Pileus Git - ~andy/gtk/blob - gtk/gtkviewport.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 Lesser 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  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser 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
  20 /*
  21  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GTK+ Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #include "config.h"
  28 #include "gtkviewport.h"
  29 #include "gtksizerequest.h"
  30 #include "gtkintl.h"
  31 #include "gtkmarshalers.h"
  32 #include "gtkprivate.h"
  33
  34
  35 /**
  36  * SECTION:gtkviewport
  37  * @Short_description: An adapter which makes widgets scrollable
  38  * @Title: GtkViewport
  39  * @See_also:#GtkScrolledWindow, #GtkAdjustment
  40  *
  41  * The #GtkViewport widget acts as an adaptor class, implementing
  42  * scrollability for child widgets that lack their own scrolling
  43  * capabilities. Use #GtkViewport to scroll child widgets such as
  44  * #GtkTable, #GtkBox, and so on.
  45  *
  46  * If a widget has native scrolling abilities, such as #GtkTextView,
  47  * #GtkTreeView or #GtkIconview, it can be added to a #GtkScrolledWindow
  48  * with gtk_container_add(). If a widget does not, you must first add the
  49  * widget to a #GtkViewport, then add the viewport to the scrolled window.
  50  * The convenience function gtk_scrolled_window_add_with_viewport() does
  51  * exactly this, so you can ignore the presence of the viewport.
  52  */
  53
  54 enum {
  55   PROP_0,
  56   PROP_HADJUSTMENT,
  57   PROP_VADJUSTMENT,
  58   PROP_SHADOW_TYPE
  59 };
  60
  61
  62 static void gtk_viewport_finalize                 (GObject          *object);
  63 static void gtk_viewport_destroy                  (GtkObject        *object);
  64 static void gtk_viewport_set_property             (GObject         *object,
  65                                                    guint            prop_id,
  66                                                    const GValue    *value,
  67                                                    GParamSpec      *pspec);
  68 static void gtk_viewport_get_property             (GObject         *object,
  69                                                    guint            prop_id,
  70                                                    GValue          *value,
  71                                                    GParamSpec      *pspec);
  72 static void gtk_viewport_set_scroll_adjustments   (GtkViewport      *viewport,
  73                                                    GtkAdjustment    *hadjustment,
  74                                                    GtkAdjustment    *vadjustment);
  75 static void gtk_viewport_realize                  (GtkWidget        *widget);
  76 static void gtk_viewport_unrealize                (GtkWidget        *widget);
  77 static void gtk_viewport_paint                    (GtkWidget        *widget,
  78                                                    GdkRectangle     *area);
  79 static gint gtk_viewport_expose                   (GtkWidget        *widget,
  80                                                    GdkEventExpose   *event);
  81 static void gtk_viewport_add                      (GtkContainer     *container,
  82                                                    GtkWidget        *widget);
  83 static void gtk_viewport_size_allocate            (GtkWidget        *widget,
  84                                                    GtkAllocation    *allocation);
  85 static void gtk_viewport_adjustment_value_changed (GtkAdjustment    *adjustment,
  86                                                    gpointer          data);
  87 static void gtk_viewport_style_set                (GtkWidget *widget,
  88                                                    GtkStyle  *previous_style);
  89
  90 static void gtk_viewport_size_request_init        (GtkSizeRequestIface *iface);
  91 static void gtk_viewport_get_width                (GtkSizeRequest       *widget,
  92                                                    gint                 *minimum_size,
  93                                                    gint                 *natural_size);
  94 static void gtk_viewport_get_height               (GtkSizeRequest       *widget,
  95                                                    gint                 *minimum_size,
  96                                                    gint                 *natural_size);
  97
  98
  99 G_DEFINE_TYPE_WITH_CODE (GtkViewport, gtk_viewport, GTK_TYPE_BIN,
 100                          G_IMPLEMENT_INTERFACE (GTK_TYPE_SIZE_REQUEST,
 101                                                 gtk_viewport_size_request_init))
 102
 103 static void
 104 gtk_viewport_class_init (GtkViewportClass *class)
 105 {
 106   GtkObjectClass *object_class;
 107   GObjectClass   *gobject_class;
 108   GtkWidgetClass *widget_class;
 109   GtkContainerClass *container_class;
 110
 111   object_class = (GtkObjectClass*) class;
 112   gobject_class = G_OBJECT_CLASS (class);
 113   widget_class = (GtkWidgetClass*) class;
 114   container_class = (GtkContainerClass*) class;
 115
 116   gobject_class->finalize = gtk_viewport_finalize;
 117   gobject_class->set_property = gtk_viewport_set_property;
 118   gobject_class->get_property = gtk_viewport_get_property;
 119   object_class->destroy = gtk_viewport_destroy;
 120
 121   widget_class->realize = gtk_viewport_realize;
 122   widget_class->unrealize = gtk_viewport_unrealize;
