Pileus Git - ~andy/gtk/blob - gtk/gtkscrolledwindow.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19 #include "gtkscrolledwindow.h"
  20 #include "gtksignal.h"
  21
  22
  23 #define SCROLLBAR_SPACING(w) (GTK_SCROLLED_WINDOW_CLASS (GTK_OBJECT (w)->klass)->scrollbar_spacing)
  24
  25
  26 static void gtk_scrolled_window_class_init         (GtkScrolledWindowClass *klass);
  27 static void gtk_scrolled_window_init               (GtkScrolledWindow      *scrolled_window);
  28 static void gtk_scrolled_window_destroy            (GtkObject              *object);
  29 static void gtk_scrolled_window_finalize           (GtkObject              *object);
  30 static void gtk_scrolled_window_map                (GtkWidget              *widget);
  31 static void gtk_scrolled_window_unmap              (GtkWidget              *widget);
  32 static void gtk_scrolled_window_draw               (GtkWidget              *widget,
  33                                                     GdkRectangle           *area);
  34 static void gtk_scrolled_window_size_request       (GtkWidget              *widget,
  35                                                     GtkRequisition         *requisition);
  36 static void gtk_scrolled_window_size_allocate      (GtkWidget              *widget,
  37                                                     GtkAllocation          *allocation);
  38 static void gtk_scrolled_window_add                (GtkContainer           *container,
  39                                                     GtkWidget              *widget);
  40 static void gtk_scrolled_window_remove             (GtkContainer           *container,
  41                                                     GtkWidget              *widget);
  42 static void gtk_scrolled_window_foreach            (GtkContainer           *container,
  43                                                     GtkCallback             callback,
  44                                                     gpointer                callback_data);
  45 static void gtk_scrolled_window_viewport_allocate  (GtkWidget              *widget,
  46                                                     GtkAllocation          *allocation);
  47 static void gtk_scrolled_window_adjustment_changed (GtkAdjustment          *adjustment,
  48                                                     gpointer                data);
  49
  50
  51 static GtkContainerClass *parent_class = NULL;
  52
  53
  54 guint
  55 gtk_scrolled_window_get_type (void)
  56 {
  57   static guint scrolled_window_type = 0;
  58
  59   if (!scrolled_window_type)
  60     {
  61       GtkTypeInfo scrolled_window_info =
  62       {
  63         "GtkScrolledWindow",
  64         sizeof (GtkScrolledWindow),
  65         sizeof (GtkScrolledWindowClass),
  66         (GtkClassInitFunc) gtk_scrolled_window_class_init,
  67         (GtkObjectInitFunc) gtk_scrolled_window_init,
  68         /* reserved_1 */ NULL,
  69         /* reserved_2 */ NULL,
  70         (GtkClassInitFunc) NULL,
  71       };
  72
  73       scrolled_window_type = gtk_type_unique (gtk_container_get_type (), &scrolled_window_info);
  74     }
  75
  76   return scrolled_window_type;
  77 }
  78
  79 static void
  80 gtk_scrolled_window_class_init (GtkScrolledWindowClass *class)
  81 {
  82   GtkObjectClass *object_class;
  83   GtkWidgetClass *widget_class;
  84   GtkContainerClass *container_class;
  85
  86   object_class = (GtkObjectClass*) class;
  87   widget_class = (GtkWidgetClass*) class;
  88   container_class = (GtkContainerClass*) class;
  89
  90   parent_class = gtk_type_class (gtk_container_get_type ());
  91
  92   object_class->destroy = gtk_scrolled_window_destroy;
  93   object_class->finalize = gtk_scrolled_window_finalize;
  94
  95   widget_class->map = gtk_scrolled_window_map;
  96   widget_class->unmap = gtk_scrolled_window_unmap;
  97   widget_class->draw = gtk_scrolled_window_draw;
  98   widget_class->size_request = gtk_scrolled_window_size_request;
  99   widget_class->size_allocate = gtk_scrolled_window_size_allocate;
