org.eclipse.swt.graphics.Path.java Source code

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/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.graphics;

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

/**
 * Instances of this class represent paths through the two-dimensional
 * coordinate system. Paths do not have to be continuous, and can be
 * described using lines, rectangles, arcs, cubic or quadratic bezier curves,
 * glyphs, or other paths.
 * <p>
 * Application code must explicitly invoke the <code>Path.dispose()</code>
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required.
 * </p>
 * <p>
 * This class requires the operating system's advanced graphics subsystem
 * which may not be available on some platforms.
 * </p>
 *
 * @see <a href="http://www.eclipse.org/swt/snippets/#path">Path, Pattern snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: GraphicsExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 *
 * @since 3.1
 */
public class Path extends Resource {

    /**
     * the OS resource for the Path
     * (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>
     *
     * @noreference This field is not intended to be referenced by clients.
     */
    public NSBezierPath handle;

    boolean closed = true;

    /**
     * Constructs a new empty Path.
     * <p>
     * This operation requires the operating system's advanced
     * graphics subsystem which may not be available on some
     * platforms.
     * </p>
     * <p>
     * You must dispose the path when it is no longer required.
     * </p>
     *
     * @param device the device on which to allocate the path
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
     * </ul>
     * @exception SWTError <ul>
     *    <li>ERROR_NO_HANDLES if a handle for the path could not be obtained</li>
     * </ul>
     *
     * @see #dispose()
     */
    public Path(Device device) {
        super(device);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            handle = NSBezierPath.bezierPath();
            if (handle == null)
                SWT.error(SWT.ERROR_NO_HANDLES);
            handle.retain();
            handle.moveToPoint(new NSPoint());
            init();
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Constructs a new Path that is a copy of <code>path</code>. If
     * <code>flatness</code> is less than or equal to zero, an unflatten
     * copy of the path is created. Otherwise, it specifies the maximum
     * error between the path and its flatten copy. Smaller numbers give
     * better approximation.
     * <p>
     * This operation requires the operating system's advanced
     * graphics subsystem which may not be available on some
     * platforms.
     * </p>
     * <p>
     * You must dispose the path when it is no longer required.
     * </p>
     *
     * @param device the device on which to allocate the path
     * @param path the path to make a copy
     * @param flatness the flatness value
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device</li>
     *    <li>ERROR_NULL_ARGUMENT - if the path is null</li>
     *    <li>ERROR_INVALID_ARGUMENT - if the path has been disposed</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
     * </ul>
     * @exception SWTError <ul>
     *    <li>ERROR_NO_HANDLES if a handle for the path could not be obtained</li>
     * </ul>
     *
     * @see #dispose()
     * @since 3.4
     */
    public Path(Device device, Path path, float flatness) {
        super(device);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            if (path == null)
                SWT.error(SWT.ERROR_NULL_ARGUMENT);
            if (path.isDisposed())
                SWT.error(SWT.ERROR_INVALID_ARGUMENT);
            flatness = Math.max(0, flatness);
            if (flatness == 0) {
                handle = new NSBezierPath(path.handle.copy().id);
            } else {
                double defaultFlatness = NSBezierPath.defaultFlatness();
                NSBezierPath.setDefaultFlatness(flatness);
                handle = path.handle.bezierPathByFlatteningPath();
                handle.retain();
                NSBezierPath.setDefaultFlatness(defaultFlatness);
            }
            if (handle == null)
                SWT.error(SWT.ERROR_NO_HANDLES);
            init();
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Constructs a new Path with the specified PathData.
     * <p>
     * This operation requires the operating system's advanced
     * graphics subsystem which may not be available on some
     * platforms.
     * </p>
     * <p>
     * You must dispose the path when it is no longer required.
     * </p>
     *
     * @param device the device on which to allocate the path
     * @param data the data for the path
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device</li>
     *    <li>ERROR_NULL_ARGUMENT - if the data is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li>
     * </ul>
     * @exception SWTError <ul>
     *    <li>ERROR_NO_HANDLES if a handle for the path could not be obtained</li>
     * </ul>
     *
     * @see #dispose()
     * @since 3.4
     */
    public Path(Device device, PathData data) {
        this(device);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            if (data == null)
                SWT.error(SWT.ERROR_NULL_ARGUMENT);
            init(data);
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Adds to the receiver a circular or elliptical arc that lies within
     * the specified rectangular area.
     * <p>
     * The resulting arc begins at <code>startAngle</code> and extends
     * for <code>arcAngle</code> degrees.
     * 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> points wide
     * by <code>height + 1</code> points tall.
     * </p>
     *
     * @param x the x coordinate of the upper-left corner of the arc
     * @param y the y coordinate of the upper-left corner of the arc
     * @param width the width of the arc
     * @param height the height of the arc
     * @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 addArc(float x, float y, float width, float height, float startAngle, float arcAngle) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSAffineTransform transform = NSAffineTransform.transform();
            transform.translateXBy(x + width / 2f, y + height / 2f);
            transform.scaleXBy(width / 2f, height / 2f);
            NSBezierPath path = NSBezierPath.bezierPath();
            NSPoint center = new NSPoint();
            float sAngle = -startAngle;
            float eAngle = -(startAngle + arcAngle);
            path.appendBezierPathWithArcWithCenter(center, 1, sAngle, eAngle, arcAngle > 0);
            path.transformUsingAffineTransform(transform);
            //      handle.appendBezierPath(path);
            appendBezierPath(path);
            if (closed = (Math.abs(arcAngle) >= 360)) {
                handle.closePath();
            }
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    void appendBezierPath(NSBezierPath path) {
        int count = (int) path.elementCount();
        long points = C.malloc(3 * NSPoint.sizeof);
        if (points == 0)
            SWT.error(SWT.ERROR_NO_HANDLES);
        NSPoint pt1 = new NSPoint();
        NSPoint pt2 = new NSPoint();
        NSPoint pt3 = new NSPoint();
        for (int i = 0; i < count; i++) {
            int element = (int) path.elementAtIndex(i, points);
            switch (element) {
            case OS.NSMoveToBezierPathElement:
                OS.memmove(pt1, points, NSPoint.sizeof);
                if (closed) {
                    handle.moveToPoint(pt1);
                } else {
                    handle.lineToPoint(pt1);
                }
                break;
            case OS.NSLineToBezierPathElement:
                OS.memmove(pt1, points, NSPoint.sizeof);
                handle.lineToPoint(pt1);
                closed = false;
                break;
            case OS.NSCurveToBezierPathElement:
                OS.memmove(pt1, points, NSPoint.sizeof);
                OS.memmove(pt2, points + NSPoint.sizeof, NSPoint.sizeof);
                OS.memmove(pt3, points + NSPoint.sizeof + NSPoint.sizeof, NSPoint.sizeof);
                handle.curveToPoint(pt3, pt1, pt2);
                closed = false;
                break;
            case OS.NSClosePathBezierPathElement:
                handle.closePath();
                closed = true;
                break;
            }
        }
        C.free(points);
    }

