src/gtk/win_gtk.c

   1 /* ///////////////////////////////////////////////////////////////////////////
   2 // Name:        src/gtk/win_gtk.c
   3 // Purpose:     Native GTK+ widget for wxWidgets, based on GtkLayout and
   4 //              GtkFixed. It makes use of the gravity window property and
   5 //              therefore does not work with GTK 1.0.
   6 // Author:      Robert Roebling
   7 // Id:          $Id$
   8 // Copyright:   (c) 1998 Robert Roebling
   9 // Licence:     wxWidgets licence
  10 /////////////////////////////////////////////////////////////////////////// */
  11
  12 #ifdef VMS
  13 #define XCheckIfEvent XCHECKIFEVENT
  14 #endif
  15
  16 #include "wx/platform.h"
  17 #include "wx/gtk/win_gtk.h"
  18
  19 #ifdef __cplusplus
  20 extern "C" {
  21 #endif /* __cplusplus */
  22
  23 typedef struct _GtkPizzaChild GtkPizzaChild;
  24 typedef struct _GtkPizzaClass GtkPizzaClass;
  25
  26 struct _GtkPizzaClass
  27 {
  28   GtkContainerClass parent_class;
  29
  30   void  (*set_scroll_adjustments)   (GtkPizza     *pizza,
  31                                      GtkAdjustment  *hadjustment,
  32                                      GtkAdjustment  *vadjustment);
  33 };
  34
  35 struct _GtkPizzaChild
  36 {
  37     GtkWidget *widget;
  38     gint x;
  39     gint y;
  40 };
  41
  42 static void gtk_pizza_class_init    (GtkPizzaClass    *klass);
  43 static void gtk_pizza_init          (GtkPizza         *pizza);
  44
  45 static void gtk_pizza_realize       (GtkWidget        *widget);
  46 static void gtk_pizza_unrealize     (GtkWidget        *widget);
  47
  48 static void gtk_pizza_map           (GtkWidget        *widget);
  49
  50 static void gtk_pizza_size_request  (GtkWidget        *widget,
  51                                      GtkRequisition   *requisition);
  52 static void gtk_pizza_size_allocate (GtkWidget        *widget,
  53                                      GtkAllocation    *allocation);
  54 static void gtk_pizza_style_set     (GtkWidget *widget,
  55                                      GtkStyle  *previous_style);
  56 static void gtk_pizza_add           (GtkContainer     *container,
  57                                      GtkWidget        *widget);
  58 static void gtk_pizza_remove        (GtkContainer     *container,
  59                                      GtkWidget        *widget);
  60 static void gtk_pizza_forall        (GtkContainer     *container,
  61                                      gboolean          include_internals,
  62                                      GtkCallback       callback,
  63                                      gpointer          callback_data);
  64
  65 static void     gtk_pizza_allocate_child     (GtkPizza      *pizza,
  66                                               GtkPizzaChild *child);
  67
  68 static GtkType gtk_pizza_child_type (GtkContainer     *container);
  69
  70 static void  gtk_pizza_scroll_set_adjustments (GtkPizza      *pizza,
  71                                                GtkAdjustment *hadj,
  72                                                GtkAdjustment *vadj);
  73
  74 static GtkWidgetClass* pizza_parent_class;
  75
  76 GtkType
  77 gtk_pizza_get_type ()
  78 {
  79     static GtkType pizza_type = 0;
  80
  81     if (!pizza_type)
  82     {
  83         const GTypeInfo pizza_info =
  84         {
  85             sizeof (GtkPizzaClass),
  86             NULL,           /* base_init */
  87             NULL,           /* base_finalize */
  88             (GClassInitFunc) gtk_pizza_class_init,