 100
 101   container_class->add = gtk_scrolled_window_add;
 102   container_class->remove = gtk_scrolled_window_remove;
 103   container_class->foreach = gtk_scrolled_window_foreach;
 104
 105   class->scrollbar_spacing = 5;
 106 }
 107
 108 static void
 109 gtk_scrolled_window_init (GtkScrolledWindow *scrolled_window)
 110 {
 111   GTK_WIDGET_SET_FLAGS (scrolled_window, GTK_NO_WINDOW);
 112
 113   gtk_container_set_resize_mode (GTK_CONTAINER (scrolled_window), GTK_RESIZE_QUEUE);
 114
 115   scrolled_window->hscrollbar = NULL;
 116   scrolled_window->vscrollbar = NULL;
 117   scrolled_window->hscrollbar_policy = GTK_POLICY_ALWAYS;
 118   scrolled_window->vscrollbar_policy = GTK_POLICY_ALWAYS;
 119 }
 120
 121 GtkWidget*
 122 gtk_scrolled_window_new (GtkAdjustment *hadjustment,
 123                          GtkAdjustment *vadjustment)
 124 {
 125   GtkWidget *scrolled_window;
 126
 127   scrolled_window = gtk_type_new (gtk_scrolled_window_get_type ());
 128
 129   gtk_scrolled_window_construct (GTK_SCROLLED_WINDOW (scrolled_window), hadjustment, vadjustment);
 130
 131   return scrolled_window;
 132 }
 133
 134 void
 135 gtk_scrolled_window_construct (GtkScrolledWindow *scrolled_window,
 136                                GtkAdjustment     *hadjustment,
 137                                GtkAdjustment     *vadjustment)
 138 {
 139   g_return_if_fail (scrolled_window != NULL);
 140   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
 141   g_return_if_fail (scrolled_window->viewport == NULL);
 142
 143   scrolled_window->viewport = gtk_viewport_new (hadjustment, vadjustment);
 144   hadjustment = gtk_viewport_get_hadjustment (GTK_VIEWPORT (scrolled_window->viewport));
 145   vadjustment = gtk_viewport_get_vadjustment (GTK_VIEWPORT (scrolled_window->viewport));
 146   gtk_container_set_resize_mode (GTK_CONTAINER (scrolled_window->viewport), GTK_RESIZE_PARENT);
 147
 148   gtk_signal_connect (GTK_OBJECT (hadjustment), "changed",
 149                       (GtkSignalFunc) gtk_scrolled_window_adjustment_changed,
 150                       (gpointer) scrolled_window);
 151   gtk_signal_connect (GTK_OBJECT (vadjustment), "changed",
 152                       (GtkSignalFunc) gtk_scrolled_window_adjustment_changed,
 153                       (gpointer) scrolled_window);
 154
 155   scrolled_window->hscrollbar = gtk_hscrollbar_new (hadjustment);
 156   scrolled_window->vscrollbar = gtk_vscrollbar_new (vadjustment);
 157
 158   gtk_widget_set_parent (scrolled_window->viewport, GTK_WIDGET (scrolled_window));
 159   gtk_widget_set_parent (scrolled_window->hscrollbar, GTK_WIDGET (scrolled_window));
 160   gtk_widget_set_parent (scrolled_window->vscrollbar, GTK_WIDGET (scrolled_window));
 161
 162   gtk_widget_show (scrolled_window->viewport);
 163   gtk_widget_show (scrolled_window->hscrollbar);
 164   gtk_widget_show (scrolled_window->vscrollbar);
 165
 166   gtk_widget_ref (scrolled_window->viewport);
 167   gtk_widget_ref (scrolled_window->hscrollbar);
 168   gtk_widget_ref (scrolled_window->vscrollbar);
 169 }
 170
 171 GtkAdjustment*
 172 gtk_scrolled_window_get_hadjustment (GtkScrolledWindow *scrolled_window)
 173 {
 174   g_return_val_if_fail (scrolled_window != NULL, NULL);
 175   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
 176
 177   return gtk_range_get_adjustment (GTK_RANGE (scrolled_window->hscrollbar));
 178 }
 179
 180 GtkAdjustment*
 181 gtk_scrolled_window_get_vadjustment (GtkScrolledWindow *scrolled_window)
 182 {
 183   g_return_val_if_fail (scrolled_window != NULL, NULL);
 184   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
 185
 186   return gtk_range_get_adjustment (GTK_RANGE (scrolled_window->vscrollbar));
 187 }
 188
 189 void
 190 gtk_scrolled_window_set_policy (GtkScrolledWindow *scrolled_window,
 191                                 GtkPolicyType      hscrollbar_policy,
 192                                 GtkPolicyType      vscrollbar_policy)
 193 {
 194   g_return_if_fail (scrolled_window != NULL);
 195   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