    /**
     * Adds to the receiver the path described by the parameter.
     *
     * @param path the path to add to the receiver
     *
     * @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>
     */
    public void addPath(Path path) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        if (path == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        if (path.isDisposed())
            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            handle.appendBezierPath(path.handle);
            closed = path.closed;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Adds to the receiver the rectangle specified by x, y, width and height.
     *
     * @param x the x coordinate of the rectangle to add
     * @param y the y coordinate of the rectangle to add
     * @param width the width of the rectangle to add
     * @param height the height of the rectangle to add
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void addRectangle(float x, float y, float width, float height) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSRect rect = new NSRect();
        rect.x = x;
        rect.y = y;
        rect.width = width;
        rect.height = height;
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            handle.appendBezierPathWithRect(rect);
            closed = true;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Adds to the receiver the pattern of glyphs generated by drawing
     * the given string using the given font starting at the point (x, y).
     *
     * @param string the text to use
     * @param x the x coordinate of the starting point
     * @param y the y coordinate of the starting point
     * @param font the font to use
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the font is null</li>
     *    <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 addString(String string, float x, float y, Font font) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        if (font == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        if (font.isDisposed())
            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            closed = true;
            NSString str = NSString.stringWith(string);
            NSTextStorage textStorage = (NSTextStorage) new NSTextStorage().alloc().init();
            NSLayoutManager layoutManager = (NSLayoutManager) new NSLayoutManager().alloc().init();
            NSTextContainer textContainer = (NSTextContainer) new NSTextContainer().alloc();
            NSSize size = new NSSize();
            size.width = OS.MAX_TEXT_CONTAINER_SIZE;
            size.height = OS.MAX_TEXT_CONTAINER_SIZE;
            textContainer.initWithContainerSize(size);
            textContainer.setLineFragmentPadding(0);
            textStorage.addLayoutManager(layoutManager);
            layoutManager.addTextContainer(textContainer);
            NSRange range = new NSRange();
            range.length = str.length();
            /*
            * Feature in Cocoa. Adding attributes directly to a NSTextStorage causes
            * output to the console and eventually a segmentation fault when printing
            * on a thread other than the main thread. The fix is to add attributes to
            * a separate NSMutableAttributedString and add it to text storage when done.
            */
            NSMutableAttributedString attrStr = (NSMutableAttributedString) new NSMutableAttributedString().alloc();
            attrStr.id = attrStr.initWithString(str).id;
            attrStr.beginEditing();
            attrStr.addAttribute(OS.NSFontAttributeName, font.handle, range);
            font.addTraits(attrStr, range);
            attrStr.endEditing();
            textStorage.setAttributedString(attrStr);
            attrStr.release();
            range = layoutManager.glyphRangeForTextContainer(textContainer);
            if (range.length != 0) {
                long glyphs = C.malloc((range.length + 1) * 4);
                long count = layoutManager.getGlyphs(glyphs, range);
                NSBezierPath path = NSBezierPath.bezierPath();
                for (int i = 0; i < count; i++) {
                    NSPoint pt = layoutManager.locationForGlyphAtIndex(i);
                    NSRect lineFragmentRect = layoutManager.lineFragmentUsedRectForGlyphAtIndex(i, 0);
                    NSFont actualFont = new NSFont(textStorage.attribute(OS.NSFontAttributeName,
                            layoutManager.characterIndexForGlyphAtIndex(i), 0));
                    pt.x = pt.x + x + lineFragmentRect.x;
                    pt.y = -pt.y - y - lineFragmentRect.y;
                    path.moveToPoint(pt);
                    path.appendBezierPathWithGlyphs(glyphs + (i * 4), 1, actualFont);
                }
                C.free(glyphs);
                NSAffineTransform transform = NSAffineTransform.transform();
                transform.scaleXBy(1, -1);
                path.transformUsingAffineTransform(transform);
                handle.appendBezierPath(path);
            }
            textContainer.release();
            layoutManager.release();
            textStorage.release();
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Closes the current sub path by adding to the receiver a line
