/*******************************************************************************
* Copyright (c) 2008, 2015 Innoopract Informationssysteme GmbH.
* 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:
* Innoopract Informationssysteme GmbH - initial API and implementation
* EclipseSource - ongoing development
******************************************************************************/
package org.eclipse.swt.graphics;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
/**
* Instances of this class manage operating system resources that specify the
* appearance of the on-screen pointer.
*
* <p>To obtain cursors, it is recommended to use one of the
* <code>getSystemCursor</code> method from class <code>Display</code>.
* </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>
* <p>
* Note: Only one of the above styles may be specified.
* </p>
*
* @since 1.2
*/
public class Cursor extends Resource {
private final int value;
// used by ResourceFactory#getCursor()
private Cursor( int style ) {
super( null );
checkStyle( style );
value = style;
}
/**
* 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>
* NOTE:
* It is recommended to use {@link org.eclipse.swt.widgets.Display#getSystemCursor(int)}
* instead of using this constructor. This way you can avoid the
* overhead of disposing the Cursor resource.
*
* @param device the device on which to allocate the cursor
* @param style the style of cursor to allocate
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
* <li>ERROR_INVALID_ARGUMENT - when an unknown style is specified</li>
* </ul>
* @exception SWTError <ul>
* <li>ERROR_NO_HANDLES - if a handle could not be obtained for cursor creation</li>
* </ul>
*
* @see SWT#CURSOR_ARROW
* @see SWT#CURSOR_WAIT
* @see SWT#CURSOR_CROSS
* @see SWT#CURSOR_APPSTARTING
* @see SWT#CURSOR_HELP
* @see SWT#CURSOR_SIZEALL
* @see SWT#CURSOR_SIZENESW
* @see SWT#CURSOR_SIZENS
* @see SWT#CURSOR_SIZENWSE
* @see SWT#CURSOR_SIZEWE
* @see SWT#CURSOR_SIZEN
* @see SWT#CURSOR_SIZES
* @see SWT#CURSOR_SIZEE
* @see SWT#CURSOR_SIZEW
* @see SWT#CURSOR_SIZENE
* @see SWT#CURSOR_SIZESE
* @see SWT#CURSOR_SIZESW
* @see SWT#CURSOR_SIZENW
* @see SWT#CURSOR_UPARROW
* @see SWT#CURSOR_IBEAM
* @see SWT#CURSOR_NO
* @see SWT#CURSOR_HAND
* @see org.eclipse.swt.widgets.Display#getSystemCursor(int)
*
* @since 1.3
*/
public Cursor( Device device, int style ) {
super( checkDevice( device ) );
checkStyle( style );
value = style;
}
/**
* 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
*/
@Override
public boolean equals( Object object ) {
boolean result;
if( object == this ) {
result = true;
} else if( object instanceof Cursor ) {
Cursor cursor = ( Cursor )object;
result = cursor.value == value;
} else {
result = false;
}
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
*/
@Override
public int hashCode() {
return 101 * value;
}
/**
* Returns a string containing a concise, human-readable
* description of the receiver.
*
* @return a string representation of the receiver
*/
@Override
public String toString () {
String result;
if (isDisposed()) {
result = "Cursor {*DISPOSED*}";
} else {
result = "Cursor {" + value + "}";
}
return result;
}
private static void checkStyle( int style ) {
switch( style ) {
case SWT.CURSOR_ARROW:
case SWT.CURSOR_WAIT:
case SWT.CURSOR_APPSTARTING:
case SWT.CURSOR_CROSS:
case SWT.CURSOR_HELP:
case SWT.CURSOR_SIZEALL:
case SWT.CURSOR_SIZENESW:
case SWT.CURSOR_SIZENS:
case SWT.CURSOR_SIZENWSE:
case SWT.CURSOR_SIZEWE:
case SWT.CURSOR_SIZEN:
case SWT.CURSOR_SIZES:
case SWT.CURSOR_SIZEE:
case SWT.CURSOR_SIZEW:
case SWT.CURSOR_SIZENE:
case SWT.CURSOR_SIZESE:
case SWT.CURSOR_SIZESW:
case SWT.CURSOR_SIZENW:
case SWT.CURSOR_IBEAM:
case SWT.CURSOR_HAND:
case SWT.CURSOR_UPARROW:
case SWT.CURSOR_NO:
break;
default:
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
}
}