| /******************************************************************************* |
| * 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 |
| *******************************************************************************/ |
| package org.eclipse.swt.widgets; |
| |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.graphics.*; |
| |
| /** |
| * 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 () { |
| /* Do Nothing - Subclassing is allowed */ |
| } |
| |
| /** |
| * 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; |
| } |
| |
| boolean updateTextDirection(int textDirection) { |
| if (((style & SWT.FLIP_TEXT_DIRECTION) ^ textDirection) != 0) { |
| style ^= SWT.FLIP_TEXT_DIRECTION; |
| return true; |
| } |
| return false; |
| } |
| |
| |
| } |