/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * 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
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.graphics;

import org.eclipse.swt.internal.wpf.*;
import org.eclipse.swt.*;

/**
 * Class <code>GC</code> is where all of the drawing capabilities that are 
 * supported by SWT are located. Instances are used to draw on either an 
 * <code>Image</code>, a <code>Control</code>, or directly on a <code>Display</code>.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>LEFT_TO_RIGHT, RIGHT_TO_LEFT</dd>
 * </dl>
 * 
 * <p>
 * The SWT drawing coordinate system is the two-dimensional space with the origin
 * (0,0) at the top left corner of the drawing area and with (x,y) values increasing
 * to the right and downward respectively.
 * </p>
 * 
 * <p>
 * The result of drawing on an image that was created with an indexed
 * palette using a color that is not in the palette is platform specific.
 * Some platforms will match to the nearest color while other will draw
 * the color itself. This happens because the allocated image might use
 * a direct palette on platforms that do not support indexed palette.
 * </p>
 * 
 * <p>
 * Application code must explicitly invoke the <code>GC.dispose()</code> 
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required. This is <em>particularly</em>
 * important on Windows95 and Windows98 where the operating system has a limited
 * number of device contexts available.
 * </p>
 * 
 * <p>
 * Note: Only one of LEFT_TO_RIGHT and RIGHT_TO_LEFT may be specified.
 * </p>
 *
 * @see org.eclipse.swt.events.PaintEvent
 * @see <a href="http://www.eclipse.org/swt/snippets/#gc">GC snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Examples: GraphicsExample, PaintExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */

public final class GC extends Resource {
	
	/**
	 * the handle to the OS device context
	 * (Warning: This field is platform dependent)
	 * <p>
	 * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT
	 * public API. It is marked public only so that it can be shared
	 * within the packages provided by SWT. It is not available on all
	 * platforms and should never be accessed from application code.
	 * </p>
	 */
	public int handle;

	Drawable drawable;
	GCData data;

	static final int FOREGROUND = 1 << 0;
	static final int BACKGROUND = 1 << 1;
	static final int FONT = 1 << 2;
	static final int LINE_STYLE = 1 << 3;
	static final int LINE_WIDTH = 1 << 4;
	static final int LINE_CAP = 1 << 5;
	static final int LINE_JOIN = 1 << 6;
	static final int LINE_MITERLIMIT = 1 << 7;
	static final int ALPHA = 1 << 8;
	static final int CLIPPING = 1 << 9;
	static final int TRANSFORM = 1 << 10;

	static final int DRAW = FOREGROUND | LINE_STYLE | LINE_WIDTH | LINE_CAP | LINE_JOIN | ALPHA | CLIPPING | TRANSFORM;
	static final int FILL = BACKGROUND | ALPHA | CLIPPING | TRANSFORM;
	static final int IMAGE = ALPHA | CLIPPING | TRANSFORM;

	static final double[] LINE_DOT_ZERO = new double[]{3, 3};
	static final double[] LINE_DASH_ZERO = new double[]{18, 6};
	static final double[] LINE_DASHDOT_ZERO = new double[]{9, 6, 3, 6};
	static final double[] LINE_DASHDOTDOT_ZERO = new double[]{9, 3, 3, 3, 3, 3};

/**
 * Prevents uninitialized instances from being created outside the package.
 */
GC() {
}

/**	 
 * Constructs a new instance of this class which has been
 * configured to draw on the specified drawable. Sets the
 * foreground color, background color and font in the GC
 * to match those in the drawable.
 * <p>
 * You must dispose the graphics context when it is no longer required. 
 * </p>
 * @param drawable the drawable to draw on
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the drawable is null</li>
 *    <li>ERROR_NULL_ARGUMENT - if there is no current device</li>
 *    <li>ERROR_INVALID_ARGUMENT
 *          - if the drawable is an image that is not a bitmap or an icon
 *          - if the drawable is an image or printer that is already selected
 *            into another graphics context</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for GC creation</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS if not called from the thread that created the drawable</li>
 * </ul>
 */
public GC(Drawable drawable) {
	this(drawable, SWT.NONE);
}

/**	 
 * Constructs a new instance of this class which has been
 * configured to draw on the specified drawable. Sets the
 * foreground color, background color and font in the GC
 * to match those in the drawable.
 * <p>
 * You must dispose the graphics context when it is no longer required. 
 * </p>
 * 
 * @param drawable the drawable to draw on
 * @param style the style of GC to construct
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the drawable is null</li>
 *    <li>ERROR_NULL_ARGUMENT - if there is no current device</li>
 *    <li>ERROR_INVALID_ARGUMENT
 *          - if the drawable is an image that is not a bitmap or an icon
 *          - if the drawable is an image or printer that is already selected
 *            into another graphics context</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for GC creation</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS if not called from the thread that created the drawable</li>
 * </ul>
 *  
 * @since 2.1.2
 */
public GC(Drawable drawable, int style) {
	if (drawable == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	GCData data = new GCData ();
	data.style = checkStyle(style);
	int hDC = drawable.internal_new_GC(data);
	Device device = data.device;
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	this.device = data.device = device;
	init (drawable, data, hDC);
	init();
}

static int checkStyle(int style) {
	if ((style & SWT.LEFT_TO_RIGHT) != 0) style &= ~SWT.RIGHT_TO_LEFT;
	return style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
}

void checkGC(int mask) {
	int state = data.state;
	if ((state & mask) == mask) return;
	state = (state ^ mask) & mask;
	data.state |= mask;
	if ((state & (FOREGROUND | LINE_WIDTH | LINE_STYLE | LINE_JOIN | LINE_CAP | LINE_MITERLIMIT)) != 0) {
		int pen = data.pen;
		if (pen != 0) OS.GCHandle_Free(pen); 
		pen = data.pen = OS.gcnew_Pen();
		int brush;
		Pattern pattern = data.foregroundPattern;
		if (pattern != null) {
			brush = pattern.handle;
		} else {
			int foreground = data.foreground;
			brush = OS.gcnew_SolidColorBrush(foreground);
			if (brush == 0) SWT.error(SWT.ERROR_NO_HANDLES);
		}
		OS.Pen_Brush(pen, brush);
		if (pattern == null) OS.GCHandle_Free(brush);
		float width = data.lineWidth;
		OS.Pen_Thickness(pen, width == 0 ? 1 : width);
		double[] dashes = null;
		int dashStyle = 0; 
		switch (data.lineStyle) {
			case SWT.LINE_SOLID: dashStyle = OS.DashStyles_Solid(); break;
			case SWT.LINE_DOT: if (width == 0) dashes = LINE_DOT_ZERO; else dashStyle = OS.DashStyles_Dot(); break;
			case SWT.LINE_DASH: if (width == 0) dashes = LINE_DASH_ZERO; else dashStyle = OS.DashStyles_Dash(); break;
			case SWT.LINE_DASHDOT: if (width == 0) dashes = LINE_DASHDOT_ZERO; else dashStyle = OS.DashStyles_DashDot(); break;
			case SWT.LINE_DASHDOTDOT: if (width == 0) dashes = LINE_DASHDOTDOT_ZERO; else dashStyle = OS.DashStyles_DashDotDot(); break;
			case SWT.LINE_CUSTOM: {
				if (data.lineDashes != null) {
					dashes = new double[data.lineDashes.length * 2];
					for (int i = 0; i < data.lineDashes.length; i++) {
						double dash = (double)data.lineDashes[i] / Math.max (1, width);
						dashes[i] = dash;
						dashes[i + data.lineDashes.length] = dash;
					}
				} else {
					dashStyle = OS.DashStyles_Solid();
				}
			}
		}
		if (dashes != null) {
			int list = OS.gcnew_DoubleCollection(dashes.length);
			for (int i = 0; i < dashes.length; i++) {
				OS.DoubleCollection_Add(list, dashes[i]);
			}
			dashStyle = OS.gcnew_DashStyle(list, data.lineDashesOffset);
			OS.GCHandle_Free(list);
		}
		OS.Pen_DashStyle(pen, dashStyle);
		OS.GCHandle_Free(dashStyle);
		int joinStyle = 0;
		switch (data.lineJoin) {
			case SWT.JOIN_MITER: joinStyle = OS.PenLineJoin_Miter; break;
			case SWT.JOIN_BEVEL: joinStyle = OS.PenLineJoin_Bevel; break;
			case SWT.JOIN_ROUND: joinStyle = OS.PenLineJoin_Round; break;
		}
		OS.Pen_LineJoin(pen, joinStyle);
		int capStyle = OS.PenLineCap_Flat;
		switch (data.lineCap) {
			case SWT.CAP_FLAT: capStyle = OS.PenLineCap_Flat; break;
			case SWT.CAP_ROUND: capStyle = OS.PenLineCap_Round; break;
			case SWT.CAP_SQUARE: capStyle = OS.PenLineCap_Square; break;
		}
		OS.Pen_DashCap(pen, capStyle);
		OS.Pen_EndLineCap(pen, capStyle);
		OS.Pen_StartLineCap(pen, capStyle);
		OS.Pen_MiterLimit(pen, data.lineMiterLimit);
	}
	if ((state & BACKGROUND) != 0) {
		if (data.brush != 0) OS.GCHandle_Free(data.brush);
		data.brush = 0;
		Pattern pattern = data.backgroundPattern;
		if (pattern != null) {
			data.currentBrush = pattern.handle;
		} else {
			int background = data.background;
			int brush = OS.gcnew_SolidColorBrush(background);
			if (brush == 0) SWT.error(SWT.ERROR_NO_HANDLES);
			data.currentBrush = data.brush = brush;
		}
	}
	if ((state & (ALPHA | CLIPPING | TRANSFORM)) != 0) {
		for (int i = 0; i < data.pushCount; i++) OS.DrawingContext_Pop(handle);
		data.pushCount = 0;
		if (data.alpha != 0xFF) {
			OS.DrawingContext_PushOpacity(handle, (data.alpha & 0xFF) / (double)0xFF);
			data.pushCount++;
		}
		if (data.clip != 0) {
			OS.DrawingContext_PushClip(handle, data.clip);
			data.pushCount++;
		}
		if (data.transform != 0) {
			OS.DrawingContext_PushTransform(handle, data.transform);
			data.pushCount++;
		}
	}

