/*******************************************************************************
 * Copyright (c) 2010 Oak Ridge National Laboratory.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 ******************************************************************************/
package org.csstudio.swt.xygraph.util;

import org.eclipse.draw2d.FigureUtilities;
import org.eclipse.draw2d.Graphics;
import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Drawable;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.graphics.Transform;
import org.eclipse.swt.widgets.Display;

/**Utility function for graphics operations.
 * @author Xihui Chen
 *
 */
public final class GraphicsUtil {

	/**Draw vertical text.
	 * @param graphics draw2D graphics.
	 * @param text text to be drawn.
	 * @param x the x coordinate of the text, which is the left upper corner.
	 * @param y the y coordinate of the text, which is the left upper corner.
	 */
	public static final void drawVerticalText(Graphics graphics, String text, int x, int y, boolean upToDown){
		try {
			graphics.pushState();
			graphics.translate(x, y);
			if(upToDown){
				graphics.rotate(90);
				graphics.drawText(text, 0, -FigureUtilities.getTextExtents(text, graphics.getFont()).height);
			}else{
				graphics.rotate(270);			
				graphics.drawText(text, -FigureUtilities.getTextWidth(text, graphics.getFont()), 0);
			}
			graphics.popState();
		} catch (Exception e) {//If rotate is not supported by the graphics.
			graphics.popState();
			final Dimension titleSize = FigureUtilities.getTextExtents(text, graphics.getFont());

			final int w = titleSize.height;
			final int h = titleSize.width +1;
			Image image = new Image(Display.getCurrent(),w, h);			
					try {
					    final GC gc = createGC(image);	
					    final Color titleColor = graphics.getForegroundColor();
					    RGB transparentRGB = new RGB(240, 240, 240);		
										
						gc.setBackground(XYGraphMediaFactory.getInstance().getColor(transparentRGB));
						gc.fillRectangle(image.getBounds());
						gc.setForeground(titleColor);
						gc.setFont(graphics.getFont());
						final Transform tr = new Transform(Display.getCurrent());
						if(!upToDown){
							tr.translate(0, h);
							tr.rotate(-90);
							setTransform(gc, tr);
						}else{
							tr.translate(w, 0);
							tr.rotate(90);
							setTransform(gc, tr);
						}
						gc.drawText(text, 0, 0);
						tr.dispose();
						gc.dispose();
						final ImageData imageData = image.getImageData();				
						image.dispose();
						imageData.transparentPixel = imageData.palette.getPixel(transparentRGB);
						image = new Image(Display.getCurrent(), imageData);				
								
						graphics.drawImage(image, x, y);
						
					} finally{
						image.dispose();		
					}
		}
	}
	
	
	/** Draw vertical text.
	 * @param graphics draw2D graphics.
	 * @param text text to be drawn.
	 * @param location the left upper corner coordinates of the text.
	 */
	public static final void drawVerticalText(Graphics graphics, String text, Point location, boolean upToDown){
		drawVerticalText(graphics, text, location.x, location.y, upToDown);
	}
	
	/**
	 * Used for single sourcing, returns null if called in RAP Context.
	 * @param image
	 * @return
	 */
	public static GC createGC(Drawable image) {
		try {
		    return GC.class.getConstructor(Drawable.class).newInstance(image);
		} catch (Exception ne) {
			return null;
		}
	}
	
	public static void setTransform(GC gc, Transform transform) {
		try {
			GC.class.getMethod("setTransform", Transform.class).invoke(gc, transform);
		} catch (Exception ne) {
			return;
		}
	}


	public static Cursor createCursor(Device device, ImageData imageData, int width, int height) {
		try {
			return Cursor.class.getConstructor(Device.class, ImageData.class, int.class, int.class).newInstance(device, imageData, width, height);
		} catch (Exception ne) {
			return null;
		}
	}
}