package it.freedomotic.gwtclient.client.utils;
import java.util.HashMap;
import com.google.gwt.canvas.client.Canvas;
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.event.dom.client.ErrorEvent;
import com.google.gwt.event.dom.client.ErrorHandler;
import com.google.gwt.event.dom.client.LoadEvent;
import com.google.gwt.event.dom.client.LoadHandler;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.RootPanel;
public class ImageUtils {
public static HashMap<String,Image> CachedImages = new HashMap<String,Image>();
public static HashMap<String,String> queuedImages = new HashMap<String,String>();
//TODO: move to a get/set.
//used to know if the web server must be refreshed
public static boolean newData = true;
// This is important to use a handler!
public static void loadImage(final String name) {
//doGet(name);
final Image img = new Image(name);
img.setVisible(false);
RootPanel.get().add(img);
img.addLoadHandler(new LoadHandler() {
public void onLoad(LoadEvent event) {
//queuedImages.remove(name);
CachedImages.put(name, img);
newData = true;
}
});
img.addErrorHandler(new ErrorHandler() {
@Override
public void onError(ErrorEvent event) {
// TODO Auto-generated method stub
// Window.alert("The image: "+ name+ " could not be loaded. Trying again");
loadImage(name);
}
});
}
public static void queueImage(String name)
{
if (!queuedImages.containsKey(name))
{
queuedImages.put(name, name);
loadImage(name);
}
}
public static ImageData scaleImage(Image image, double scaleToRatio) {
return scaleImage(image, scaleToRatio,scaleToRatio);
}
public static ImageData scaleImage(Image image, double scaleToRatioh,double scaleToRatiow) {
Canvas canvasTmp = Canvas.createIfSupported();
Context2d context = canvasTmp.getContext2d();
double ch = (image.getHeight() * scaleToRatioh);// + 100;
double cw = (image.getWidth() * scaleToRatiow); //+ 100;
canvasTmp.setCoordinateSpaceHeight((int) ch);
canvasTmp.setCoordinateSpaceWidth((int) cw);
ImageElement imageElement = ImageElement.as(image.getElement());
// s = source
// d = destination
double sx = 0;
double sy = 0;
double sw = imageElement.getWidth();
double sh = imageElement.getHeight();
double dx = 0;
double dy = 0;
double dw = imageElement.getWidth();
double dh = imageElement.getHeight();
// tell it to scale image
context.scale(scaleToRatioh, scaleToRatiow);
// draw image to canvas
context.drawImage(imageElement, sx, sy, sw, sh, dx, dy, dw, dh);
// get image data
double w = dw * scaleToRatioh;
double h = dh * scaleToRatiow;
ImageData imageData = context.getImageData(0, 0, w, h);
return imageData;
}
public static ImageData fillImage(Image image, double cw,double ch) {
Canvas canvasTmp = Canvas.createIfSupported();
Context2d context = canvasTmp.getContext2d();
//double ch = (image.getHeight() * scaleToRatioh) + 100;
//double cw = (image.getWidth() * scaleToRatiow) + 100;
canvasTmp.setCoordinateSpaceHeight((int) ch);
canvasTmp.setCoordinateSpaceWidth((int) cw);
ImageElement imageElement = ImageElement.as(image.getElement());
// s = source
// d = destination
double sx = 0;
double sy = 0;
double sw = imageElement.getWidth();
double sh = imageElement.getHeight();
double dx = 0;
double dy = 0;
double dw = imageElement.getWidth();
double dh = imageElement.getHeight();
// tell it to scale image
//context.scale(scaleToRatioh, scaleToRatiow);
// draw image to canvas
context.drawImage(imageElement, sx, sy, sw, sh, dx, dy, cw, ch);
// get image data
//double w = dw * scaleToRatioh;
//double h = dh * scaleToRatiow;
ImageData imageData = context.getImageData(0, 0, cw, ch);
return imageData;
}
}