1 /*******************************************************************************
2  * Copyright (c) 2000, 2008 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  * Port to the D programming language:
11  *     Frank Benoit <benoit@tionex.de>
12  *******************************************************************************/
13 module org.eclipse.swt.widgets.Button;
14 
15 import java.lang.all;
16 
17 import org.eclipse.swt.widgets.Control;
18 
19 import org.eclipse.swt.internal.gtk.OS;
20 import org.eclipse.swt.SWT;
21 import org.eclipse.swt.graphics.Point;
22 import org.eclipse.swt.graphics.Image;
23 import org.eclipse.swt.widgets.ImageList;
24 import org.eclipse.swt.widgets.Composite;
25 import org.eclipse.swt.events.SelectionListener;
26 import org.eclipse.swt.widgets.TypedListener;
27 import org.eclipse.swt.widgets.Decorations;
28 
29 
30 /**
31  * Instances of this class represent a selectable user interface object that
32  * issues notification when pressed and released.
33  * <dl>
34  * <dt><b>Styles:</b></dt>
35  * <dd>ARROW, CHECK, PUSH, RADIO, TOGGLE, FLAT</dd>
36  * <dd>UP, DOWN, LEFT, RIGHT, CENTER</dd>
37  * <dt><b>Events:</b></dt>
38  * <dd>Selection</dd>
39  * </dl>
40  * <p>
41  * Note: Only one of the styles ARROW, CHECK, PUSH, RADIO, and TOGGLE
42  * may be specified.
43  * </p><p>
44  * Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified.
45  * </p><p>
46  * Note: Only one of the styles UP, DOWN, LEFT, and RIGHT may be specified
47  * when the ARROW style is specified.
48  * </p><p>
49  * IMPORTANT: This class is intended to be subclassed <em>only</em>
50  * within the SWT implementation.
51  * </p>
52  * 
53  * @see <a href="http://www.eclipse.org/swt/snippets/#button">Button snippets</a>
54  * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
55  * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
56  */
57 public class Button : Control {
58 
59     alias Control.computeSize computeSize;
60     alias Control.mnemonicHit mnemonicHit;
61     alias Control.mnemonicMatch mnemonicMatch;
62     alias Control.setBackgroundColor setBackgroundColor;
63     alias Control.setForegroundColor setForegroundColor;
64 
65     GtkWidget* boxHandle, labelHandle, imageHandle, arrowHandle, groupHandle;
66     bool selected, grayed;
67     ImageList imageList;
68     Image image;
69     String text;
70 
71 /**
72  * Constructs a new instance of this class given its parent
73  * and a style value describing its behavior and appearance.
74  * <p>
75  * The style value is either one of the style constants defined in
76  * class <code>SWT</code> which is applicable to instances of this
77  * class, or must be built by <em>bitwise OR</em>'ing together
78  * (that is, using the <code>int</code> "|" operator) two or more
79  * of those <code>SWT</code> style constants. The class description
80  * lists the style constants that are applicable to the class.
81  * Style bits are also inherited from superclasses.
82  * </p>
83  *
84  * @param parent a composite control which will be the parent of the new instance (cannot be null)
85  * @param style the style of control to construct
86  *
87  * @exception IllegalArgumentException <ul>
88  *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
89  * </ul>
90  * @exception SWTException <ul>
91  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
92  *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
93  * </ul>
94  *
95  * @see SWT#ARROW
96  * @see SWT#CHECK
97  * @see SWT#PUSH
98  * @see SWT#RADIO
99  * @see SWT#TOGGLE
100  * @see SWT#FLAT
101  * @see SWT#LEFT
102  * @see SWT#RIGHT
103  * @see SWT#CENTER
104  * @see Widget#checkSubclass
105  * @see Widget#getStyle
106  */
107 public this (Composite parent, int style) {
108     super (parent, checkStyle (style));
109 }
110 
111 static int checkStyle (int style) {
112     style = checkBits (style, SWT.PUSH, SWT.ARROW, SWT.CHECK, SWT.RADIO, SWT.TOGGLE, 0);
113     if ((style & (SWT.PUSH | SWT.TOGGLE)) !is 0) {
114         return checkBits (style, SWT.CENTER, SWT.LEFT, SWT.RIGHT, 0, 0, 0);
115     }
116     if ((style & (SWT.CHECK | SWT.RADIO)) !is 0) {
117         return checkBits (style, SWT.LEFT, SWT.RIGHT, SWT.CENTER, 0, 0, 0);
118     }
119     if ((style & SWT.ARROW) !is 0) {
120         style |= SWT.NO_FOCUS;
121         return checkBits (style, SWT.UP, SWT.DOWN, SWT.LEFT, SWT.RIGHT, 0, 0);
122     }
123     return style;
124 }
125 
126 /**
127  * Adds the listener to the collection of listeners who will
128  * be notified when the control is selected by the user, by sending
129  * it one of the messages defined in the <code>SelectionListener</code>
130  * interface.
