summaryrefslogtreecommitdiffstats
path: root/src/gui_gtk_f.c
blob: 1ae1bd795e7bd1d457f76dbb8075be3068637269 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved		by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * (C) 1998,1999 by Marcin Dalecki <martin@dalecki.de>
 *
 * Support for GTK+ 2 was added by:
 * (C) 2002,2003  Jason Hildebrand  <jason@peaceworks.ca>
 *		  Daniel Elstner  <daniel.elstner@gmx.net>
 *
 * This is a special purpose container widget, which manages arbitrary
 * children at arbitrary positions width arbitrary sizes.  This finally puts
 * an end on our resize problems with which we where struggling for such a
 * long time.
 *
 * Support for GTK+ 3 was added by:
 * 2016  Kazunobu Kuriyama  <kazunobu.kuriyama@gmail.com>
 */

#include "vim.h"
#include <gtk/gtk.h>	// without this it compiles, but gives errors at
			// runtime!
#include "gui_gtk_f.h"
#if !GTK_CHECK_VERSION(3,0,0)
# include <gtk/gtksignal.h>
#endif
#ifdef MSWIN
# include <gdk/gdkwin32.h>
#else
# include <gdk/gdkx.h>
#endif

typedef struct _GtkFormChild GtkFormChild;

struct _GtkFormChild
{
    GtkWidget *widget;
    GdkWindow *window;
    gint x;		// relative subwidget x position
    gint y;		// relative subwidget y position
    gint mapped;
};


static void gui_gtk_form_class_init(GtkFormClass *klass);
#if GTK_CHECK_VERSION(3,0,0)
static void gui_gtk_form_init(GtkForm *form);
#else
static void gui_gtk_form_init(GtkForm *form, void *g_class);
#endif

static void form_realize(GtkWidget *widget);
static void form_unrealize(GtkWidget *widget);
static void form_map(GtkWidget *widget);
static void form_size_request(GtkWidget *widget, GtkRequisition *requisition);
#if GTK_CHECK_VERSION(3,0,0)
static void form_get_preferred_width(GtkWidget *widget, gint *minimal_width, gint *natural_width);
static void form_get_preferred_height(GtkWidget *widget, gint *minimal_height, gint *natural_height);
#endif
static void form_size_allocate(GtkWidget *widget, GtkAllocation *allocation);
#if GTK_CHECK_VERSION(3,0,0)
static gboolean form_draw(GtkWidget *widget, cairo_t *cr);
#else
static gint form_expose(GtkWidget *widget, GdkEventExpose *event);
#endif

static void form_remove(GtkContainer *container, GtkWidget *widget);
static void form_forall(GtkContainer *container, gboolean include_internals, GtkCallback callback, gpointer callback_data);

static void form_attach_child_window(GtkForm *form, GtkFormChild *child);
static void form_realize_child(GtkForm *form, GtkFormChild *child);
static void form_position_child(GtkForm *form, GtkFormChild *child, gboolean force_allocate);
static void form_position_children(GtkForm *form);

static void form_send_configure(GtkForm *form);

static void form_child_map(GtkWidget *widget, gpointer user_data);
static void form_child_unmap(GtkWidget *widget, gpointer user_data);

#if !GTK_CHECK_VERSION(3,0,0)
static GtkWidgetClass *parent_class = NULL;
#endif

// Public interface

    GtkWidget *
gui_gtk_form_new(void)
{
    GtkForm *form;

#if GTK_CHECK_VERSION(3,0,0)
    form = g_object_new(GTK_TYPE_FORM, NULL);
#else
    form = gtk_type_new(gui_gtk_form_get_type());
#endif

    return GTK_WIDGET(form);
}

    void
gui_gtk_form_put(
	GtkForm	*form,
	GtkWidget	*child_widget,
	gint	x,
	gint	y)
{
    GtkFormChild *child;

    g_return_if_fail(GTK_IS_FORM(form));

    // LINTED: avoid warning: conversion to 'unsigned long'
    child = g_new(GtkFormChild, 1);
    if (child == NULL)
	return;

    child->widget = child_widget;
    child->window = NULL;
    child->x = x;
    child->y = y;
#if GTK_CHECK_VERSION(3,0,0)
    gtk_widget_set_size_request(child->widget, -1, -1);
#else
    child->widget->requisition.width = 0;
    child->widget->requisition.height = 0;
#endif
    child->mapped = FALSE;

    form->children = g_list_append(form->children, child);

