TabItem


1   /*******************************************************************************
2    * Copyright (c) 2000, 2006 IBM Corporation and others.
3    * All rights reserved. This program and the accompanying materials
4    * are made available under the terms of the Eclipse Public License v1.0
5    * which accompanies this distribution, and is available at
6    * http://www.eclipse.org/legal/epl-v10.html
7    *
8    * Contributors:
9    *     IBM Corporation - initial API and implementation
10   *******************************************************************************/
11  package org.eclipse.swt.widgets;
12  
13  
14  import org.eclipse.swt.internal.win32.*;
15  import org.eclipse.swt.*;
16  import org.eclipse.swt.graphics.*;
17  
18  /**
19   * Instances of this class represent a selectable user interface object
20   * corresponding to a tab for a page in a tab folder.
21   * <dl>
22   * <dt><b>Styles:</b></dt>
23   * <dd>(none)</dd>
24   * <dt><b>Events:</b></dt>
25   * <dd>(none)</dd>
26   * </dl>
27   * <p>
28   * IMPORTANT: This class is <em>not</em> intended to be subclassed.
29   * </p>
30   */
31  
32  public class TabItem extends Item {
33      TabFolder parent;
34      Control control;
35      String   toolTipText;
36  
37  /**
38   * Constructs a new instance of this class given its parent
39   * (which must be a <code>TabFolder</code>) and a style value
40   * describing its behavior and appearance. The item is added
41   * to the end of the items maintained by its parent.
42   * <p>
43   * The style value is either one of the style constants defined in
44   * class <code>SWT</code> which is applicable to instances of this
45   * class, or must be built by <em>bitwise OR</em>'ing together 
46   * (that is, using the <code>int</code> "|" operator) two or more
47   * of those <code>SWT</code> style constants. The class description
48   * lists the style constants that are applicable to the class.
49   * Style bits are also inherited from superclasses.
50   * </p>
51   *
52   * @param parent a composite control which will be the parent of the new instance (cannot be null)
53   * @param style the style of control to construct
54   *
55   * @exception IllegalArgumentException <ul>
56   *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
57   * </ul>
58   * @exception SWTException <ul>
59   *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
60   *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
61   * </ul>
62   *
63   * @see SWT
64   * @see Widget#checkSubclass
65   * @see Widget#getStyle
66   */
67  public TabItem (TabFolder parent, int style) {
68      super (parent, style);
69      this.parent = parent;
70      parent.createItem (this, parent.getItemCount ());
71  }
72  
73  /**
74   * Constructs a new instance of this class given its parent
75   * (which must be a <code>TabFolder</code>), a style value
76   * describing its behavior and appearance, and the index
77   * at which to place it in the items maintained by its parent.
78   * <p>
79   * The style value is either one of the style constants defined in
80   * class <code>SWT</code> which is applicable to instances of this
81   * class, or must be built by <em>bitwise OR</em>'ing together 
82   * (that is, using the <code>int</code> "|" operator) two or more
83   * of those <code>SWT</code> style constants. The class description
84   * lists the style constants that are applicable to the class.
85   * Style bits are also inherited from superclasses.
86   * </p>
87   *
88   * @param parent a composite control which will be the parent of the new instance (cannot be null)
89   * @param style the style of control to construct
90   * @param index the zero-relative index to store the receiver in its parent
91   *
92   * @exception IllegalArgumentException <ul>
93   *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
94   *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)</li>
95   * </ul>
96   * @exception SWTException <ul>
97   *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
98   *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
99   * </ul>
100  *
101  * @see SWT
102  * @see Widget#checkSubclass
103  * @see Widget#getStyle
104  */
105 public TabItem (TabFolder parent, int style, int index) {
106     super (parent, style);
107     this.parent = parent;
108     parent.createItem (this, index);
109 }
110 
111 void _setText (int index, String   string) {
112     /*
113     * Bug in Windows.  In version 6.00 of COMCTL32.DLL, tab
114     * items with an image and a label that includes '&' cause
115     * the tab to draw incorrectly (even when doubled '&&').
116     * The image overlaps the label.  The fix is to remove
117     * all '&' characters from the string. 
118     */
119     if (OS.COMCTL32_MAJOR >= 6 && image != null) {
120         if (string.indexOf ('&') != -1) {
121             int length = string.length ();
122             char[] text = new char [length];
123             string.getChars ( 0, length, text, 0);
124             int i = 0, j = 0;
125             for (i=0; i<length; i++) {
126                 if (text[i] != '&') text [j++] = text [i];
127             }
128             if (j < i) string = new String   (text, 0, j);
129         }
130     }
131     int hwnd = parent.handle;
132     int hHeap = OS.GetProcessHeap ();
133     TCHAR buffer = new TCHAR (parent.getCodePage (), string, true);
134     int byteCount = buffer.length () * TCHAR.sizeof;
135     int pszText = OS.HeapAlloc (hHeap, OS.HEAP_ZERO_MEMORY, byteCount);
136     OS.MoveMemory (pszText, buffer, byteCount); 
137     TCITEM tcItem = new TCITEM ();
138     tcItem.mask = OS.TCIF_TEXT;
139     tcItem.pszText = pszText;
140     OS.SendMessage (hwnd, OS.TCM_SETITEM, index, tcItem);
141     OS.HeapFree (hHeap, 0, pszText);
142 }
143 
144 protected void checkSubclass () {
145     if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
146 }
147 
148 void destroyWidget () {
149     parent.destroyItem (this);
150     releaseHandle ();
151 }
152 
153 /**
154  * Returns the control that is used to fill the client area of
155  * the tab folder when the user selects the tab item.  If no
156  * control has been set, return <code>null</code>.