}

/**
 * Copies a rectangular area of the receiver at the specified
 * position into the image, which must be of type <code>SWT.BITMAP</code>.
 *
 * @param image the image to copy into
 * @param x the x coordinate in the receiver of the area to be copied
 * @param y the y coordinate in the receiver of the area to be copied
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the image is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image is not a bitmap or has been disposed</li> 
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void copyArea(Image image, int x, int y) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (image == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (image.type != SWT.BITMAP || image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);

	//TODO - implement copyArea
}

/**
 * Copies a rectangular area of the receiver at the source
 * position onto the receiver at the destination position.
 *
 * @param srcX the x coordinate in the receiver of the area to be copied
 * @param srcY the y coordinate in the receiver of the area to be copied
 * @param width the width of the area to copy
 * @param height the height of the area to copy
 * @param destX the x coordinate in the receiver of the area to copy to
 * @param destY the y coordinate in the receiver of the area to copy to
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void copyArea(int srcX, int srcY, int width, int height, int destX, int destY) {
	copyArea(srcX, srcY, width, height, destX, destY, true);
}

/**
 * Copies a rectangular area of the receiver at the source
 * position onto the receiver at the destination position.
 *
 * @param srcX the x coordinate in the receiver of the area to be copied
 * @param srcY the y coordinate in the receiver of the area to be copied
 * @param width the width of the area to copy
 * @param height the height of the area to copy
 * @param destX the x coordinate in the receiver of the area to copy to
 * @param destY the y coordinate in the receiver of the area to copy to
 * @param paint if <code>true</code> paint events will be generated for old and obscured areas
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public void copyArea(int srcX, int srcY, int width, int height, int destX, int destY, boolean paint) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);

	//TODO - implement copyArea

//	/*
//	* Feature in WinCE.  The function WindowFromDC is not part of the
//	* WinCE SDK.  The fix is to remember the HWND.
//	*/
//	int hwnd = data.hwnd;
//	if (hwnd == 0) {
//		OS.BitBlt(handle, destX, destY, width, height, handle, srcX, srcY, OS.SRCCOPY);
//	} else {
//		RECT lprcClip = null;
//		int hrgn = OS.CreateRectRgn(0, 0, 0, 0);
//		if (OS.GetClipRgn(handle, hrgn) == 1) {
//			lprcClip = new RECT();
//			OS.GetRgnBox(hrgn, lprcClip);
//		}
//		OS.DeleteObject(hrgn);
//		RECT lprcScroll = new RECT();
//		OS.SetRect(lprcScroll, srcX, srcY, srcX + width, srcY + height);
//		int flags = paint ? OS.SW_INVALIDATE | OS.SW_ERASE : 0;
//		int res = OS.ScrollWindowEx(hwnd, destX - srcX, destY - srcY, lprcScroll, lprcClip, 0, null, flags); 
//
//		/*
//		* Feature in WinCE.  ScrollWindowEx does not accept combined
//		* vertical and horizontal scrolling.  The fix is to do a
//		* BitBlt and invalidate the appropriate source area.
//		*/
//		if (res == 0 && OS.IsWinCE) {
//			OS.BitBlt(handle, destX, destY, width, height, handle, srcX, srcY, OS.SRCCOPY);
//			if (paint) {
//				int deltaX = destX - srcX, deltaY = destY - srcY;
//				boolean disjoint = (destX + width < srcX) || (srcX + width < destX) || (destY + height < srcY) || (srcY + height < destY);
//				if (disjoint) {
//					OS.InvalidateRect(hwnd, lprcScroll, true);
//				} else {
//					if (deltaX != 0) {
//						int newX = destX - deltaX;
//						if (deltaX < 0) newX = destX + width;
//						OS.SetRect(lprcScroll, newX, srcY, newX + Math.abs(deltaX), srcY + height);
//						OS.InvalidateRect(hwnd, lprcScroll, true);
//					}
//					if (deltaY != 0) {
//						int newY = destY - deltaY;
//						if (deltaY < 0) newY = destY + height;
//						OS.SetRect(lprcScroll, srcX, newY, srcX + width, newY + Math.abs(deltaY));
//						OS.InvalidateRect(hwnd, lprcScroll, true);
//					}
//				}
//			}
//		}
//	}
}

void destroy() {
	int brush = data.brush;
	if (brush != 0) OS.GCHandle_Free(brush);
	data.brush = 0;
	int pen = data.pen;
	if (pen != 0) OS.GCHandle_Free(pen);
	data.pen = 0;
	int clip = data.clip;
	if (clip != 0) OS.GCHandle_Free(clip);
	data.clip = 0;
	int transform = data.transform;
	if (transform != 0) OS.GCHandle_Free(transform);
	data.transform = 0;

	Image image = data.image;
	if (image != null) image.memGC = null;
	
	if (drawable != null) drawable.internal_dispose_GC(handle, data);
	drawable = null;
	handle = 0;
	data.image = null;
	data = null;
}

/**
 * Draws the outline of a circular or elliptical arc 
 * within the specified rectangular area.
 * <p>
 * The resulting arc begins at <code>startAngle</code> and extends  
 * for <code>arcAngle</code> degrees, using the current color.
 * Angles are interpreted such that 0 degrees is at the 3 o'clock
 * position. A positive value indicates a counter-clockwise rotation
 * while a negative value indicates a clockwise rotation.
 * </p><p>
 * The center of the arc is the center of the rectangle whose origin 
 * is (<code>x</code>, <code>y</code>) and whose size is specified by the 
 * <code>width</code> and <code>height</code> arguments. 
 * </p><p>
 * The resulting arc covers an area <code>width + 1</code> pixels wide
 * by <code>height + 1</code> pixels tall.
 * </p>
 *
 * @param x the x coordinate of the upper-left corner of the arc to be drawn
 * @param y the y coordinate of the upper-left corner of the arc to be drawn
 * @param width the width of the arc to be drawn
 * @param height the height of the arc to be drawn
 * @param startAngle the beginning angle
 * @param arcAngle the angular extent of the arc, relative to the start angle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawArc (int x, int y, int width, int height, int startAngle, int arcAngle) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(DRAW);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	if (width == 0 || height == 0 || arcAngle == 0) return;
	double offset = 0;
	if (data.lineWidth == 0 || (data.lineWidth % 2) == 1) offset = 0.5;
	if (arcAngle >= 360 || arcAngle <= -360) {
		int center = OS.gcnew_Point(x + offset + width / 2f, y + offset + height / 2f);
		OS.DrawingContext_DrawEllipse(handle, 0, data.pen, center, width / 2f, height / 2f);
		OS.GCHandle_Free(center);
		return;
	}
	boolean isNegative = arcAngle < 0;
	boolean isLargeAngle = arcAngle > 180 || arcAngle < -180;
	arcAngle = arcAngle + startAngle;
	if (isNegative) {
		// swap angles
	   	int tmp = startAngle;
		startAngle = arcAngle;
		arcAngle = tmp;
	}
	double x1 = Math.cos(startAngle * Math.PI / 180) * width/2.0 + x + offset + width/2.0;
	double y1 = -1 * Math.sin(startAngle * Math.PI / 180) * height/2.0 + y + offset + height/2.0;
	double x2 = Math.cos(arcAngle * Math.PI / 180) * width/2.0 + x + offset + width/2.0;
	double y2 = -1 * Math.sin(arcAngle * Math.PI / 180) * height/2.0 + y + offset + height/2.0; 
	int startPoint = OS.gcnew_Point(x1, y1);
	int endPoint = OS.gcnew_Point(x2, y2);
	int size = OS.gcnew_Size(width / 2.0, height / 2.0);
	int arc = OS.gcnew_ArcSegment(endPoint, size, 0, isLargeAngle, OS.SweepDirection_Clockwise, true);
	int figure = OS.gcnew_PathFigure();
	OS.PathFigure_StartPoint(figure, startPoint);
	int segments = OS.PathFigure_Segments(figure);
	OS.PathSegmentCollection_Add(segments, arc);
	int path = OS.gcnew_PathGeometry();
	int figures = OS.PathGeometry_Figures(path);
	OS.PathFigureCollection_Add(figures, figure);
	OS.DrawingContext_DrawGeometry(handle, 0, data.pen, path);
	OS.GCHandle_Free(figures);
	OS.GCHandle_Free(path);
	OS.GCHandle_Free(segments);
	OS.GCHandle_Free(figure);
	OS.GCHandle_Free(arc);
	OS.GCHandle_Free(size);
	OS.GCHandle_Free(endPoint);
	OS.GCHandle_Free(startPoint);
}

/** 
 * Draws a rectangle, based on the specified arguments, which has
 * the appearance of the platform's <em>focus rectangle</em> if the
 * platform supports such a notion, and otherwise draws a simple
 * rectangle in the receiver's foreground color.
 *
 * @param x the x coordinate of the rectangle
 * @param y the y coordinate of the rectangle
 * @param width the width of the rectangle
 * @param height the height of the rectangle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRectangle(int, int, int, int)
 */	 
public void drawFocus (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	//TODO - implement drawFocus
}

/**
 * Draws the given image in the receiver at the specified
 * coordinates.
 *
 * @param image the image to draw
 * @param x the x coordinate of where to draw
 * @param y the y coordinate of where to draw
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the image is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the given coordinates are outside the bounds of the image</li>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if no handles are available to perform the operation</li>
 * </ul>
 */
public void drawImage(Image image, int x, int y) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (image == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	drawImage(image, 0, 0, -1, -1, x, y, -1, -1, true);
}