131  * <p>
132  * <code>widgetSelected</code> is called when the control is selected by the user.
133  * <code>widgetDefaultSelected</code> is not called.
134  * </p>
135  *
136  * @param listener the listener which should be notified
137  *
138  * @exception IllegalArgumentException <ul>
139  *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
140  * </ul>
141  * @exception SWTException <ul>
142  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
143  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
144  * </ul>
145  *
146  * @see SelectionListener
147  * @see #removeSelectionListener
148  * @see SelectionEvent
149  */
150 public void addSelectionListener (SelectionListener listener) {
151     checkWidget ();
152     if (listener is null) error (SWT.ERROR_NULL_ARGUMENT);
153     TypedListener typedListener = new TypedListener (listener);
154     addListener (SWT.Selection,typedListener);
155     addListener (SWT.DefaultSelection,typedListener);
156 }
157 
158 override public Point computeSize (int wHint, int hHint, bool changed) {
159     checkWidget ();
160     if (wHint !is SWT.DEFAULT && wHint < 0) wHint = 0;
161     if (hHint !is SWT.DEFAULT && hHint < 0) hHint = 0;
162     /*
163     * Feature in GTK, GtkCheckButton and GtkRadioButton allocate
164     * only the minimum size necessary for its child. This causes the child
165     * alignment to fail. The fix is to set the child size to the size
166     * of the button.
167     */
168     forceResize ();
169     int reqWidth = -1, reqHeight = -1;
170     if ((style & (SWT.CHECK | SWT.RADIO)) !is 0) {
171         OS.gtk_widget_get_size_request (boxHandle, &reqWidth, &reqHeight);
172         OS.gtk_widget_set_size_request (boxHandle, -1, -1);
173     }
174     Point size = computeNativeSize (handle, wHint, hHint, changed);
175     if ((style & (SWT.CHECK | SWT.RADIO)) !is 0) {
176         OS.gtk_widget_set_size_request (boxHandle, reqWidth, reqHeight);
177     }
178     if (wHint !is SWT.DEFAULT || hHint !is SWT.DEFAULT) {
179         if ((OS.GTK_WIDGET_FLAGS (handle) & OS.GTK_CAN_DEFAULT) !is 0) {
180             GtkBorder border;
181             GtkBorder* buffer;
182             OS.gtk_widget_style_get1 (handle, OS.default_border.ptr, cast(int*)&buffer );
183             if (buffer !is null) {
184                 border = *buffer;
185             } else {
186                 /* Use the GTK+ default value of 1 for each. */
187                 border.left = border.right = border.top = border.bottom = 1;
188             }
189             if (wHint !is SWT.DEFAULT) size.x += border.left + border.right;
190             if (hHint !is SWT.DEFAULT) size.y += border.top + border.bottom;
191         }
192     }
193     return size;
194 }
195 
196 override void createHandle (int index) {
197     state |= HANDLE;
198     if ((style & (SWT.PUSH | SWT.TOGGLE)) is 0) state |= THEME_BACKGROUND;
199     int bits = SWT.ARROW | SWT.TOGGLE | SWT.CHECK | SWT.RADIO | SWT.PUSH;
200     fixedHandle = cast(GtkWidget*)OS.g_object_new (display.gtk_fixed_get_type (), null);
201     if (fixedHandle is null) error (SWT.ERROR_NO_HANDLES);
202     OS.gtk_fixed_set_has_window (cast(GtkFixed*)fixedHandle, true);
203     switch (style & bits) {
204         case SWT.ARROW:
205             int arrow_type = OS.GTK_ARROW_UP;
206             if ((style & SWT.UP) !is 0) arrow_type = OS.GTK_ARROW_UP;
207             if ((style & SWT.DOWN) !is 0) arrow_type = OS.GTK_ARROW_DOWN;
208             if ((style & SWT.LEFT) !is 0) arrow_type = OS.GTK_ARROW_LEFT;
209             if ((style & SWT.RIGHT) !is 0) arrow_type = OS.GTK_ARROW_RIGHT;
210             handle = OS.gtk_button_new ();
211             if (handle is null) error (SWT.ERROR_NO_HANDLES);
212             arrowHandle = OS.gtk_arrow_new (arrow_type, OS.GTK_SHADOW_OUT);