  89             NULL,           /* class_finalize */
  90             NULL,           /* class_data */
  91             sizeof (GtkPizza),
  92             16,             /* n_preallocs */
  93             (GInstanceInitFunc) gtk_pizza_init,
  94             NULL
  95         };
  96         pizza_type = g_type_register_static (GTK_TYPE_CONTAINER, "GtkPizza", &pizza_info, (GTypeFlags)0);
  97     }
  98
  99     return pizza_type;
 100 }
 101
 102 /* Marshaller needed for set_scroll_adjustments signal,
 103    generated with GLib-2.4.6 glib-genmarshal */
 104 #define g_marshal_value_peek_object(v)   g_value_get_object (v)
 105 static void
 106 g_cclosure_user_marshal_VOID__OBJECT_OBJECT (GClosure     *closure,
 107                                              GValue       *return_value,
 108                                              guint         n_param_values,
 109                                              const GValue *param_values,
 110                                              gpointer      invocation_hint,
 111                                              gpointer      marshal_data)
 112 {
 113   typedef void (*GMarshalFunc_VOID__OBJECT_OBJECT) (gpointer     data1,
 114                                                     gpointer     arg_1,
 115                                                     gpointer     arg_2,
 116                                                     gpointer     data2);
 117   register GMarshalFunc_VOID__OBJECT_OBJECT callback;
 118   register GCClosure *cc = (GCClosure*) closure;
 119   register gpointer data1, data2;
 120
 121   g_return_if_fail (n_param_values == 3);
 122
 123   if (G_CCLOSURE_SWAP_DATA (closure))
 124     {
 125       data1 = closure->data;
 126       data2 = g_value_peek_pointer (param_values + 0);
 127     }
 128   else
 129     {
 130       data1 = g_value_peek_pointer (param_values + 0);
 131       data2 = closure->data;
 132     }
 133   callback = (GMarshalFunc_VOID__OBJECT_OBJECT) (marshal_data ? marshal_data : cc->callback);
 134
 135   callback (data1,
 136             g_marshal_value_peek_object (param_values + 1),
 137             g_marshal_value_peek_object (param_values + 2),
 138             data2);
 139 }
 140
 141 static void
 142 gtk_pizza_class_init (GtkPizzaClass *klass)
 143 {
 144     GtkObjectClass *object_class;
 145     GtkWidgetClass *widget_class;
 146     GtkContainerClass *container_class;
 147
 148     object_class = (GtkObjectClass*) klass;
 149     widget_class = (GtkWidgetClass*) klass;
 150     container_class = (GtkContainerClass*) klass;
 151     pizza_parent_class = gtk_type_class (GTK_TYPE_CONTAINER);
 152
 153     widget_class->map = gtk_pizza_map;
 154     widget_class->realize = gtk_pizza_realize;
 155     widget_class->unrealize = gtk_pizza_unrealize;
 156     widget_class->size_request = gtk_pizza_size_request;
 157     widget_class->size_allocate = gtk_pizza_size_allocate;
 158     widget_class->style_set = gtk_pizza_style_set;
 159
 160     container_class->add = gtk_pizza_add;
 161     container_class->remove = gtk_pizza_remove;
 162     container_class->forall = gtk_pizza_forall;
 163
 164     container_class->child_type = gtk_pizza_child_type;
 165
 166     klass->set_scroll_adjustments = gtk_pizza_scroll_set_adjustments;
 167
 168     widget_class->set_scroll_adjustments_signal =
 169         g_signal_new(
 170             "set_scroll_adjustments",
 171             G_TYPE_FROM_CLASS(object_class),
 172             G_SIGNAL_RUN_LAST,
 173             G_STRUCT_OFFSET(GtkPizzaClass, set_scroll_adjustments),
 174             NULL,