/**
 * Copies a rectangular area from the source image into a (potentially
 * different sized) rectangular area in the receiver. If the source
 * and destination areas are of differing sizes, then the source
 * area will be stretched or shrunk to fit the destination area
 * as it is copied. The copy fails if any part of the source rectangle
 * lies outside the bounds of the source image, or if any of the width
 * or height arguments are negative.
 *
 * @param image the source image
 * @param srcX the x coordinate in the source image to copy from
 * @param srcY the y coordinate in the source image to copy from
 * @param srcWidth the width in pixels to copy from the source
 * @param srcHeight the height in pixels to copy from the source
 * @param destX the x coordinate in the destination to copy to
 * @param destY the y coordinate in the destination to copy to
 * @param destWidth the width in pixels of the destination rectangle
 * @param destHeight the height in pixels of the destination rectangle
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the image is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 *    <li>ERROR_INVALID_ARGUMENT - if any of the width or height arguments are negative.
 *    <li>ERROR_INVALID_ARGUMENT - if the source rectangle is not contained within the bounds of the source image</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if no handles are available to perform the operation</li>
 * </ul>
 */
public void drawImage(Image image, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (srcWidth == 0 || srcHeight == 0 || destWidth == 0 || destHeight == 0) return;
	if (srcX < 0 || srcY < 0 || srcWidth < 0 || srcHeight < 0 || destWidth < 0 || destHeight < 0) {
		SWT.error (SWT.ERROR_INVALID_ARGUMENT);
	}
	if (image == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	drawImage(image, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, false);	
}

void drawImage(Image image, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight, boolean simple) {
	checkGC(IMAGE);
	int imageHandle = image.handle;
	int imgWidth = OS.BitmapSource_PixelWidth(imageHandle);
	int imgHeight = OS.BitmapSource_PixelHeight(imageHandle);
 	if (simple) {
 		srcWidth = destWidth = imgWidth;
 		srcHeight = destHeight = imgHeight;
 	} else {
 		simple = srcX == 0 && srcY == 0 &&
 			srcWidth == destWidth && destWidth == imgWidth &&
 			srcHeight == destHeight && destHeight == imgHeight;
		if (srcX + srcWidth > imgWidth || srcY + srcHeight > imgHeight) {
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		}
 	}
 	int mode = 0;
	switch (data.interpolation) {
		case SWT.DEFAULT: mode = OS.BitmapScalingMode_Unspecified; break;
		case SWT.NONE: mode = OS.BitmapScalingMode_LowQuality; break;
		case SWT.LOW: mode = OS.BitmapScalingMode_LowQuality; break;
		case SWT.HIGH: mode = OS.BitmapScalingMode_HighQuality; break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
 	if (srcX != 0 || srcY != 0 || srcWidth != imgWidth || srcHeight != imgHeight) {
 		int rect = OS.gcnew_Int32Rect(srcX, srcY, srcWidth, srcHeight);
 		imageHandle = OS.gcnew_CroppedBitmap(imageHandle, rect);
 		OS.RenderOptions_SetBitmapScalingMode(imageHandle, mode);
 		OS.GCHandle_Free(rect);
 	} else {
 		if (mode != OS.RenderOptions_GetBitmapScalingMode(imageHandle)) {
 			imageHandle = OS.Freezable_Clone(imageHandle); 
 			OS.RenderOptions_SetBitmapScalingMode(imageHandle, mode);
 		}
 	}
	int rect = OS.gcnew_Rect(destX, destY, destWidth, destHeight);
	OS.DrawingContext_DrawImage(handle, imageHandle, rect);
	OS.GCHandle_Free(rect);
	if (image.handle != imageHandle) OS.GCHandle_Free(imageHandle);
}

/** 
 * Draws a line, using the foreground color, between the points 
 * (<code>x1</code>, <code>y1</code>) and (<code>x2</code>, <code>y2</code>).
 *
 * @param x1 the first point's x coordinate
 * @param y1 the first point's y coordinate
 * @param x2 the second point's x coordinate
 * @param y2 the second point's y coordinate
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawLine (int x1, int y1, int x2, int y2) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(DRAW);
	double offset = 0;
	if (data.lineWidth == 0 || (data.lineWidth % 2) == 1) offset = 0.5;
	int point0 = OS.gcnew_Point(x1 + offset, y1 + offset);
	int point1 = OS.gcnew_Point(x2 + offset, y2 + offset);
	OS.DrawingContext_DrawLine(handle, data.pen, point0, point1);
	OS.GCHandle_Free(point0);
	OS.GCHandle_Free(point1);
}

/** 
 * Draws the outline of an oval, using the foreground color,
 * within the specified rectangular area.
 * <p>
 * The result is a circle or ellipse that fits within the 
 * rectangle specified by the <code>x</code>, <code>y</code>, 
 * <code>width</code>, and <code>height</code> arguments. 
 * </p><p> 
 * The oval covers an area that is <code>width + 1</code> 
 * pixels wide and <code>height + 1</code> pixels tall.
 * </p>
 *
 * @param x the x coordinate of the upper left corner of the oval to be drawn
 * @param y the y coordinate of the upper left corner of the oval to be drawn
 * @param width the width of the oval to be drawn
 * @param height the height of the oval to be drawn
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */	 
public void drawOval (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(DRAW);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	double offset = 0;
	if (data.lineWidth == 0 || (data.lineWidth % 2) == 1) offset = 0.5;
	int center = OS.gcnew_Point(x + offset + width / 2f, y + offset + height / 2f);
	OS.DrawingContext_DrawEllipse(handle, 0, data.pen, center, width / 2f, height / 2f);
	OS.GCHandle_Free(center);
}

/** 
 * Draws the path described by the parameter.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param path the path to draw
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Path
 * 
 * @since 3.1
 */
public void drawPath (Path path) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (path == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (path.handle == 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	checkGC(DRAW);
	//TODO - check offset to draw in the midle of pixel
	OS.PathGeometry_FillRule(path.handle, data.fillRule == SWT.FILL_EVEN_ODD ? OS.FillRule_EvenOdd : OS.FillRule_Nonzero);
	OS.DrawingContext_DrawGeometry(handle, 0, data.pen, path.handle);
}

/** 
 * Draws a pixel, using the foreground color, at the specified
 * point (<code>x</code>, <code>y</code>).
 * <p>
 * Note that the receiver's line attributes do not affect this
 * operation.
 * </p>
 *
 * @param x the point's x coordinate
 * @param y the point's y coordinate
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *  
 * @since 3.0
 */
public void drawPoint (int x, int y) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(DRAW);
	int rect = OS.gcnew_Rect(x, y, 1, 1);
	int brush = OS.Pen_Brush(data.pen);
	OS.DrawingContext_DrawRectangle(handle, brush, 0, rect);
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(rect);
}

/** 
 * Draws the closed polygon which is defined by the specified array
 * of integer coordinates, using the receiver's foreground color. The array 
 * contains alternating x and y values which are considered to represent
 * points which are the vertices of the polygon. Lines are drawn between
 * each consecutive pair, and between the first pair and last pair in the
 * array.
 *
 * @param pointArray an array of alternating x and y values which are the vertices of the polygon
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT if pointArray is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawPolygon(int[] pointArray) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	checkGC(DRAW);
	drawPolyLineSegment(pointArray, true, true);
}

void drawPolyLineSegment(int[] pointArray, boolean closed, boolean stroked) {
	if (pointArray.length < 4) return;
	int list = OS.gcnew_PointCollection(pointArray.length / 2);
	double offset = 0;
	if (stroked && (data.lineWidth == 0 || (data.lineWidth % 2) == 1)) offset = 0.5;
	for (int i = 2; i < pointArray.length; i += 2) {
		int point = OS.gcnew_Point(pointArray[i] + offset, pointArray[i + 1] + offset);
		OS.PointCollection_Add(list, point);
		OS.GCHandle_Free(point);
	}
	int poly = OS.gcnew_PolyLineSegment(list, stroked);
	OS.GCHandle_Free(list);
	int figure = OS.gcnew_PathFigure();
	int startPoint = OS.gcnew_Point(pointArray[0] + offset, pointArray[1] + offset);
	OS.PathFigure_StartPoint(figure, startPoint);
	OS.PathFigure_IsClosed(figure, closed);
	int segments = OS.PathFigure_Segments(figure);
	OS.PathSegmentCollection_Add(segments, poly);
	int path = OS.gcnew_PathGeometry();
//	int mode = 0;
//	switch (data.antialias) {
//		case SWT.DEFAULT:
//		case SWT.ON: mode = OS.EdgeMode_Unspecified; break;
//		case SWT.OFF: mode = OS.EdgeMode_Aliased; break;
//	}
//	OS.RenderOptions_SetEdgeMode(path, mode);
	if (!stroked) OS.PathGeometry_FillRule(path, data.fillRule == SWT.FILL_EVEN_ODD ? OS.FillRule_EvenOdd : OS.FillRule_Nonzero);
	int figures = OS.PathGeometry_Figures(path);
	OS.PathFigureCollection_Add(figures, figure);
	OS.DrawingContext_DrawGeometry(handle, stroked ? 0 : data.currentBrush, stroked ? data.pen : 0, path);
	OS.GCHandle_Free(figures);
	OS.GCHandle_Free(path);
	OS.GCHandle_Free(segments);
	OS.GCHandle_Free(figure);
	OS.GCHandle_Free(startPoint);
	OS.GCHandle_Free(poly);
}

/** 
 * Draws the polyline which is defined by the specified array
 * of integer coordinates, using the receiver's foreground color. The array 
 * contains alternating x and y values which are considered to represent
 * points which are the corners of the polyline. Lines are drawn between
 * each consecutive pair, but not between the first pair and last pair in
 * the array.
 *
 * @param pointArray an array of alternating x and y values which are the corners of the polyline
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point array is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawPolyline(int[] pointArray) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	checkGC(DRAW);
	drawPolyLineSegment(pointArray, false, true);
}

/** 
 * Draws the outline of the rectangle specified by the arguments,
 * using the receiver's foreground color. The left and right edges
 * of the rectangle are at <code>x</code> and <code>x + width</code>. 
 * The top and bottom edges are at <code>y</code> and <code>y + height</code>. 
 *
 * @param x the x coordinate of the rectangle to be drawn
 * @param y the y coordinate of the rectangle to be drawn
 * @param width the width of the rectangle to be drawn
 * @param height the height of the rectangle to be drawn
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawRectangle (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(DRAW);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	double offset = 0;
	if (data.lineWidth == 0 || (data.lineWidth % 2) == 1) offset = 0.5;
	int rect = OS.gcnew_Rect(x + offset, y + offset, width, height);
	OS.DrawingContext_DrawRectangle(handle, 0, data.pen, rect);
	OS.GCHandle_Free(rect);
}

/** 
 * Draws the outline of the specified rectangle, using the receiver's
 * foreground color. The left and right edges of the rectangle are at
 * <code>rect.x</code> and <code>rect.x + rect.width</code>. The top 
 * and bottom edges are at <code>rect.y</code> and 
 * <code>rect.y + rect.height</code>. 
 *
 * @param rect the rectangle to draw
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the rectangle is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawRectangle (Rectangle rect) {
	if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	drawRectangle (rect.x, rect.y, rect.width, rect.height);
}