157  * <p>
158  * @return the control
159  *
160  * @exception SWTException <ul>
161  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
162  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
163  * </ul>
164  */
165 public Control getControl () {
166     checkWidget();
167     return control;
168 }
169 
170 /**
171  * Returns the receiver's parent, which must be a <code>TabFolder</code>.
172  *
173  * @return the receiver's parent
174  *
175  * @exception SWTException <ul>
176  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
177  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
178  * </ul>
179  */
180 public TabFolder getParent () {
181     checkWidget();
182     return parent;
183 }
184 
185 /**
186  * Returns the receiver's tool tip text, or null if it has
187  * not been set.
188  *
189  * @return the receiver's tool tip text
190  *
191  * @exception SWTException <ul>
192  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
193  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
194  * </ul>
195  */
196 public String   getToolTipText () {
197     checkWidget();
198     return toolTipText;
199 }
200 
201 void releaseHandle () {
202     super.releaseHandle ();
203     parent = null;
204 }
205 
206 void releaseParent () {
207     super.releaseParent ();
208     int index = parent.indexOf (this);
209     if (index == parent.getSelectionIndex ()) {
210         if (control != null) control.setVisible (false);
211     }
212 }
213 
214 void releaseWidget () {
215     super.releaseWidget ();
216     control = null;
217 }
218 
219 /**
220  * Sets the control that is used to fill the client area of
221  * the tab folder when the user selects the tab item.
222  * <p>
223  * @param control the new control (or null)
224  *
225  * @exception IllegalArgumentException <ul>
226  *    <li>ERROR_INVALID_ARGUMENT - if the control has been disposed</li> 
227  *    <li>ERROR_INVALID_PARENT - if the control is not in the same widget tree</li>
228  * </ul>
229  * @exception SWTException <ul>
230  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
231  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
232  * </ul>
233  */
234 public void setControl (Control control) {
235     checkWidget();
236     if (control != null) {
237         if (control.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
238         if (control.parent != parent) error (SWT.ERROR_INVALID_PARENT);
239     }
240     if (this.control != null && this.control.isDisposed ()) {
241         this.control = null;
242     }
243     Control oldControl = this.control, newControl = control;
244     this.control = control;
245     int index = parent.indexOf (this);
246     if (index != parent.getSelectionIndex ()) {
247         if (newControl != null) newControl.setVisible (false);
248         return;
249     }
250     if (newControl != null) {
251         newControl.setBounds (parent.getClientArea ());
252         newControl.setVisible (true);
253     }
254     if (oldControl != null) oldControl.setVisible (false);
255 }
256 
257 public void setImage (Image image) {
258     checkWidget();
259     int index = parent.indexOf (this);
260     if (index == -1) return;
261     super.setImage (image);
262     /*
263     * Bug in Windows.  In version 6.00 of COMCTL32.DLL, tab
264     * items with an image and a label that includes '&' cause
265     * the tab to draw incorrectly (even when doubled '&&').
266     * The image overlaps the label.  The fix is to remove
267     * all '&' characters from the string and set the text
268     * whenever the image or text is changed.
269     */
270     if (OS.COMCTL32_MAJOR >= 6) {
271         if (text.indexOf ('&') != -1) _setText (index, text);
272     }
273     int hwnd = parent.handle;
274     TCITEM tcItem = new TCITEM ();
275     tcItem.mask = OS.TCIF_IMAGE;
276     tcItem.iImage = parent.imageIndex (image);
277     OS.SendMessage (hwnd, OS.TCM_SETITEM, index, tcItem);
278 }
279 /**
280  * Sets the receiver's text.  The string may include
281  * the mnemonic character.
282  * </p>
283  * <p>
284  * Mnemonics are indicated by an '&amp;' that causes the next
285  * character to be the mnemonic.  When the user presses a
286  * key sequence that matches the mnemonic, a selection
287  * event occurs. On most platforms, the mnemonic appears
288  * underlined but may be emphasised in a platform specific
289  * manner.  The mnemonic indicator character '&amp;' can be
290  * escaped by doubling it in the string, causing a single
291  * '&amp;' to be displayed.
292  * </p>
293  * 
294  * @param string the new text
295  *
296  * @exception IllegalArgumentException <ul>
297  *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
298  * </ul>
299  * @exception SWTException <ul>
300  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
301  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
302  * </ul>
303  * 
304  */
305 public void setText (String   string) {
306     checkWidget();
307     if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
308     if (string.equals (text)) return;
309     int index = parent.indexOf (this);
310     if (index == -1) return;
311     super.setText (string);
312     _setText (index, string);
313 }
314 
315 /**
316  * Sets the receiver's tool tip text to the argument, which
317  * may be null indicating that no tool tip text should be shown.
318  *
319  * @param string the new tool tip text (or null)
320  *
321  * @exception SWTException <ul>
322  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
323  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
324  * </ul>
325  */
326 public void setToolTipText (String   string) {
327     checkWidget();
328     toolTipText = string;
329 }
330 
331 }
332
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