Pileus Git - ~andy/gtk/blob - gtk/gtkframe.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 <string.h>
  28 #include "gtkframe.h"
  29 #include "gtklabel.h"
  30 #include "gtkintl.h"
  31
  32 #define LABEL_PAD 1
  33 #define LABEL_SIDE_PAD 2
  34
  35 enum {
  36   PROP_0,
  37   PROP_LABEL,
  38   PROP_LABEL_XALIGN,
  39   PROP_LABEL_YALIGN,
  40   PROP_SHADOW,
  41   PROP_SHADOW_TYPE,
  42   PROP_LABEL_WIDGET
  43 };
  44
  45
  46 static void gtk_frame_class_init    (GtkFrameClass  *klass);
  47 static void gtk_frame_init          (GtkFrame       *frame);
  48 static void gtk_frame_set_property (GObject      *object,
  49                                     guint         param_id,
  50                                     const GValue *value,
  51                                     GParamSpec   *pspec);
  52 static void gtk_frame_get_property (GObject     *object,
  53                                     guint        param_id,
  54                                     GValue      *value,
  55                                     GParamSpec  *pspec);
  56 static void gtk_frame_paint         (GtkWidget      *widget,
  57                                      GdkRectangle   *area);
  58 static gint gtk_frame_expose        (GtkWidget      *widget,
  59                                      GdkEventExpose *event);
  60 static void gtk_frame_size_request  (GtkWidget      *widget,
  61                                      GtkRequisition *requisition);
  62 static void gtk_frame_size_allocate (GtkWidget      *widget,
  63                                      GtkAllocation  *allocation);
  64 static void gtk_frame_remove        (GtkContainer   *container,
  65                                      GtkWidget      *child);
  66 static void gtk_frame_forall        (GtkContainer   *container,
  67                                      gboolean        include_internals,
  68                                      GtkCallback     callback,
  69                                      gpointer        callback_data);
  70
  71 static void gtk_frame_compute_child_allocation      (GtkFrame      *frame,
  72                                                      GtkAllocation *child_allocation);
  73 static void gtk_frame_real_compute_child_allocation (GtkFrame      *frame,
  74                                                      GtkAllocation *child_allocation);
  75
  76 static GtkBinClass *parent_class = NULL;
  77
  78
  79 GType
  80 gtk_frame_get_type (void)
  81 {
  82   static GType frame_type = 0;
  83
  84   if (!frame_type)
  85     {
  86       static const GTypeInfo frame_info =
  87       {
  88         sizeof (GtkFrameClass),
  89         NULL,           /* base_init */
  90         NULL,           /* base_finalize */
  91         (GClassInitFunc) gtk_frame_class_init,
  92         NULL,           /* class_finalize */
  93         NULL,           /* class_data */
  94         sizeof (GtkFrame),
  95         0,              /* n_preallocs */
  96         (GInstanceInitFunc) gtk_frame_init,
  97       };
  98
  99       frame_type = g_type_register_static (GTK_TYPE_BIN, "GtkFrame",
 100                                            &frame_info, 0);
 101     }
 102
 103   return frame_type;
 104 }
 105
 106 static void
 107 gtk_frame_class_init (GtkFrameClass *class)
 108 {
 109   GObjectClass *gobject_class;
 110   GtkWidgetClass *widget_class;
 111   GtkContainerClass *container_class;
 112
 113   gobject_class = (GObjectClass*) class;
 114   widget_class = GTK_WIDGET_CLASS (class);
 115   container_class = GTK_CONTAINER_CLASS (class);
 116
 117   parent_class = g_type_class_peek_parent (class);
 118
 119   gobject_class->set_property = gtk_frame_set_property;
 120   gobject_class->get_property = gtk_frame_get_property;
 121
 122   g_object_class_install_property (gobject_class,
 123                                    PROP_LABEL,
 124                                    g_param_spec_string ("label",
 125                                                         _("Label"),
 126                                                         _("Text of the frame's label"),
 127                                                         NULL,
 128                                                         G_PARAM_READABLE |
 129                                                         G_PARAM_WRITABLE));
 130   g_object_class_install_property (gobject_class,
 131                                    PROP_LABEL_XALIGN,
 132                                    g_param_spec_float ("label_xalign",
 133                                                        _("Label xalign"),
 134                                                        _("The horizontal alignment of the label"),
 135                                                        0.0,
 136                                                        1.0,
 137                                                        0.5,
 138                                                        G_PARAM_READABLE |
 139                                                        G_PARAM_WRITABLE));
 140   g_object_class_install_property (gobject_class,