/** 
 * Draws the outline of the round-cornered rectangle specified by 
 * the arguments, using the receiver's foreground color. The left and
 * right edges of the rectangle are at <code>x</code> and <code>x + width</code>. 
 * The top and bottom edges are at <code>y</code> and <code>y + height</code>.
 * The <em>roundness</em> of the corners is specified by the 
 * <code>arcWidth</code> and <code>arcHeight</code> arguments, which
 * are respectively the width and height of the ellipse used to draw
 * the corners.
 *
 * @param x the x coordinate of the rectangle to be drawn
 * @param y the y coordinate of the rectangle to be drawn
 * @param width the width of the rectangle to be drawn
 * @param height the height of the rectangle to be drawn
 * @param arcWidth the width of the arc
 * @param arcHeight the height of the arc
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawRoundRectangle (int x, int y, int width, int height, int arcWidth, int arcHeight) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (arcWidth < 0 || arcHeight < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	checkGC(DRAW);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	if (arcWidth < 0) arcWidth = -arcWidth;
	if (arcHeight < 0) arcHeight = -arcHeight;
	double offset = 0;
	if (data.lineWidth == 0 || (data.lineWidth % 2) == 1) offset = 0.5;
	int rect = OS.gcnew_Rect(x + offset, y + offset, width, height);
	OS.DrawingContext_DrawRoundedRectangle(handle, 0, data.pen, rect, arcWidth / 2f, arcHeight / 2f);
	OS.GCHandle_Free(rect);
}

/** 
 * Draws the given string, using the receiver's current font and
 * foreground color. No tab expansion or carriage return processing
 * will be performed. The background of the rectangular area where
 * the string is being drawn will be filled with the receiver's
 * background color.
 *
 * @param string the string to be drawn
 * @param x the x coordinate of the top left corner of the rectangular area where the string is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the string is to be drawn
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawString (String string, int x, int y) {
	drawString(string, x, y, false);
}

/** 
 * Draws the given string, using the receiver's current font and
 * foreground color. No tab expansion or carriage return processing
 * will be performed. If <code>isTransparent</code> is <code>true</code>,
 * then the background of the rectangular area where the string is being
 * drawn will not be modified, otherwise it will be filled with the
 * receiver's background color.
 *
 * @param string the string to be drawn
 * @param x the x coordinate of the top left corner of the rectangular area where the string is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the string is to be drawn
 * @param isTransparent if <code>true</code> the background will be transparent, otherwise it will be opaque
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawString (String string, int x, int y, boolean isTransparent) {
	drawText(string, x, y, isTransparent ? SWT.DRAW_TRANSPARENT : 0);
}

/** 
 * Draws the given string, using the receiver's current font and
 * foreground color. Tab expansion and carriage return processing
 * are performed. The background of the rectangular area where
 * the text is being drawn will be filled with the receiver's
 * background color.
 *
 * @param string the string to be drawn
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawText (String string, int x, int y) {
	drawText(string, x, y, SWT.DRAW_DELIMITER | SWT.DRAW_TAB);
}

/** 
 * Draws the given string, using the receiver's current font and
 * foreground color. Tab expansion and carriage return processing
 * are performed. If <code>isTransparent</code> is <code>true</code>,
 * then the background of the rectangular area where the text is being
 * drawn will not be modified, otherwise it will be filled with the
 * receiver's background color.
 *
 * @param string the string to be drawn
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param isTransparent if <code>true</code> the background will be transparent, otherwise it will be opaque
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawText (String string, int x, int y, boolean isTransparent) {
	int flags = SWT.DRAW_DELIMITER | SWT.DRAW_TAB;
	if (isTransparent) flags |= SWT.DRAW_TRANSPARENT;
	drawText(string, x, y, flags);
}

/** 
 * Draws the given string, using the receiver's current font and
 * foreground color. Tab expansion, line delimiter and mnemonic
 * processing are performed according to the specified flags. If
 * <code>flags</code> includes <code>DRAW_TRANSPARENT</code>,
 * then the background of the rectangular area where the text is being
 * drawn will not be modified, otherwise it will be filled with the
 * receiver's background color.
 * <p>
 * The parameter <code>flags</code> may be a combination of:
 * <dl>
 * <dt><b>DRAW_DELIMITER</b></dt>
 * <dd>draw multiple lines</dd>
 * <dt><b>DRAW_TAB</b></dt>
 * <dd>expand tabs</dd>
 * <dt><b>DRAW_MNEMONIC</b></dt>
 * <dd>underline the mnemonic character</dd>
 * <dt><b>DRAW_TRANSPARENT</b></dt>
 * <dd>transparent background</dd>
 * </dl>
 * </p>
 *
 * @param string the string to be drawn
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param flags the flags specifying how to process the text
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawText (String string, int x, int y, int flags) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (string == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	int length = string.length ();
	if (length == 0) return;
	checkGC(FONT | FOREGROUND | ALPHA | CLIPPING | TRANSFORM | ((flags & SWT.DRAW_TRANSPARENT) != 0 ? 0 : BACKGROUND));
	char [] buffer = new char [length + 1];
	string.getChars(0, length, buffer, 0);
	int mask = SWT.DRAW_DELIMITER | SWT.DRAW_TAB | SWT.DRAW_MNEMONIC;
	int mnemonic = -1;
	if ((flags & mask) != mask) {
		for (int i = 0, j = 0; i < buffer.length; i++) {
			char c = buffer[i];
			switch (c) {
				case '&': {
					if ((flags & SWT.DRAW_MNEMONIC) != 0) {
						if (i + 1 < length) {
							if (buffer[i + 1] == '&') {
								i++;
							} else {
								if (mnemonic == -1) mnemonic = j;
							}
						}
						continue;
					}
					break;
				}
				case '\r':
				case '\n':
					if ((flags & SWT.DRAW_DELIMITER) == 0) continue;
					break;
				case '\t':
					if ((flags & SWT.DRAW_TAB) == 0) continue;
					break;
			}
			buffer[j++] = c;
		}
	}
	int str = OS.gcnew_String (buffer);
	int culture = OS.CultureInfo_CurrentUICulture();
	Font font = data.font;
	int direction = (data.style & SWT.RIGHT_TO_LEFT) != 0 ? OS.FlowDirection_RightToLeft : OS.FlowDirection_LeftToRight;
	int brush = OS.Pen_Brush(data.pen);
	int text = OS.gcnew_FormattedText(str, culture, direction, font.handle, font.size, brush);
	int point = OS.gcnew_Point(x, y);
	if (mnemonic != -1) {
		int underline = OS.TextDecorations_Underline();
		OS.FormattedText_SetTextDecorations(text, underline, mnemonic, 1);
		OS.GCHandle_Free(underline);
	}
	if ((flags & SWT.DRAW_TRANSPARENT) == 0) {
		double width = OS.FormattedText_WidthIncludingTrailingWhitespace(text);
		double height = OS.FormattedText_Height(text);
		int rect = OS.gcnew_Rect(x, y, width, height);
		OS.DrawingContext_DrawRectangle(handle, data.currentBrush, 0, rect);
		OS.GCHandle_Free(rect);

	}
	OS.DrawingContext_DrawText(handle, text, point);
	OS.GCHandle_Free(point);
	OS.GCHandle_Free(culture);
	OS.GCHandle_Free(str);
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(text);
}

/**
 * Compares the argument to the receiver, and returns true
 * if they represent the <em>same</em> object using a class
 * specific comparison.
 *
 * @param object the object to compare with this object
 * @return <code>true</code> if the object is the same as this object and <code>false</code> otherwise
 *
 * @see #hashCode
 */
public boolean equals (Object object) {
	return (object == this) || ((object instanceof GC) && (handle == ((GC)object).handle));
}

/**
 * Fills the interior of a circular or elliptical arc within
 * the specified rectangular area, with the receiver's background
 * color.
 * <p>
 * The resulting arc begins at <code>startAngle</code> and extends  
 * for <code>arcAngle</code> degrees, using the current color.
 * Angles are interpreted such that 0 degrees is at the 3 o'clock
 * position. A positive value indicates a counter-clockwise rotation
 * while a negative value indicates a clockwise rotation.
 * </p><p>
 * The center of the arc is the center of the rectangle whose origin 
 * is (<code>x</code>, <code>y</code>) and whose size is specified by the 
 * <code>width</code> and <code>height</code> arguments. 
 * </p><p>
 * The resulting arc covers an area <code>width + 1</code> pixels wide
 * by <code>height + 1</code> pixels tall.
 * </p>
 *
 * @param x the x coordinate of the upper-left corner of the arc to be filled
 * @param y the y coordinate of the upper-left corner of the arc to be filled
 * @param width the width of the arc to be filled
 * @param height the height of the arc to be filled
 * @param startAngle the beginning angle
 * @param arcAngle the angular extent of the arc, relative to the start angle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawArc
 */
public void fillArc (int x, int y, int width, int height, int startAngle, int arcAngle) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FILL);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	if (width == 0 || height == 0 || arcAngle == 0) return;
	if (arcAngle >= 360 || arcAngle <= -360) {
		int center = OS.gcnew_Point(x + width / 2f, y + height / 2f);
		OS.DrawingContext_DrawEllipse(handle, data.currentBrush, 0, center, width / 2f, height / 2f);
		OS.GCHandle_Free(center);
		return;
	}
	boolean isNegative = arcAngle < 0;
	boolean isLargeAngle = arcAngle > 180 || arcAngle < -180;
	arcAngle = arcAngle + startAngle;
	if (isNegative) {
		// swap angles
	   	int tmp = startAngle;
		startAngle = arcAngle;
		arcAngle = tmp;
	}
	double x1 = Math.cos(startAngle * Math.PI / 180) * width/2.0 + x + width/2.0;
	double y1 = -1 * Math.sin(startAngle * Math.PI / 180) * height/2.0 + y + height/2.0;
	double x2 = Math.cos(arcAngle * Math.PI / 180) * width/2.0 + x + width/2.0;
	double y2 = -1 * Math.sin(arcAngle * Math.PI / 180) * height/2.0 + y + height/2.0; 
	int startPoint = OS.gcnew_Point(x1, y1);
	int endPoint = OS.gcnew_Point(x2, y2);
	int center = OS.gcnew_Point(x + width / 2.0, y + height / 2.0);
	int size = OS.gcnew_Size(width / 2.0, height / 2.0);
	int arc = OS.gcnew_ArcSegment(endPoint, size, 0, isLargeAngle, OS.SweepDirection_Clockwise, false);
	int line = OS.gcnew_LineSegment(center, false);
	int figure = OS.gcnew_PathFigure();
	OS.PathFigure_StartPoint(figure, startPoint);
	int segments = OS.PathFigure_Segments(figure);
	OS.PathSegmentCollection_Add(segments, arc);
	OS.PathSegmentCollection_Add(segments, line);
	int path = OS.gcnew_PathGeometry();
	int figures = OS.PathGeometry_Figures(path);
	OS.PathFigureCollection_Add(figures, figure);
	OS.DrawingContext_DrawGeometry(handle, data.currentBrush, 0, path);
	OS.GCHandle_Free(figures);
	OS.GCHandle_Free(path);
	OS.GCHandle_Free(segments);
	OS.GCHandle_Free(figure);
	OS.GCHandle_Free(arc);
	OS.GCHandle_Free(line);
	OS.GCHandle_Free(size);
	OS.GCHandle_Free(endPoint);
	OS.GCHandle_Free(startPoint);
}