 196
 197   if ((scrolled_window->hscrollbar_policy != hscrollbar_policy) ||
 198       (scrolled_window->vscrollbar_policy != vscrollbar_policy))
 199     {
 200       scrolled_window->hscrollbar_policy = hscrollbar_policy;
 201       scrolled_window->vscrollbar_policy = vscrollbar_policy;
 202
 203       if (GTK_WIDGET (scrolled_window)->parent)
 204         gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
 205     }
 206 }
 207
 208
 209 static void
 210 gtk_scrolled_window_destroy (GtkObject *object)
 211 {
 212   GtkScrolledWindow *scrolled_window;
 213
 214   g_return_if_fail (object != NULL);
 215   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (object));
 216
 217   scrolled_window = GTK_SCROLLED_WINDOW (object);
 218
 219   gtk_widget_destroy (scrolled_window->viewport);
 220   gtk_widget_destroy (scrolled_window->hscrollbar);
 221   gtk_widget_destroy (scrolled_window->vscrollbar);
 222
 223   if (GTK_OBJECT_CLASS (parent_class)->destroy)
 224     (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
 225 }
 226
 227 static void
 228 gtk_scrolled_window_finalize (GtkObject *object)
 229 {
 230   GtkScrolledWindow *scrolled_window;
 231
 232   scrolled_window = GTK_SCROLLED_WINDOW (object);
 233   gtk_widget_unref (scrolled_window->viewport);
 234   gtk_widget_unref (scrolled_window->hscrollbar);
 235   gtk_widget_unref (scrolled_window->vscrollbar);
 236
 237   GTK_OBJECT_CLASS (parent_class)->finalize (object);
 238 }
 239
 240 static void
 241 gtk_scrolled_window_map (GtkWidget *widget)
 242 {
 243   GtkScrolledWindow *scrolled_window;
 244
 245   g_return_if_fail (widget != NULL);
 246   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
 247
 248   if (!GTK_WIDGET_MAPPED (widget))
 249     {
 250       GTK_WIDGET_SET_FLAGS (widget, GTK_MAPPED);
 251       scrolled_window = GTK_SCROLLED_WINDOW (widget);
 252
 253       if (GTK_WIDGET_VISIBLE (scrolled_window->viewport) &&
 254           !GTK_WIDGET_MAPPED (scrolled_window->viewport))
 255         gtk_widget_map (scrolled_window->viewport);
 256
 257       if (GTK_WIDGET_VISIBLE (scrolled_window->hscrollbar) &&
 258           !GTK_WIDGET_MAPPED (scrolled_window->hscrollbar))
 259         gtk_widget_map (scrolled_window->hscrollbar);
 260
 261       if (GTK_WIDGET_VISIBLE (scrolled_window->vscrollbar) &&
 262           !GTK_WIDGET_MAPPED (scrolled_window->vscrollbar))
 263         gtk_widget_map (scrolled_window->vscrollbar);
 264     }
 265 }
 266
 267 static void
 268 gtk_scrolled_window_unmap (GtkWidget *widget)
 269 {
 270   GtkScrolledWindow *scrolled_window;
 271
 272   g_return_if_fail (widget != NULL);
 273   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
 274
 275   if (GTK_WIDGET_MAPPED (widget))
 276     {
 277       GTK_WIDGET_UNSET_FLAGS (widget, GTK_MAPPED);
 278       scrolled_window = GTK_SCROLLED_WINDOW (widget);
 279
 280       if (GTK_WIDGET_MAPPED (scrolled_window->viewport))
 281         gtk_widget_unmap (scrolled_window->viewport);
 282
 283       if (GTK_WIDGET_MAPPED (scrolled_window->hscrollbar))
 284         gtk_widget_unmap (scrolled_window->hscrollbar);
 285
 286       if (GTK_WIDGET_MAPPED (scrolled_window->vscrollbar))
 287         gtk_widget_unmap (scrolled_window->vscrollbar);
 288     }
 289 }
 290
 291 static void
 292 gtk_scrolled_window_draw (GtkWidget    *widget,
 293                           GdkRectangle *area)
 294 {
 295   GtkScrolledWindow *scrolled_window;
 296   GdkRectangle child_area;
 297
 298   g_return_if_fail (widget != NULL);
 299   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
 300   g_return_if_fail (area != NULL);
 301
 302   if (GTK_WIDGET_DRAWABLE (widget))
 303     {
 304       scrolled_window = GTK_SCROLLED_WINDOW (widget);
 305
 306       if (gtk_widget_intersect (scrolled_window->viewport, area, &child_area))
 307         gtk_widget_draw (scrolled_window->viewport, &child_area);
 308
 309       if (gtk_widget_intersect (scrolled_window->hscrollbar, area, &child_area))
 310         gtk_widget_draw (scrolled_window->hscrollbar, &child_area);
 311
