseWidth();
		int dh = getShowcaseHeight();

		if (mShowcaseRect.left == cx - dw / 2) {
			return false;
		}

		Log.d("ShowcaseView", "Recalculated");

		mShowcaseRect.left = cx - dw / 2;
		mShowcaseRect.top = cy - dh / 2;
		mShowcaseRect.right = cx + dw / 2;
		mShowcaseRect.bottom = cy + dh / 2;

		return true;

	}

	@Override
	public Rect getShowcaseRect() {
		return mShowcaseRect;
	}

}