org.eclipse.swt.graphics.Region Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2000, 2018 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.cairo.*;
import org.eclipse.swt.internal.gtk.*;
/**
* Instances of this class represent areas of an x-y coordinate
* system that are aggregates of the areas covered by a number
* of polygons.
*
* Application code must explicitly invoke the Region.dispose()
* method to release the operating system resources managed by each instance
* when those instances are no longer required.
*
*
* @see SWT Example: GraphicsExample
* @see Sample code and further information
*/
public final class Region extends Resource {
/**
* the OS resource for the region
* (Warning: This field is platform dependent)
*
* IMPORTANT: This field is not 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.
*
*
* @noreference This field is not intended to be referenced by clients.
*/
public long handle;
/**
* Constructs a new empty region.
*
* You must dispose the region when it is no longer required.
*
*
* @exception SWTError
* - ERROR_NO_HANDLES if a handle could not be obtained for region creation
*
*
* @see #dispose()
*/
public Region() {
this(null);
}
/**
* Constructs a new empty region.
*
* You must dispose the region when it is no longer required.
*
*
* @param device the device on which to allocate the region
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if device is null and there is no current device
*
* @exception SWTError
* - ERROR_NO_HANDLES if a handle could not be obtained for region creation
*
*
* @see #dispose()
*
* @since 3.0
*/
public Region(Device device) {
super(device);
handle = Cairo.cairo_region_create();
if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
init();
}
Region(Device device, long handle) {
super(device);
this.handle = handle;
}
static long gdk_region_polygon(int[] pointArray, int npoints, int fill_rule) {
//TODO this does not perform well and could fail if the polygon is too big
int minX = pointArray[0], maxX = minX;
int minY = pointArray[1], maxY = minY;
int count = npoints * 2;
for (int i=2; i maxX) maxX = x;
if (y < minY) minY = y;
if (y > maxY) maxY = y;
}
long surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_FORMAT_ARGB32, maxX - minX, maxY - minY);
if (surface == 0) SWT.error(SWT.ERROR_NO_HANDLES);
long cairo = Cairo.cairo_create(surface);
if (cairo == 0) SWT.error(SWT.ERROR_NO_HANDLES);
Cairo.cairo_move_to(cairo, pointArray[0] - minX, pointArray[1] - minY);
for (int i=2; i
* ERROR_NULL_ARGUMENT - if the argument is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
addInPixels(DPIUtil.autoScaleUp(pointArray));
}
void addInPixels (int[] pointArray) {
/*
* Bug in GTK. If gdk_region_polygon() is called with one point,
* it segment faults. The fix is to make sure that it is called
* with enough points for a polygon.
*/
if (pointArray.length < 6) return;
long polyRgn = gdk_region_polygon(pointArray, pointArray.length / 2, GDK.GDK_EVEN_ODD_RULE);
Cairo.cairo_region_union(handle, polyRgn);
Cairo.cairo_region_destroy(polyRgn);
}
/**
* 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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void add(Rectangle rect) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
addInPixels(DPIUtil.autoScaleUp(rect));
}
void addInPixels(Rectangle rect) {
addInPixels (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
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
add(new Rectangle(x, y, width, height));
}
void addInPixels(int x, int y, int width, int height) {
cairo_rectangle_int_t rect = new cairo_rectangle_int_t();
rect.x = x;
rect.y = y;
rect.width = width;
rect.height = height;
Cairo.cairo_region_union_rectangle(handle, rect);
}
/**
* 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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the argument has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
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);
Cairo.cairo_region_union(handle, region.handle);
}
/**
* Returns true
if the point specified by the
* arguments is inside the area specified by the receiver,
* and false
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 true
if the region contains the point and false
otherwise
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public boolean contains(int x, int y) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return contains(new Point(x, y));
}
boolean containsInPixels(int x, int y) {
return Cairo.cairo_region_contains_point(handle, x, y);
}
/**
* Returns true
if the given point is inside the
* area specified by the receiver, and false
* otherwise.
*
* @param pt the point to test for containment
* @return true
if the region contains the point and false
otherwise
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the argument is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public boolean contains(Point pt) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return containsInPixels(DPIUtil.autoScaleUp(pt));
}
boolean containsInPixels(Point pt) {
if (pt == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
return containsInPixels(pt.x, pt.y);
}
@Override
void destroy() {
Cairo.cairo_region_destroy(handle);
handle = 0;
}
/**
* Compares the argument to the receiver, and returns true
* if they represent the same object using a class
* specific comparison.
*
* @param object the object to compare with this object
* @return true
if the object is the same as this object and false
otherwise
*
* @see #hashCode
*/
@Override
public boolean equals(Object object) {
if (this == object) return true;
if (!(object instanceof Region)) return false;
Region region = (Region)object;
return handle == region.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
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see Rectangle#union
*/
public Rectangle getBounds() {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return DPIUtil.autoScaleDown(getBoundsInPixels());
}
Rectangle getBoundsInPixels() {
cairo_rectangle_int_t rect = new cairo_rectangle_int_t();
Cairo.cairo_region_get_extents(handle, rect);
return new Rectangle(rect.x, rect.y, rect.width, rect.height);
}
/**
* Invokes platform specific functionality to allocate a new region.