    // child->window must be created and attached to the widget _before_
    // it has been realized, or else things will break with GTK2.  Note
    // that gtk_widget_set_parent() realizes the widget if it's visible
    // and its parent is mapped.
    if (gtk_widget_get_realized(GTK_WIDGET(form)))
	form_attach_child_window(form, child);

    gtk_widget_set_parent(child_widget, GTK_WIDGET(form));

    if (gtk_widget_get_realized(GTK_WIDGET(form))
	    && !gtk_widget_get_realized(child_widget))
	form_realize_child(form, child);

    form_position_child(form, child, TRUE);
}

    void
gui_gtk_form_move(
	GtkForm	*form,
	GtkWidget	*child_widget,
	gint	x,
	gint	y)
{
    GList *tmp_list;
    GtkFormChild *child;

    g_return_if_fail(GTK_IS_FORM(form));

    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
    {
	child = tmp_list->data;
	if (child->widget == child_widget)
	{
	    child->x = x;
	    child->y = y;

	    form_position_child(form, child, TRUE);
	    return;
	}
    }
}

    void
gui_gtk_form_freeze(GtkForm *form)
{
    g_return_if_fail(GTK_IS_FORM(form));

    ++form->freeze_count;
}

    void
gui_gtk_form_thaw(GtkForm *form)
{
    g_return_if_fail(GTK_IS_FORM(form));

    if (!form->freeze_count)
	return;

    if (!(--form->freeze_count))
    {
	form_position_children(form);
	gtk_widget_queue_draw(GTK_WIDGET(form));
    }
}

// Basic Object handling procedures

#if GTK_CHECK_VERSION(3,0,0)
G_DEFINE_TYPE(GtkForm, gui_gtk_form, GTK_TYPE_CONTAINER)
#else
    GtkType
gui_gtk_form_get_type(void)
{
    static GtkType form_type = 0;

    if (!form_type)
    {
	GtkTypeInfo form_info;

	CLEAR_FIELD(form_info);
	form_info.type_name = "GtkForm";
	form_info.object_size = sizeof(GtkForm);
	form_info.class_size = sizeof(GtkFormClass);
	form_info.class_init_func = (GtkClassInitFunc)gui_gtk_form_class_init;
	form_info.object_init_func = (GtkObjectInitFunc)gui_gtk_form_init;

	form_type = gtk_type_unique(GTK_TYPE_CONTAINER, &form_info);
    }
    return form_type;
}
#endif // !GTK_CHECK_VERSION(3,0,0)

    static void
gui_gtk_form_class_init(GtkFormClass *klass)
{
    GtkWidgetClass *widget_class;
    GtkContainerClass *container_class;

    widget_class = (GtkWidgetClass *) klass;
    container_class = (GtkContainerClass *) klass;

#if !GTK_CHECK_VERSION(3,0,0)
    parent_class = gtk_type_class(gtk_container_get_type());
#endif

    widget_class->realize = form_realize;
    widget_class->unrealize = form_unrealize;
    widget_class->map = form_map;
#if GTK_CHECK_VERSION(3,0,0)
    widget_class->get_preferred_width = form_get_preferred_width;
    widget_class->get_preferred_height = form_get_preferred_height;
#else
    widget_class->size_request = form_size_request;
#endif
    widget_class->size_allocate = form_size_allocate;
#if GTK_CHECK_VERSION(3,0,0)
    widget_class->draw = form_draw;
#else
    widget_class->expose_event = form_expose;
#endif

    container_class->remove = form_remove;
    container_class->forall = form_forall;
}

    static void
gui_gtk_form_init(GtkForm *form
#if !GTK_CHECK_VERSION(3,0,0)
	, void *g_class UNUSED
#endif
	)
{
#if GTK_CHECK_VERSION(3,0,0)
    gtk_widget_set_has_window(GTK_WIDGET(form), TRUE);
#endif
    form->children = NULL;
    form->bin_window = NULL;
    form->freeze_count = 0;
}