 123   widget_class->expose_event = gtk_viewport_expose;
 124   widget_class->size_allocate = gtk_viewport_size_allocate;
 125   widget_class->style_set = gtk_viewport_style_set;
 126
 127   container_class->add = gtk_viewport_add;
 128
 129   class->set_scroll_adjustments = gtk_viewport_set_scroll_adjustments;
 130
 131   g_object_class_install_property (gobject_class,
 132                                    PROP_HADJUSTMENT,
 133                                    g_param_spec_object ("hadjustment",
 134                                                         P_("Horizontal adjustment"),
 135                                                         P_("The GtkAdjustment that determines the values of the horizontal position for this viewport"),
 136                                                         GTK_TYPE_ADJUSTMENT,
 137                                                         GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT));
 138
 139   g_object_class_install_property (gobject_class,
 140                                    PROP_VADJUSTMENT,
 141                                    g_param_spec_object ("vadjustment",
 142                                                         P_("Vertical adjustment"),
 143                                                         P_("The GtkAdjustment that determines the values of the vertical position for this viewport"),
 144                                                         GTK_TYPE_ADJUSTMENT,
 145                                                         GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT));
 146
 147   g_object_class_install_property (gobject_class,
 148                                    PROP_SHADOW_TYPE,
 149                                    g_param_spec_enum ("shadow-type",
 150                                                       P_("Shadow type"),
 151                                                       P_("Determines how the shadowed box around the viewport is drawn"),
 152                                                       GTK_TYPE_SHADOW_TYPE,
 153                                                       GTK_SHADOW_IN,
 154                                                       GTK_PARAM_READWRITE));
 155
 156   /**
 157    * GtkViewport::set-scroll-adjustments
 158    * @horizontal: the horizontal #GtkAdjustment
 159    * @vertical: the vertical #GtkAdjustment
 160    *
 161    * Set the scroll adjustments for the viewport. Usually scrolled containers
 162    * like #GtkScrolledWindow will emit this signal to connect two instances
 163    * of #GtkScrollbar to the scroll directions of the #GtkViewport.
 164    */
 165   widget_class->set_scroll_adjustments_signal =
 166     g_signal_new (I_("set-scroll-adjustments"),
 167                   G_OBJECT_CLASS_TYPE (gobject_class),
 168                   G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
 169                   G_STRUCT_OFFSET (GtkViewportClass, set_scroll_adjustments),
 170                   NULL, NULL,
 171                   _gtk_marshal_VOID__OBJECT_OBJECT,
 172                   G_TYPE_NONE, 2,
 173                   GTK_TYPE_ADJUSTMENT,
 174                   GTK_TYPE_ADJUSTMENT);
 175 }
 176
 177 static void
 178 gtk_viewport_set_property (GObject         *object,
 179                            guint            prop_id,
 180                            const GValue    *value,
 181                            GParamSpec      *pspec)
 182 {
 183   GtkViewport *viewport;
 184
 185   viewport = GTK_VIEWPORT (object);
 186
 187   switch (prop_id)
 188     {
 189     case PROP_HADJUSTMENT:
 190       gtk_viewport_set_hadjustment (viewport, g_value_get_object (value));
 191       break;
 192     case PROP_VADJUSTMENT:
 193       gtk_viewport_set_vadjustment (viewport, g_value_get_object (value));
 194       break;
 195     case PROP_SHADOW_TYPE:
 196       gtk_viewport_set_shadow_type (viewport, g_value_get_enum (value));
 197       break;
 198     default:
 199       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 200       break;
 201     }
 202 }
 203
 204 static void
 205 gtk_viewport_get_property (GObject         *object,
 206                            guint            prop_id,
 207                            GValue          *value,
 208                            GParamSpec      *pspec)
 209 {
 210   GtkViewport *viewport;
 211
 212   viewport = GTK_VIEWPORT (object);
 213
 214   switch (prop_id)
 215     {
 216     case PROP_HADJUSTMENT:
 217       g_value_set_object (value, viewport->hadjustment);
 218       break;
 219     case PROP_VADJUSTMENT:
 220       g_value_set_object (value, viewport->vadjustment);
 221       break;
 222     case PROP_SHADOW_TYPE:
 223       g_value_set_enum (value, viewport->shadow_type);
 224       break;
 225     default:
 226       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 227       break;
 228     }
 229 }
 230
 231 static void
 232 gtk_viewport_init (GtkViewport *viewport)
 233 {
 234   gtk_widget_set_has_window (GTK_WIDGET (viewport), TRUE);
 235
 236   gtk_widget_set_redraw_on_allocate (GTK_WIDGET (viewport), FALSE);
 237   gtk_container_set_resize_mode (GTK_CONTAINER (viewport), GTK_RESIZE_QUEUE);
 238
 239   viewport->shadow_type = GTK_SHADOW_IN;
 240   viewport->view_window = NULL;
 241   viewport->bin_window = NULL;
 242   viewport->hadjustment = NULL;
 243   viewport->vadjustment = NULL;
 244 }
 245
 246 /**
 247  * gtk_viewport_new:
 248  * @hadjustment: horizontal adjustment.