213             if (arrowHandle is null) error (SWT.ERROR_NO_HANDLES);
214             break;
215         case SWT.TOGGLE:
216             handle = OS.gtk_toggle_button_new ();
217             if (handle is null) error (SWT.ERROR_NO_HANDLES);
218             break;
219         case SWT.CHECK:
220             handle = OS.gtk_check_button_new ();
221             if (handle is null) error (SWT.ERROR_NO_HANDLES);
222             break;
223         case SWT.RADIO:
224             /*
225             * Feature in GTK.  In GTK, radio button must always be part of
226             * a radio button group.  In a GTK radio group, one button is always
227             * selected.  This means that it is not possible to have a single
228             * radio button that is unselected.  This is necessary to allow
229             * applications to implement their own radio behavior or use radio
230             * buttons outside of radio groups.  The fix is to create a hidden
231             * radio button for each radio button we create and add them
232             * to the same group.  This allows the visible button to be
233             * unselected.
234             */
235             groupHandle = cast(GtkWidget*)OS.gtk_radio_button_new (null);
236             if (groupHandle is null) error (SWT.ERROR_NO_HANDLES);
237             OS.g_object_ref (groupHandle);
238             OS.gtk_object_sink (cast(GtkObject*)groupHandle);
239             handle = OS.gtk_radio_button_new ( OS.gtk_radio_button_get_group (cast(GtkRadioButton*)groupHandle));
240             if (handle is null) error (SWT.ERROR_NO_HANDLES);
241             break;
242         case SWT.PUSH:
243         default:
244             handle = OS.gtk_button_new ();
245             if (handle is null) error (SWT.ERROR_NO_HANDLES);
246             OS.GTK_WIDGET_SET_FLAGS(handle, OS.GTK_CAN_DEFAULT);
247             break;
248     }
249     if ((style & SWT.ARROW) !is 0) {
250         OS.gtk_container_add (cast(GtkContainer*)handle, arrowHandle);
251     } else {
252         boxHandle = OS.gtk_hbox_new (false, 4);
253         if (boxHandle is null) error (SWT.ERROR_NO_HANDLES);
254         labelHandle = OS.gtk_label_new_with_mnemonic (null);
255         if (labelHandle is null) error (SWT.ERROR_NO_HANDLES);
256         imageHandle = OS.gtk_image_new ();
257         if (imageHandle is null) error (SWT.ERROR_NO_HANDLES);
258         OS.gtk_container_add (cast(GtkContainer*)handle, boxHandle);
259         OS.gtk_container_add (cast(GtkContainer*)boxHandle, imageHandle);
260         OS.gtk_container_add (cast(GtkContainer*)boxHandle, labelHandle);
261     }
262     OS.gtk_container_add (cast(GtkContainer*)fixedHandle, handle);
263 
264     if ((style & SWT.ARROW) !is 0) return;
265     _setAlignment (style & (SWT.LEFT | SWT.CENTER | SWT.RIGHT));
266 }
267 
268 override void createWidget (int index) {
269     super.createWidget (index);
270     text = "";
271 }
272 
273 override void deregister () {
274     super.deregister ();
275     if (boxHandle !is null) display.removeWidget (boxHandle);
276     if (labelHandle !is null) display.removeWidget (labelHandle);
277     if (imageHandle !is null) display.removeWidget (imageHandle);
278     if (arrowHandle !is null) display.removeWidget (arrowHandle);
279 }
280 
281 override GtkWidget* fontHandle () {
282     if (labelHandle !is null) return labelHandle;
283     return super.fontHandle ();
284 }
285 
286 /**
287  * Returns a value which describes the position of the
288  * text or image in the receiver. The value will be one of
289  * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code>
290  * unless the receiver is an <code>ARROW</code> button, in
291  * which case, the alignment will indicate the direction of
292  * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>,
293  * <code>UP</code> or <code>DOWN</code>).