/*
 * Widget methods
 */

    static void
form_realize(GtkWidget *widget)
{
    GList *tmp_list;
    GtkForm *form;
    GdkWindowAttr attributes;
    gint attributes_mask;
    GtkAllocation allocation;

    g_return_if_fail(GTK_IS_FORM(widget));

    form = GTK_FORM(widget);
    gtk_widget_set_realized(widget, TRUE);

    gtk_widget_get_allocation(widget, &allocation);
    attributes.window_type = GDK_WINDOW_CHILD;
    attributes.x = allocation.x;
    attributes.y = allocation.y;
    attributes.width = allocation.width;
    attributes.height = allocation.height;
    attributes.wclass = GDK_INPUT_OUTPUT;
    attributes.visual = gtk_widget_get_visual(widget);
#if GTK_CHECK_VERSION(3,0,0)
    attributes.event_mask = GDK_EXPOSURE_MASK;
#else
    attributes.colormap = gtk_widget_get_colormap(widget);
    attributes.event_mask = GDK_VISIBILITY_NOTIFY_MASK;
#endif

#if GTK_CHECK_VERSION(3,0,0)
    attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
#else
    attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
#endif

    gtk_widget_set_window(widget,
			  gdk_window_new(gtk_widget_get_parent_window(widget),
					 &attributes, attributes_mask));
    gdk_window_set_user_data(gtk_widget_get_window(widget), widget);

    attributes.x = 0;
    attributes.y = 0;
    attributes.event_mask = gtk_widget_get_events(widget);

    form->bin_window = gdk_window_new(gtk_widget_get_window(widget),
				      &attributes, attributes_mask);
    gdk_window_set_user_data(form->bin_window, widget);

#if GTK_CHECK_VERSION(3,0,0)
    {
	GtkStyleContext * const sctx = gtk_widget_get_style_context(widget);

	gtk_style_context_add_class(sctx, "gtk-form");
	gtk_style_context_set_state(sctx, GTK_STATE_FLAG_NORMAL);
# if !GTK_CHECK_VERSION(3,18,0)
	gtk_style_context_set_background(sctx, gtk_widget_get_window(widget));
	gtk_style_context_set_background(sctx, form->bin_window);
# endif
    }
#else
    widget->style = gtk_style_attach(widget->style, widget->window);
    gtk_style_set_background(widget->style, widget->window, GTK_STATE_NORMAL);
    gtk_style_set_background(widget->style, form->bin_window, GTK_STATE_NORMAL);
#endif

    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
    {
	GtkFormChild *child = tmp_list->data;

	form_attach_child_window(form, child);

	if (gtk_widget_get_visible(child->widget))
	    form_realize_child(form, child);
    }
}


// After reading the documentation at
// http://developer.gnome.org/doc/API/2.0/gtk/gtk-changes-2-0.html
// I think it should be possible to remove this function when compiling
// against gtk-2.0.  It doesn't seem to cause problems, though.
//
// Well, I reckon at least the gdk_window_show(form->bin_window)
// is necessary.  GtkForm is anything but a usual container widget.
    static void
form_map(GtkWidget *widget)
{
    GList *tmp_list;
    GtkForm *form;

    g_return_if_fail(GTK_IS_FORM(widget));

    form = GTK_FORM(widget);

    gtk_widget_set_mapped(widget, TRUE);

    gdk_window_show(gtk_widget_get_window(widget));
    gdk_window_show(form->bin_window);

    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
    {
	GtkFormChild *child = tmp_list->data;

	if (gtk_widget_get_visible(child->widget)
		&& !gtk_widget_get_mapped(child->widget))
	    gtk_widget_map(child->widget);
    }
}

    static void
form_unrealize(GtkWidget *widget)
{
    GList *tmp_list;
    GtkForm *form;

    g_return_if_fail(GTK_IS_FORM(widget));

    form = GTK_FORM(widget);

    tmp_list = form->children;

    gdk_window_set_user_data(form->bin_window, NULL);
    gdk_window_destroy(form->bin_window);
    form->bin_window = NULL;

    while (tmp_list)
    {
	GtkFormChild *child = tmp_list->data;

	if (child->window != NULL)
	{
	    g_signal_handlers_disconnect_by_func(G_OBJECT(child->widget),
		    FUNC2GENERIC(form_child_map),
		    child);
	    g_signal_handlers_disconnect_by_func(G_OBJECT(child->widget),
		    FUNC2GENERIC(form_child_unmap),
		    child);

	    gdk_window_set_user_data(child->window, NULL);
	    gdk_window_destroy(child->window);