 312       if (gtk_widget_intersect (scrolled_window->vscrollbar, area, &child_area))
 313         gtk_widget_draw (scrolled_window->vscrollbar, &child_area);
 314     }
 315 }
 316
 317 static void
 318 gtk_scrolled_window_size_request (GtkWidget      *widget,
 319                                   GtkRequisition *requisition)
 320 {
 321   GtkScrolledWindow *scrolled_window;
 322   gint extra_height;
 323   gint extra_width;
 324
 325   g_return_if_fail (widget != NULL);
 326   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
 327   g_return_if_fail (requisition != NULL);
 328
 329   scrolled_window = GTK_SCROLLED_WINDOW (widget);
 330
 331   requisition->width = 0;
 332   requisition->height = 0;
 333
 334   if (GTK_WIDGET_VISIBLE (scrolled_window->viewport))
 335     {
 336       gtk_widget_size_request (scrolled_window->viewport, &scrolled_window->viewport->requisition);
 337
 338       requisition->width += scrolled_window->viewport->requisition.width;
 339       requisition->height += scrolled_window->viewport->requisition.height;
 340     }
 341
 342   extra_width = 0;
 343   extra_height = 0;
 344
 345   if ((scrolled_window->hscrollbar_policy == GTK_POLICY_AUTOMATIC) ||
 346       GTK_WIDGET_VISIBLE (scrolled_window->hscrollbar))
 347     {
 348       gtk_widget_size_request (scrolled_window->hscrollbar,
 349                                &scrolled_window->hscrollbar->requisition);
 350
 351       requisition->width = MAX (requisition->width, scrolled_window->hscrollbar->requisition.width);
 352       extra_height = SCROLLBAR_SPACING (scrolled_window) + scrolled_window->hscrollbar->requisition.height;
 353     }
 354
 355   if ((scrolled_window->vscrollbar_policy == GTK_POLICY_AUTOMATIC) ||
 356       GTK_WIDGET_VISIBLE (scrolled_window->vscrollbar))
 357     {
 358       gtk_widget_size_request (scrolled_window->vscrollbar,
 359                                &scrolled_window->vscrollbar->requisition);
 360
 361       requisition->height = MAX (requisition->height, scrolled_window->vscrollbar->requisition.height);
 362       extra_width = SCROLLBAR_SPACING (scrolled_window) + scrolled_window->vscrollbar->requisition.width;
 363     }
 364
 365   requisition->width += GTK_CONTAINER (widget)->border_width * 2 + extra_width;
 366   requisition->height += GTK_CONTAINER (widget)->border_width * 2 + extra_height;
 367 }
 368
 369 static void
 370 gtk_scrolled_window_size_allocate (GtkWidget     *widget,
 371                                    GtkAllocation *allocation)
 372 {
 373   GtkScrolledWindow *scrolled_window;
 374   GtkAllocation viewport_allocation;
 375   GtkAllocation child_allocation;
 376   guint previous_hvis;
 377   guint previous_vvis;
 378   gint count;
 379
 380   g_return_if_fail (widget != NULL);
 381   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
 382   g_return_if_fail (allocation != NULL);
 383
 384   scrolled_window = GTK_SCROLLED_WINDOW (widget);
 385   widget->allocation = *allocation;
 386
 387   if (scrolled_window->hscrollbar_policy == GTK_POLICY_ALWAYS)
 388     scrolled_window->hscrollbar_visible = TRUE;
 389   if (scrolled_window->vscrollbar_policy == GTK_POLICY_ALWAYS)
 390     scrolled_window->vscrollbar_visible = TRUE;
 391
 392   if (GTK_WIDGET_VISIBLE (scrolled_window->viewport))
 393     {
 394       count = 0;
 395
 396       do {
 397         gtk_scrolled_window_viewport_allocate (widget, &viewport_allocation);
 398
 399         child_allocation.x = viewport_allocation.x + allocation->x;
 400         child_allocation.y = viewport_allocation.y + allocation->y;
 401         child_allocation.width = viewport_allocation.width;
 402         child_allocation.height = viewport_allocation.height;
 403
 404         previous_hvis = scrolled_window->hscrollbar_visible;
 405         previous_vvis = scrolled_window->vscrollbar_visible;
 406
 407         gtk_widget_size_allocate (scrolled_window->viewport, &child_allocation);
 408         /* If, after the first iteration, the hscrollbar and the
 409          * vscrollbar flip visiblity, then we need both.