/**
 * Fills the interior of the specified rectangle with a gradient
 * sweeping from left to right or top to bottom progressing
 * from the receiver's foreground color to its background color.
 *
 * @param x the x coordinate of the rectangle to be filled
 * @param y the y coordinate of the rectangle to be filled
 * @param width the width of the rectangle to be filled, may be negative
 *        (inverts direction of gradient if horizontal)
 * @param height the height of the rectangle to be filled, may be negative
 *        (inverts direction of gradient if vertical)
 * @param vertical if true sweeps from top to bottom, else 
 *        sweeps from left to right
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRectangle(int, int, int, int)
 */
public void fillGradientRectangle(int x, int y, int width, int height, boolean vertical) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (width == 0 || height == 0) return;
	checkGC(FILL);

	int fromColor = data.foreground;
	int toColor   = data.background;

	boolean swapColors = false;
	if (width < 0) {
		x += width; width = -width;
		if (! vertical) swapColors = true;
	}
	if (height < 0) {
		y += height; height = -height;
		if (vertical) swapColors = true;
	}
	if (swapColors) {
		int temp = fromColor;
		fromColor = toColor;
		toColor   = temp;
	}
	int brush = OS.gcnew_LinearGradientBrush(fromColor, toColor, vertical ? 90 : 0);
	int rect = OS.gcnew_Rect(x, y, width, height);
	OS.DrawingContext_DrawRectangle(handle, brush, 0, rect);
	OS.GCHandle_Free(rect);
	OS.GCHandle_Free(brush);
}

/** 
 * Fills the interior of an oval, within the specified
 * rectangular area, with the receiver's background
 * color.
 *
 * @param x the x coordinate of the upper left corner of the oval to be filled
 * @param y the y coordinate of the upper left corner of the oval to be filled
 * @param width the width of the oval to be filled
 * @param height the height of the oval to be filled
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawOval
 */	 
public void fillOval (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FILL);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	int center = OS.gcnew_Point(x + width / 2f, y + height / 2f);
	OS.DrawingContext_DrawEllipse(handle, data.currentBrush, 0, center, width / 2f, height / 2f);
	OS.GCHandle_Free(center);
}

/** 
 * Fills the path described by the parameter.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 *
 * @param path the path to fill
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Path
 * 
 * @since 3.1
 */
public void fillPath (Path path) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (path == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (path.handle == 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	checkGC(FILL);
	OS.PathGeometry_FillRule(path.handle, data.fillRule == SWT.FILL_EVEN_ODD ? OS.FillRule_EvenOdd : OS.FillRule_Nonzero);
	OS.DrawingContext_DrawGeometry(handle, data.currentBrush, 0, path.handle);
}

/** 
 * Fills the interior of the closed polygon which is defined by the
 * specified array of integer coordinates, using the receiver's
 * background color. The array contains alternating x and y values
 * which are considered to represent points which are the vertices of
 * the polygon. Lines are drawn between each consecutive pair, and
 * between the first pair and last pair in the array.
 *
 * @param pointArray an array of alternating x and y values which are the vertices of the polygon
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT if pointArray is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawPolygon	
 */
public void fillPolygon(int[] pointArray) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	checkGC(FILL);
	drawPolyLineSegment(pointArray, true, false);
}

/** 
 * Fills the interior of the rectangle specified by the arguments,
 * using the receiver's background color. 
 *
 * @param x the x coordinate of the rectangle to be filled
 * @param y the y coordinate of the rectangle to be filled
 * @param width the width of the rectangle to be filled
 * @param height the height of the rectangle to be filled
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRectangle(int, int, int, int)
 */
public void fillRectangle (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FILL);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	int rect = OS.gcnew_Rect(x, y, width, height);
	OS.DrawingContext_DrawRectangle(handle, data.currentBrush, 0, rect);
	OS.GCHandle_Free(rect);
}

/** 
 * Fills the interior of the specified rectangle, using the receiver's
 * background color. 
 *
 * @param rect the rectangle to be filled
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the rectangle is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRectangle(int, int, int, int)
 */
public void fillRectangle (Rectangle rect) {
	if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	fillRectangle (rect.x, rect.y, rect.width, rect.height);
}

/** 
 * Fills the interior of the round-cornered rectangle specified by 
 * the arguments, using the receiver's background color. 
 *
 * @param x the x coordinate of the rectangle to be filled
 * @param y the y coordinate of the rectangle to be filled
 * @param width the width of the rectangle to be filled
 * @param height the height of the rectangle to be filled
 * @param arcWidth the width of the arc
 * @param arcHeight the height of the arc
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRoundRectangle
 */
public void fillRoundRectangle (int x, int y, int width, int height, int arcWidth, int arcHeight) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FILL);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	if (arcWidth < 0) arcWidth = -arcWidth;
	if (arcHeight < 0) arcHeight = -arcHeight;
	int rect = OS.gcnew_Rect(x, y, width, height);
	OS.DrawingContext_DrawRoundedRectangle(handle, data.currentBrush, 0, rect, arcWidth / 2f, arcHeight / 2f);
	OS.GCHandle_Free(rect);
}

/**
 * Returns the <em>advance width</em> of the specified character in
 * the font which is currently selected into the receiver.
 * <p>
 * The advance width is defined as the horizontal distance the cursor
 * should move after printing the character in the selected font.
 * </p>
 *
 * @param ch the character to measure
 * @return the distance in the x direction to move past the character before painting the next
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getAdvanceWidth(char ch) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	//NOT DONE
	return stringExtent(new String(new char[]{ch})).x;
}

/**
 * Returns <code>true</code> if receiver is using the operating system's
 * advanced graphics subsystem.  Otherwise, <code>false</code> is returned
 * to indicate that normal graphics are in use.
 * <p>
 * Advanced graphics may not be installed for the operating system.  In this
 * case, <code>false</code> is always returned.  Some operating system have
 * only one graphics subsystem.  If this subsystem supports advanced graphics,
 * then <code>true</code> is always returned.  If any graphics operation such
 * as alpha, antialias, patterns, interpolation, paths, clipping or transformation
 * has caused the receiver to switch from regular to advanced graphics mode,
 * <code>true</code> is returned.  If the receiver has been explicitly switched
 * to advanced mode and this mode is supported, <code>true</code> is returned.
 * </p>
 *
 * @return the advanced value
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public boolean getAdvanced() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return true;
}

/**
 * Returns the receiver's alpha value. The alpha value
 * is between 0 (transparent) and 255 (opaque).
 *
 * @return the alpha value
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1
 */
public int getAlpha() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.alpha;
}

/**
 * Returns the receiver's anti-aliasing setting value, which will be
 * one of <code>SWT.DEFAULT</code>, <code>SWT.OFF</code> or
 * <code>SWT.ON</code>. Note that this controls anti-aliasing for all
 * <em>non-text drawing</em> operations.
 *
 * @return the anti-aliasing setting
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getTextAntialias
 * 
 * @since 3.1
 */
public int getAntialias() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.antialias;
}

/** 
 * Returns the background color.
 *
 * @return the receiver's background color
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Color getBackground() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return Color.wpf_new(data.device, data.background);
}

/** 
 * Returns the background pattern. The default value is
 * <code>null</code>.
 *
 * @return the receiver's background pattern
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see Pattern
 * 
 * @since 3.1
 */
public Pattern getBackgroundPattern() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.backgroundPattern;
}

/**
 * Returns the width of the specified character in the font
 * selected into the receiver. 
 * <p>
 * The width is defined as the space taken up by the actual
 * character, not including the leading and tailing whitespace
 * or overhang.
 * </p>
 *
 * @param ch the character to measure
 * @return the width of the character
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getCharWidth(char ch) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	//NOT DONE
	return stringExtent(new String(new char[]{ch})).x;
}

/** 
 * Returns the bounding rectangle of the receiver's clipping
 * region. If no clipping region is set, the return value
 * will be a rectangle which covers the entire bounds of the
 * object the receiver is drawing on.
 *
 * @return the bounding rectangle of the clipping region
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Rectangle getClipping() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	int x = 0, y = 0, width = 0, height = 0;
	int visualType = OS.Object_GetType(data.visual);
	int drawingVisualType = OS.DrawingVisual_typeid();
	if (OS.Object_Equals(visualType, drawingVisualType)) {			
		int clip = OS.ContainerVisual_Clip(data.visual);
		int rect = OS.Geometry_Bounds(clip);
		width = (int)OS.Rect_Width(rect);
		height = (int)OS.Rect_Height(rect);
		OS.GCHandle_Free(rect);
		OS.GCHandle_Free(clip);
	} else {
		width = (int)OS.FrameworkElement_ActualWidth(data.visual);
		height = (int)OS.FrameworkElement_ActualHeight(data.visual);
	}
	OS.GCHandle_Free(drawingVisualType);
	OS.GCHandle_Free(visualType);
	if (data.clip != 0) {
		int bounds = OS.gcnew_Rect(x, y, width, height);
		int rect = OS.Geometry_Bounds(data.clip);
		OS.Rect_Intersect(bounds, rect);
		x = (int)OS.Rect_X(bounds);
		y = (int)OS.Rect_Y(bounds);
		width = (int)OS.Rect_Width(bounds);
		height = (int)OS.Rect_Height(bounds);
		OS.GCHandle_Free(rect);
		OS.GCHandle_Free(bounds);
	}
	return new Rectangle(x, y, width, height);
}