	    child->window = NULL;
	}

	tmp_list = tmp_list->next;
    }

#if GTK_CHECK_VERSION(3,0,0)
    if (GTK_WIDGET_CLASS (gui_gtk_form_parent_class)->unrealize)
	 (* GTK_WIDGET_CLASS (gui_gtk_form_parent_class)->unrealize) (widget);
#else
    if (GTK_WIDGET_CLASS (parent_class)->unrealize)
	 (* GTK_WIDGET_CLASS (parent_class)->unrealize) (widget);
#endif
}

    static void
form_size_request(GtkWidget *widget, GtkRequisition *requisition)
{
    g_return_if_fail(GTK_IS_FORM(widget));
    g_return_if_fail(requisition != NULL);

    requisition->width = 1;
    requisition->height = 1;
}

#if GTK_CHECK_VERSION(3,0,0)
    static void
form_get_preferred_width(GtkWidget *widget,
			     gint      *minimal_width,
			     gint      *natural_width)
{
    GtkRequisition requisition;

    form_size_request(widget, &requisition);

    *minimal_width = requisition.width;
    *natural_width = requisition.width;
}

    static void
form_get_preferred_height(GtkWidget *widget,
			      gint	*minimal_height,
			      gint	*natural_height)
{
    GtkRequisition requisition;

    form_size_request(widget, &requisition);

    *minimal_height = requisition.height;
    *natural_height = requisition.height;
}
#endif // GTK_CHECK_VERSION(3,0,0)

    static void
form_size_allocate(GtkWidget *widget, GtkAllocation *allocation)
{
    GList *tmp_list;
    GtkForm *form;
    gboolean need_reposition;
    GtkAllocation cur_alloc;

    g_return_if_fail(GTK_IS_FORM(widget));

    gtk_widget_get_allocation(widget, &cur_alloc);

    if (cur_alloc.x == allocation->x
	    && cur_alloc.y == allocation->y
	    && cur_alloc.width == allocation->width
	    && cur_alloc.height == allocation->height)
	return;

    need_reposition = cur_alloc.width != allocation->width
		   || cur_alloc.height != allocation->height;
    form = GTK_FORM(widget);

    if (need_reposition)
    {
	tmp_list = form->children;

	while (tmp_list)
	{
	    GtkFormChild *child = tmp_list->data;
	    form_position_child(form, child, TRUE);

	    tmp_list = tmp_list->next;
	}
    }

    if (gtk_widget_get_realized(widget))
    {
	gdk_window_move_resize(gtk_widget_get_window(widget),
			       allocation->x, allocation->y,
			       allocation->width, allocation->height);
	gdk_window_move_resize(GTK_FORM(widget)->bin_window,
			       0, 0,
			       allocation->width, allocation->height);
    }
    gtk_widget_set_allocation(widget, allocation);
    if (need_reposition)
	form_send_configure(form);
}

#if GTK_CHECK_VERSION(3,0,0)
    static void
gtk_form_render_background(GtkWidget *widget, cairo_t *cr)
{
    gtk_render_background(gtk_widget_get_style_context(widget), cr,
			  0, 0,
			  gtk_widget_get_allocated_width(widget),
			  gtk_widget_get_allocated_height(widget));
}

    static gboolean
form_draw(GtkWidget *widget, cairo_t *cr)
{
    GList   *tmp_list = NULL;
    GtkForm *form     = NULL;

    g_return_val_if_fail(GTK_IS_FORM(widget), FALSE);

    gtk_form_render_background(widget, cr);

    form = GTK_FORM(widget);
    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
    {
	GtkFormChild * const formchild = tmp_list->data;

	if (!gtk_widget_get_has_window(formchild->widget) &&
		gtk_cairo_should_draw_window(cr, formchild->window))
	{
	    // To get gtk_widget_draw() to work, it is required to call
	    // gtk_widget_size_allocate() in advance with a well-posed
	    // allocation for a given child widget in order to set a
	    // certain private GtkWidget variable, called
	    // widget->priv->alloc_need, to the proper value; otherwise,
	    // gtk_widget_draw() fails and the relevant scrollbar won't
	    // appear on the screen.
	    //
	    // Calling form_position_child() like this is one of ways
	    // to make sure of that.
	    form_position_child(form, formchild, TRUE);

	    gtk_form_render_background(formchild->widget, cr);
	}
    }

    return GTK_WIDGET_CLASS(gui_gtk_form_parent_class)->draw(widget, cr);
}
#else // !GTK_CHECK_VERSION(3,0,0)
    static gint
form_expose(GtkWidget *widget, GdkEventExpose *event)
{
    GList   *tmp_list;
    GtkForm *form;

    g_return_val_if_fail(GTK_IS_FORM(widget), FALSE);

    form = GTK_FORM(widget);

    if (event->window == form->bin_window)
	return FALSE;