294  *
295  * @return the alignment
296  *
297  * @exception SWTException <ul>
298  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
299  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
300  * </ul>
301  */
302 public int getAlignment () {
303     checkWidget ();
304     if ((style & SWT.ARROW) !is 0) {
305         if ((style & SWT.UP) !is 0) return SWT.UP;
306         if ((style & SWT.DOWN) !is 0) return SWT.DOWN;
307         if ((style & SWT.LEFT) !is 0) return SWT.LEFT;
308         if ((style & SWT.RIGHT) !is 0) return SWT.RIGHT;
309         return SWT.UP;
310     }
311     if ((style & SWT.LEFT) !is 0) return SWT.LEFT;
312     if ((style & SWT.CENTER) !is 0) return SWT.CENTER;
313     if ((style & SWT.RIGHT) !is 0) return SWT.RIGHT;
314     return SWT.LEFT;
315 }
316 
317 /**
318  * Returns <code>true</code> if the receiver is grayed,
319  * and false otherwise. When the widget does not have
320  * the <code>CHECK</code> style, return false.
321  *
322  * @return the grayed state of the checkbox
323  *
324  * @exception SWTException <ul>
325  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
326  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
327  * </ul>
328  * 
329  * @since 3.4
330  */
331 public bool getGrayed () {
332     checkWidget();
333     if ((style & SWT.CHECK) is 0) return false;
334     return grayed;
335 }
336 
337 /**
338  * Returns the receiver's image if it has one, or null
339  * if it does not.
340  *
341  * @return the receiver's image
342  *
343  * @exception SWTException <ul>
344  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
345  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
346  * </ul>
347  */
348 public Image getImage () {
349     checkWidget ();
350     return image;
351 }
352 
353 override String getNameText () {
354     return getText ();
355 }
356 
357 /**
358  * Returns <code>true</code> if the receiver is selected,
359  * and false otherwise.
360  * <p>
361  * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>,
362  * it is selected when it is checked. When it is of type <code>TOGGLE</code>,
363  * it is selected when it is pushed in. If the receiver is of any other type,
364  * this method returns false.
365  *
366  * @return the selection state
367  *
368  * @exception SWTException <ul>
369  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
370  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
371  * </ul>
372  */
373 public bool getSelection () {
374     checkWidget ();
375     if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) is 0) return false;
376     return cast(bool)OS.gtk_toggle_button_get_active (cast(GtkToggleButton*)handle);
377 }
378 
379 /**
380  * Returns the receiver's text, which will be an empty
381  * string if it has never been set or if the receiver is
382  * an <code>ARROW</code> button.
383  *
384  * @return the receiver's text
385  *
386  * @exception SWTException <ul>
387  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
388  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
389  * </ul>
390  */
391 public String getText () {
392     checkWidget();
393     if ((style & SWT.ARROW) !is 0) return "";
394     return text;
395 }
396 
397 override int gtk_button_press_event (GtkWidget* widget, GdkEventButton* event) {
398     auto result = super.gtk_button_press_event (widget, event);
399     if (result !is 0) return result;
400     if ((style & SWT.RADIO) !is 0) selected  = getSelection ();
401     return result;
402 }
403 
404 override int gtk_clicked (GtkWidget* widget) {
405     if ((style & SWT.RADIO) !is 0) {
406         if ((parent.getStyle () & SWT.NO_RADIO_GROUP) !is 0) {
407             setSelection (!selected);
408         } else {
409             selectRadio ();
410         }
411     } else {
412         if ((style & SWT.CHECK) !is 0) {
413             if (grayed) {
414                 if (OS.gtk_toggle_button_get_active (handle)) {
415                     OS.gtk_toggle_button_set_inconsistent (handle, true);
416                 } else {
417                     OS.gtk_toggle_button_set_inconsistent (handle, false);
418                 }
419             }
420         }
421     }
422     postEvent (SWT.Selection);
423     return 0;
424 }
425 
426 override int gtk_focus_in_event (GtkWidget* widget, GdkEventFocus* event) {
427     auto result = super.gtk_focus_in_event (widget, event);
428     // widget could be disposed at this point
429     if (handle is null) return 0;
