/*******************************************************************************
* Copyright (c) 2000, 2008, 2012 IBM Corporation, Gerhardt Informatics Kft. 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
* Gerhardt Informatics Kft. - GEFGWT port
*******************************************************************************/
package org.eclipse.swt.widgets;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Image;
/**
* This class is the abstract superclass of all non-windowed user interface
* objects that occur within specific controls. For example, a tree will contain
* tree items.
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>(none)</dd>
* <dt><b>Events:</b></dt>
* <dd>(none)</dd>
* </dl>
*
* @see <a href="http://www.eclipse.org/swt/">Sample code and further
* information</a>
*/
public abstract class Item extends Widget {
String text;
Image image;
/**
* Constructs a new instance of this class given its parent and a style
* value describing its behavior and appearance. The item is added to the
* end of the items maintained by its parent.
* <p>
* The style value is either one of the style constants defined in class
* <code>SWT</code> which is applicable to instances of this class, or must
* be built by <em>bitwise OR</em>'ing together (that is, using the
* <code>int</code> "|" operator) two or more of those <code>SWT</code>
* style constants. The class description lists the style constants that are
* applicable to the class. Style bits are also inherited from superclasses.
* </p>
*
* @param parent
* a widget which will be the parent of the new instance (cannot
* be null)
* @param style
* the style of item to construct
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the parent</li>
* </ul>
*
* @see SWT
* @see Widget#getStyle
*/
public Item(Widget parent, int style) {
super(parent, style);
text = "";
}
/**
* Constructs a new instance of this class given its parent and a style
* value describing its behavior and appearance, and the index at which to
* place it in the items maintained by its parent.
* <p>
* The style value is either one of the style constants defined in class
* <code>SWT</code> which is applicable to instances of this class, or must
* be built by <em>bitwise OR</em>'ing together (that is, using the
* <code>int</code> "|" operator) two or more of those <code>SWT</code>
* style constants. The class description lists the style constants that are
* applicable to the class. Style bits are also inherited from superclasses.
* </p>
*
* @param parent
* a widget which will be the parent of the new instance (cannot
* be null)
* @param style
* the style of item to construct
* @param index
* the zero-relative index at which to store the receiver in its
* parent
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
* <li>ERROR_INVALID_RANGE - if the index is not between 0
* and the number of elements in the parent (inclusive)</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the parent</li>
* </ul>
*
* @see SWT
* @see Widget#getStyle
*/
public Item(Widget parent, int style, int index) {
this(parent, style);
}
protected void checkSubclass() {
}
/**
* Returns the receiver's image if it has one, or null if it does not.
*
* @return the receiver's image
*
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Image getImage() {
checkWidget();
return image;
}
String getNameText() {
return getText();
}
/**
* Returns the receiver's text, which will be an empty string if it has
* never been set.
*
* @return the receiver's text
*
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public String getText() {
checkWidget();
return text;
}
void releaseWidget() {
super.releaseWidget();
text = null;
image = null;
}
/**
* Sets the receiver's image to the argument, which may be null indicating
* that no image should be displayed.
*
* @param image
* the image to display on the receiver (may be null)
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_INVALID_ARGUMENT - if the image has been
* disposed</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setImage(Image image) {
checkWidget();
if (image != null && image.isDisposed())
error(SWT.ERROR_INVALID_ARGUMENT);
this.image = image;
}
/**
* Sets the receiver's text.
*
* @param string
* the new text
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the text is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setText(String string) {
checkWidget();
if (string == null)
error(SWT.ERROR_NULL_ARGUMENT);
text = string;
}
}