    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
	gtk_container_propagate_expose(GTK_CONTAINER(widget),
		GTK_WIDGET(((GtkFormChild *)tmp_list->data)->widget),
		event);

    return FALSE;
}
#endif // !GTK_CHECK_VERSION(3,0,0)

// Container method
    static void
form_remove(GtkContainer *container, GtkWidget *widget)
{
    GList *tmp_list;
    GtkForm *form;
    GtkFormChild *child = NULL;	    // init for gcc

    g_return_if_fail(GTK_IS_FORM(container));

    form = GTK_FORM(container);

    tmp_list = form->children;
    while (tmp_list)
    {
	child = tmp_list->data;
	if (child->widget == widget)
	    break;
	tmp_list = tmp_list->next;
    }

    if (tmp_list == NULL)
	return;

#if GTK_CHECK_VERSION(3,0,0)
    const gboolean was_visible = gtk_widget_get_visible(widget);
#endif
    if (child->window)
    {
	g_signal_handlers_disconnect_by_func(G_OBJECT(child->widget),
		FUNC2GENERIC(&form_child_map), child);
	g_signal_handlers_disconnect_by_func(G_OBJECT(child->widget),
		FUNC2GENERIC(&form_child_unmap), child);

	// FIXME: This will cause problems for reparenting NO_WINDOW
	// widgets out of a GtkForm
	gdk_window_set_user_data(child->window, NULL);
	gdk_window_destroy(child->window);
    }
    gtk_widget_unparent(widget);
#if GTK_CHECK_VERSION(3,0,0)
    if (was_visible)
	gtk_widget_queue_resize(GTK_WIDGET(container));
#endif
    form->children = g_list_remove_link(form->children, tmp_list);
    g_list_free_1(tmp_list);
    g_free(child);
}

    static void
form_forall(GtkContainer	*container,
		gboolean	include_internals UNUSED,
		GtkCallback	callback,
		gpointer	callback_data)
{
    GtkForm *form;
    GtkFormChild *child;
    GList *tmp_list;

    g_return_if_fail(GTK_IS_FORM(container));
    g_return_if_fail(callback != NULL);

    form = GTK_FORM(container);

    tmp_list = form->children;
    while (tmp_list)
    {
	child = tmp_list->data;
	tmp_list = tmp_list->next;

	(*callback) (child->widget, callback_data);
    }
}

// Operations on children

    static void
form_attach_child_window(GtkForm *form, GtkFormChild *child)
{
    if (child->window != NULL)
	return; // been there, done that

    if (!gtk_widget_get_has_window(child->widget))
    {
	GtkWidget	*widget;
	GdkWindowAttr	attributes;
	gint		attributes_mask;
	GtkRequisition	requisition;

	widget = GTK_WIDGET(form);

#if GTK_CHECK_VERSION(3,0,0)
	gtk_widget_get_preferred_size(child->widget, &requisition, NULL);
#else
	requisition = child->widget->requisition;
#endif
	attributes.window_type = GDK_WINDOW_CHILD;
	attributes.x = child->x;
	attributes.y = child->y;
	attributes.width = requisition.width;
	attributes.height = requisition.height;
	attributes.wclass = GDK_INPUT_OUTPUT;
	attributes.visual = gtk_widget_get_visual(widget);
#if !GTK_CHECK_VERSION(3,0,0)
	attributes.colormap = gtk_widget_get_colormap(widget);
#endif
	attributes.event_mask = GDK_EXPOSURE_MASK;

#if GTK_CHECK_VERSION(3,0,0)
	attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
#else
	attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
#endif
	child->window = gdk_window_new(form->bin_window,
				       &attributes, attributes_mask);
	gdk_window_set_user_data(child->window, widget);