 175             NULL,
 176             g_cclosure_user_marshal_VOID__OBJECT_OBJECT,
 177             G_TYPE_NONE,
 178             2,
 179             GTK_TYPE_ADJUSTMENT,
 180             GTK_TYPE_ADJUSTMENT);
 181 }
 182
 183 static GtkType
 184 gtk_pizza_child_type (GtkContainer     *container)
 185 {
 186     return GTK_TYPE_WIDGET;
 187 }
 188
 189 static void
 190 gtk_pizza_init (GtkPizza *pizza)
 191 {
 192     GTK_WIDGET_SET_FLAGS (pizza, GTK_CAN_FOCUS);
 193     GTK_WIDGET_UNSET_FLAGS (pizza, GTK_NO_WINDOW);
 194
 195     pizza->children = NULL;
 196
 197     pizza->bin_window = NULL;
 198
 199     pizza->m_xoffset = 0;
 200     pizza->m_yoffset = 0;
 201 }
 202
 203 GtkWidget*
 204 gtk_pizza_new ()
 205 {
 206     GtkPizza *pizza;
 207
 208     pizza = g_object_new (gtk_pizza_get_type (), NULL);
 209
 210     pizza->m_noscroll = FALSE;
 211
 212     return GTK_WIDGET (pizza);
 213 }
 214
 215 GtkWidget*
 216 gtk_pizza_new_no_scroll ()
 217 {
 218     GtkPizza *pizza;
 219
 220     pizza = g_object_new (gtk_pizza_get_type (), NULL);
 221
 222     pizza->m_noscroll = TRUE;
 223
 224     return GTK_WIDGET (pizza);
 225 }
 226
 227 gint       gtk_pizza_get_xoffset     (GtkPizza          *pizza)
 228 {
 229     g_return_val_if_fail ( (pizza != NULL), -1 );
 230     g_return_val_if_fail ( (GTK_IS_PIZZA (pizza)), -1 );
 231
 232     return pizza->m_xoffset;
 233 }
 234
 235 gint       gtk_pizza_get_yoffset     (GtkPizza          *pizza)
 236 {
 237     g_return_val_if_fail ( (pizza != NULL), -1 );
 238     g_return_val_if_fail ( (GTK_IS_PIZZA (pizza)), -1 );
 239
 240     return pizza->m_yoffset;
 241 }
 242
 243 void       gtk_pizza_set_xoffset     (GtkPizza          *pizza, gint xoffset)
 244 {
 245     g_return_if_fail (pizza != NULL);
 246     g_return_if_fail (GTK_IS_PIZZA (pizza));
 247
 248     pizza->m_xoffset = xoffset;
 249     /* do something */
 250 }
 251
 252 void       gtk_pizza_set_yoffset     (GtkPizza          *pizza, gint yoffset)
 253 {
 254     g_return_if_fail (pizza != NULL);
 255     g_return_if_fail (GTK_IS_PIZZA (pizza));
 256
 257     pizza->m_xoffset = yoffset;
 258     /* do something */
 259 }
 260
 261 gint       gtk_pizza_get_rtl_offset  (GtkPizza          *pizza)
 262 {
 263     gint border;
 264
 265     g_return_val_if_fail ( (pizza != NULL), 0 );
 266     g_return_val_if_fail ( (GTK_IS_PIZZA (pizza)), 0 );
 267
 268     if (!pizza->bin_window) return 0;
 269
 270     border = pizza->container.border_width;
 271
 272     return GTK_WIDGET(pizza)->allocation.width - border*2;
 273 }
 274
 275
 276 static void
 277 gtk_pizza_scroll_set_adjustments (GtkPizza     *pizza,
 278                                     GtkAdjustment  *hadj,
 279                                     GtkAdjustment  *vadj)
 280 {
 281    /* We handle scrolling in the wxScrolledWindow, not here. */
 282 }
 283
 284 void
 285 gtk_pizza_put (GtkPizza   *pizza,
 286                GtkWidget  *widget,
 287                gint        x,
 288                gint        y,
 289                gint        width,
 290                gint        height)
 291 {
 292     GtkPizzaChild *child_info;
 293
 294     g_return_if_fail (pizza != NULL);
 295     g_return_if_fail (GTK_IS_PIZZA (pizza));
 296     g_return_if_fail (widget != NULL);
 297
 298     child_info = g_new (GtkPizzaChild, 1);
 299
 300     child_info->widget = widget;
 301     child_info->x = x;
 302     child_info->y = y;
 303
 304     pizza->children = g_list_append (pizza->children, child_info);
 305
 306     if (GTK_WIDGET_REALIZED (pizza))