 141                                    PROP_LABEL_YALIGN,
 142                                    g_param_spec_float ("label_yalign",
 143                                                        _("Label yalign"),
 144                                                        _("The vertical alignment of the label"),
 145                                                        0.0,
 146                                                        1.0,
 147                                                        0.5,
 148                                                        G_PARAM_READABLE |
 149                                                        G_PARAM_WRITABLE));
 150   g_object_class_install_property (gobject_class,
 151                                    PROP_SHADOW,
 152                                    g_param_spec_enum ("shadow", NULL,
 153                                                       _("Deprecated property, use shadow_type instead"),
 154                                                       GTK_TYPE_SHADOW_TYPE,
 155                                                       GTK_SHADOW_ETCHED_IN,
 156                                                       G_PARAM_READABLE | G_PARAM_WRITABLE));
 157   g_object_class_install_property (gobject_class,
 158                                    PROP_SHADOW_TYPE,
 159                                    g_param_spec_enum ("shadow_type",
 160                                                       _("Frame shadow"),
 161                                                       _("Appearance of the frame border"),
 162                                                       GTK_TYPE_SHADOW_TYPE,
 163                                                       GTK_SHADOW_ETCHED_IN,
 164                                                       G_PARAM_READABLE | G_PARAM_WRITABLE));
 165
 166   g_object_class_install_property (gobject_class,
 167                                    PROP_LABEL_WIDGET,
 168                                    g_param_spec_object ("label_widget",
 169                                                         _("Label widget"),
 170                                                         _("A widget to display in place of the usual frame label"),
 171                                                         GTK_TYPE_WIDGET,
 172                                                         G_PARAM_READABLE | G_PARAM_WRITABLE));
 173
 174   widget_class->expose_event = gtk_frame_expose;
 175   widget_class->size_request = gtk_frame_size_request;
 176   widget_class->size_allocate = gtk_frame_size_allocate;
 177
 178   container_class->remove = gtk_frame_remove;
 179   container_class->forall = gtk_frame_forall;
 180
 181   class->compute_child_allocation = gtk_frame_real_compute_child_allocation;
 182 }
 183
 184 static void
 185 gtk_frame_init (GtkFrame *frame)
 186 {
 187   frame->label_widget = NULL;
 188   frame->shadow_type = GTK_SHADOW_ETCHED_IN;
 189   frame->label_xalign = 0.0;
 190   frame->label_yalign = 0.5;
 191 }
 192
 193 static void
 194 gtk_frame_set_property (GObject         *object,
 195                         guint            prop_id,
 196                         const GValue    *value,
 197                         GParamSpec      *pspec)
 198 {
 199   GtkFrame *frame;
 200
 201   frame = GTK_FRAME (object);
 202
 203   switch (prop_id)
 204     {
 205     case PROP_LABEL:
 206       gtk_frame_set_label (frame, g_value_get_string (value));
 207       break;
 208     case PROP_LABEL_XALIGN:
 209       gtk_frame_set_label_align (frame, g_value_get_float (value),
 210                                  frame->label_yalign);
 211       break;
 212     case PROP_LABEL_YALIGN:
 213       gtk_frame_set_label_align (frame, frame->label_xalign,
 214                                  g_value_get_float (value));
 215       break;
 216     case PROP_SHADOW:
 217     case PROP_SHADOW_TYPE:
 218       gtk_frame_set_shadow_type (frame, g_value_get_enum (value));
 219       break;
 220     case PROP_LABEL_WIDGET:
 221       gtk_frame_set_label_widget (frame, g_value_get_object (value));
 222       break;
 223     default:
 224       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 225       break;
 226     }
 227 }
 228
 229 static void
 230 gtk_frame_get_property (GObject         *object,
 231                         guint            prop_id,
 232                         GValue          *value,
 233                         GParamSpec      *pspec)
 234 {
 235   GtkFrame *frame;
 236
 237   frame = GTK_FRAME (object);
 238
 239   switch (prop_id)
 240     {
 241     case PROP_LABEL:
 242       g_value_set_string (value, gtk_frame_get_label (frame));
 243       break;
 244     case PROP_LABEL_XALIGN:
 245       g_value_set_float (value, frame->label_xalign);
 246       break;
 247     case PROP_LABEL_YALIGN:
 248       g_value_set_float (value, frame->label_yalign);
 249       break;
 250     case PROP_SHADOW:
 251     case PROP_SHADOW_TYPE:
 252       g_value_set_enum (value, frame->shadow_type);
 253       break;
 254     case PROP_LABEL_WIDGET:
 255       g_value_set_object (value,
 256                           frame->label_widget ?