 249  * @vadjustment: vertical adjustment.
 250  * @returns: a new #GtkViewport.
 251  *
 252  * Creates a new #GtkViewport with the given adjustments.
 253  *
 254  **/
 255 GtkWidget*
 256 gtk_viewport_new (GtkAdjustment *hadjustment,
 257                   GtkAdjustment *vadjustment)
 258 {
 259   GtkWidget *viewport;
 260
 261   viewport = g_object_new (GTK_TYPE_VIEWPORT,
 262                              "hadjustment", hadjustment,
 263                              "vadjustment", vadjustment,
 264                              NULL);
 265
 266   return viewport;
 267 }
 268
 269 #define ADJUSTMENT_POINTER(viewport, orientation)         \
 270   (((orientation) == GTK_ORIENTATION_HORIZONTAL) ?        \
 271      &(viewport)->hadjustment : &(viewport)->vadjustment)
 272
 273 static void
 274 viewport_disconnect_adjustment (GtkViewport    *viewport,
 275                                 GtkOrientation  orientation)
 276 {
 277   GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (viewport, orientation);
 278
 279   if (*adjustmentp)
 280     {
 281       g_signal_handlers_disconnect_by_func (*adjustmentp,
 282                                             gtk_viewport_adjustment_value_changed,
 283                                             viewport);
 284       g_object_unref (*adjustmentp);
 285       *adjustmentp = NULL;
 286     }
 287 }
 288
 289 static void
 290 gtk_viewport_finalize (GObject *object)
 291 {
 292   GtkViewport *viewport = GTK_VIEWPORT (object);
 293
 294   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL);
 295   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_VERTICAL);
 296
 297   G_OBJECT_CLASS (gtk_viewport_parent_class)->finalize (object);
 298 }
 299
 300 static void
 301 gtk_viewport_destroy (GtkObject *object)
 302 {
 303   GtkViewport *viewport = GTK_VIEWPORT (object);
 304
 305   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL);
 306   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_VERTICAL);
 307
 308   GTK_OBJECT_CLASS (gtk_viewport_parent_class)->destroy (object);
 309 }
 310
 311 /**
 312  * gtk_viewport_get_hadjustment:
 313  * @viewport: a #GtkViewport.
 314  *
 315  * Returns the horizontal adjustment of the viewport.
 316  *
 317  * Return value: the horizontal adjustment of @viewport.
 318  **/
 319 GtkAdjustment*
 320 gtk_viewport_get_hadjustment (GtkViewport *viewport)
 321 {
 322   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 323
 324   if (!viewport->hadjustment)
 325     gtk_viewport_set_hadjustment (viewport, NULL);
 326
 327   return viewport->hadjustment;
 328 }
 329
 330 /**
 331  * gtk_viewport_get_vadjustment:
 332  * @viewport: a #GtkViewport.
 333  *
 334  * Returns the vertical adjustment of the viewport.
 335  *
 336  * Return value: the vertical adjustment of @viewport.