/** 
 * Sets the region managed by the argument to the current
 * clipping region of the receiver.
 *
 * @param region the region to fill with the clipping region
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the region is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the region is disposed</li>
 * </ul>	
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void getClipping (Region region) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (region == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (region.isDisposed()) SWT.error (SWT.ERROR_INVALID_ARGUMENT);
	int bounds;
	int visualType = OS.Object_GetType(data.visual);
	int drawingVisualType = OS.DrawingVisual_typeid();
	if (OS.Object_Equals(visualType, drawingVisualType)) {			
		bounds = OS.ContainerVisual_Clip(data.visual);
	} else {
		double width = OS.FrameworkElement_ActualWidth(data.visual);
		double height = OS.FrameworkElement_ActualHeight(data.visual);
		int rect = OS.gcnew_Rect(0, 0, width, height);
		bounds = OS.gcnew_RectangleGeometry(rect);
		OS.GCHandle_Free(rect);
	}
	OS.GCHandle_Free(drawingVisualType);
	OS.GCHandle_Free(visualType);
	int geometries = OS.GeometryGroup_Children(region.handle);
	OS.GeometryCollection_Clear(geometries);
	if (data.clip != 0) {
		int clip = OS.Geometry_GetFlattenedPathGeometry(data.clip);
		int newGeometry = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Intersect, bounds, clip);
		OS.GeometryCollection_Add(geometries, newGeometry);
		OS.GCHandle_Free(clip);
		OS.GCHandle_Free(newGeometry);
	} else {
		OS.GeometryCollection_Add(geometries, bounds);
	}
	OS.GCHandle_Free(bounds);
	OS.GCHandle_Free(geometries);
}

/** 
 * Returns the receiver's fill rule, which will be one of
 * <code>SWT.FILL_EVEN_ODD</code> or <code>SWT.FILL_WINDING</code>.
 *
 * @return the receiver's fill rule
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1
 */
public int getFillRule() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.fillRule;
}

/** 
 * Returns the font currently being used by the receiver
 * to draw and measure text.
 *
 * @return the receiver's font
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Font getFont () {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.font;
}

/**
 * Returns a FontMetrics which contains information
 * about the font currently being used by the receiver
 * to draw and measure text.
 *
 * @return font metrics for the receiver's font
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public FontMetrics getFontMetrics() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	checkGC(FONT);
	//TODO - find a better way of getting font metrics
	String string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
	int length = string.length();
	char [] buffer = new char [length + 1];
	string.getChars (0, length, buffer, 0);
	int str = OS.gcnew_String (buffer);
	int culture = OS.CultureInfo_CurrentUICulture();
	Font font = data.font;
	int direction = (data.style & SWT.RIGHT_TO_LEFT) != 0 ? OS.FlowDirection_RightToLeft : OS.FlowDirection_LeftToRight;
	int brush = OS.Brushes_White();
	int text = OS.gcnew_FormattedText(str, culture, direction, font.handle, font.size, brush);
	double width = OS.FormattedText_WidthIncludingTrailingWhitespace(text);
	double height = OS.FormattedText_Height(text);
	double baseline = OS.FormattedText_Baseline(text);
	OS.GCHandle_Free(text);
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(culture);
	OS.GCHandle_Free(str);
	return FontMetrics.wpf_new((int)baseline, (int)(height - baseline), (int)width / string.length(), 0, (int)height);
}

/** 
 * Returns the receiver's foreground color.
 *
 * @return the color used for drawing foreground things
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Color getForeground() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return Color.wpf_new(data.device, data.foreground);
}

/** 
 * Returns the foreground pattern. The default value is
 * <code>null</code>.
 *
 * @return the receiver's foreground pattern
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see Pattern
 * 
 * @since 3.1
 */
public Pattern getForegroundPattern() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.foregroundPattern;
}

/** 
 * Returns the GCData.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>GC</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @return the receiver's GCData
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see GCData
 * 
 * @since 3.2
 * @noreference This method is not intended to be referenced by clients.
 */
public GCData getGCData() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data;
}

/** 
 * Returns the receiver's interpolation setting, which will be one of
 * <code>SWT.DEFAULT</code>, <code>SWT.NONE</code>, 
 * <code>SWT.LOW</code> or <code>SWT.HIGH</code>.
 *
 * @return the receiver's interpolation setting
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1
 */
public int getInterpolation() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.interpolation;
}

/** 
 * Returns the receiver's line attributes.
 *
 * @return the line attributes used for drawing lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.3 
 */
public LineAttributes getLineAttributes() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	float[] dashes = null;
	if (data.lineDashes != null) {
		dashes = new float[data.lineDashes.length];
		System.arraycopy(data.lineDashes, 0, dashes, 0, dashes.length);
	}
	return new LineAttributes(data.lineWidth, data.lineCap, data.lineJoin, data.lineStyle, dashes, data.lineDashesOffset, data.lineMiterLimit);
}

/** 
 * Returns the receiver's line cap style, which will be one
 * of the constants <code>SWT.CAP_FLAT</code>, <code>SWT.CAP_ROUND</code>,
 * or <code>SWT.CAP_SQUARE</code>.
 *
 * @return the cap style used for drawing lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public int getLineCap() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.lineCap;
}

/** 
 * Returns the receiver's line dash style. The default value is
 * <code>null</code>.
 *
 * @return the line dash style used for drawing lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public int[] getLineDash() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (data.lineDashes == null) return null;
	int[] lineDashes = new int[data.lineDashes.length];
	System.arraycopy(data.lineDashes, 0, lineDashes, 0, lineDashes.length);
	return lineDashes;	
}

/** 
 * Returns the receiver's line join style, which will be one
 * of the constants <code>SWT.JOIN_MITER</code>, <code>SWT.JOIN_ROUND</code>,
 * or <code>SWT.JOIN_BEVEL</code>.
 *
 * @return the join style used for drawing lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public int getLineJoin() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.lineJoin;
}

/** 
 * Returns the receiver's line style, which will be one
 * of the constants <code>SWT.LINE_SOLID</code>, <code>SWT.LINE_DASH</code>,
 * <code>SWT.LINE_DOT</code>, <code>SWT.LINE_DASHDOT</code> or
 * <code>SWT.LINE_DASHDOTDOT</code>.
 *
 * @return the style used for drawing lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getLineStyle() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.lineStyle;
}

/** 
 * Returns the width that will be used when drawing lines
 * for all of the figure drawing operations (that is,
 * <code>drawLine</code>, <code>drawRectangle</code>, 
 * <code>drawPolyline</code>, and so forth.
 *
 * @return the receiver's line width 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getLineWidth() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return (int)data.lineWidth;
}

/**
 * Returns the receiver's style information.
 * <p>
 * Note that the value which is returned by this method <em>may
 * not match</em> the value which was provided to the constructor
 * when the receiver was created. This can occur when the underlying
 * operating system does not support a particular combination of
 * requested styles. 
 * </p>
 *
 * @return the style bits
 *  
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *   
 * @since 2.1.2
 */
public int getStyle () {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.style;
}

/**
 * Returns the receiver's text drawing anti-aliasing setting value,
 * which will be one of <code>SWT.DEFAULT</code>, <code>SWT.OFF</code> or
 * <code>SWT.ON</code>. Note that this controls anti-aliasing
 * <em>only</em> for text drawing operations.
 *
 * @return the anti-aliasing setting
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getAntialias
 * 
 * @since 3.1
 */
public int getTextAntialias() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.textAntialias;
}

/** 
 * Sets the parameter to the transform that is currently being
 * used by the receiver.
 *
 * @param transform the destination to copy the transform into
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see Transform
 * 
 * @since 3.1
 */
public void getTransform(Transform transform) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (transform == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (transform.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.transform != 0) {
		OS.MatrixTransform_Matrix(transform.handle, data.transform);
	} else {
		transform.setElements(1, 0, 0, 1, 0, 0);
	}
}

/** 
 * Returns <code>true</code> if this GC is drawing in the mode
 * where the resulting color in the destination is the
 * <em>exclusive or</em> of the color values in the source
 * and the destination, and <code>false</code> if it is
 * drawing in the mode where the destination color is being
 * replaced with the source color value.
 *
 * @return <code>true</code> true if the receiver is in XOR mode, and false otherwise
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public boolean getXORMode() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.xorMode;
}

void init(Drawable drawable, GCData data, int hDC) {
	int foreground = data.foreground;
	if (foreground != -1) data.state &= ~FOREGROUND;
	int background = data.background;
	if (background != 0) data.state &= ~BACKGROUND;
	Font font = data.font;
	if (font != null) data.state &= ~FONT;
	Image image = data.image;
	if (image != null) image.memGC = this;
//	int layout = data.layout;
//	if (layout != -1) {
//		if (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION(4, 10)) {
//			int flags = OS.GetLayout(hDC);
//			if ((flags & OS.LAYOUT_RTL) != (layout & OS.LAYOUT_RTL)) {
//				flags &= ~OS.LAYOUT_RTL;
//				OS.SetLayout(hDC, flags | layout);
//			}
//			if ((data.style & SWT.RIGHT_TO_LEFT) != 0) data.style |= SWT.MIRRORED;
//		}
//	}	
	this.drawable = drawable;
	this.data = data;
	handle = hDC;
}

/**
 * Returns an integer hash code for the receiver. Any two 
 * objects that return <code>true</code> when passed to 
 * <code>equals</code> must return the same value for this
 * method.
 *
 * @return the receiver's hash
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #equals
 */
public int hashCode () {
	return handle;
}

/**
 * Returns <code>true</code> if the receiver has a clipping
 * region set into it, and <code>false</code> otherwise.
 * If this method returns false, the receiver will draw on all
 * available space in the destination. If it returns true, 
 * it will draw only in the area that is covered by the region
 * that can be accessed with <code>getClipping(region)</code>.
 *
 * @return <code>true</code> if the GC has a clipping region, and <code>false</code> otherwise
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public boolean isClipped() {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return data.clip != 0;
}

/**
 * Returns <code>true</code> if the GC has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the GC.
 * When a GC has been disposed, it is an error to
 * invoke any other method using the GC.
 *
 * @return <code>true</code> when the GC is disposed and <code>false</code> otherwise
 */
public boolean isDisposed() {
	return handle == 0;
}