 257                           G_OBJECT (frame->label_widget) : NULL);
 258       break;
 259     default:
 260       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 261       break;
 262     }
 263 }
 264
 265 GtkWidget*
 266 gtk_frame_new (const gchar *label)
 267 {
 268   return g_object_new (GTK_TYPE_FRAME, "label", label, NULL);
 269 }
 270
 271 static void
 272 gtk_frame_remove (GtkContainer *container,
 273                   GtkWidget    *child)
 274 {
 275   GtkFrame *frame = GTK_FRAME (container);
 276
 277   if (frame->label_widget == child)
 278     gtk_frame_set_label_widget (frame, NULL);
 279   else
 280     GTK_CONTAINER_CLASS (parent_class)->remove (container, child);
 281 }
 282
 283 static void
 284 gtk_frame_forall (GtkContainer *container,
 285                   gboolean      include_internals,
 286                   GtkCallback   callback,
 287                   gpointer      callback_data)
 288 {
 289   GtkBin *bin = GTK_BIN (container);
 290   GtkFrame *frame = GTK_FRAME (container);
 291
 292   if (bin->child)
 293     (* callback) (bin->child, callback_data);
 294
 295   if (frame->label_widget)
 296     (* callback) (frame->label_widget, callback_data);
 297 }
 298
 299 void
 300 gtk_frame_set_label (GtkFrame *frame,
 301                      const gchar *label)
 302 {
 303   g_return_if_fail (GTK_IS_FRAME (frame));
 304
 305   if (!label)
 306     {
 307       gtk_frame_set_label_widget (frame, NULL);
 308     }
 309   else
 310     {
 311       GtkWidget *child = gtk_label_new (label);
 312       gtk_widget_show (child);
 313
 314       gtk_frame_set_label_widget (frame, child);
 315     }
 316
 317   g_object_notify (G_OBJECT (frame), "label");
 318 }
 319
 320 /**
 321  * gtk_frame_get_label:
 322  * @frame: a #GtkFrame
 323  *
 324  * If the frame's label widget is a #GtkLabel, return the
 325  * text in the label widget. (The frame will have a #GtkLabel
 326  * for the label widget if a non-%NULL argument was passed
 327  * to gtk_frame_new().)
 328  *
 329  * Return value: the text in the label, or %NULL if there
 330  *               was no label widget or the lable widget was not
 331  *               a #GtkLabel. This string is owned by GTK+ and
 332  *               must not be modified or freed.
 333  **/
 334 G_CONST_RETURN gchar *
 335 gtk_frame_get_label (GtkFrame *frame)
 336 {
 337   g_return_val_if_fail (GTK_IS_FRAME (frame), NULL);
 338
 339   if (frame->label_widget && GTK_IS_LABEL (frame->label_widget))
 340     return gtk_label_get_text (GTK_LABEL (frame->label_widget));
 341   else
 342     return NULL;
 343 }
 344
 345 /**
 346  * gtk_frame_set_label_widget:
 347  * @frame: a #GtkFrame
 348  * @label_widget: the new label widget
 349  *
 350  * Set the label widget for the frame. This is the widget that
 351  * will appear embedded in the top edge of the frame as a
 352  * title.