     * from the current point of the path back to the starting point
     * of the sub path.
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void close() {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            handle.closePath();
            closed = true;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Returns <code>true</code> if the specified point is contained by
     * the receiver and false otherwise.
     * <p>
     * If outline is <code>true</code>, the point (x, y) checked for containment in
     * the receiver's outline. If outline is <code>false</code>, the point is
     * checked to see if it is contained within the bounds of the (closed) area
     * covered by the receiver.
     *
     * @param x the x coordinate of the point to test for containment
     * @param y the y coordinate of the point to test for containment
     * @param gc the GC to use when testing for containment
     * @param outline controls whether to check the outline or contained area of the path
     * @return <code>true</code> if the path contains the point and <code>false</code> otherwise
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
     *    <li>ERROR_INVALID_ARGUMENT - if the gc has been disposed</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public boolean contains(float x, float y, GC gc, boolean outline) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        if (gc == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        if (gc.isDisposed())
            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            //TODO - see windows
            if (outline) {
                long pixel = C.malloc(4);
                if (pixel == 0)
                    SWT.error(SWT.ERROR_NO_HANDLES);
                int[] buffer = new int[] { 0xFFFFFFFF };
                C.memmove(pixel, buffer, 4);
                long colorspace = OS.CGColorSpaceCreateDeviceRGB();
                long context = OS.CGBitmapContextCreate(pixel, 1, 1, 8, 4, colorspace,
                        OS.kCGImageAlphaNoneSkipFirst);
                OS.CGColorSpaceRelease(colorspace);
                if (context == 0) {
                    C.free(pixel);
                    SWT.error(SWT.ERROR_NO_HANDLES);
                }
                GCData data = gc.data;
                int capStyle = 0;
                switch (data.lineCap) {
                case SWT.CAP_ROUND:
                    capStyle = OS.kCGLineCapRound;
                    break;
                case SWT.CAP_FLAT:
                    capStyle = OS.kCGLineCapButt;
                    break;
                case SWT.CAP_SQUARE:
                    capStyle = OS.kCGLineCapSquare;
                    break;
                }
                OS.CGContextSetLineCap(context, capStyle);
                int joinStyle = 0;
                switch (data.lineJoin) {
                case SWT.JOIN_MITER:
                    joinStyle = OS.kCGLineJoinMiter;
                    break;
                case SWT.JOIN_ROUND:
                    joinStyle = OS.kCGLineJoinRound;
                    break;
                case SWT.JOIN_BEVEL:
                    joinStyle = OS.kCGLineJoinBevel;
                    break;
                }
                OS.CGContextSetLineJoin(context, joinStyle);
                OS.CGContextSetLineWidth(context, data.lineWidth);
                OS.CGContextTranslateCTM(context, -x + 0.5f, -y + 0.5f);
                long path = GC.createCGPathRef(handle);
                OS.CGContextAddPath(context, path);
                OS.CGPathRelease(path);
                OS.CGContextStrokePath(context);
                OS.CGContextRelease(context);
                C.memmove(buffer, pixel, 4);
                C.free(pixel);
                return buffer[0] != 0xFFFFFFFF;
            } else {
                NSPoint point = new NSPoint();
                point.x = x;
                point.y = y;
                return handle.containsPoint(point);
            }
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Adds to the receiver a cubic bezier curve based on the parameters.
     *
     * @param cx1 the x coordinate of the first control point of the spline
     * @param cy1 the y coordinate of the first control of the spline
     * @param cx2 the x coordinate of the second control of the spline
     * @param cy2 the y coordinate of the second control of the spline
     * @param x the x coordinate of the end point of the spline
     * @param y the y coordinate of the end point of the spline
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void cubicTo(float cx1, float cy1, float cx2, float cy2, float x, float y) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSPoint pt = new NSPoint();
            pt.x = x;
            pt.y = y;
            NSPoint ct1 = new NSPoint();
            ct1.x = cx1;
            ct1.y = cy1;
            NSPoint ct2 = new NSPoint();
            ct2.x = cx2;
            ct2.y = cy2;
            handle.curveToPoint(pt, ct1, ct2);
            closed = false;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    @Override
    void destroy() {
        handle.release();
        handle = null;
    }