 307         gtk_widget_set_parent_window (widget, pizza->bin_window);
 308
 309     gtk_widget_set_parent (widget, GTK_WIDGET (pizza));
 310
 311     gtk_widget_set_size_request( widget, width, height );
 312 }
 313
 314 void
 315 gtk_pizza_set_size (GtkPizza   *pizza,
 316                     GtkWidget  *widget,
 317                     gint        x,
 318                     gint        y,
 319                     gint        width,
 320                     gint        height)
 321 {
 322     GtkPizzaChild *child;
 323     GList *children;
 324
 325     g_return_if_fail (pizza != NULL);
 326     g_return_if_fail (GTK_IS_PIZZA (pizza));
 327     g_return_if_fail (widget != NULL);
 328
 329 #ifndef WX_WARN_ILLEGAL_SETSIZE
 330     /* this really shouldn't happen -- but it does, a lot, right now and we
 331        can't pass negative values to gtk_widget_set_size_request() without getting
 332        a warning printed out, so filter them out here */
 333     if ( width < 0 )
 334         width = 0;
 335     if ( height < 0 )
 336         height = 0;
 337 #endif
 338
 339     children = pizza->children;
 340     while (children)
 341     {
 342         child = children->data;
 343         children = children->next;
 344
 345         if (child->widget == widget)
 346         {
 347             if (child->x != x || child->y != y)
 348             {
 349                 child->x = x;
 350                 child->y = y;
 351                 gtk_widget_queue_resize(widget);
 352             }
 353
 354             gtk_widget_set_size_request (widget, width, height);
 355
 356             return;
 357         }
 358     }
 359 }
 360
 361 static void
 362 gtk_pizza_map (GtkWidget *widget)
 363 {
 364     GtkPizza *pizza;
 365     GtkPizzaChild *child;
 366     GList *children;
 367
 368     g_return_if_fail (widget != NULL);
 369     g_return_if_fail (GTK_IS_PIZZA (widget));
 370
 371     GTK_WIDGET_SET_FLAGS (widget, GTK_MAPPED);
 372     pizza = GTK_PIZZA (widget);
 373
 374     children = pizza->children;
 375     while (children)
 376     {
 377         child = children->data;
 378         children = children->next;
 379
 380         if ( GTK_WIDGET_VISIBLE (child->widget) &&
 381             !GTK_WIDGET_MAPPED (child->widget) )
 382         {
 383             gtk_widget_map (child->widget);
 384         }
 385     }
 386
 387     gdk_window_show (widget->window);
 388     gdk_window_show (pizza->bin_window);
 389 }
 390
 391 static void
 392 gtk_pizza_realize (GtkWidget *widget)
 393 {
 394     GtkPizza *pizza;
 395     GdkWindowAttr attributes;
 396     gint attributes_mask;
 397     GtkPizzaChild *child;
 398     GList *children;
 399     int border;
 400     int w, h;
 401
 402     g_return_if_fail (widget != NULL);
 403     g_return_if_fail (GTK_IS_PIZZA (widget));
 404
 405     pizza = GTK_PIZZA (widget);
 406     GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);
 407
 408     attributes.window_type = GDK_WINDOW_CHILD;
 409
 410     attributes.x = widget->allocation.x;
 411     attributes.y = widget->allocation.y;
 412     attributes.width = widget->allocation.width;
 413     attributes.height = widget->allocation.height;
 414
 415     /* minimal size */
 416     if (attributes.width < 2) attributes.width = 2;
 417     if (attributes.height < 2) attributes.height = 2;
 418
 419     border = pizza->container.border_width;
 420     w = attributes.width  - 2 * border;
 421     h = attributes.height - 2 * border;
 422     if (w < 2) w = 2;
 423     if (h < 2) h = 2;
 424
 425     if (!pizza->m_noscroll)
 426     {