/**
 * Sets the receiver to always use the operating system's advanced graphics
 * subsystem for all graphics operations if the argument is <code>true</code>.
 * If the argument is <code>false</code>, the advanced graphics subsystem is 
 * no longer used, advanced graphics state is cleared and the normal graphics
 * subsystem is used from now on.
 * <p>
 * Normally, the advanced graphics subsystem is invoked automatically when
 * any one of the alpha, antialias, patterns, interpolation, paths, clipping
 * or transformation operations in the receiver is requested.  When the receiver
 * is switched into advanced mode, the advanced graphics subsystem performs both
 * advanced and normal graphics operations.  Because the two subsystems are
 * different, their output may differ.  Switching to advanced graphics before
 * any graphics operations are performed ensures that the output is consistent.
 * </p><p>
 * Advanced graphics may not be installed for the operating system.  In this
 * case, this operation does nothing.  Some operating system have only one
 * graphics subsystem, so switching from normal to advanced graphics does
 * nothing.  However, switching from advanced to normal graphics will always
 * clear the advanced graphics state, even for operating systems that have
 * only one graphics subsystem.
 * </p>
 *
 * @param advanced the new advanced graphics state
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setAlpha
 * @see #setAntialias
 * @see #setBackgroundPattern
 * @see #setClipping(Path)
 * @see #setForegroundPattern
 * @see #setLineAttributes
 * @see #setInterpolation
 * @see #setTextAntialias
 * @see #setTransform
 * @see #getAdvanced
 * 
 * @since 3.1
 */
public void setAdvanced(boolean advanced) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (!advanced) {
		setAlpha(0xFF);
		setAntialias(SWT.DEFAULT);
		setBackgroundPattern(null);
		setClipping((Rectangle)null);
		setForegroundPattern(null);
		setInterpolation(SWT.DEFAULT);
		setTextAntialias(SWT.DEFAULT);
		setTransform(null);
	}
}

/**
 * Sets the receiver's anti-aliasing value to the parameter, 
 * which must be one of <code>SWT.DEFAULT</code>, <code>SWT.OFF</code>
 * or <code>SWT.ON</code>. Note that this controls anti-aliasing for all
 * <em>non-text drawing</em> operations.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 *
 * @param antialias the anti-aliasing setting
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter is not one of <code>SWT.DEFAULT</code>,
 *                                 <code>SWT.OFF</code> or <code>SWT.ON</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see #getAdvanced
 * @see #setAdvanced
 * @see #setTextAntialias
 * 
 * @since 3.1
 */
public void setAntialias(int antialias) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	switch (antialias) {
		case SWT.DEFAULT:
		case SWT.OFF:
		case SWT.ON:
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.antialias = antialias;
}

/**
 * Sets the receiver's alpha value which must be
 * between 0 (transparent) and 255 (opaque).
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * @param alpha the alpha value
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setAlpha(int alpha) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	data.alpha = alpha & 0xFF;
	data.state &= ~ALPHA;
}

/**
 * Sets the background color. The background color is used
 * for fill operations and as the background color when text
 * is drawn.
 *
 * @param color the new background color for the receiver
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the color is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the color has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setBackground (Color color) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (color == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (color.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.backgroundPattern == null && data.background == color.handle) return;
	data.backgroundPattern = null;
	data.background = color.handle;
	data.state &= ~BACKGROUND;
}

/** 
 * Sets the background pattern. The default value is <code>null</code>.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param pattern the new background pattern
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Pattern
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setBackgroundPattern (Pattern pattern) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (pattern != null && pattern.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.backgroundPattern == pattern) return;
	data.backgroundPattern = pattern;
	data.state &= ~BACKGROUND;
}

/**
 * Sets the area of the receiver which can be changed
 * by drawing operations to the rectangular area specified
 * by the arguments.
 *
 * @param x the x coordinate of the clipping rectangle
 * @param y the y coordinate of the clipping rectangle
 * @param width the width of the clipping rectangle
 * @param height the height of the clipping rectangle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setClipping (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	int rect = OS.gcnew_Rect(x, y, width, height);
	int clip = OS.gcnew_RectangleGeometry(rect);
	OS.GCHandle_Free(rect);
	if (data.clip != 0) OS.GCHandle_Free(data.clip);
	data.clip = clip;
	data.state &= ~CLIPPING;
}

/**
 * Sets the area of the receiver which can be changed
 * by drawing operations to the path specified
 * by the argument.  
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param path the clipping path.
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the path has been disposed</li>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Path
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setClipping (Path path) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (path != null && path.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.clip != 0) OS.GCHandle_Free(data.clip);
	data.clip = path != null ? OS.Geometry_Clone(path.handle) : 0;
	data.state &= ~CLIPPING;
}

/**
 * Sets the area of the receiver which can be changed
 * by drawing operations to the rectangular area specified
 * by the argument.  Specifying <code>null</code> for the
 * rectangle reverts the receiver's clipping area to its
 * original value.
 *
 * @param rect the clipping rectangle or <code>null</code>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setClipping (Rectangle rect) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (rect == null) {
		if (data.clip != 0) OS.GCHandle_Free(data.clip);
		data.clip = 0;
		data.state &= ~CLIPPING;
	} else {
		setClipping(rect.x, rect.y, rect.width, rect.height);
	}
}

/**
 * Sets the area of the receiver which can be changed
 * by drawing operations to the region specified
 * by the argument.  Specifying <code>null</code> for the
 * region reverts the receiver's clipping area to its
 * original value.
 *
 * @param region the clipping region or <code>null</code>
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the region has been disposed</li>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setClipping (Region region) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (region != null && region.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.clip != 0) OS.GCHandle_Free(data.clip);
	data.clip = region != null ? OS.Geometry_Clone(region.handle) : 0;
	data.state &= ~CLIPPING;
}

/** 
 * Sets the receiver's fill rule to the parameter, which must be one of
 * <code>SWT.FILL_EVEN_ODD</code> or <code>SWT.FILL_WINDING</code>.
 *
 * @param rule the new fill rule
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the rule is not one of <code>SWT.FILL_EVEN_ODD</code>
 *                                 or <code>SWT.FILL_WINDING</code></li>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1
 */
public void setFillRule(int rule) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	switch (rule) {
		case SWT.FILL_WINDING:
		case SWT.FILL_EVEN_ODD: break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.fillRule = rule;
}

/** 
 * Sets the font which will be used by the receiver
 * to draw and measure text to the argument. If the
 * argument is null, then a default font appropriate
 * for the platform will be used instead.
 *
 * @param font the new font for the receiver, or null to indicate a default font
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the font has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setFont (Font font) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (font != null && font.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	data.font = font != null ? font : data.device.systemFont;
	data.state &= ~FONT;
}

/**
 * Sets the foreground color. The foreground color is used
 * for drawing operations including when text is drawn.
 *
 * @param color the new foreground color for the receiver
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the color is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the color has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setForeground (Color color) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (color == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (color.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.foregroundPattern == null && color.handle == data.foreground) return;
	data.foregroundPattern = null;
	data.foreground = color.handle;
	data.state &= ~FOREGROUND;
}

/** 
 * Sets the foreground pattern. The default value is <code>null</code>.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * @param pattern the new foreground pattern
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Pattern
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setForegroundPattern (Pattern pattern) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (pattern != null && pattern.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (data.foregroundPattern == pattern) return;
	data.foregroundPattern = pattern;
	data.state &= ~FOREGROUND;
}

/** 
 * Sets the receiver's interpolation setting to the parameter, which
 * must be one of <code>SWT.DEFAULT</code>, <code>SWT.NONE</code>, 
 * <code>SWT.LOW</code> or <code>SWT.HIGH</code>.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param interpolation the new interpolation setting
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the rule is not one of <code>SWT.DEFAULT</code>, 
 *                                 <code>SWT.NONE</code>, <code>SWT.LOW</code> or <code>SWT.HIGH</code>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setInterpolation(int interpolation) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	switch (interpolation) {
		case SWT.DEFAULT: break;
		case SWT.NONE: break;
		case SWT.LOW: break;
		case SWT.HIGH: break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.interpolation = interpolation;
}

/**
 * Sets the receiver's line attributes.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * @param attributes the line attributes
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the attributes is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if any of the line attributes is not valid</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see LineAttributes
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.3
 */
public void setLineAttributes(LineAttributes attributes) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (attributes == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	int mask = 0;
	float lineWidth = attributes.width;
	if (lineWidth != data.lineWidth) {
		mask |= LINE_WIDTH;
	}
	int lineStyle = attributes.style;
	if (lineStyle != data.lineStyle) {
		mask |= LINE_STYLE;
		switch (lineStyle) {
			case SWT.LINE_SOLID:
			case SWT.LINE_DASH:
			case SWT.LINE_DOT:
			case SWT.LINE_DASHDOT:
			case SWT.LINE_DASHDOTDOT:
				break;
			case SWT.LINE_CUSTOM:
				if (attributes.dash == null) lineStyle = SWT.LINE_SOLID;
				break;
			default:
				SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		}
	}
	int join = attributes.join;
	if (join != data.lineJoin) {
		mask |= LINE_JOIN;
		switch (join) {
			case SWT.CAP_ROUND:
			case SWT.CAP_FLAT:
			case SWT.CAP_SQUARE:
				break;
			default:
				SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		}
	}
	int cap = attributes.cap;
	if (cap != data.lineCap) {
		mask |= LINE_CAP;
		switch (cap) {
			case SWT.JOIN_MITER:
			case SWT.JOIN_ROUND:
			case SWT.JOIN_BEVEL:
				break;
			default:
				SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		}
	}
	float[] dashes = attributes.dash;
	float[] lineDashes = data.lineDashes;
	if (dashes != null && dashes.length > 0) {
		boolean changed = lineDashes == null || lineDashes.length != dashes.length;
		for (int i = 0; i < dashes.length; i++) {
			float dash = dashes[i];
			if (dash <= 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
			if (!changed && lineDashes[i] != dash) changed = true;
		}
		if (changed) {
			float[] newDashes = new float[dashes.length];
			System.arraycopy(dashes, 0, newDashes, 0, dashes.length);
			dashes = newDashes;
			mask |= LINE_STYLE;
		} else {
			dashes = lineDashes;
		}
	} else {
		if (lineDashes != null && lineDashes.length > 0) {
			mask |= LINE_STYLE;
		} else {
			dashes = lineDashes;
		}
	}
	float dashOffset = attributes.dashOffset;
	if (dashOffset != data.lineDashesOffset) {
		mask |= LINE_STYLE;
	}
	float miterLimit = attributes.miterLimit;
	if (miterLimit != data.lineMiterLimit) {
		mask |= LINE_MITERLIMIT;
	}
	if (mask == 0) return;
	data.lineWidth = lineWidth;
	data.lineStyle = lineStyle;
	data.lineCap = cap;
	data.lineJoin = join;
	data.lineDashes = dashes;
	data.lineDashesOffset = dashOffset;
	data.lineMiterLimit = miterLimit;
	data.state &= ~mask;
}

/** 
 * Sets the receiver's line cap style to the argument, which must be one
 * of the constants <code>SWT.CAP_FLAT</code>, <code>SWT.CAP_ROUND</code>,
 * or <code>SWT.CAP_SQUARE</code>.
 *
 * @param cap the cap style to be used for drawing lines
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the style is not valid</li>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public void setLineCap(int cap) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (data.lineCap == cap) return;
	switch (cap) {
		case SWT.CAP_ROUND:
		case SWT.CAP_FLAT:
		case SWT.CAP_SQUARE:
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.lineCap = cap;
	data.state &= ~LINE_CAP;
}

