bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Cursor.java

package org.eclipse.swt.graphics;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved
 */

import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;

/**
 * Instances of this class manage operating system resources that
 * specify the appearance of the on-screen pointer. To create a
 * cursor you specify the device and either a simple cursor style
 * describing one of the standard operating system provided cursors
 * or the image and mask data for the desired appearance.
 * <p>
 * Application code must explicitly invoke the <code>Cursor.dispose()</code> 
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required.
 * </p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>
 *   CURSOR_ARROW, CURSOR_WAIT, CURSOR_CROSS, CURSOR_APPSTARTING, CURSOR_HELP,
 *   CURSOR_SIZEALL, CURSOR_SIZENESW, CURSOR_SIZENS, CURSOR_SIZENWSE, CURSOR_SIZEWE,
 *   CURSOR_SIZEN, CURSOR_SIZES, CURSOR_SIZEE, CURSOR_SIZEW, CURSOR_SIZENE, CURSOR_SIZESE,
 *   CURSOR_SIZESW, CURSOR_SIZENW, CURSOR_UPARROW, CURSOR_IBEAM, CURSOR_NO, CURSOR_HAND
 * </dd>
 * </dl>
 */

public final class Cursor {
	
	/**
	 * the handle to the OS cursor resource
	 * (Warning: This field is platform dependent)
	 */
	public int handle;
	
	/**
	 * the device where this cursor was created
	 */
	Device device;
	
	/**
	 * data used to create a HAND cursor.
	 */
	static final byte[] HAND_SOURCE = {
		(byte)0xf9,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0x3f,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0x07,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0x03,(byte)0xff,(byte)0xff,
		(byte)0xf0,(byte)0x00,(byte)0xff,(byte)0xff,

		(byte)0x10,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0x00,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0x80,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0xc0,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0xe0,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0xf0,(byte)0x00,(byte)0x7f,(byte)0xff,
		(byte)0xf8,(byte)0x00,(byte)0xff,(byte)0xff,
		(byte)0xfc,(byte)0x01,(byte)0xff,(byte)0xff,

		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,

		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff,
		(byte)0xff,(byte)0xff,(byte)0xff,(byte)0xff
	};
	static final byte[] HAND_MASK = {
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0xc0,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0xd8,(byte)0x00,(byte)0x00,
		(byte)0x06,(byte)0xd8,(byte)0x00,(byte)0x00,

		(byte)0x07,(byte)0xdb,(byte)0x00,(byte)0x00,
		(byte)0x67,(byte)0xfb,(byte)0x00,(byte)0x00,
		(byte)0x3f,(byte)0xff,(byte)0x00,(byte)0x00,
		(byte)0x1f,(byte)0xff,(byte)0x00,(byte)0x00,
		(byte)0x0f,(byte)0xff,(byte)0x00,(byte)0x00,
		(byte)0x07,(byte)0xff,(byte)0x00,(byte)0x00,
		(byte)0x03,(byte)0xfe,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,

		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,

		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00,
		(byte)0x00,(byte)0x00,(byte)0x00,(byte)0x00
	};

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

/**	 
 * Constructs a new cursor given a device and a style
 * constant describing the desired cursor appearance.
 * <p>
 * You must dispose the cursor when it is no longer required. 
 * </p>
 *
 * @param device the device on which to allocate the cursor
 * @param style the style of cursor to allocate
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - when an unknown style is specified</li>
 * </ul>
 *
 * @see Cursor for the supported style values
 */
public Cursor(Device device, int style) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	this.device = device;
	int lpCursorName = 0;
	switch (style) {
		case SWT.CURSOR_HAND: 		lpCursorName = OS.IDC_HAND; break;
		case SWT.CURSOR_ARROW: 		lpCursorName = OS.IDC_ARROW; break;
		case SWT.CURSOR_WAIT: 		lpCursorName = OS.IDC_WAIT; break;
		case SWT.CURSOR_CROSS: 		lpCursorName = OS.IDC_CROSS; break;
		case SWT.CURSOR_APPSTARTING: 	lpCursorName = OS.IDC_APPSTARTING; break;
		case SWT.CURSOR_HELP: 		lpCursorName = OS.IDC_HELP; break;
		case SWT.CURSOR_SIZEALL: 	lpCursorName = OS.IDC_SIZEALL; break;
		case SWT.CURSOR_SIZENESW: 	lpCursorName = OS.IDC_SIZENESW; break;
		case SWT.CURSOR_SIZENS: 	lpCursorName = OS.IDC_SIZENS; break;
		case SWT.CURSOR_SIZENWSE: 	lpCursorName = OS.IDC_SIZENWSE; break;
		case SWT.CURSOR_SIZEWE: 	lpCursorName = OS.IDC_SIZEWE; break;
		case SWT.CURSOR_SIZEN: 		lpCursorName = OS.IDC_SIZENS; break;
		case SWT.CURSOR_SIZES: 		lpCursorName = OS.IDC_SIZENS; break;
		case SWT.CURSOR_SIZEE: 		lpCursorName = OS.IDC_SIZEWE; break;
		case SWT.CURSOR_SIZEW: 		lpCursorName = OS.IDC_SIZEWE; break;
		case SWT.CURSOR_SIZENE: 	lpCursorName = OS.IDC_SIZENESW; break;
		case SWT.CURSOR_SIZESE: 	lpCursorName = OS.IDC_SIZENWSE; break;
		case SWT.CURSOR_SIZESW: 	lpCursorName = OS.IDC_SIZENESW; break;
		case SWT.CURSOR_SIZENW: 	lpCursorName = OS.IDC_SIZENWSE; break;
		case SWT.CURSOR_UPARROW: 	lpCursorName = OS.IDC_UPARROW; break;
		case SWT.CURSOR_IBEAM: 		lpCursorName = OS.IDC_IBEAM; break;
		case SWT.CURSOR_NO: 		lpCursorName = OS.IDC_NO; break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	handle = OS.LoadCursor(0, lpCursorName);
	/*
	* IDC_HAND is supported only on Windows 2000 and Windows 98.
	* Create a hand cursor if running in other Windows platforms.
	*/
	if (handle == 0 && style == SWT.CURSOR_HAND) {
		int width = OS.GetSystemMetrics(OS.SM_CXCURSOR);
		int height = OS.GetSystemMetrics(OS.SM_CYCURSOR);
		if (width == 32 && height == 32) {
			int hInst = OS.GetModuleHandle(null);
			if (OS.IsWinCE) SWT.error(SWT.ERROR_NOT_IMPLEMENTED);
			handle = OS.CreateCursor(hInst, 5, 0, 32, 32, HAND_SOURCE, HAND_MASK);

