Java tutorial
/******************************************************************************* * 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.*; /** * Instances of this class represent areas of an x-y coordinate * system that are aggregates of the areas covered by a number * of polygons. * <p> * Application code must explicitly invoke the <code>Region.dispose()</code> * method to release the operating system resources managed by each instance * when those instances are no longer required. * </p> * * @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> */ public final class Region extends Resource { /** * the OS resource for the region * (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 int handle; /** * Constructs a new empty region. * * @exception SWTError <ul> * <li>ERROR_NO_HANDLES if a handle could not be obtained for region creation</li> * </ul> */ public Region() { this(null); } /** * Constructs a new empty region. * <p> * You must dispose the region when it is no longer required. * </p> * * @param device the device on which to allocate the region * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li> * </ul> * @exception SWTError <ul> * <li>ERROR_NO_HANDLES if a handle could not be obtained for region creation</li> * </ul> * * @see #dispose * * @since 3.0 */ public Region(Device device) { super(device); handle = OS.gcnew_GeometryGroup(); if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES); init(); } /** * Constructs a new region given a handle to the operating * system resources that it should represent. * * @param handle the handle for the result */ Region(Device device, int handle) { super(device); this.handle = handle; } /** * Adds the given polygon to the collection of polygons * the receiver maintains to describe its area. * * @param pointArray points that describe the polygon to merge with the receiver * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 * */ public void add(int[] pointArray) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); combine(pointArray, OS.GeometryCombineMode_Union); } /** * Adds the given rectangle to the collection of polygons * the receiver maintains to describe its area. * * @param rect the rectangle to merge with the receiver * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */ public void add(Rectangle rect) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); add(rect.x, rect.y, rect.width, rect.height); } /** * Adds the given rectangle to the collection of polygons * the receiver maintains to describe its area. * * @param x the x coordinate of the rectangle * @param y the y coordinate of the rectangle * @param width the width coordinate of the rectangle * @param height the height coordinate of the rectangle * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.1 */ public void add(int x, int y, int width, int height) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (width < 0 || height < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT); int rect = OS.gcnew_Rect(x, y, width, height); int geometry1 = OS.gcnew_RectangleGeometry(rect); int geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) == 0) { OS.GeometryCollection_Add(geometries, geometry1); } else { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Union, geometry1, geometry2); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(rect); OS.GCHandle_Free(geometry1); OS.GCHandle_Free(geometries); } /** * Adds all of the polygons which make up the area covered * by the argument to the collection of polygons the receiver * maintains to describe its area. * * @param region the region to merge * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */ public void add(Region region) { if (isDisposed()) 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 geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) == 0) { OS.GeometryCollection_Add(geometries, region.handle); } else { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Union, region.handle, geometry2); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(geometries); } void combine(int[] pointArray, int mode) { if (pointArray.length < 4) return; int list = OS.gcnew_PointCollection(pointArray.length / 2); for (int i = 2; i < pointArray.length; i += 2) { int point = OS.gcnew_Point(pointArray[i], pointArray[i + 1]); OS.PointCollection_Add(list, point); OS.GCHandle_Free(point); } int poly = OS.gcnew_PolyLineSegment(list, true); OS.GCHandle_Free(list); int figure = OS.gcnew_PathFigure(); int startPoint = OS.gcnew_Point(pointArray[0], pointArray[1]); OS.PathFigure_StartPoint(figure, startPoint); OS.PathFigure_IsClosed(figure, true); int segments = OS.PathFigure_Segments(figure); OS.PathSegmentCollection_Add(segments, poly); int path = OS.gcnew_PathGeometry(); int figures = OS.PathGeometry_Figures(path); OS.PathFigureCollection_Add(figures, figure); int geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) == 0) { if (mode == OS.GeometryCombineMode_Union) OS.GeometryCollection_Add(geometries, path); } else { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(mode, geometry2, path); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(geometries); OS.GCHandle_Free(figures); OS.GCHandle_Free(path); OS.GCHandle_Free(segments); OS.GCHandle_Free(figure); OS.GCHandle_Free(startPoint); OS.GCHandle_Free(poly); } /** * Returns <code>true</code> if the point specified by the * arguments is inside the area specified by the receiver, * and <code>false</code> otherwise. * * @param