package ca.vektor.swttests;

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.layout.*;

public class Bug87577 {

	public boolean rescale = true;
	public float scale = 2.0f;
	public int numTiles = 40;
	
	public static void main (String [] args) {
		
		/*
		if (args.length < 1) {
			System.err.println("Usage: java gov.nasa.jpl.maestro.core.common.view.snippetsImageCanvasSnippet <imageFilename>");
			return;
		}*/
		
		Bug87577 snippet = new Bug87577("c:\\testimage.jpg");
		//Bug87577 snippet = new Bug87577("/tmp/testimage.jpg");
	}

	public Bug87577(String imageFilename) {
		Display display = new Display ();
		Shell shell = new Shell (display);
		shell.setLayout(new FillLayout());
	    
		ScrolledComposite scrolledComposite = 
			new ScrolledComposite(shell, SWT.H_SCROLL | SWT.V_SCROLL);
		Image imageFromFile = new Image(display, imageFilename);
		MyImageCanvas canvas = 
			new Bug87577.MyImageCanvas(imageFromFile, scrolledComposite, /*SWT.NO_BACKGROUND*/SWT.NONE);
	    scrolledComposite.setContent(canvas);
	    scrolledComposite.setExpandHorizontal(true);
	    scrolledComposite.setExpandVertical(true);
	    scrolledComposite.setMinWidth((int)((rescale ? scale : 1.0f) * imageFromFile.getBounds().width * numTiles));
	    scrolledComposite.setMinHeight((int)((rescale ? scale : 1.0f) * imageFromFile.getBounds().height * numTiles));
	    
	    final ScrollBar hBar = scrolledComposite.getHorizontalBar();
	    final ScrollBar vBar = scrolledComposite.getVerticalBar();
	    hBar.setPageIncrement(1024);
	    vBar.setPageIncrement(1024);
	    shell.setSize(1024, 768);
	    shell.open ();

	    while (!shell.isDisposed ()) {
	    	if (!display.readAndDispatch ()) display.sleep ();
		}
		display.dispose ();
	}

	public class MyImageCanvas extends Canvas {

		Image image;
		
		/**
		 * @param parent
		 * @param style
		 */
		public MyImageCanvas(Image image, Composite parent, int style) {
			super(parent, style);
			this.image = image;
			
			addPaintListener(new PaintListener() {
				public void paintControl(PaintEvent e) {
					MyImageCanvas.this.paintCanvas(e);
				}
			});
			
			addControlListener(new ControlListener() {
				public void controlMoved(ControlEvent e) {
					redraw();
				}

				public void controlResized(ControlEvent e) {
					redraw();
				}
			});
		}
		
		public void paintCanvas(PaintEvent e) {
			GC gc = e.gc;
			Rectangle clipping = gc.getClipping();
			int width = image.getBounds().width, height = image.getBounds().height;
			for (int i = 0; i < numTiles; i++) {
				for (int j = 0; j < numTiles; j++) {
					Rectangle cur = new Rectangle((int)(i * width * scale), (int)(j*height*scale), (int)(width*scale), (int)(height*scale));
					if(!cur.intersects(clipping)) continue;
					if (rescale) {
						long before = System.currentTimeMillis();
						gc.drawImage(image, 0, 0, width, height, 
								    (int)(i*width*scale), (int)(j*height*scale),
								    (int)(width*scale), (int)(height*scale));
						System.out.println("ms to paint an image: "+(System.currentTimeMillis()-before));
					}
					else {
						long before = System.currentTimeMillis();
						gc.drawImage(image, i*width, j*height);
						System.out.println("ms to paint an image: "+(System.currentTimeMillis()-before));
					}
				}
			}
		}

	}
}