/*******************************************************************************
 * 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module org.eclipse.swt.graphics.Region;

import java.lang.all;


import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Resource;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.internal.gtk.OS;


/**
 * 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 : 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>
     */
    public GdkRegion* 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 this() {
    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 this(Device device) {
    super(device);
    handle = OS.gdk_region_new();
    if (handle is null) SWT.error(SWT.ERROR_NO_HANDLES);
    init_();
}

this(Device device, GdkRegion* 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 is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    /*
    * 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;
    auto polyRgn = OS.gdk_region_polygon(cast(GdkPoint*)pointArray.ptr,
                      cast(int)/*64bit*/pointArray.length / 2, OS.GDK_EVEN_ODD_RULE);
    OS.gdk_region_union(handle, polyRgn);
    OS.gdk_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 <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 is 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);
    GdkRectangle* gdkRect = new GdkRectangle();
    gdkRect.x = x;
    gdkRect.y = y;
    gdkRect.width = width;
    gdkRect.height = height;
    OS.gdk_region_union_with_rect(handle, gdkRect);
}

/**
 * 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 is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    if (region.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
    OS.gdk_region_union(handle, region.handle);
}

/**
 * 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 bool contains(int x, int y) {
    if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
    return cast(bool)OS.gdk_region_point_in(handle, x, y);
}

/**
 * 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 bool contains(Point pt) {
    if (pt is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    return contains(pt.x, pt.y);
}

override
void destroy() {
    OS.gdk_region_destroy(handle);
    handle = null;
}

/**
 * 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 override equals_t opEquals(Object object) {
    if (this is object) return true;
    if ( auto region = cast(Region)object ){
        return handle is region.handle;
    }
    return false;
}

/**
 * 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);
    GdkRectangle* gdkRect = new GdkRectangle();
    OS.gdk_region_get_clipbox(handle, gdkRect);
    return new Rectangle(gdkRect.x, gdkRect.y, gdkRect.width, gdkRect.height);
}

public static Region gtk_new(Device device, GdkRegion* handle) {
    return new Region(device, handle);
}

/**
 * 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 override hash_t toHash() {
    return cast(hash_t)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 is 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);
    GdkRectangle* gdkRect = new GdkRectangle();
    gdkRect.x = x;
    gdkRect.y = y;
    gdkRect.width = width;
    gdkRect.height = height;
    auto rectRgn = OS.gdk_region_rectangle(gdkRect);
    OS.gdk_region_intersect(handle, rectRgn);
    OS.gdk_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 <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 is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    if (region.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
    OS.gdk_region_intersect(handle, region.handle);
}

/**
 * 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 bool intersects (int x, int y, int width, int height) {
    if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
    GdkRectangle* gdkRect = new GdkRectangle();
    gdkRect.x = x;
    gdkRect.y = y;
    gdkRect.width = width;
    gdkRect.height = height;
    return OS.gdk_region_rect_in(handle, gdkRect) !is OS.GDK_OVERLAP_RECTANGLE_OUT;
}
/**
 * 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 bool intersects(Rectangle rect) {
    if (rect is 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 using the region.
 *
 * @return <code>true</code> when the region is disposed, and <code>false</code> otherwise
 */
public override bool isDisposed() {
    return handle is null;
}

/**
 * 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 bool isEmpty() {
    if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
    return cast(bool)OS.gdk_region_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 <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 is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    /*
    * 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;
    auto polyRgn = OS.gdk_region_polygon( cast(GdkPoint*)pointArray.ptr,
                      cast(int)/*64bit*/pointArray.length / 2, OS.GDK_EVEN_ODD_RULE);
    OS.gdk_region_subtract(handle, polyRgn);
    OS.gdk_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 <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 is 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);
    GdkRectangle* gdkRect = new GdkRectangle();
    gdkRect.x = x;
    gdkRect.y = y;
    gdkRect.width = width;
    gdkRect.height = height;
    auto rectRgn = OS.gdk_region_rectangle(gdkRect);
    OS.gdk_region_subtract(handle, rectRgn);
    OS.gdk_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 <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 is null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
    if (region.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
    OS.gdk_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 <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);
    OS.gdk_region_offset (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 <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 is 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 override String toString () {
    if (isDisposed()) return "Region {*DISPOSED*}";
    return Format( "Region {{{}}", handle );
}
}