430     if ((style & SWT.PUSH) !is 0 && OS.GTK_WIDGET_HAS_DEFAULT (handle)) {
431         Decorations menuShell = menuShell ();
432         menuShell.defaultButton = this;
433     }
434     return result;
435 }
436 
437 override int gtk_focus_out_event (GtkWidget* widget, GdkEventFocus* event) {
438     auto result = super.gtk_focus_out_event (widget, event);
439     // widget could be disposed at this point
440     if (handle is null) return 0;
441     if ((style & SWT.PUSH) !is 0 && !OS.GTK_WIDGET_HAS_DEFAULT (handle)) {
442         Decorations menuShell = menuShell ();
443         if (menuShell.defaultButton is this) {
444             menuShell.defaultButton = null;
445         }
446     }
447     return result;
448 }
449 
450 override int gtk_key_press_event (GtkWidget* widget, GdkEventKey* event) {
451     auto result = super.gtk_key_press_event (widget, event);
452     if (result !is 0) return result;
453     if ((style & SWT.RADIO) !is 0) selected  = getSelection ();
454     return result;
455 }
456 
457 override void hookEvents () {
458     super.hookEvents();
459     OS.g_signal_connect_closure (handle, OS.clicked.ptr, display.closures [CLICKED], false);
460     if (labelHandle !is null) {
461         OS.g_signal_connect_closure_by_id (cast(void*)labelHandle, display.signalIds [MNEMONIC_ACTIVATE], 0, display.closures [MNEMONIC_ACTIVATE], false);
462     }
463 }
464 
465 override bool isDescribedByLabel () {
466     return false;
467 }
468 
469 override bool mnemonicHit (wchar key) {
470     if (labelHandle is null) return false;
471     bool result = super.mnemonicHit (labelHandle, key);
472     if (result) setFocus ();
473     return result;
474 }
475 
476 override bool mnemonicMatch (wchar key) {
477     if (labelHandle is null) return false;
478     return mnemonicMatch (labelHandle, key);
479 }
480 
481 override void register () {
482     super.register ();
483     if (boxHandle !is null) display.addWidget (boxHandle, this);
484     if (labelHandle !is null) display.addWidget (labelHandle, this);
485     if (imageHandle !is null) display.addWidget (imageHandle, this);
486     if (arrowHandle !is null) display.addWidget (arrowHandle, this);
487 }
488 
489 override void releaseHandle () {
490     super.releaseHandle ();
491     boxHandle = imageHandle = labelHandle = arrowHandle = null;
492 }
493 
494 override void releaseWidget () {
495     super.releaseWidget ();
496     if (groupHandle !is null) OS.g_object_unref (groupHandle);
497     groupHandle = null;
498     if (imageList !is null) imageList.dispose ();
499     imageList = null;
500     image = null;
501     text = null;
502 }
503 
504 /**
505  * Removes the listener from the collection of listeners who will
506  * be notified when the control is selected by the user.
507  *
508  * @param listener the listener which should no longer be notified
509  *
510  * @exception IllegalArgumentException <ul>
511  *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
512  * </ul>
513  * @exception SWTException <ul>
514  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
515  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
516  * </ul>
517  *
518  * @see SelectionListener
519  * @see #addSelectionListener
520  */
521 public void removeSelectionListener (SelectionListener listener) {
522     checkWidget();
523     if (listener is null) error (SWT.ERROR_NULL_ARGUMENT);
524     if (eventTable is null) return;
525     eventTable.unhook (SWT.Selection, listener);
526     eventTable.unhook (SWT.DefaultSelection,listener);
527 }
528 
529 override void resizeHandle (int width, int height) {
530     super.resizeHandle (width, height);
531     /*
532     * Feature in GTK, GtkCheckButton and GtkRadioButton allocate
533     * only the minimum size necessary for its child. This causes the child
534     * alignment to fail. The fix is to set the child size to the size
535     * of the button.
536     */
537     if ((style & (SWT.CHECK | SWT.RADIO)) !is 0) {
538         OS.gtk_widget_set_size_request (boxHandle, width, -1);
539     }
540 }
541 
542 void selectRadio () {
543     /*
544     * This code is intentionally commented.  When two groups
545     * of radio buttons with the same parent are separated by
546     * another control, the correct behavior should be that
547     * the two groups act independently.  This is consistent
548     * with radio tool and menu items.  The commented code
549     * implements this behavior.