 427         attributes.x += border;
 428         attributes.y += border;
 429         attributes.width  = w;
 430         attributes.height = h;
 431     }
 432
 433     attributes.wclass = GDK_INPUT_OUTPUT;
 434     attributes.visual = gtk_widget_get_visual (widget);
 435     attributes.colormap = gtk_widget_get_colormap (widget);
 436     attributes.event_mask = GDK_VISIBILITY_NOTIFY_MASK;
 437     attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
 438
 439     widget->window = gdk_window_new(gtk_widget_get_parent_window (widget),
 440                                      &attributes, attributes_mask);
 441     gdk_window_set_user_data (widget->window, widget);
 442
 443     attributes.x = 0;
 444     attributes.y = 0;
 445     if (pizza->m_noscroll)
 446     {
 447         attributes.x = border;
 448         attributes.y = border;
 449         attributes.width  = w;
 450         attributes.height = h;
 451     }
 452
 453     attributes.event_mask = gtk_widget_get_events (widget);
 454     attributes.event_mask |= GDK_EXPOSURE_MASK              |
 455                              GDK_SCROLL_MASK                |
 456                              GDK_POINTER_MOTION_MASK        |
 457                              GDK_POINTER_MOTION_HINT_MASK   |
 458                              GDK_BUTTON_MOTION_MASK         |
 459                              GDK_BUTTON1_MOTION_MASK        |
 460                              GDK_BUTTON2_MOTION_MASK        |
 461                              GDK_BUTTON3_MOTION_MASK        |
 462                              GDK_BUTTON_PRESS_MASK          |
 463                              GDK_BUTTON_RELEASE_MASK        |
 464                              GDK_KEY_PRESS_MASK             |
 465                              GDK_KEY_RELEASE_MASK           |
 466                              GDK_ENTER_NOTIFY_MASK          |
 467                              GDK_LEAVE_NOTIFY_MASK          |
 468                              GDK_FOCUS_CHANGE_MASK;
 469
 470     pizza->bin_window = gdk_window_new(widget->window,
 471                                           &attributes, attributes_mask);
 472     gdk_window_set_user_data (pizza->bin_window, widget);
 473
 474     widget->style = gtk_style_attach (widget->style, widget->window);
 475     gtk_style_set_background (widget->style, widget->window, GTK_STATE_NORMAL);
 476     gtk_style_set_background (widget->style, pizza->bin_window, GTK_STATE_NORMAL );
 477
 478 /*
 479     gdk_window_set_back_pixmap( widget->window, NULL, FALSE );
 480     gdk_window_set_back_pixmap( pizza->bin_window, NULL, FALSE );
 481 */
 482
 483     /* cannot be done before realisation */
 484     children = pizza->children;
 485     while (children)
 486     {
 487         child = children->data;
 488         children = children->next;
 489
 490         gtk_widget_set_parent_window (child->widget, pizza->bin_window);
 491     }
 492 }
 493
 494 static void
 495 gtk_pizza_unrealize (GtkWidget *widget)
 496 {
 497     GtkPizza *pizza;
 498
 499     g_return_if_fail (widget != NULL);
 500     g_return_if_fail (GTK_IS_PIZZA (widget));
 501
 502     pizza = GTK_PIZZA (widget);
 503
 504     gdk_window_set_user_data (pizza->bin_window, NULL);
 505     gdk_window_destroy (pizza->bin_window);
 506     pizza->bin_window = NULL;
 507
 508     if (pizza_parent_class->unrealize)
 509         pizza_parent_class->unrealize(widget);
 510 }
 511
 512 static void
 513 gtk_pizza_size_request (GtkWidget      *widget,
 514                         GtkRequisition *requisition)
 515 {