    /**
     * Replaces the first four elements in the parameter with values that
     * describe the smallest rectangle that will completely contain the
     * receiver (i.e. the bounding box).
     *
     * @param bounds the array to hold the result
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
     *    <li>ERROR_INVALID_ARGUMENT - if the parameter is too small to hold the bounding box</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void getBounds(float[] bounds) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        if (bounds == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        if (bounds.length < 4)
            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSRect rect = handle.controlPointBounds();
            bounds[0] = (float) rect.x;
            bounds[1] = (float) rect.y;
            bounds[2] = (float) rect.width;
            bounds[3] = (float) rect.height;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Replaces the first two elements in the parameter with values that
     * describe the current point of the path.
     *
     * @param point the array to hold the result
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the parameter is null</li>
     *    <li>ERROR_INVALID_ARGUMENT - if the parameter is too small to hold the end point</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void getCurrentPoint(float[] point) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        if (point == null)
            SWT.error(SWT.ERROR_NULL_ARGUMENT);
        if (point.length < 2)
            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSPoint pt = handle.currentPoint();
            point[0] = (float) pt.x;
            point[1] = (float) pt.y;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Returns a device independent representation of the receiver.
     *
     * @return the PathData for the receiver
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     *
     * @see PathData
     */
    public PathData getPathData() {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            int count = (int) handle.elementCount();
            int pointCount = 0, typeCount = 0;
            byte[] types = new byte[count];
            float[] pointArray = new float[count * 6];
            long points = C.malloc(3 * NSPoint.sizeof);
            if (points == 0)
                SWT.error(SWT.ERROR_NO_HANDLES);
            NSPoint pt = new NSPoint();
            for (int i = 0; i < count; i++) {
                int element = (int) handle.elementAtIndex(i, points);
                switch (element) {
                case OS.NSMoveToBezierPathElement:
                    types[typeCount++] = SWT.PATH_MOVE_TO;
                    OS.memmove(pt, points, NSPoint.sizeof);
                    pointArray[pointCount++] = (float) pt.x;
                    pointArray[pointCount++] = (float) pt.y;
                    break;
                case OS.NSLineToBezierPathElement:
                    types[typeCount++] = SWT.PATH_LINE_TO;
                    OS.memmove(pt, points, NSPoint.sizeof);
                    pointArray[pointCount++] = (float) pt.x;
                    pointArray[pointCount++] = (float) pt.y;
                    break;
                case OS.NSCurveToBezierPathElement:
                    types[typeCount++] = SWT.PATH_CUBIC_TO;
                    OS.memmove(pt, points, NSPoint.sizeof);
                    pointArray[pointCount++] = (float) pt.x;
                    pointArray[pointCount++] = (float) pt.y;
                    OS.memmove(pt, points + NSPoint.sizeof, NSPoint.sizeof);
                    pointArray[pointCount++] = (float) pt.x;
                    pointArray[pointCount++] = (float) pt.y;
                    OS.memmove(pt, points + NSPoint.sizeof + NSPoint.sizeof, NSPoint.sizeof);
                    pointArray[pointCount++] = (float) pt.x;
                    pointArray[pointCount++] = (float) pt.y;
                    break;
                case OS.NSClosePathBezierPathElement:
                    types[typeCount++] = SWT.PATH_CLOSE;
                    break;
                }
            }
            C.free(points);
            if (pointCount != pointArray.length) {
                float[] temp = new float[pointCount];
                System.arraycopy(pointArray, 0, temp, 0, pointCount);
                pointArray = temp;
            }
            PathData data = new PathData();
            data.types = types;
            data.points = pointArray;
            return data;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    void init(PathData data) {
        byte[] types = data.types;
        float[] points = data.points;
        for (int i = 0, j = 0; i < types.length; i++) {
            switch (types[i]) {
            case SWT.PATH_MOVE_TO:
                moveTo(points[j++], points[j++]);
                break;
            case SWT.PATH_LINE_TO:
                lineTo(points[j++], points[j++]);
                break;
            case SWT.PATH_CUBIC_TO:
                cubicTo(points[j++], points[j++], points[j++], points[j++], points[j++], points[j++]);
                break;
            case SWT.PATH_QUAD_TO:
                quadTo(points[j++], points[j++], points[j++], points[j++]);
                break;
            case SWT.PATH_CLOSE:
                close();
                break;
            default:
                dispose();
                SWT.error(SWT.ERROR_INVALID_ARGUMENT);
            }
        }
    }