550     */
551 //  int index = 0;
552 //  Control [] children = parent._getChildren ();
553 //  while (index < children.length && children [index] !is this) index++;
554 //  int i = index - 1;
555 //  while (i >= 0 && children [i].setRadioSelection (false)) --i;
556 //  int j = index + 1;
557 //  while (j < children.length && children [j].setRadioSelection (false)) j++;
558 //  setSelection (true);
559     Control [] children = parent._getChildren ();
560     for (int i=0; i<children.length; i++) {
561         Control child = children [i];
562         if (this !is child) child.setRadioSelection (false);
563     }
564     setSelection (true);
565 }
566 
567 /**
568  * Controls how text, images and arrows will be displayed
569  * in the receiver. The argument should be one of
570  * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code>
571  * unless the receiver is an <code>ARROW</code> button, in
572  * which case, the argument indicates the direction of
573  * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>,
574  * <code>UP</code> or <code>DOWN</code>).
575  *
576  * @param alignment the new alignment
577  *
578  * @exception SWTException <ul>
579  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
580  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
581  * </ul>
582  */
583 public void setAlignment (int alignment) {
584     checkWidget ();
585     _setAlignment (alignment);
586 }
587 
588 void _setAlignment (int alignment) {
589     if ((style & SWT.ARROW) !is 0) {
590         if ((style & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT)) is 0) return;
591         style &= ~(SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT);
592         style |= alignment & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT);
593         int arrow_type = OS.GTK_ARROW_UP;
594         bool isRTL = (style & SWT.RIGHT_TO_LEFT) !is 0;
595         switch (alignment) {
596             case SWT.UP: arrow_type = OS.GTK_ARROW_UP; break;
597             case SWT.DOWN: arrow_type = OS.GTK_ARROW_DOWN; break;
598             case SWT.LEFT: arrow_type = isRTL ? OS.GTK_ARROW_RIGHT : OS.GTK_ARROW_LEFT; break;
599             case SWT.RIGHT: arrow_type = isRTL ? OS.GTK_ARROW_LEFT : OS.GTK_ARROW_RIGHT; break;
600             default:
601         }
602         OS.gtk_arrow_set (cast(GtkArrow*)arrowHandle, arrow_type, OS.GTK_SHADOW_OUT);
603         return;
604     }
605     if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) is 0) return;
606     style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER);
607     style |= alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER);
608     /* Alignment not honoured when image and text are visible */
609     bool bothVisible = OS.GTK_WIDGET_VISIBLE (labelHandle) && OS.GTK_WIDGET_VISIBLE (imageHandle);
610     if (bothVisible) {
611         if ((style & (SWT.RADIO | SWT.CHECK)) !is 0) alignment = SWT.LEFT;
612         if ((style & (SWT.PUSH | SWT.TOGGLE)) !is 0) alignment = SWT.CENTER;
613     }
614     if ((alignment & SWT.LEFT) !is 0) {
615         if (bothVisible) {
616             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, labelHandle, false, false, 0, OS.GTK_PACK_START);
617             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, imageHandle, false, false, 0, OS.GTK_PACK_START);
618         }
619         OS.gtk_misc_set_alignment (cast(GtkMisc*)labelHandle, 0.0f, 0.5f);
620         OS.gtk_label_set_justify (cast(GtkLabel*)labelHandle, OS.GTK_JUSTIFY_LEFT);
621         OS.gtk_misc_set_alignment (cast(GtkMisc*)imageHandle, 0.0f, 0.5f);
622         return;
623     }
624     if ((alignment & SWT.CENTER) !is 0) {
625         if (bothVisible) {
626             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, labelHandle, true, true, 0, OS.GTK_PACK_END);
627             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, imageHandle, true, true, 0, OS.GTK_PACK_START);
628             OS.gtk_misc_set_alignment (cast(GtkMisc*)labelHandle, 0f, 0.5f);
629             OS.gtk_misc_set_alignment (cast(GtkMisc*)imageHandle, 1f, 0.5f);
630         } else {
631             OS.gtk_misc_set_alignment (cast(GtkMisc*)labelHandle, 0.5f, 0.5f);
632             OS.gtk_label_set_justify (cast(GtkLabel*)labelHandle, OS.GTK_JUSTIFY_CENTER);
633             OS.gtk_misc_set_alignment (cast(GtkMisc*)imageHandle, 0.5f, 0.5f);
634         }
635         return;
636     }
637     if ((alignment & SWT.RIGHT) !is 0) {
638         if (bothVisible) {
639             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, labelHandle, false, false, 0, OS.GTK_PACK_END);
640             OS.gtk_box_set_child_packing (cast(GtkBox*)boxHandle, imageHandle, false, false, 0, OS.GTK_PACK_END);
641         }
642         OS.gtk_misc_set_alignment (cast(GtkMisc*)labelHandle, 1.0f, 0.5f);