 410          */
 411         if ((count++) &&
 412             (previous_hvis != scrolled_window->hscrollbar_visible) &&
 413             (previous_vvis != scrolled_window->vscrollbar_visible))
 414           {
 415             scrolled_window->hscrollbar_visible = TRUE;
 416             scrolled_window->vscrollbar_visible = TRUE;
 417             break;
 418           }
 419
 420         count++;
 421       } while ((previous_hvis != scrolled_window->hscrollbar_visible) ||
 422                (previous_vvis != scrolled_window->vscrollbar_visible));
 423     }
 424
 425   if (scrolled_window->hscrollbar_visible)
 426     {
 427       if (!GTK_WIDGET_VISIBLE (scrolled_window->hscrollbar))
 428         gtk_widget_show (scrolled_window->hscrollbar);
 429
 430       child_allocation.x = viewport_allocation.x;
 431       child_allocation.y = viewport_allocation.y + viewport_allocation.height + SCROLLBAR_SPACING (scrolled_window);
 432       child_allocation.width = viewport_allocation.width;
 433       child_allocation.height = scrolled_window->hscrollbar->requisition.height;
 434       child_allocation.x += allocation->x;
 435       child_allocation.y += allocation->y;
 436
 437       gtk_widget_size_allocate (scrolled_window->hscrollbar, &child_allocation);
 438     }
 439   else
 440     {
 441       if (GTK_WIDGET_VISIBLE (scrolled_window->hscrollbar))
 442         gtk_widget_hide (scrolled_window->hscrollbar);
 443     }
 444
 445   if (scrolled_window->vscrollbar_visible)
 446     {
 447       if (!GTK_WIDGET_VISIBLE (scrolled_window->vscrollbar))
 448         gtk_widget_show (scrolled_window->vscrollbar);
 449
 450       child_allocation.x = viewport_allocation.x + viewport_allocation.width + SCROLLBAR_SPACING (scrolled_window);
 451       child_allocation.y = viewport_allocation.y;
 452       child_allocation.width = scrolled_window->vscrollbar->requisition.width;
 453       child_allocation.height = viewport_allocation.height;
 454       child_allocation.x += allocation->x;
 455       child_allocation.y += allocation->y;
 456
 457       gtk_widget_size_allocate (scrolled_window->vscrollbar, &child_allocation);
 458     }
 459   else
 460     {
 461       if (GTK_WIDGET_VISIBLE (scrolled_window->vscrollbar))
 462         gtk_widget_hide (scrolled_window->vscrollbar);
 463     }
 464 }
 465
 466 static void
 467 gtk_scrolled_window_add (GtkContainer *container,
 468                          GtkWidget    *widget)
 469 {
 470   GtkScrolledWindow *scrolled_window;
 471
 472   g_return_if_fail (container != NULL);
 473   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (container));
 474   g_return_if_fail (widget != NULL);
 475
 476   scrolled_window = GTK_SCROLLED_WINDOW (container);
 477   gtk_container_add (GTK_CONTAINER (scrolled_window->viewport), widget);
 478 }
 479
 480 static void
 481 gtk_scrolled_window_remove (GtkContainer *container,
 482                             GtkWidget    *widget)
 483 {
 484   GtkScrolledWindow *scrolled_window;
 485
 486   g_return_if_fail (container != NULL);
 487   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (container));
 488   g_return_if_fail (widget != NULL);
 489
 490   scrolled_window = GTK_SCROLLED_WINDOW (container);
 491
 492   if (scrolled_window->viewport == widget ||
 493       scrolled_window->hscrollbar == widget ||