 353  **/
 354 void
 355 gtk_frame_set_label_widget (GtkFrame  *frame,
 356                             GtkWidget *label_widget)
 357 {
 358   gboolean need_resize = FALSE;
 359
 360   g_return_if_fail (GTK_IS_FRAME (frame));
 361   g_return_if_fail (label_widget == NULL || GTK_IS_WIDGET (label_widget));
 362   g_return_if_fail (label_widget == NULL || label_widget->parent == NULL);
 363
 364   if (frame->label_widget == label_widget)
 365     return;
 366
 367   if (frame->label_widget)
 368     {
 369       need_resize = GTK_WIDGET_VISIBLE (frame->label_widget);
 370       gtk_widget_unparent (frame->label_widget);
 371     }
 372
 373   frame->label_widget = label_widget;
 374
 375   if (label_widget)
 376     {
 377       frame->label_widget = label_widget;
 378       gtk_widget_set_parent (label_widget, GTK_WIDGET (frame));
 379       need_resize |= GTK_WIDGET_VISIBLE (label_widget);
 380     }
 381
 382   if (GTK_WIDGET_VISIBLE (frame) && need_resize)
 383     gtk_widget_queue_resize (GTK_WIDGET (frame));
 384
 385   g_object_notify (G_OBJECT (frame), "label_widget");
 386 }
 387
 388 /**
 389  * gtk_frame_get_label_widget:
 390  * @frame: a #GtkFrame
 391  *
 392  * Retrieves the label widget for the frame. See
 393  * gtk_frame_set_label_widget().
 394  *
 395  * Return value: the label widget, or %NULL if there is none.
 396  **/
 397 GtkWidget *
 398 gtk_frame_get_label_widget (GtkFrame *frame)
 399 {
 400   g_return_val_if_fail (GTK_IS_FRAME (frame), NULL);
 401
 402   return frame->label_widget;
 403 }
 404
 405 void
 406 gtk_frame_set_label_align (GtkFrame *frame,
 407                            gfloat    xalign,
 408                            gfloat    yalign)
 409 {
 410   g_return_if_fail (GTK_IS_FRAME (frame));
 411
 412   xalign = CLAMP (xalign, 0.0, 1.0);
 413   yalign = CLAMP (yalign, 0.0, 1.0);
 414
 415   g_object_freeze_notify (G_OBJECT (frame));
 416   if (xalign != frame->label_xalign)
 417     {
 418       frame->label_xalign = xalign;
 419       g_object_notify (G_OBJECT (frame), "label_xalign");
 420     }
 421
 422   if (yalign != frame->label_yalign)
 423     {
 424       frame->label_yalign = yalign;
 425       g_object_notify (G_OBJECT (frame), "label_yalign");
 426     }
 427
 428   g_object_thaw_notify (G_OBJECT (frame));
 429   gtk_widget_queue_resize (GTK_WIDGET (frame));
 430 }
 431
 432 /**
 433  * gtk_frame_get_label_align:
 434  * @frame: a #GtkFrame
 435  * @xalign: location to store X alignment of frame's label, or %NULL
 436  * @yalign: location to store X alignment of frame's label, or %NULL
 437  *
 438  * Retrieves the X and Y alignment of the frame's label. See
 439  * gtk_frame_set_label_align().
 440  **/
 441 void
 442 gtk_frame_get_label_align (GtkFrame *frame,
 443                            gfloat   *xalign,
 444                            gfloat   *yalign)
 445 {
 446   g_return_if_fail (GTK_IS_FRAME (frame));
 447
 448   if (xalign)
 449     *xalign = frame->label_xalign;
 450   if (yalign)
 451     *yalign = frame->label_yalign;
 452 }
 453
 454 void
 455 gtk_frame_set_shadow_type (GtkFrame      *frame,
 456                            GtkShadowType  type)
 457 {
 458   g_return_if_fail (GTK_IS_FRAME (frame));
 459
 460   if ((GtkShadowType) frame->shadow_type != type)
 461     {
 462       frame->shadow_type = type;
 463       g_object_notify (G_OBJECT (frame), "shadow_type");
 464
 465       if (GTK_WIDGET_DRAWABLE (frame))
 466         {
 467           gtk_widget_queue_draw (GTK_WIDGET (frame));
 468         }
 469
 470       gtk_widget_queue_resize (GTK_WIDGET (frame));
 471     }
 472 }
 473
 474 /**
 475  * gtk_frame_get_shadow_type:
 476  * @frame: a #GtkFrame
 477  *
 478  * Retrieves the shadow type of the frame. See
 479  * gtk_frame_set_shadow_type().