x the x coordinate of the point to test for containment * @param y the y coordinate of the point to test for containment * @return <code>true</code> if the region contains the point and <code>false</code> otherwise * * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */ public boolean contains(int x, int y) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); int point = OS.gcnew_Point(x, y); boolean result = OS.Geometry_FillContains(handle, point); OS.GCHandle_Free(point); return result; } /** * Returns <code>true</code> if the given point is inside the * area specified by the receiver, and <code>false</code> * otherwise. * * @param pt the point to test for containment * @return <code>true</code> if the region contains the point and <code>false</code> otherwise * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */ public boolean contains(Point pt) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (pt == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); return contains(pt.x, pt.y); } void destroy() { OS.GCHandle_Free(handle); handle = 0; } /** * 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) { if (this == object) return true; if (!(object instanceof Region)) return false; Region rgn = (Region) object; return handle == rgn.handle; } /** * Returns a rectangle which represents the rectangular * union of the collection of polygons the receiver * maintains to describe its area. * * @return a bounding rectangle for the region * * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see Rectangle#union */ public Rectangle getBounds() { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (OS.Geometry_IsEmpty(handle)) return new Rectangle(0, 0, 0, 0); int rect = OS.Geometry_Bounds(handle); Rectangle result = new Rectangle((int) OS.Rect_X(rect), (int) OS.Rect_Y(rect), (int) OS.Rect_Width(rect), (int) OS.Rect_Height(rect)); OS.GCHandle_Free(rect); return result; } /** * 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 * * @see #equals */ public int hashCode() { return handle; } /** * Intersects the given rectangle to the collection of polygons * the receiver maintains to describe its area. * * @param rect the rectangle to intersect with the receiver * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 */ public void intersect(Rectangle rect) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); intersect(rect.x, rect.y, rect.width, rect.height); } /** * Intersects the given rectangle to the collection of polygons * the receiver maintains to describe its area. * * @param x the x coordinate of the rectangle * @param y the y coordinate of the rectangle * @param width the width coordinate of the rectangle * @param height the height coordinate of the rectangle * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.1 */ public void intersect(int x, int y, int width, int height) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (width < 0 || height < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT); int rect = OS.gcnew_Rect(x, y, width, height); int geometry1 = OS.gcnew_RectangleGeometry(rect); int geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) != 0) { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Intersect, geometry1, geometry2); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(rect); OS.GCHandle_Free(geometry1); OS.GCHandle_Free(geometries); } /** * Intersects all of the polygons which make up the area covered * by the argument to the collection of polygons the receiver * maintains to describe its area. * * @param region the region to intersect * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 */ public void intersect(Region region) { if (isDisposed()) 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 geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) != 0) { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Intersect, region.handle, geometry2); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(geometries); } /** * Returns <code>true</code> if the rectangle described by the * arguments intersects with any of the polygons the receiver * maintains to describe its area, and <code>false</code> otherwise. * * @param x the x coordinate of the origin of the rectangle * @param y the y coordinate of the origin of the rectangle * @param width the width of the rectangle * @param height the height of the rectangle * @return <code>true</code> if the rectangle intersects with the receiver, and <code>false</code> otherwise * * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see Rectangle#intersects(Rectangle) */ public boolean intersects(int x, int y, int width, int height) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); int rect = OS.gcnew_Rect(x, y, width, height); int geometry = OS.gcnew_RectangleGeometry(rect); int result = OS.Geometry_FillContainsWithDetail(handle, geometry); OS.GCHandle_Free(geometry); OS.GCHandle_Free(rect); return result != OS.IntersectionDetail_Empty; } /** * Returns <code>true</code> if the given rectangle intersects * with any of the polygons the receiver maintains to describe * its area and <code>false</code> otherwise. * * @param rect the rectangle to test for intersection * @return <code>true</code> if the rectangle intersects with the receiver, and <code>false</code> otherwise * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see Rectangle#intersects(Rectangle) */ public boolean intersects(Rectangle rect) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); return