 337  **/
 338 GtkAdjustment*
 339 gtk_viewport_get_vadjustment (GtkViewport *viewport)
 340 {
 341   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 342
 343   if (!viewport->vadjustment)
 344     gtk_viewport_set_vadjustment (viewport, NULL);
 345
 346   return viewport->vadjustment;
 347 }
 348
 349 static void
 350 viewport_get_view_allocation (GtkViewport   *viewport,
 351                               GtkAllocation *view_allocation)
 352 {
 353   GtkWidget *widget = GTK_WIDGET (viewport);
 354   GtkAllocation *allocation = &widget->allocation;
 355   guint border_width;
 356
 357   border_width = gtk_container_get_border_width (GTK_CONTAINER (viewport));
 358
 359   view_allocation->x = 0;
 360   view_allocation->y = 0;
 361
 362   if (viewport->shadow_type != GTK_SHADOW_NONE)
 363     {
 364       view_allocation->x = widget->style->xthickness;
 365       view_allocation->y = widget->style->ythickness;
 366     }
 367
 368   view_allocation->width = MAX (1, allocation->width - view_allocation->x * 2 - border_width * 2);
 369   view_allocation->height = MAX (1, allocation->height - view_allocation->y * 2 - border_width * 2);
 370 }
 371
 372 static void
 373 viewport_reclamp_adjustment (GtkAdjustment *adjustment,
 374                              gboolean      *value_changed)
 375 {
 376   gdouble value = adjustment->value;
 377
 378   value = CLAMP (value, 0, adjustment->upper - adjustment->page_size);
 379   if (value != adjustment->value)
 380     {
 381       adjustment->value = value;
 382       if (value_changed)
 383         *value_changed = TRUE;
 384     }
 385   else if (value_changed)
 386     *value_changed = FALSE;
 387 }
 388
 389 static void
 390 viewport_set_hadjustment_values (GtkViewport *viewport,
 391                                  gboolean    *value_changed)
 392 {
 393   GtkBin *bin = GTK_BIN (viewport);
 394   GtkAllocation view_allocation;
 395   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 396   GtkWidget *child;
 397   gdouble old_page_size;
 398   gdouble old_upper;
 399   gdouble old_value;
 400
 401   viewport_get_view_allocation (viewport, &view_allocation);
 402
 403   old_page_size = hadjustment->page_size;
 404   old_upper = hadjustment->upper;
 405   old_value = hadjustment->value;
 406   hadjustment->page_size = view_allocation.width;
 407   hadjustment->step_increment = view_allocation.width * 0.1;
 408   hadjustment->page_increment = view_allocation.width * 0.9;
 409
 410   hadjustment->lower = 0;
 411
 412   child = gtk_bin_get_child (bin);
 413   if (child && gtk_widget_get_visible (child))
 414     {
 415       GtkRequisition child_requisition;
 416
 417       gtk_widget_get_child_requisition (child, &child_requisition);
 418       hadjustment->upper = MAX (child_requisition.width, view_allocation.width);
 419     }
 420   else
 421     hadjustment->upper = view_allocation.width;
 422
 423   if (gtk_widget_get_direction (GTK_WIDGET (viewport)) == GTK_TEXT_DIR_RTL)
 424     {
 425       gdouble dist = old_upper - (old_value + old_page_size);
 426       hadjustment->value = hadjustment->upper - dist - hadjustment->page_size;
 427       viewport_reclamp_adjustment (hadjustment, value_changed);
 428       *value_changed = (old_value != hadjustment->value);
 429     }
 430   else
 431     viewport_reclamp_adjustment (hadjustment, value_changed);
 432 }
 433
 434 static void
 435 viewport_set_vadjustment_values (GtkViewport *viewport,
 436                                  gboolean    *value_changed)
 437 {
 438   GtkBin *bin = GTK_BIN (viewport);
 439   GtkAllocation view_allocation;
 440   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 441   GtkWidget *child;
 442
 443   viewport_get_view_allocation (viewport, &view_allocation);
 444
 445   vadjustment->page_size = view_allocation.height;
 446   vadjustment->step_increment = view_allocation.height * 0.1;
 447   vadjustment->page_increment = view_allocation.height * 0.9;
 448
 449   vadjustment->lower = 0;
 450
 451   child = gtk_bin_get_child (bin);
 452   if (child && gtk_widget_get_visible (child))
 453     {
 454       gint natural_height;
 455
 456       gtk_size_request_get_height_for_width (GTK_SIZE_REQUEST (child),
 457                                              view_allocation.width,
 458                                              NULL,
 459                                              &natural_height);
 460       vadjustment->upper = MAX (natural_height, view_allocation.height);
 461     }
 462   else
 463     vadjustment->upper = view_allocation.height;
 464
 465   viewport_reclamp_adjustment (vadjustment, value_changed);
 466 }
 467
 468 static void
 469 viewport_set_adjustment (GtkViewport    *viewport,
 470                          GtkOrientation  orientation,
 471                          GtkAdjustment  *adjustment)
 472 {
 473   GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (viewport, orientation);
 474   gboolean value_changed;
 475
 476   if (adjustment && adjustment == *adjustmentp)
 477     return;
 478
 479   if (!adjustment)
 480     adjustment = GTK_ADJUSTMENT (gtk_adjustment_new (0.0, 0.0, 0.0,
 481                                                      0.0, 0.0, 0.0));
 482   viewport_disconnect_adjustment (viewport, orientation);
 483   *adjustmentp = adjustment;
 484   g_object_ref_sink (adjustment);
 485
 486   if (orientation == GTK_ORIENTATION_HORIZONTAL)
 487     viewport_set_hadjustment_values (viewport, &value_changed);
 488   else
 489     viewport_set_vadjustment_values (viewport, &value_changed);
 490
 491   g_signal_connect (adjustment, "value-changed",
 492                     G_CALLBACK (gtk_viewport_adjustment_value_changed),
 493                     viewport);
 494
 495   gtk_adjustment_changed (adjustment);
 496
 497   if (value_changed)
 498     gtk_adjustment_value_changed (adjustment);
 499   else
 500     gtk_viewport_adjustment_value_changed (adjustment, viewport);
 501 }
 502
 503 /**
 504  * gtk_viewport_set_hadjustment:
 505  * @viewport: a #GtkViewport.