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

    /**
     * Adds to the receiver a line from the current point to
     * the point specified by (x, y).
     *
     * @param x the x coordinate of the end of the line to add
     * @param y the y coordinate of the end of the line to add
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void lineTo(float x, float y) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSPoint pt = new NSPoint();
            pt.x = x;
            pt.y = y;
            handle.lineToPoint(pt);
            closed = false;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Sets the current point of the receiver to the point
     * specified by (x, y). Note that this starts a new
     * sub path.
     *
     * @param x the x coordinate of the new end point
     * @param y the y coordinate of the new end point
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void moveTo(float x, float y) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSPoint pt = new NSPoint();
            pt.x = x;
            pt.y = y;
            handle.moveToPoint(pt);
            closed = true;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

    /**
     * Adds to the receiver a quadratic curve based on the parameters.
     *
     * @param cx the x coordinate of the control point of the spline
     * @param cy the y coordinate of the control point of the spline
     * @param x the x coordinate of the end point of the spline
     * @param y the y coordinate of the end point of the spline
     *
     * @exception SWTException <ul>
     *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
     * </ul>
     */
    public void quadTo(float cx, float cy, float x, float y) {
        if (isDisposed())
            SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
        NSAutoreleasePool pool = null;
        if (!NSThread.isMainThread())
            pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
        try {
            NSPoint current = handle.isEmpty() ? new NSPoint() : handle.currentPoint();
            NSPoint ct1 = new NSPoint();
            ct1.x = current.x + 2 * (cx - current.x) / 3;
            ct1.y = current.y + 2 * (cy - current.y) / 3;
            NSPoint ct2 = new NSPoint();
            ct2.x = ct1.x + (x - current.x) / 3;
            ct2.y = ct1.y + (y - current.y) / 3;
            NSPoint pt = new NSPoint();
            pt.x = x;
            pt.y = y;
            handle.curveToPoint(pt, ct1, ct2);
            closed = false;
        } finally {
            if (pool != null)
                pool.release();
        }
    }

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

}