/*
* Copyright 2014 Daniel Kurka
*
* 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.googlecode.mgwt.image.client;
import com.google.gwt.canvas.client.Canvas;
import com.google.gwt.canvas.dom.client.CanvasPixelArray;
import com.google.gwt.canvas.dom.client.Context2d;
import com.google.gwt.canvas.dom.client.ImageData;
import com.google.gwt.dom.client.ImageElement;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.safehtml.shared.SafeUri;
public class ImageConverter {
static class ConversionContext {
Canvas canvas;
Context2d context;
CanvasPixelArray canvasPixelArray;
}
private class ConvertedImageResource implements ImageResource {
private final String dataUrl;
private final int width;
private final int height;
public ConvertedImageResource(String dataUrl, int width, int height) {
this.dataUrl = dataUrl;
this.width = width;
this.height = height;
}
@Override
public String getName() {
return "";
}
@Override
public int getHeight() {
return height;
}
@Override
public int getLeft() {
return 0;
}
@Override
public SafeUri getSafeUri() {
return new SafeUri() {
@Override
public String asString() {
return dataUrl;
}
@Override
public int hashCode() {
return dataUrl.hashCode();
}
@Override
public boolean equals(Object obj) {
return dataUrl.equals(obj);
}
};
}
@Override
public int getTop() {
return 0;
}
@Override
public String getURL() {
return dataUrl;
}
@Override
public int getWidth() {
return width;
}
@Override
public boolean isAnimated() {
return false;
}
}
public ImageResource convert(ImageResource resource, String color) {
if (color == null) {
throw new IllegalArgumentException();
}
if (!color.startsWith("#")) {
throw new IllegalArgumentException();
}
int hexColor = Integer.parseInt(color.substring(1), 16);
int red = hexColor >> 16 & 0xFF;
int green = hexColor >> 8 & 0xFF;
int blue = hexColor & 0xFF;
int height = resource.getHeight();
int width = resource.getWidth();
ImageElement imageElement = loadImage(resource.getSafeUri().asString(),
width, height);
Canvas canvas = Canvas.createIfSupported();
canvas.getElement().setPropertyInt("height", height);
canvas.getElement().setPropertyInt("width", width);
Context2d context = canvas.getContext2d();
context.drawImage(imageElement, 0, 0);
ImageData imageData = context.getImageData(0, 0, width,
height);
CanvasPixelArray canvasPixelArray = imageData.getData();
for (int i = 0; i < canvasPixelArray.getLength(); i += 4) {
canvasPixelArray.set(i, red);
canvasPixelArray.set(i + 1, green);
canvasPixelArray.set(i + 2, blue);
canvasPixelArray.set(i + 3,
canvasPixelArray.get(i + 3));
}
context.putImageData(imageData, 0, 0);
return new ConvertedImageResource(
canvas.toDataUrl("image/png"), resource.getWidth(),
resource.getHeight());
}
protected native ImageElement loadImage(String dataUrl, int width, int height) /*-{
var img = new Image();
img.width = width;
img.height = height;
img.src = dataUrl;
return img;
}-*/;
}