 506  * @adjustment: (allow-none): a #GtkAdjustment.
 507  *
 508  * Sets the horizontal adjustment of the viewport.
 509  **/
 510 void
 511 gtk_viewport_set_hadjustment (GtkViewport   *viewport,
 512                               GtkAdjustment *adjustment)
 513 {
 514   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 515   if (adjustment)
 516     g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 517
 518   viewport_set_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL, adjustment);
 519
 520   g_object_notify (G_OBJECT (viewport), "hadjustment");
 521 }
 522
 523 /**
 524  * gtk_viewport_set_vadjustment:
 525  * @viewport: a #GtkViewport.
 526  * @adjustment: (allow-none): a #GtkAdjustment.
 527  *
 528  * Sets the vertical adjustment of the viewport.
 529  **/
 530 void
 531 gtk_viewport_set_vadjustment (GtkViewport   *viewport,
 532                               GtkAdjustment *adjustment)
 533 {
 534   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 535   if (adjustment)
 536     g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 537
 538   viewport_set_adjustment (viewport, GTK_ORIENTATION_VERTICAL, adjustment);
 539
 540   g_object_notify (G_OBJECT (viewport), "vadjustment");
 541 }
 542
 543 static void
 544 gtk_viewport_set_scroll_adjustments (GtkViewport      *viewport,
 545                                      GtkAdjustment    *hadjustment,
 546                                      GtkAdjustment    *vadjustment)
 547 {
 548   gtk_viewport_set_hadjustment (viewport, hadjustment);
 549   gtk_viewport_set_vadjustment (viewport, vadjustment);
 550 }
 551
 552 /**
 553  * gtk_viewport_set_shadow_type:
 554  * @viewport: a #GtkViewport.
 555  * @type: the new shadow type.
 556  *
 557  * Sets the shadow type of the viewport.
 558  **/
 559 void
 560 gtk_viewport_set_shadow_type (GtkViewport   *viewport,
 561                               GtkShadowType  type)
 562 {
 563   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 564
 565   if ((GtkShadowType) viewport->shadow_type != type)
 566     {
 567       viewport->shadow_type = type;
 568
 569       if (gtk_widget_get_visible (GTK_WIDGET (viewport)))
 570         {
 571           gtk_widget_size_allocate (GTK_WIDGET (viewport), &(GTK_WIDGET (viewport)->allocation));
 572           gtk_widget_queue_draw (GTK_WIDGET (viewport));
 573         }
 574
 575       g_object_notify (G_OBJECT (viewport), "shadow-type");
 576     }
 577 }
 578
 579 /**
 580  * gtk_viewport_get_shadow_type:
 581  * @viewport: a #GtkViewport
 582  *
 583  * Gets the shadow type of the #GtkViewport. See
 584  * gtk_viewport_set_shadow_type().
 585
 586  * Return value: the shadow type
 587  **/
 588 GtkShadowType
 589 gtk_viewport_get_shadow_type (GtkViewport *viewport)
 590 {
 591   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), GTK_SHADOW_NONE);
 592
 593   return viewport->shadow_type;
 594 }
 595
 596 /**
 597  * gtk_viewport_get_bin_window:
 598  * @viewport: a #GtkViewport
 599  *
 600  * Gets the bin window of the #GtkViewport.
