CircularDrawable.java

package dev.dworks.libs.actionbarplus.widget;

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.ComposeShader;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff;
import android.graphics.RadialGradient;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;

public class CircularDrawable extends Drawable {
	private static final boolean USE_VIGNETTE = true;

	private final float mCornerRadius;
	private final RectF mRect = new RectF();
	private final BitmapShader mBitmapShader;
	private final Paint mPaint;
	private final int mMargin;

	CircularDrawable(Bitmap bitmap, float cornerRadius, int margin) {
		mCornerRadius = cornerRadius;

		mBitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);

		mPaint = new Paint();
		mPaint.setAntiAlias(true);
		mPaint.setShader(mBitmapShader);

		mMargin = margin;
	}

	@Override
	protected void onBoundsChange(Rect bounds) {
		super.onBoundsChange(bounds);
		mRect.set(mMargin, mMargin, bounds.width() - mMargin, bounds.height() - mMargin);

		if (USE_VIGNETTE) {
			RadialGradient vignette = new RadialGradient(mRect.centerX(),
					mRect.centerY() * 1.0f / 0.7f,
					mRect.centerX() * 1.3f,
					new int[] { 0, 0, 0x7f000000 },
					new float[] { 0.0f, 0.7f, 1.0f },
					Shader.TileMode.CLAMP);

			Matrix oval = new Matrix();
			oval.setScale(1.0f, 0.7f);
			vignette.setLocalMatrix(oval);

			mPaint.setShader(new ComposeShader(mBitmapShader, vignette, PorterDuff.Mode.SRC_OVER));
		}
	}

	@Override
	public void draw(Canvas canvas) {
		canvas.drawCircle(mCornerRadius, mCornerRadius, mCornerRadius, mPaint);
	}

	@Override
	public int getOpacity() {
		return PixelFormat.TRANSLUCENT;
	}

	@Override
	public void setAlpha(int alpha) {
		mPaint.setAlpha(alpha);
	}

	@Override
	public void setColorFilter(ColorFilter cf) {
		mPaint.setColorFilter(cf);
	}
}