RoundedBitmapDisplayer.java

/*******************************************************************************
 * Copyright 2011-2013 Sergey Tarasevich
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package com.nostra13.universalimageloader.core.display;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.widget.ImageView;

import com.nostra13.universalimageloader.utils.L;

/**
 * Displays bitmap with rounded corners. <br />
 * <b>NOTE:</b> It's strongly recommended your {@link ImageView} has defined width (<i>layout_width</i>) and height
 * (<i>layout_height</i>) .<br />
 * <b>NOTE:</b> New {@link Bitmap} object is created for displaying. So this class needs more memory and can cause
 * {@link OutOfMemoryError}.
 * 
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.5.6
 */
public class RoundedBitmapDisplayer implements BitmapDisplayer {

	private final int roundPixels;

	public RoundedBitmapDisplayer(int roundPixels) {
		this.roundPixels = roundPixels;
	}

	@Override
	public Bitmap display(Bitmap bitmap, ImageView imageView) {
		Bitmap roundedBitmap = roundCorners(bitmap, imageView, roundPixels);
		imageView.setImageBitmap(roundedBitmap);
		return roundedBitmap;
	}

	/**
	 * Process incoming {@linkplain Bitmap} to make rounded corners according to target {@link ImageView}.<br />
	 * This method <b>doesn't display</b> result bitmap in {@link ImageView}
	 * 
	 * @param bitmap Incoming Bitmap to process
	 * @param imageView Target {@link ImageView} to display bitmap in
	 * @param roundPixels
	 * @return Result bitmap with rounded corners
	 */
	public static Bitmap roundCorners(Bitmap bitmap, ImageView imageView, int roundPixels) {
		Bitmap roundBitmap;

		int bw = bitmap.getWidth();
		int bh = bitmap.getHeight();
		int vw = imageView.getWidth();
		int vh = imageView.getHeight();
		if (vw <= 0) vw = bw;
		if (vh <= 0) vh = bh;

		int width, height;
		Rect srcRect;
		Rect destRect;
		switch (imageView.getScaleType()) {
			case CENTER_INSIDE:
				float vRation = (float) vw / vh;
				float bRation = (float) bw / bh;
				int destWidth;
				int destHeight;
				if (vRation > bRation) {
					destHeight = Math.min(vh, bh);
					destWidth = (int) (bw / ((float) bh / destHeight));
				} else {
					destWidth = Math.min(vw, bw);
					destHeight = (int) (bh / ((float) bw / destWidth));
				}
				int x = (vw - destWidth) / 2;
				int y = (vh - destHeight) / 2;
				srcRect = new Rect(0, 0, bw, bh);
				destRect = new Rect(x, y, x + destWidth, y + destHeight);
				width = vw;
				height = vh;
				break;
			case FIT_CENTER:
			case FIT_START:
			case FIT_END:
			default:
				vRation = (float) vw / vh;
				bRation = (float) bw / bh;
				if (vRation > bRation) {
					width = (int) (bw / ((float) bh / vh));
					height = vh;
				} else {
					width = vw;
					height = (int) (bh / ((float) bw / vw));
				}
				srcRect = new Rect(0, 0, bw, bh);
				destRect = new Rect(0, 0, width, height);
				break;
			case CENTER_CROP:
				vRation = (float) vw / vh;
				bRation = (float) bw / bh;
				int srcWidth;
				int srcHeight;
				if (vRation > bRation) {
					srcWidth = bw;
					srcHeight = (int) (vh * ((float) bw / vw));
					x = 0;
					y = (bh - srcHeight) / 2;
				} else {
					srcWidth = (int) (vw * ((float) bh / vh));
					srcHeight = bh;
					x = (bw - srcWidth) / 2;
					y = 0;
				}
				width = Math.min(vw, bw);
				height = Math.min(vh, bh);
				srcRect = new Rect(x, y, x + srcWidth, y + srcHeight);
				destRect = new Rect(0, 0, width, height);
				break;
			case FIT_XY:
				width = vw;
				height = vh;
				srcRect = new Rect(0, 0, bw, bh);
				destRect = new Rect(0, 0, width, height);
				break;
			case CENTER:
			case MATRIX:
				width = Math.min(vw, bw);
				height = Math.min(vh, bh);
				x = (bw - width) / 2;
				y = (bh - height) / 2;
				srcRect = new Rect(x, y, x + width, y + height);
				destRect = new Rect(0, 0, width, height);
				break;
		}

		try {
			roundBitmap = getRoundedCornerBitmap(bitmap, roundPixels, srcRect, destRect, width, height);
		} catch (OutOfMemoryError e) {
			L.e(e, "Can't create bitmap with rounded corners. Not enough memory.");
			roundBitmap = bitmap;
		}

		return roundBitmap;
	}

	private static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int roundPixels, Rect srcRect, Rect destRect, int width, int height) {
		Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
		Canvas canvas = new Canvas(output);

		final Paint paint = new Paint();
		final RectF destRectF = new RectF(destRect);

		paint.setAntiAlias(true);
		canvas.drawARGB(0, 0, 0, 0);
		paint.setColor(0xFF000000);
		canvas.drawRoundRect(destRectF, roundPixels, roundPixels, paint);

		paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
		canvas.drawBitmap(bitmap, srcRect, destRectF, paint);

		return output;
	}
}