 601  *
 602  * Return value: a #GdkWindow
 603  *
 604  * Since: 2.20
 605  **/
 606 GdkWindow*
 607 gtk_viewport_get_bin_window (GtkViewport *viewport)
 608 {
 609   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 610
 611   return viewport->bin_window;
 612 }
 613
 614 /**
 615  * gtk_viewport_get_view_window:
 616  * @viewport: a #GtkViewport
 617  *
 618  * Gets the view window of the #GtkViewport.
 619  *
 620  * Return value: (transfer none): a #GdkWindow
 621  *
 622  * Since: 2.22
 623  **/
 624 GdkWindow*
 625 gtk_viewport_get_view_window (GtkViewport *viewport)
 626 {
 627   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 628
 629   return viewport->view_window;
 630 }
 631
 632 static void
 633 gtk_viewport_realize (GtkWidget *widget)
 634 {
 635   GtkViewport *viewport = GTK_VIEWPORT (widget);
 636   GtkBin *bin = GTK_BIN (widget);
 637   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 638   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 639   GtkAllocation view_allocation;
 640   GtkWidget *child;
 641   GdkWindowAttr attributes;
 642   gint attributes_mask;
 643   gint event_mask;
 644   guint border_width;
 645
 646   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 647
 648   gtk_widget_set_realized (widget, TRUE);
 649
 650   attributes.x = widget->allocation.x + border_width;
 651   attributes.y = widget->allocation.y + border_width;
 652   attributes.width = widget->allocation.width - border_width * 2;
 653   attributes.height = widget->allocation.height - border_width * 2;
 654   attributes.window_type = GDK_WINDOW_CHILD;
 655   attributes.wclass = GDK_INPUT_OUTPUT;
 656   attributes.visual = gtk_widget_get_visual (widget);
 657   attributes.colormap = gtk_widget_get_colormap (widget);
 658
 659   event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
 660   /* We select on button_press_mask so that button 4-5 scrolls are trapped.
 661    */
 662   attributes.event_mask = event_mask | GDK_BUTTON_PRESS_MASK;
 663
 664   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
 665
 666   widget->window = gdk_window_new (gtk_widget_get_parent_window (widget),
 667                                    &attributes, attributes_mask);
 668   gdk_window_set_user_data (widget->window, viewport);
 669
 670   viewport_get_view_allocation (viewport, &view_allocation);
 671
 672   attributes.x = view_allocation.x;
 673   attributes.y = view_allocation.y;
 674   attributes.width = view_allocation.width;
 675   attributes.height = view_allocation.height;
 676   attributes.event_mask = 0;
 677
 678   viewport->view_window = gdk_window_new (widget->window, &attributes, attributes_mask);
 679   gdk_window_set_user_data (viewport->view_window, viewport);
 680
 681   gdk_window_set_back_pixmap (viewport->view_window, NULL, FALSE);
 682
 683   attributes.x = - hadjustment->value;
 684   attributes.y = - vadjustment->value;
 685   attributes.width = hadjustment->upper;
 686   attributes.height = vadjustment->upper;
 687
 688   attributes.event_mask = event_mask;
 689
 690   viewport->bin_window = gdk_window_new (viewport->view_window, &attributes, attributes_mask);
 691   gdk_window_set_user_data (viewport->bin_window, viewport);
 692
 693   child = gtk_bin_get_child (bin);
 694   if (child)
 695     gtk_widget_set_parent_window (child, viewport->bin_window);
 696
 697   widget->style = gtk_style_attach (widget->style, widget->window);
 698   gtk_style_set_background (widget->style, widget->window, GTK_STATE_NORMAL);
 699   gtk_style_set_background (widget->style, viewport->bin_window, GTK_STATE_NORMAL);
 700
 701   /* Call paint here to allow a theme to set the background without flashing
 702    */
 703   gtk_paint_flat_box(widget->style, viewport->bin_window, GTK_STATE_NORMAL,
 704                      GTK_SHADOW_NONE,
 705                      NULL, widget, "viewportbin",
 706                      0, 0, -1, -1);
 707
 708   gdk_window_show (viewport->bin_window);
 709   gdk_window_show (viewport->view_window);
 710 }
 711
 712 static void
 713 gtk_viewport_unrealize (GtkWidget *widget)
 714 {
 715   GtkViewport *viewport = GTK_VIEWPORT (widget);
 716
 717   gdk_window_set_user_data (viewport->view_window, NULL);
 718   gdk_window_destroy (viewport->view_window);
 719   viewport->view_window = NULL;
 720
 721   gdk_window_set_user_data (viewport->bin_window, NULL);