 480  *
 481  * Return value: the current shadow type of the frame.
 482  **/
 483 GtkShadowType
 484 gtk_frame_get_shadow_type (GtkFrame *frame)
 485 {
 486   g_return_val_if_fail (GTK_IS_FRAME (frame), GTK_SHADOW_ETCHED_IN);
 487
 488   return frame->shadow_type;
 489 }
 490
 491 static void
 492 gtk_frame_paint (GtkWidget    *widget,
 493                  GdkRectangle *area)
 494 {
 495   GtkFrame *frame;
 496   gint x, y, width, height;
 497
 498   if (GTK_WIDGET_DRAWABLE (widget))
 499     {
 500       frame = GTK_FRAME (widget);
 501
 502       x = frame->child_allocation.x - widget->style->xthickness;
 503       y = frame->child_allocation.y - widget->style->ythickness;
 504       width = frame->child_allocation.width + 2 * widget->style->xthickness;
 505       height =  frame->child_allocation.height + 2 * widget->style->ythickness;
 506
 507       if (frame->label_widget)
 508         {
 509           GtkRequisition child_requisition;
 510           gfloat xalign;
 511           gint height_extra;
 512           gint x2;
 513
 514           gtk_widget_get_child_requisition (frame->label_widget, &child_requisition);
 515
 516           if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR)
 517             xalign = frame->label_xalign;
 518           else
 519             xalign = 1 - frame->label_xalign;
 520
 521           height_extra = MAX (0, child_requisition.height - widget->style->xthickness);
 522           y -= height_extra * (1 - frame->label_yalign);
 523           height += height_extra * (1 - frame->label_yalign);
 524
 525           x2 = widget->style->xthickness + (frame->child_allocation.width - child_requisition.width - 2 * LABEL_PAD - 2 * LABEL_SIDE_PAD) * xalign + LABEL_SIDE_PAD;
 526
 527
 528           gtk_paint_shadow_gap (widget->style, widget->window,
 529                                 GTK_STATE_NORMAL, frame->shadow_type,
 530                                 area, widget, "frame",
 531                                 x, y, width, height,
 532                                 GTK_POS_TOP,
 533                                 x2, child_requisition.width + 2 * LABEL_PAD);
 534         }
 535        else
 536          gtk_paint_shadow (widget->style, widget->window,
 537                            GTK_STATE_NORMAL, frame->shadow_type,
 538                            area, widget, "frame",
 539                            x, y, width, height);
 540     }
 541 }
 542
 543 static gboolean
 544 gtk_frame_expose (GtkWidget      *widget,
 545                   GdkEventExpose *event)
 546 {
 547   if (GTK_WIDGET_DRAWABLE (widget))
 548     {
 549       gtk_frame_paint (widget, &event->area);
 550
 551       (* GTK_WIDGET_CLASS (parent_class)->expose_event) (widget, event);
 552     }
 553
 554   return FALSE;
 555 }
 556
 557 static void
 558 gtk_frame_size_request (GtkWidget      *widget,
 559                         GtkRequisition *requisition)
 560 {
 561   GtkFrame *frame = GTK_FRAME (widget);
 562   GtkBin *bin = GTK_BIN (widget);
 563   GtkRequisition child_requisition;
 564
 565   if (frame->label_widget && GTK_WIDGET_VISIBLE (frame->label_widget))
 566     {
 567       gtk_widget_size_request (frame->label_widget, &child_requisition);
 568
 569       requisition->width = child_requisition.width + 2 * LABEL_PAD + 2 * LABEL_SIDE_PAD;
 570       requisition->height =
 571         MAX (0, child_requisition.height - GTK_WIDGET (widget)->style->xthickness);
 572     }
 573   else
 574     {
 575       requisition->width = 0;
 576       requisition->height = 0;
 577     }
 578
 579   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 580     {
 581       gtk_widget_size_request (bin->child, &child_requisition);
 582
 583       requisition->width = MAX (requisition->width, child_requisition.width);
 584       requisition->height += child_requisition.height;
 585     }
 586
 587   requisition->width += (GTK_CONTAINER (widget)->border_width +
 588                          GTK_WIDGET (widget)->style->xthickness) * 2;
 589   requisition->height += (GTK_CONTAINER (widget)->border_width +
 590                           GTK_WIDGET (widget)->style->ythickness) * 2;
 591 }
 592
 593 static void
 594 gtk_frame_size_allocate (GtkWidget     *widget,
 595                          GtkAllocation *allocation)
 596 {
 597   GtkFrame *frame = GTK_FRAME (widget);
 598   GtkBin *bin = GTK_BIN (widget);
 599   GtkAllocation new_allocation;
 600
 601   widget->allocation = *allocation;
 602
 603   gtk_frame_compute_child_allocation (frame, &new_allocation);
 604
 605   /* If the child allocation changed, that means that the frame is drawn
 606    * in a new place, so we must redraw the entire widget.