643         OS.gtk_label_set_justify (cast(GtkLabel*)labelHandle, OS.GTK_JUSTIFY_RIGHT);
644         OS.gtk_misc_set_alignment (cast(GtkMisc*)imageHandle, 1.0f, 0.5f);
645         return;
646     }
647 }
648 
649 override void setBackgroundColor (GdkColor* color) {
650     super.setBackgroundColor (color);
651     setBackgroundColor(fixedHandle, color);
652     if (labelHandle !is null) setBackgroundColor(labelHandle, color);
653     if (imageHandle !is null) setBackgroundColor(imageHandle, color);
654 }
655 
656 override void setFontDescription (PangoFontDescription* font) {
657     super.setFontDescription (font);
658     if (labelHandle !is null) OS.gtk_widget_modify_font (labelHandle, font);
659     if (imageHandle !is null) OS.gtk_widget_modify_font (imageHandle, font);
660 }
661 
662 override bool setRadioSelection (bool value) {
663     if ((style & SWT.RADIO) is 0) return false;
664     if (getSelection () !is value) {
665         setSelection (value);
666         postEvent (SWT.Selection);
667     }
668     return true;
669 }
670 
671 override void setForegroundColor (GdkColor* color) {
672     super.setForegroundColor (color);
673     setForegroundColor (fixedHandle, color);
674     if (labelHandle !is null) setForegroundColor (labelHandle, color);
675     if (imageHandle !is null) setForegroundColor (imageHandle, color);
676 }
677 
678 /**
679  * Sets the grayed state of the receiver.  This state change 
680  * only applies if the control was created with the SWT.CHECK
681  * style.
682  *
683  * @param grayed the new grayed state
684  *
685  * @exception SWTException <ul>
686  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
687  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
688  * </ul>
689  * 
690  * @since 3.4
691  */
692 public void setGrayed (bool grayed) {
693     checkWidget();
694     if ((style & SWT.CHECK) is 0) return;
695     this.grayed = grayed;
696     if (grayed && OS.gtk_toggle_button_get_active (handle)) {
697         OS.gtk_toggle_button_set_inconsistent (handle, true);
698     } else {
699         OS.gtk_toggle_button_set_inconsistent (handle, false);
700     }
701 }
702 
703 /**
704  * Sets the receiver's image to the argument, which may be
705  * <code>null</code> indicating that no image should be displayed.
706  * <p>
707  * Note that a Button can display an image and text simultaneously
708  * on Windows (starting with XP), GTK+ and OSX.  On other platforms,
709  * a Button that has an image and text set into it will display the
710  * image or text that was set most recently.
711  * </p>
712  * @param image the image to display on the receiver (may be <code>null</code>)
713  *
714  * @exception IllegalArgumentException <ul>
715  *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
716  * </ul>
717  * @exception SWTException <ul>
718  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
719  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
720  * </ul>
721  */
722 public void setImage (Image image) {
723     checkWidget ();
724     if ((style & SWT.ARROW) !is 0) return;
725     if (imageList !is null) imageList.dispose ();
726     imageList = null;
727     if (image !is null) {
728         if (image.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
729         imageList = new ImageList ();
730         int imageIndex = imageList.add (image);
731         auto pixbuf = imageList.getPixbuf (imageIndex);
732         OS.gtk_image_set_from_pixbuf (cast(GtkImage*)imageHandle, pixbuf);
733         if (text.length is 0) OS.gtk_widget_hide (labelHandle);
734         OS.gtk_widget_show (imageHandle);
735     } else {
736         OS.gtk_image_set_from_pixbuf (cast(GtkImage*)imageHandle, null);
737         OS.gtk_widget_show (labelHandle);
738         OS.gtk_widget_hide (imageHandle);
739     }
740     this.image = image;
741     _setAlignment (style);
742 }
743 
744 override void setOrientation () {
745     super.setOrientation ();
746     if ((style & SWT.RIGHT_TO_LEFT) !is 0) {
747         if (boxHandle !is null) OS.gtk_widget_set_direction (boxHandle, OS.GTK_TEXT_DIR_RTL);
748         if (labelHandle !is null) OS.gtk_widget_set_direction (labelHandle, OS.GTK_TEXT_DIR_RTL);
749         if (imageHandle !is null) OS.gtk_widget_set_direction (imageHandle, OS.GTK_TEXT_DIR_RTL);
750         if (arrowHandle !is null) {
751             switch (style & (SWT.LEFT | SWT.RIGHT)) {
752                 case SWT.LEFT: OS.gtk_arrow_set (cast(GtkArrow*)arrowHandle, OS.GTK_ARROW_RIGHT, OS.GTK_SHADOW_OUT); break;
753                 case SWT.RIGHT: OS.gtk_arrow_set (cast(GtkArrow*)arrowHandle, OS.GTK_ARROW_LEFT, OS.GTK_SHADOW_OUT); break;
754                 default:
755             }
756         }
757     }
758 }
759 
760 /**
761  * Sets the selection state of the receiver, if it is of type <code>CHECK</code>,
762  * <code>RADIO</code>, or <code>TOGGLE</code>.