 722   gdk_window_destroy (viewport->bin_window);
 723   viewport->bin_window = NULL;
 724
 725   GTK_WIDGET_CLASS (gtk_viewport_parent_class)->unrealize (widget);
 726 }
 727
 728 static void
 729 gtk_viewport_paint (GtkWidget    *widget,
 730                     GdkRectangle *area)
 731 {
 732   if (gtk_widget_is_drawable (widget))
 733     {
 734       GtkViewport *viewport = GTK_VIEWPORT (widget);
 735
 736       gtk_paint_shadow (widget->style, widget->window,
 737                         GTK_STATE_NORMAL, viewport->shadow_type,
 738                         area, widget, "viewport",
 739                         0, 0, -1, -1);
 740     }
 741 }
 742
 743 static gint
 744 gtk_viewport_expose (GtkWidget      *widget,
 745                      GdkEventExpose *event)
 746 {
 747   GtkViewport *viewport;
 748
 749   if (gtk_widget_is_drawable (widget))
 750     {
 751       viewport = GTK_VIEWPORT (widget);
 752
 753       if (event->window == widget->window)
 754         gtk_viewport_paint (widget, &event->area);
 755       else if (event->window == viewport->bin_window)
 756         {
 757           gtk_paint_flat_box(widget->style, viewport->bin_window,
 758                              GTK_STATE_NORMAL, GTK_SHADOW_NONE,
 759                              &event->area, widget, "viewportbin",
 760                              0, 0, -1, -1);
 761
 762           GTK_WIDGET_CLASS (gtk_viewport_parent_class)->expose_event (widget, event);
 763         }
 764     }
 765
 766   return FALSE;
 767 }
 768
 769 static void
 770 gtk_viewport_add (GtkContainer *container,
 771                   GtkWidget    *child)
 772 {
 773   GtkBin *bin = GTK_BIN (container);
 774
 775   g_return_if_fail (gtk_bin_get_child (bin) == NULL);
 776
 777   gtk_widget_set_parent_window (child, GTK_VIEWPORT (bin)->bin_window);
 778
 779   GTK_CONTAINER_CLASS (gtk_viewport_parent_class)->add (container, child);
 780 }
 781
 782 static void
 783 gtk_viewport_size_allocate (GtkWidget     *widget,
 784                             GtkAllocation *allocation)
 785 {
 786   GtkViewport *viewport = GTK_VIEWPORT (widget);
 787   GtkBin *bin = GTK_BIN (widget);
 788   guint border_width;
 789   gboolean hadjustment_value_changed, vadjustment_value_changed;
 790   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 791   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 792   GtkAllocation child_allocation;
 793   GtkWidget *child;
 794
 795   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 796
 797   /* If our size changed, and we have a shadow, queue a redraw on widget->window to
 798    * redraw the shadow correctly.
 799    */
 800   if (gtk_widget_get_mapped (widget) &&
 801       viewport->shadow_type != GTK_SHADOW_NONE &&
 802       (widget->allocation.width != allocation->width ||
 803        widget->allocation.height != allocation->height))
 804     gdk_window_invalidate_rect (widget->window, NULL, FALSE);
 805
 806   widget->allocation = *allocation;
 807
 808   viewport_set_hadjustment_values (viewport, &hadjustment_value_changed);
 809   viewport_set_vadjustment_values (viewport, &vadjustment_value_changed);
 810
 811   child_allocation.x = 0;
 812   child_allocation.y = 0;
 813   child_allocation.width = hadjustment->upper;
 814   child_allocation.height = vadjustment->upper;
 815   if (gtk_widget_get_realized (widget))
 816     {
 817       GtkAllocation view_allocation;
 818       gdk_window_move_resize (widget->window,
 819                               allocation->x + border_width,
 820                               allocation->y + border_width,
 821                               allocation->width - border_width * 2,
 822                               allocation->height - border_width * 2);
 823
 824       viewport_get_view_allocation (viewport, &view_allocation);
 825       gdk_window_move_resize (viewport->view_window,
 826                               view_allocation.x,
 827                               view_allocation.y,
 828                               view_allocation.width,
 829                               view_allocation.height);
 830       gdk_window_move_resize (viewport->bin_window,
 831                               - hadjustment->value,
 832                               - vadjustment->value,
 833                               child_allocation.width,