/** 
 * Sets the receiver's line dash style to the argument. The default
 * value is <code>null</code>. If the argument is not <code>null</code>,
 * the receiver's line style is set to <code>SWT.LINE_CUSTOM</code>, otherwise
 * it is set to <code>SWT.LINE_SOLID</code>.
 *
 * @param dashes the dash style to be used for drawing lines
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if any of the values in the array is less than or equal 0</li>
 * </ul> 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public void setLineDash(int[] dashes) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	float[] lineDashes = data.lineDashes;
	if (dashes != null && dashes.length > 0) {
		boolean changed = data.lineStyle != SWT.LINE_CUSTOM || lineDashes == null || lineDashes.length != dashes.length;
		for (int i = 0; i < dashes.length; i++) {
			int dash = dashes[i];
			if (dash <= 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
			if (!changed && lineDashes[i] != dash) changed = true;
		}
		if (!changed) return;
		data.lineDashes = new float[dashes.length];
		for (int i = 0; i < dashes.length; i++) {
			data.lineDashes[i] = dashes[i];
		}
		data.lineStyle = SWT.LINE_CUSTOM;
	} else {
		if (data.lineStyle == SWT.LINE_SOLID && (lineDashes == null || lineDashes.length == 0)) return;
		data.lineDashes = null;
		data.lineStyle = SWT.LINE_SOLID;
	}
	data.state &= ~LINE_STYLE;
}

/** 
 * Sets the receiver's line join style to the argument, which must be one
 * of the constants <code>SWT.JOIN_MITER</code>, <code>SWT.JOIN_ROUND</code>,
 * or <code>SWT.JOIN_BEVEL</code>.
 *
 * @param join the join style to be used for drawing lines
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the style is not valid</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.1 
 */
public void setLineJoin(int join) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (data.lineJoin == join) return;
	switch (join) {
		case SWT.JOIN_MITER:
		case SWT.JOIN_ROUND:
		case SWT.JOIN_BEVEL:
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.lineJoin = join;
	data.state &= ~LINE_JOIN;
}

/** 
 * Sets the receiver's line style to the argument, which must be one
 * of the constants <code>SWT.LINE_SOLID</code>, <code>SWT.LINE_DASH</code>,
 * <code>SWT.LINE_DOT</code>, <code>SWT.LINE_DASHDOT</code> or
 * <code>SWT.LINE_DASHDOTDOT</code>.
 *
 * @param lineStyle the style to be used for drawing lines
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the style is not valid</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setLineStyle(int lineStyle) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (data.lineStyle == lineStyle) return;
	switch (lineStyle) {
		case SWT.LINE_SOLID:
		case SWT.LINE_DASH:
		case SWT.LINE_DOT:
		case SWT.LINE_DASHDOT:
		case SWT.LINE_DASHDOTDOT:
			break;
		case SWT.LINE_CUSTOM:
			if (data.lineDashes == null) lineStyle = SWT.LINE_SOLID;
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.lineStyle = lineStyle;
	data.state &= ~LINE_STYLE;
}

/** 
 * Sets the width that will be used when drawing lines
 * for all of the figure drawing operations (that is,
 * <code>drawLine</code>, <code>drawRectangle</code>, 
 * <code>drawPolyline</code>, and so forth.
 * <p>
 * Note that line width of zero is used as a hint to
 * indicate that the fastest possible line drawing
 * algorithms should be used. This means that the
 * output may be different from line width one.
 * </p>
 *
 * @param lineWidth the width of a line
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setLineWidth(int lineWidth) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (data.lineWidth == lineWidth) return;
	data.lineWidth = lineWidth;
	data.state &= ~LINE_WIDTH;
	switch (data.lineStyle) {
		case SWT.LINE_DOT:
		case SWT.LINE_DASH:
		case SWT.LINE_DASHDOT:
		case SWT.LINE_DASHDOTDOT:
			data.state &= ~LINE_STYLE;
	}
}

/** 
 * If the argument is <code>true</code>, puts the receiver
 * in a drawing mode where the resulting color in the destination
 * is the <em>exclusive or</em> of the color values in the source
 * and the destination, and if the argument is <code>false</code>,
 * puts the receiver in a drawing mode where the destination color
 * is replaced with the source color value.
 * <p>
 * Note that this mode in fundamentally unsupportable on certain
 * platforms, notably Carbon (Mac OS X). Clients that want their
 * code to run on all platforms need to avoid this method.
 * </p>
 *
 * @param xor if <code>true</code>, then <em>xor</em> mode is used, otherwise <em>source copy</em> mode is used
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @deprecated this functionality is not supported on some platforms
 */
public void setXORMode(boolean xor) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	data.xorMode = xor;
}

/**
 * Sets the receiver's text anti-aliasing value to the parameter, 
 * which must be one of <code>SWT.DEFAULT</code>, <code>SWT.OFF</code>
 * or <code>SWT.ON</code>. Note that this controls anti-aliasing only
 * for all <em>text drawing</em> operations.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param antialias the anti-aliasing setting
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter is not one of <code>SWT.DEFAULT</code>,
 *                                 <code>SWT.OFF</code> or <code>SWT.ON</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see #getAdvanced
 * @see #setAdvanced
 * @see #setAntialias
 * 
 * @since 3.1
 */
public void setTextAntialias(int antialias) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	switch (antialias) {
		case SWT.DEFAULT:
		case SWT.OFF:
		case SWT.ON:
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	data.textAntialias = antialias;
}

/**
 * Sets the transform that is currently being used by the receiver. If
 * the argument is <code>null</code>, the current transform is set to
 * the identity transform.
 * <p>
 * This operation requires the operating system's advanced
 * graphics subsystem which may not be available on some
 * platforms.
 * </p>
 * 
 * @param transform the transform to set
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
 * </ul>
 * 
 * @see Transform
 * @see #getAdvanced
 * @see #setAdvanced
 * 
 * @since 3.1
 */
public void setTransform(Transform transform) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (transform != null && transform.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	data.transform = transform != null ? OS.gcnew_MatrixTransform(transform.handle) : 0;
	data.state &= ~TRANSFORM;
}

/**
 * Returns the extent of the given string. No tab
 * expansion or carriage return processing will be performed.
 * <p>
 * The <em>extent</em> of a string is the width and height of
 * the rectangular area it would cover if drawn in a particular
 * font (in this case, the current font in the receiver).
 * </p>
 *
 * @param string the string to measure
 * @return a point containing the extent of the string
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Point stringExtent(String string) {
	return textExtent(string, 0);
}

/**
 * Returns the extent of the given string. Tab expansion and
 * carriage return processing are performed.
 * <p>
 * The <em>extent</em> of a string is the width and height of
 * the rectangular area it would cover if drawn in a particular
 * font (in this case, the current font in the receiver).
 * </p>
 *
 * @param string the string to measure
 * @return a point containing the extent of the string
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Point textExtent(String string) {
	return textExtent(string, SWT.DRAW_DELIMITER | SWT.DRAW_TAB);
}

/**
 * Returns the extent of the given string. Tab expansion, line
 * delimiter and mnemonic processing are performed according to
 * the specified flags, which can be a combination of:
 * <dl>
 * <dt><b>DRAW_DELIMITER</b></dt>
 * <dd>draw multiple lines</dd>
 * <dt><b>DRAW_TAB</b></dt>
 * <dd>expand tabs</dd>
 * <dt><b>DRAW_MNEMONIC</b></dt>
 * <dd>underline the mnemonic character</dd>
 * <dt><b>DRAW_TRANSPARENT</b></dt>
 * <dd>transparent background</dd>
 * </dl>
 * <p>
 * The <em>extent</em> of a string is the width and height of
 * the rectangular area it would cover if drawn in a particular
 * font (in this case, the current font in the receiver).
 * </p>
 *
 * @param string the string to measure
 * @param flags the flags specifying how to process the text
 * @return a point containing the extent of the string
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Point textExtent(String string, int flags) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (string == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	checkGC(FONT);
	int length = string.length();
	char [] buffer = new char [length + 1];
	string.getChars (0, length, buffer, 0);
	if ((flags & (SWT.DRAW_DELIMITER | SWT.DRAW_TAB)) != (SWT.DRAW_DELIMITER | SWT.DRAW_TAB)) {
		for (int i = 0, j = 0; i < buffer.length; i++) {
			char c = buffer[i];
			switch (c) {
				case '\r':
				case '\n':
					if ((flags & SWT.DRAW_DELIMITER) == 0) continue;
					break;
				case '\t':
					if ((flags & SWT.DRAW_TAB) == 0) continue;
					break;
			}
			buffer[j++] = c;
		}
	}
	int str = OS.gcnew_String (buffer);
	int culture = OS.CultureInfo_CurrentUICulture();
	Font font = data.font;
	int direction = (data.style & SWT.RIGHT_TO_LEFT) != 0 ? OS.FlowDirection_RightToLeft : OS.FlowDirection_LeftToRight;
	int brush = OS.Brushes_White();
	int text = OS.gcnew_FormattedText(str, culture, direction, font.handle, font.size, brush);
	double width = OS.FormattedText_WidthIncludingTrailingWhitespace(text);
	double height = OS.FormattedText_Height(text);
	OS.GCHandle_Free(text);
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(culture);
	OS.GCHandle_Free(str);
	return new Point((int)width, (int)height);
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	if (isDisposed()) return "GC {*DISPOSED*}";
	return "GC {" + handle + "}";
}

/**	 
 * Invokes platform specific functionality to allocate a new graphics context.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>GC</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param drawable the Drawable for the receiver.
 * @param data the data for the receiver.
 *
 * @return a new <code>GC</code>
 */
public static GC wpf_new(Drawable drawable, GCData data) {
	GC gc = new GC();
	int hDC = drawable.internal_new_GC(data);
	gc.device = data.device;
	gc.init(drawable, data, hDC);
	return gc;
}

/**	 
 * Invokes platform specific functionality to wrap a graphics context.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>GC</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param hDC the Windows HDC.
 * @param data the data for the receiver.
 *
 * @return a new <code>GC</code>
 */
public static GC wpf_new(int hDC, GCData data) {
	GC gc = new GC();
	gc.device = data.device;
	gc.init(null, data, hDC);
	return gc;
}

}