 516     GtkPizza *pizza;
 517     GtkPizzaChild *child;
 518     GList *children;
 519     GtkRequisition child_requisition;
 520
 521     g_return_if_fail (widget != NULL);
 522     g_return_if_fail (GTK_IS_PIZZA (widget));
 523     g_return_if_fail (requisition != NULL);
 524
 525     pizza = GTK_PIZZA (widget);
 526
 527     children = pizza->children;
 528     while (children)
 529     {
 530         child = children->data;
 531         children = children->next;
 532
 533         if (GTK_WIDGET_VISIBLE (child->widget))
 534         {
 535             gtk_widget_size_request (child->widget, &child_requisition);
 536         }
 537     }
 538
 539     /* request very little, I'm not sure if requesting nothing
 540        will always have positive effects on stability... */
 541     requisition->width = 2;
 542     requisition->height = 2;
 543 }
 544
 545 static void
 546 gtk_pizza_size_allocate (GtkWidget     *widget,
 547                          GtkAllocation *allocation)
 548 {
 549     GtkPizza *pizza;
 550     gint border;
 551     gint x,y,w,h;
 552     GtkPizzaChild *child;
 553     GList *children;
 554     gboolean only_resize;
 555
 556     g_return_if_fail (widget != NULL);
 557     g_return_if_fail (GTK_IS_PIZZA(widget));
 558     g_return_if_fail (allocation != NULL);
 559
 560     pizza = GTK_PIZZA (widget);
 561
 562     only_resize = ((widget->allocation.x == allocation->x) &&
 563                    (widget->allocation.y == allocation->y));
 564     widget->allocation = *allocation;
 565
 566     if (GTK_WIDGET_REALIZED(widget))
 567     {
 568         border = pizza->container.border_width;
 569
 570         x = allocation->x + border;
 571         y = allocation->y + border;
 572         w = allocation->width - border*2;
 573         h = allocation->height - border*2;
 574         if (w < 0)
 575             w = 0;
 576         if (h < 0)
 577             h = 0;
 578
 579         if (pizza->m_noscroll)
 580         {
 581             if (only_resize)
 582                 gdk_window_resize( widget->window, allocation->width, allocation->height );
 583             else
 584                 gdk_window_move_resize( widget->window, allocation->x, allocation->y,
 585                                                         allocation->width, allocation->height );
 586
 587             gdk_window_move_resize( pizza->bin_window, border, border, w, h );
 588         }
 589         else
 590         {
 591             if (only_resize)
 592                 gdk_window_resize( widget->window, w, h );
 593             else
 594                 gdk_window_move_resize( widget->window, x, y, w, h );
 595
 596             gdk_window_resize( pizza->bin_window, w, h );
 597         }
 598     }
 599
 600     children = pizza->children;
 601     while (children)
 602     {
 603         child = children->data;
 604         children = children->next;
 605
 606         gtk_pizza_allocate_child (pizza, child);
 607     }
 608 }
 609
 610 static void
 611 gtk_pizza_style_set(GtkWidget *widget, GtkStyle  *previous_style)
 612 {
 613     if (GTK_WIDGET_REALIZED(widget))
 614     {
 615         gtk_style_set_background(widget->style, widget->window, GTK_STATE_NORMAL);
 616         gtk_style_set_background(widget->style, GTK_PIZZA(widget)->bin_window, GTK_STATE_NORMAL );
 617     }
 618
 619     pizza_parent_class->style_set(widget, previous_style);
 620 }
 621
 622 static void
 623 gtk_pizza_add (GtkContainer *container,
 624                GtkWidget    *widget)
 625 {
 626     g_return_if_fail (container != NULL);