*
* IMPORTANT: This method is not part of the public
* API for Region
. 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.
*
*
* @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 gtk_new(Device device, long handle) {
return new Region(device, handle);
}
/**
* Returns an integer hash code for the receiver. Any two
* objects that return true
when passed to
* equals
must return the same value for this
* method.
*
* @return the receiver's hash
*
* @see #equals
*/
@Override
public int hashCode() {
return (int)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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
intersectInPixels(DPIUtil.autoScaleUp(rect));
}
void intersectInPixels(Rectangle rect) {
intersectInPixels (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
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
intersect(new Rectangle(x, y, width, height));
}
void intersectInPixels(int x, int y, int width, int height) {
cairo_rectangle_int_t rect = new cairo_rectangle_int_t();
rect.x = x;
rect.y = y;
rect.width = width;
rect.height = height;
long rectRgn = Cairo.cairo_region_create_rectangle(rect);
Cairo.cairo_region_intersect(handle, rectRgn);
Cairo.cairo_region_destroy(rectRgn);
}
/**
* 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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the argument has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
Cairo.cairo_region_intersect(handle, region.handle);
}
/**
* Returns true
if the rectangle described by the
* arguments intersects with any of the polygons the receiver
* maintains to describe its area, and false
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 true
if the rectangle intersects with the receiver, and false
otherwise
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see Rectangle#intersects(Rectangle)
*/
public boolean intersects (int x, int y, int width, int height) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return intersects(new Rectangle(x, y, width, height));
}
boolean intersectsInPixels (int x, int y, int width, int height) {
cairo_rectangle_int_t rect = new cairo_rectangle_int_t();
rect.x = x;
rect.y = y;
rect.width = width;
rect.height = height;
return Cairo.cairo_region_contains_rectangle(handle, rect) != Cairo.CAIRO_REGION_OVERLAP_OUT;
}
/**
* Returns true
if the given rectangle intersects
* with any of the polygons the receiver maintains to describe
* its area and false
otherwise.
*
* @param rect the rectangle to test for intersection
* @return true
if the rectangle intersects with the receiver, and false
otherwise
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the argument is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see Rectangle#intersects(Rectangle)
*/
public boolean intersects(Rectangle rect) {
if (rect == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return intersectsInPixels(DPIUtil.autoScaleUp(rect));
}
boolean intersectsInPixels(Rectangle rect) {
return intersectsInPixels(rect.x, rect.y, rect.width, rect.height);
}
/**
* Returns true
if the region has been disposed,
* and false
otherwise.
*
* 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 true
when the region is disposed, and false
otherwise
*/
@Override
public boolean isDisposed() {
return handle == 0;
}
/**
* Returns true
if the receiver does not cover any
* area in the (x, y) coordinate plane, and false
if
* the receiver does cover some area in the plane.
*
* @return true
if the receiver is empty, and false
otherwise
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public boolean isEmpty() {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
return Cairo.cairo_region_is_empty(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
* - ERROR_NULL_ARGUMENT - if the argument is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
subtractInPixels(DPIUtil.autoScaleUp(pointArray));
}
void subtractInPixels (int[] pointArray) {
/*
* Bug in GTK. If gdk_region_polygon() is called with one point,
* it segment faults. The fix is to make sure that it is called
* with enough points for a polygon.
*/
if (pointArray.length < 6) return;
long polyRgn = gdk_region_polygon(pointArray, pointArray.length / 2, GDK.GDK_EVEN_ODD_RULE);
Cairo.cairo_region_subtract(handle, polyRgn);
Cairo.cairo_region_destroy(polyRgn);
}
/**
* 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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
subtractInPixels(DPIUtil.autoScaleUp(rect));
}
void subtractInPixels(Rectangle rect) {
subtractInPixels (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
* - ERROR_INVALID_ARGUMENT - if the rectangle's width or height is negative
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
subtract(new Rectangle(x, y, width, height));
}
void subtractInPixels(int x, int y, int width, int height) {
cairo_rectangle_int_t rect = new cairo_rectangle_int_t ();
rect.x = x;
rect.y = y;
rect.width = width;
rect.height = height;
long rectRgn = Cairo.cairo_region_create_rectangle(rect);
Cairo.cairo_region_subtract(handle, rectRgn);
Cairo.cairo_region_destroy(rectRgn);
}
/**
* 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
* - ERROR_NULL_ARGUMENT - if the argument is null
* - ERROR_INVALID_ARGUMENT - if the argument has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
Cairo.cairo_region_subtract(handle, region.handle);
}
/**
* 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
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @since 3.1
*/
public void translate (int x, int y) {
if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
translate(new Point(x, y));
}
void translateInPixels (int x, int y) {
Cairo.cairo_region_translate (handle, x, y);
}
/**
* Translate all of the polygons the receiver maintains to describe
* its area by the specified point.
*
* @param pt the point to translate
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the argument is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @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);
pt = DPIUtil.autoScaleUp(pt);
translateInPixels(pt.x, pt.y);
}
/**
* 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 "Region {*DISPOSED*}";
return "Region {" + handle + "}";
}
}