 607    */
 608   if (GTK_WIDGET_MAPPED (widget) &&
 609       (new_allocation.x != frame->child_allocation.x ||
 610        new_allocation.y != frame->child_allocation.y ||
 611        new_allocation.width != frame->child_allocation.width ||
 612        new_allocation.height != frame->child_allocation.height))
 613     gdk_window_invalidate_rect (widget->window, &widget->allocation, FALSE);
 614
 615   if (bin->child && GTK_WIDGET_VISIBLE (bin->child))
 616     gtk_widget_size_allocate (bin->child, &new_allocation);
 617
 618   frame->child_allocation = new_allocation;
 619
 620   if (frame->label_widget && GTK_WIDGET_VISIBLE (frame->label_widget))
 621     {
 622       GtkRequisition child_requisition;
 623       GtkAllocation child_allocation;
 624       gfloat xalign;
 625
 626       gtk_widget_get_child_requisition (frame->label_widget, &child_requisition);
 627
 628       if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR)
 629         xalign = frame->label_xalign;
 630       else
 631         xalign = 1 - frame->label_xalign;
 632
 633       child_allocation.x = frame->child_allocation.x + LABEL_SIDE_PAD +
 634         (frame->child_allocation.width - child_requisition.width - 2 * LABEL_PAD - 2 * LABEL_SIDE_PAD) * xalign + LABEL_PAD;
 635       child_allocation.width = child_requisition.width;
 636
 637       child_allocation.y = frame->child_allocation.y - child_requisition.height;
 638       child_allocation.height = child_requisition.height;
 639
 640       gtk_widget_size_allocate (frame->label_widget, &child_allocation);
 641     }
 642 }
 643
 644 static void
 645 gtk_frame_compute_child_allocation (GtkFrame      *frame,
 646                                     GtkAllocation *child_allocation)
 647 {
 648   g_return_if_fail (GTK_IS_FRAME (frame));
 649   g_return_if_fail (child_allocation != NULL);
 650
 651   GTK_FRAME_GET_CLASS (frame)->compute_child_allocation (frame, child_allocation);
 652 }
 653
 654 static void
 655 gtk_frame_real_compute_child_allocation (GtkFrame      *frame,
 656                                          GtkAllocation *child_allocation)
 657 {
 658   GtkWidget *widget = GTK_WIDGET (frame);
 659   GtkAllocation *allocation = &widget->allocation;
 660   GtkRequisition child_requisition;
 661   gint top_margin;
 662
 663   if (frame->label_widget)
 664     {
 665       gtk_widget_get_child_requisition (frame->label_widget, &child_requisition);
 666       top_margin = MAX (child_requisition.height, widget->style->ythickness);
 667     }
 668   else
 669     top_margin = widget->style->ythickness;
 670
 671   child_allocation->x = (GTK_CONTAINER (frame)->border_width +
 672                          widget->style->xthickness);
 673   child_allocation->width = MAX(1, (gint)allocation->width - child_allocation->x * 2);
 674
 675   child_allocation->y = (GTK_CONTAINER (frame)->border_width + top_margin);
 676   child_allocation->height = MAX (1, ((gint)allocation->height - child_allocation->y -
 677                                       (gint)GTK_CONTAINER (frame)->border_width -
 678                                       (gint)widget->style->ythickness));
 679
 680   child_allocation->x += allocation->x;
 681   child_allocation->y += allocation->y;
 682 }