 627     g_return_if_fail (GTK_IS_PIZZA (container));
 628     g_return_if_fail (widget != NULL);
 629
 630     gtk_pizza_put (GTK_PIZZA (container), widget, 0, 0, 20, 20 );
 631 }
 632
 633 static void
 634 gtk_pizza_remove (GtkContainer *container,
 635                   GtkWidget    *widget)
 636 {
 637     GtkPizza *pizza;
 638     GtkPizzaChild *child;
 639     GList *children;
 640
 641     g_return_if_fail (container != NULL);
 642     g_return_if_fail (GTK_IS_PIZZA (container));
 643     g_return_if_fail (widget != NULL);
 644
 645     pizza = GTK_PIZZA (container);
 646
 647     children = pizza->children;
 648     while (children)
 649     {
 650         child = children->data;
 651
 652         if (child->widget == widget)
 653         {
 654             gtk_widget_unparent (widget);
 655
 656             /* security checks */
 657             g_return_if_fail (GTK_IS_WIDGET (widget));
 658
 659             pizza->children = g_list_remove_link (pizza->children, children);
 660             g_list_free (children);
 661             g_free (child);
 662
 663             /* security checks */
 664             g_return_if_fail (GTK_IS_WIDGET (widget));
 665
 666             break;
 667         }
 668
 669         children = children->next;
 670     }
 671 }
 672
 673 static void
 674 gtk_pizza_forall (GtkContainer *container,
 675                   gboolean      include_internals,
 676                   GtkCallback   callback,
 677                   gpointer      callback_data)
 678 {
 679     GtkPizza *pizza;
 680     GtkPizzaChild *child;
 681     GList *children;
 682
 683     g_return_if_fail (container != NULL);
 684     g_return_if_fail (GTK_IS_PIZZA (container));
 685     g_return_if_fail (callback != (GtkCallback)NULL);
 686
 687     pizza = GTK_PIZZA (container);
 688
 689     children = pizza->children;
 690     while (children)
 691     {
 692         child = children->data;
 693         children = children->next;
 694
 695         (* callback) (child->widget, callback_data);
 696     }
 697 }
 698
 699 static void
 700 gtk_pizza_allocate_child (GtkPizza      *pizza,
 701                           GtkPizzaChild *child)
 702 {
 703     GtkAllocation allocation;
 704     GtkRequisition requisition;
 705
 706     allocation.x = child->x - pizza->m_xoffset;
 707     allocation.y = child->y - pizza->m_yoffset;
 708     gtk_widget_get_child_requisition (child->widget, &requisition);
 709     allocation.width = requisition.width;
 710     allocation.height = requisition.height;
 711
 712     if (gtk_widget_get_direction( GTK_WIDGET(pizza) ) == GTK_TEXT_DIR_RTL)
 713     {
 714         /* reverse horizontal placement */
 715         gint offset,border;
 716
 717         offset = GTK_WIDGET(pizza)->allocation.width;
 718         border = pizza->container.border_width;
 719         offset -= border*2;
 720
 721         allocation.x = offset - child->x - allocation.width + pizza->m_xoffset;
 722     }
 723
 724     gtk_widget_size_allocate (child->widget, &allocation);
 725 }
 726
 727 void
 728 gtk_pizza_scroll (GtkPizza *pizza, gint dx, gint dy)
 729 {
 730     GList *tmp_list;
 731
 732     pizza->m_xoffset += dx;
 733     pizza->m_yoffset += dy;
 734
 735     if (pizza->bin_window)
 736         gdk_window_scroll( pizza->bin_window, -dx, -dy );
 737
 738     for (tmp_list = pizza->children; tmp_list; tmp_list = tmp_list->next)
 739     {
 740         GtkPizzaChild *child = tmp_list->data;
 741         gtk_widget_queue_resize(child->widget);
 742     }
 743 }
 744
 745 #ifdef __cplusplus
 746 }
 747 #endif /* __cplusplus */