intersects(rect.x, rect.y, rect.width, rect.height); } /** * Returns <code>true</code> if the region has been disposed, * and <code>false</code> otherwise. * <p> * This method gets the dispose state for the region. * When a region has been disposed, it is an error to * invoke any other method (except {@link #dispose()}) using the region. * * @return <code>true</code> when the region is disposed, and <code>false</code> otherwise */ public boolean isDisposed() { return handle == 0; } /** * Returns <code>true</code> if the receiver does not cover any * area in the (x, y) coordinate plane, and <code>false</code> if * the receiver does cover some area in the plane. * * @return <code>true</code> if the receiver is empty, and <code>false</code> otherwise * * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */ public boolean isEmpty() { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); return OS.Geometry_IsEmpty(handle); } /** * Subtracts the given polygon from the collection of polygons * the receiver maintains to describe its area. * * @param pointArray points that describe the polygon to merge with the receiver * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 */ public void subtract(int[] pointArray) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); combine(pointArray, OS.GeometryCombineMode_Exclude); } /** * Subtracts the given rectangle from the collection of polygons * the receiver maintains to describe its area. * * @param rect the rectangle to subtract from the receiver * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 */ public void subtract(Rectangle rect) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); subtract(rect.x, rect.y, rect.width, rect.height); } /** * Subtracts the given rectangle from the collection of polygons * the receiver maintains to describe its area. * * @param x the x coordinate of the rectangle * @param y the y coordinate of the rectangle * @param width the width coordinate of the rectangle * @param height the height coordinate of the rectangle * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.1 */ public void subtract(int x, int y, int width, int height) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (width < 0 || height < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT); int rect = OS.gcnew_Rect(x, y, width, height); int geometry1 = OS.gcnew_RectangleGeometry(rect); int geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) != 0) { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Exclude, geometry2, geometry1); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(rect); OS.GCHandle_Free(geometry1); OS.GCHandle_Free(geometries); } /** * Subtracts all of the polygons which make up the area covered * by the argument from the collection of polygons the receiver * maintains to describe its area. * * @param region the region to subtract * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.0 */ public void subtract(Region region) { if (isDisposed()) 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 geometries = OS.GeometryGroup_Children(handle); if (OS.GeometryCollection_Count(geometries) != 0) { int geometry2 = OS.GeometryGroup_Children(handle, 0); int geometry3 = OS.gcnew_CombinedGeometry(OS.GeometryCombineMode_Exclude, geometry2, region.handle); OS.GeometryCollection_Remove(geometries, geometry2); OS.GeometryCollection_Add(geometries, geometry3); OS.GCHandle_Free(geometry2); OS.GCHandle_Free(geometry3); } OS.GCHandle_Free(geometries); } /** * Translate all of the polygons the receiver maintains to describe * its area by the specified point. * * @param x the x coordinate of the point to translate * @param y the y coordinate of the point to translate * * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.1 */ public void translate(int x, int y) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); int transform1 = OS.Geometry_Transform(handle); int transform2 = OS.gcnew_TranslateTransform(x, y); int transform = OS.gcnew_TransformGroup(); int transforms = OS.TransformGroup_Children(transform); OS.TransformCollection_Add(transforms, transform1); OS.TransformCollection_Add(transforms, transform2); OS.Geometry_Transform(handle, transform); OS.GCHandle_Free(transform1); OS.GCHandle_Free(transform2); OS.GCHandle_Free(transform); OS.GCHandle_Free(transforms); } /** * Translate all of the polygons the receiver maintains to describe * its area by the specified point. * * @param pt the point to translate * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * </ul> * @exception SWTException <ul> * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> * * @since 3.1 */ public void translate(Point pt) { if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); if (pt == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); translate(pt.x, pt.y); } /** * 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 "Region {*DISPOSED*}"; return "Region {" + handle + "}"; } /** * Invokes platform specific functionality to allocate a new region. * <p> * <b>IMPORTANT:</b> This method is <em>not</em> part of the public * API for <code>Region</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 device the device on which to allocate the region * @param handle the handle for the region * @return a new region object containing the specified device and handle * * @noreference This method is not intended to be referenced by clients. */ public static Region wpf_new(Device device, int handle) { return new Region(device, handle); } }