 834                               child_allocation.height);
 835     }
 836
 837   child = gtk_bin_get_child (bin);
 838   if (child && gtk_widget_get_visible (child))
 839     gtk_widget_size_allocate (child, &child_allocation);
 840
 841   gtk_adjustment_changed (hadjustment);
 842   gtk_adjustment_changed (vadjustment);
 843   if (hadjustment_value_changed)
 844     gtk_adjustment_value_changed (hadjustment);
 845   if (vadjustment_value_changed)
 846     gtk_adjustment_value_changed (vadjustment);
 847 }
 848
 849 static void
 850 gtk_viewport_adjustment_value_changed (GtkAdjustment *adjustment,
 851                                        gpointer       data)
 852 {
 853   GtkViewport *viewport = GTK_VIEWPORT (data);
 854   GtkBin *bin = GTK_BIN (data);
 855   GtkWidget *child;
 856
 857   child = gtk_bin_get_child (bin);
 858   if (child && gtk_widget_get_visible (child) &&
 859       gtk_widget_get_realized (GTK_WIDGET (viewport)))
 860     {
 861       GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 862       GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 863       gint old_x, old_y;
 864       gint new_x, new_y;
 865
 866       gdk_window_get_position (viewport->bin_window, &old_x, &old_y);
 867       new_x = - hadjustment->value;
 868       new_y = - vadjustment->value;
 869
 870       if (new_x != old_x || new_y != old_y)
 871         {
 872           gdk_window_move (viewport->bin_window, new_x, new_y);
 873           gdk_window_process_updates (viewport->bin_window, TRUE);
 874         }
 875     }
 876 }
 877
 878 static void
 879 gtk_viewport_style_set (GtkWidget *widget,
 880                         GtkStyle  *previous_style)
 881 {
 882    if (gtk_widget_get_realized (widget) &&
 883        gtk_widget_get_has_window (widget))
 884      {
 885         GtkViewport *viewport = GTK_VIEWPORT (widget);
 886
 887         gtk_style_set_background (widget->style, viewport->bin_window, GTK_STATE_NORMAL);
 888         gtk_style_set_background (widget->style, widget->window, widget->state);
 889      }
 890 }
 891
 892
 893 static void
 894 gtk_viewport_size_request_init (GtkSizeRequestIface *iface)
 895 {
 896   iface->get_width  = gtk_viewport_get_width;
 897   iface->get_height = gtk_viewport_get_height;
 898 }
 899
 900 static void
 901 gtk_viewport_get_size (GtkSizeRequest *widget,
 902                        GtkOrientation  orientation,
 903                        gint           *minimum_size,
 904                        gint           *natural_size)
 905 {
 906   GtkWidget *child;
 907   gint       child_min, child_nat;
 908   gint       minimum, natural;
 909
 910   child = gtk_bin_get_child (GTK_BIN (widget));
 911
 912   /* XXX This should probably be (border_width * 2); but GTK+ has
 913    * been doing this with a single border for a while now...
 914    */
 915   minimum = gtk_container_get_border_width (GTK_CONTAINER (widget));
 916
 917   if (GTK_VIEWPORT (widget)->shadow_type != GTK_SHADOW_NONE)
 918     {
 919       if (orientation == GTK_ORIENTATION_HORIZONTAL)
 920           minimum += 2 * GTK_WIDGET (widget)->style->xthickness;
 921       else
 922           minimum += 2 * GTK_WIDGET (widget)->style->ythickness;
 923     }
 924
 925   natural = minimum;
 926
 927   if (child && gtk_widget_get_visible (child))
 928     {
 929       if (orientation == GTK_ORIENTATION_HORIZONTAL)
 930         gtk_size_request_get_width (GTK_SIZE_REQUEST (child), &child_min, &child_nat);
 931       else
 932         gtk_size_request_get_height (GTK_SIZE_REQUEST (child), &child_min, &child_nat);
 933
 934       minimum += child_min;
 935       natural += child_nat;
 936     }
 937
 938   if (minimum_size)
 939     *minimum_size = minimum;
 940
 941   if (natural_size)
 942     *natural_size = natural;
 943 }
 944
 945 static void
 946 gtk_viewport_get_width (GtkSizeRequest *widget,
 947                         gint           *minimum_size,
 948                         gint           *natural_size)
 949 {
 950   gtk_viewport_get_size (widget, GTK_ORIENTATION_HORIZONTAL, minimum_size, natural_size);
 951 }
 952
 953 static void
 954 gtk_viewport_get_height (GtkSizeRequest *widget,
 955                          gint           *minimum_size,
 956                          gint           *natural_size)
 957 {
 958   gtk_viewport_get_size (widget, GTK_ORIENTATION_VERTICAL, minimum_size, natural_size);
 959 }