		}
	}
	if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	if (device.tracking) device.new_Object(this);
}

/**	 
 * Constructs a new cursor given a device, image and mask
 * data describing the desired cursor appearance, and the x
 * and y co-ordinates of the <em>hotspot</em> (that is, the point
 * within the area covered by the cursor which is considered
 * to be where the on-screen pointer is "pointing").
 * <p>
 * The mask data is allowed to be null, but in this case the source
 * must be an ImageData representing an icon that specifies both
 * color data and mask data.
 * <p>
 * You must dispose the cursor when it is no longer required. 
 * </p>
 *
 * @param device the device on which to allocate the cursor
 * @param source the color data for the cursor
 * @param mask the mask data for the cursor (or null)
 * @param hotspotX the x coordinate of the cursor's hotspot
 * @param hotspotY the y coordinate of the cursor's hotspot
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - when a null argument is passed that is not allowed</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the source and the mask are not the same 
 *          size, or either is not of depth one, or if the hotspot is outside 
 *          the bounds of the image</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if an error occurred constructing the cursor</li>
 * </ul>
 */
public Cursor(Device device, ImageData source, ImageData mask, int hotspotX, int hotspotY) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	this.device = device;
	if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (mask == null) {
		if (source.getTransparencyType() != SWT.TRANSPARENCY_MASK) {
			SWT.error(SWT.ERROR_NULL_ARGUMENT);
		}
		mask = source.getTransparencyMask();
	}
	/* Check the bounds. Mask must be the same size as source */
	if (mask.width != source.width || mask.height != source.height) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	/* Check color depths */
	if (mask.depth != 1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (source.depth != 1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	/* Check the hotspots */
	if (hotspotX >= source.width || hotspotX < 0 ||
		hotspotY >= source.height || hotspotY < 0) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	/* Create the cursor */
	int hInst = OS.GetModuleHandle(null);
	if (OS.IsWinCE) SWT.error (SWT.ERROR_NOT_IMPLEMENTED);
	handle = OS.CreateCursor(hInst, hotspotX, hotspotY, source.width, source.height, source.data, mask.data);
	if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	if (device.tracking) device.new_Object(this);
}

/**
 * Disposes of the operating system resources associated with
 * the cursor. Applications must dispose of all cursors which
 * they allocate.
 */
public void dispose () {
	if (handle == 0) return;
	
	/*
	* It is an error in Windows to destroy the current
	* cursor.  Check that the cursor that is about to
	* be destroyed is the current cursor.  If so, set
	* the current cursor to be IDC_ARROW.  Note that
	* Windows shares predefined cursors so the call to
	* LoadCursor() does not leak.
	*/
	if (OS.GetCursor() == handle) {
		OS.SetCursor(OS.LoadCursor(0, OS.IDC_ARROW));
	}
	
	/*
	 * The MSDN states that one should not destroy a shared
	 * cursor, that is, one obtained from LoadCursor.
	 * However, it does not appear to do any harm, so rather
	 * than keep track of how a cursor was created, we just
	 * destroy them all. If this causes problems in the future,
	 * put the flag back in.
	 */
	if (!OS.IsWinCE) OS.DestroyCursor(handle);
	handle = 0;
	if (device.tracking) device.dispose_Object(this);
	device = 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 boolean equals (Object object) {
	if (object == this) return true;
	if (!(object instanceof Cursor)) return false;
	Cursor cursor = (Cursor) object;
	return device == cursor.device && handle == cursor.handle;
}

/**
 * Returns an integer hash code for the receiver. Any two 
 * objects which 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;
}

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

/**
 * 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 "Cursor {*DISPOSED*}";
	return "Cursor {" + handle + "}";
}

/**	 
 * Invokes platform specific functionality to allocate a new cursor.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Cursor</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 color
 * @param handle the handle for the cursor
 * 
 * @private
 */
public static Cursor win32_new(Device device, int handle) {
	if (device == null) device = Device.getDevice();
	Cursor cursor = new Cursor();
	cursor.handle = handle;
	cursor.device = device;
	return cursor;
}

}