 494       scrolled_window->vscrollbar == widget)
 495     {
 496       /* this happens during destroy */
 497       gtk_widget_unparent (widget);
 498     }
 499   else
 500     gtk_container_remove (GTK_CONTAINER (scrolled_window->viewport), widget);
 501 }
 502
 503 static void
 504 gtk_scrolled_window_foreach (GtkContainer *container,
 505                              GtkCallback   callback,
 506                              gpointer      callback_data)
 507 {
 508   GtkScrolledWindow *scrolled_window;
 509
 510   g_return_if_fail (container != NULL);
 511   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (container));
 512   g_return_if_fail (callback != NULL);
 513
 514   scrolled_window = GTK_SCROLLED_WINDOW (container);
 515
 516   if (scrolled_window->viewport)
 517     (* callback) (scrolled_window->viewport, callback_data);
 518
 519   (* callback) (scrolled_window->vscrollbar, callback_data);
 520   (* callback) (scrolled_window->hscrollbar, callback_data);
 521 }
 522
 523 static void
 524 gtk_scrolled_window_viewport_allocate (GtkWidget     *widget,
 525                                        GtkAllocation *allocation)
 526 {
 527   GtkScrolledWindow *scrolled_window;
 528
 529   g_return_if_fail (widget != NULL);
 530   g_return_if_fail (allocation != NULL);
 531
 532   scrolled_window = GTK_SCROLLED_WINDOW (widget);
 533
 534   allocation->x = GTK_CONTAINER (widget)->border_width;
 535   allocation->y = GTK_CONTAINER (widget)->border_width;
 536   allocation->width = MAX (1, widget->allocation.width - allocation->x * 2);
 537   allocation->height = MAX (1, widget->allocation.height - allocation->y * 2);
 538
 539   if (scrolled_window->vscrollbar_visible)
 540     allocation->width = MAX (1,
 541       allocation->width - (scrolled_window->vscrollbar->requisition.width + SCROLLBAR_SPACING (scrolled_window)));
 542   if (scrolled_window->hscrollbar_visible)
 543     allocation->height = MAX (1,
 544       allocation->height - (scrolled_window->hscrollbar->requisition.height + SCROLLBAR_SPACING (scrolled_window)));
 545 }
 546
 547 static void
 548 gtk_scrolled_window_adjustment_changed (GtkAdjustment *adjustment,
 549                                         gpointer       data)
 550 {
 551   GtkScrolledWindow *scrolled_win;
 552
 553   g_return_if_fail (adjustment != NULL);
 554   g_return_if_fail (data != NULL);
 555
 556   scrolled_win = GTK_SCROLLED_WINDOW (data);
 557
 558   if (adjustment == gtk_range_get_adjustment (GTK_RANGE (scrolled_win->hscrollbar)))
 559     {
 560       if (scrolled_win->hscrollbar_policy == GTK_POLICY_AUTOMATIC)
 561         {
 562           scrolled_win->hscrollbar_visible =
 563             ((adjustment->upper - adjustment->lower) > adjustment->page_size);
 564         }
 565     }
 566   else if (adjustment == gtk_range_get_adjustment (GTK_RANGE (scrolled_win->vscrollbar)))
 567     {
 568       if (scrolled_win->vscrollbar_policy == GTK_POLICY_AUTOMATIC)
 569         {
 570           scrolled_win->vscrollbar_visible =
 571             ((adjustment->upper - adjustment->lower) > adjustment->page_size);
 572         }
 573     }
 574   else
 575     {
 576       g_warning ("could not determine which adjustment scrollbar received change signal for");
 577       return;
 578     }
 579 }