763  *
764  * <p>
765  * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>,
766  * it is selected when it is checked. When it is of type <code>TOGGLE</code>,
767  * it is selected when it is pushed in.
768  *
769  * @param selected the new selection state
770  *
771  * @exception SWTException <ul>
772  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
773  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
774  * </ul>
775  */
776 public void setSelection (bool selected) {
777     checkWidget();
778     if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) is 0) return;
779     OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udCLICKED);
780     OS.gtk_toggle_button_set_active (cast(GtkToggleButton*)handle, selected);
781     if ((style & SWT.CHECK) !is 0) {
782         if (selected && grayed) {
783             OS.gtk_toggle_button_set_inconsistent (handle, true);
784         } else {
785             OS.gtk_toggle_button_set_inconsistent (handle, false);
786         }
787     }
788     if ((style & SWT.RADIO) !is 0) OS.gtk_toggle_button_set_active (cast(GtkToggleButton*)groupHandle, !selected);
789     OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udCLICKED);
790 }
791 
792 /**
793  * Sets the receiver's text.
794  * <p>
795  * This method sets the button label.  The label may include
796  * the mnemonic character but must not contain line delimiters.
797  * </p>
798  * <p>
799  * Mnemonics are indicated by an '&amp;' that causes the next
800  * character to be the mnemonic.  When the user presses a
801  * key sequence that matches the mnemonic, a selection
802  * event occurs. On most platforms, the mnemonic appears
803  * underlined but may be emphasized in a platform specific
804  * manner.  The mnemonic indicator character '&amp;' can be
805  * escaped by doubling it in the string, causing a single
806  * '&amp;' to be displayed.
807  * </p><p>
808  * Note that a Button can display an image and text simultaneously
809  * on Windows (starting with XP), GTK+ and OSX.  On other platforms,
810  * a Button that has an image and text set into it will display the
811  * image or text that was set most recently.
812  * </p>
813  * @param string the new text
814  *
815  * @exception SWTException <ul>
816  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
817  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
818  * </ul>
819  */
820 public void setText (String string) {
821     checkWidget ();
822     // SWT extension: allow null for zero length string
823     //if (string is null) error (SWT.ERROR_NULL_ARGUMENT);
824     if ((style & SWT.ARROW) !is 0) return;
825     text = string;
826     char [] chars = fixMnemonic (string);
827     OS.gtk_label_set_text_with_mnemonic (cast(GtkLabel*)labelHandle, chars.toStringzValidPtr() );
828     if (image is null) OS.gtk_widget_hide (imageHandle);
829     OS.gtk_widget_show (labelHandle);
830     _setAlignment (style);
831 }
832 
833 override void showWidget () {
834     super.showWidget ();
835     if (boxHandle !is null) OS.gtk_widget_show (boxHandle);
836     if (labelHandle !is null) OS.gtk_widget_show (labelHandle);
837     if (arrowHandle !is null) OS.gtk_widget_show (arrowHandle);
838 }
839 
840 override int traversalCode (int key, GdkEventKey* event) {
841     int code = super.traversalCode (key, event);
842     if ((style & SWT.ARROW) !is 0) code &= ~(SWT.TRAVERSE_TAB_NEXT | SWT.TRAVERSE_TAB_PREVIOUS);
843     if ((style & SWT.RADIO) !is 0) code |= SWT.TRAVERSE_ARROW_NEXT | SWT.TRAVERSE_ARROW_PREVIOUS;
844     return code;
845 }
846 
847 }