#if GTK_CHECK_VERSION(3,0,0)
	{
	    GtkStyleContext * const sctx = gtk_widget_get_style_context(widget);

	    gtk_style_context_set_state(sctx, GTK_STATE_FLAG_NORMAL);
# if !GTK_CHECK_VERSION(3,18,0)
	    gtk_style_context_set_background(sctx, child->window);
# endif
	}
#else
	gtk_style_set_background(widget->style,
				 child->window,
				 GTK_STATE_NORMAL);
#endif

	gtk_widget_set_parent_window(child->widget, child->window);
	/*
	 * Install signal handlers to map/unmap child->window
	 * alongside with the actual widget.
	 */
	g_signal_connect(G_OBJECT(child->widget), "map",
			 G_CALLBACK(&form_child_map), child);
	g_signal_connect(G_OBJECT(child->widget), "unmap",
			 G_CALLBACK(&form_child_unmap), child);
    }
    else if (!gtk_widget_get_realized(child->widget))
    {
	gtk_widget_set_parent_window(child->widget, form->bin_window);
    }
}

    static void
form_realize_child(GtkForm *form, GtkFormChild *child)
{
    form_attach_child_window(form, child);
    gtk_widget_realize(child->widget);
}

    static void
form_position_child(GtkForm *form, GtkFormChild *child, gboolean force_allocate)
{
    gint x;
    gint y;

    x = child->x;
    y = child->y;

    if ((x >= G_MINSHORT) && (x <= G_MAXSHORT) &&
	(y >= G_MINSHORT) && (y <= G_MAXSHORT))
    {
	if (!child->mapped)
	{
	    if (gtk_widget_get_mapped(GTK_WIDGET(form))
		    && gtk_widget_get_visible(child->widget))
	    {
		if (!gtk_widget_get_mapped(child->widget))
		    gtk_widget_map(child->widget);

		child->mapped = TRUE;
		force_allocate = TRUE;
	    }
	}

	if (force_allocate)
	{
	    GtkAllocation allocation;
	    GtkRequisition requisition;

#if GTK_CHECK_VERSION(3,0,0)
	    gtk_widget_get_preferred_size(child->widget, &requisition, NULL);
#else
	    requisition = child->widget->requisition;
#endif

	    if (!gtk_widget_get_has_window(child->widget))
	    {
		if (child->window)
		{
		    gdk_window_move_resize(child->window,
			    x, y,
			    requisition.width,
			    requisition.height);
		}

		allocation.x = 0;
		allocation.y = 0;
	    }
	    else
	    {
		allocation.x = x;
		allocation.y = y;
	    }

	    allocation.width = requisition.width;
	    allocation.height = requisition.height;

	    gtk_widget_size_allocate(child->widget, &allocation);
	}
    }
    else
    {
	if (child->mapped)
	{
	    child->mapped = FALSE;

	    if (gtk_widget_get_mapped(child->widget))
		gtk_widget_unmap(child->widget);
	}
    }
}

    static void
form_position_children(GtkForm *form)
{
    GList *tmp_list;

    for (tmp_list = form->children; tmp_list; tmp_list = tmp_list->next)
	form_position_child(form, tmp_list->data, FALSE);
}

    void
gui_gtk_form_move_resize(GtkForm *form, GtkWidget *widget,
		     gint x, gint y, gint w, gint h)
{
#if GTK_CHECK_VERSION(3,0,0)
    gtk_widget_set_size_request(widget, w, h);
#else
    widget->requisition.width  = w;
    widget->requisition.height = h;
#endif

    gui_gtk_form_move(form, widget, x, y);
}

    static void
form_send_configure(GtkForm *form)
{
    GtkWidget *widget;
    GdkEventConfigure event;
    GtkAllocation allocation;

    widget = GTK_WIDGET(form);

    gtk_widget_get_allocation(widget, &allocation);
    event.type = GDK_CONFIGURE;
    event.window = gtk_widget_get_window(widget);
    event.x = allocation.x;
    event.y = allocation.y;
    event.width = allocation.width;
    event.height = allocation.height;

    gtk_main_do_event((GdkEvent*)&event);
}

    static void
form_child_map(GtkWidget *widget UNUSED, gpointer user_data)
{
    GtkFormChild *child;

    child = (GtkFormChild *)user_data;

    child->mapped = TRUE;
    gdk_window_show(child->window);
}

    static void
form_child_unmap(GtkWidget *widget UNUSED, gpointer user_data)
{
    GtkFormChild *child;

    child = (GtkFormChild *)user_data;

    child->mapped = FALSE;
    gdk_window_hide(child->window);
}