Pileus Git - ~andy/gtk/blob - gtk/gtkbin.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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GTK+ Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 /**
  26  * SECTION:gtkbin
  27  * @Short_description: A container with just one child
  28  * @Title: GtkBin
  29  *
  30  * The #GtkBin widget is a container with just one child.
  31  * It is not very useful itself, but it is useful for deriving subclasses,
  32  * since it provides common code needed for handling a single child widget.
  33  *
  34  * Many GTK+ widgets are subclasses of #GtkBin, including #GtkWindow,
  35  * #GtkButton, #GtkFrame, #GtkHandleBox or #GtkScrolledWindow.
  36  */
  37
  38 #include "config.h"
  39 #include "gtkbin.h"
  40 #include "gtksizerequest.h"
  41 #include "gtkintl.h"
  42
  43
  44 struct _GtkBinPrivate
  45 {
  46   GtkWidget *child;
  47 };
  48
  49 static void gtk_bin_add         (GtkContainer   *container,
  50                                  GtkWidget      *widget);
  51 static void gtk_bin_remove      (GtkContainer   *container,
  52                                  GtkWidget      *widget);
  53 static void gtk_bin_forall      (GtkContainer   *container,
  54                                  gboolean       include_internals,
  55                                  GtkCallback     callback,
  56                                  gpointer        callback_data);
  57 static GType gtk_bin_child_type (GtkContainer   *container);
  58
  59 static void               gtk_bin_get_preferred_width             (GtkWidget           *widget,
  60                                                                    gint                *minimum_width,
  61                                                                    gint                *natural_width);
  62 static void               gtk_bin_get_preferred_height            (GtkWidget           *widget,
  63                                                                    gint                *minimum_height,
  64                                                                    gint                *natural_height);
  65 static void               gtk_bin_get_preferred_width_for_height  (GtkWidget           *widget,
  66                                                                    gint                 height,
  67                                                                    gint                *minimum_width,
  68                                                                    gint                *natural_width);
  69 static void               gtk_bin_get_preferred_height_for_width  (GtkWidget           *widget,
  70                                                                    gint                 width,
  71                                                                    gint                *minimum_height,
  72                                                                    gint                *natural_height);
  73 static void               gtk_bin_size_allocate                   (GtkWidget           *widget,
  74                                                                    GtkAllocation       *allocation);
  75
  76 G_DEFINE_ABSTRACT_TYPE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER)
  77
  78 static void
  79 gtk_bin_class_init (GtkBinClass *class)
  80 {
  81   GtkWidgetClass *widget_class = (GtkWidgetClass*) class;
  82   GtkContainerClass *container_class = (GtkContainerClass*) class;
  83
  84   widget_class->get_preferred_width = gtk_bin_get_preferred_width;
  85   widget_class->get_preferred_height = gtk_bin_get_preferred_height;
  86   widget_class->get_preferred_width_for_height = gtk_bin_get_preferred_width_for_height;
  87   widget_class->get_preferred_height_for_width = gtk_bin_get_preferred_height_for_width;
  88   widget_class->size_allocate = gtk_bin_size_allocate;
  89
  90   container_class->add = gtk_bin_add;
  91   container_class->remove = gtk_bin_remove;
  92   container_class->forall = gtk_bin_forall;
  93   container_class->child_type = gtk_bin_child_type;
  94
  95   g_type_class_add_private (class, sizeof (GtkBinPrivate));
  96 }
  97
  98 static void
  99 gtk_bin_init (GtkBin *bin)
 100 {
 101   GtkBinPrivate *priv;
 102
 103   bin->priv = G_TYPE_INSTANCE_GET_PRIVATE (bin,
 104                                            GTK_TYPE_BIN,
 105                                            GtkBinPrivate);
 106   priv = bin->priv;
 107
 108   gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);
 109
 110   priv->child = NULL;
 111 }
 112
 113
 114 static GType
 115 gtk_bin_child_type (GtkContainer *container)
 116 {
 117   GtkBinPrivate *priv = GTK_BIN (container)->priv;
 118
 119   if (!priv->child)
 120     return GTK_TYPE_WIDGET;
 121   else
 122     return G_TYPE_NONE;
 123 }
 124
 125 static void
 126 gtk_bin_add (GtkContainer *container,
 127              GtkWidget    *child)
 128 {
 129   GtkBin *bin = GTK_BIN (container);
 130   GtkBinPrivate *priv = bin->priv;
 131
 132   if (priv->child != NULL)
 133     {
 134       g_warning ("Attempting to add a widget with type %s to a %s, "
 135                  "but as a GtkBin subclass a %s can only contain one widget at a time; "
 136                  "it already contains a widget of type %s",
 137                  g_type_name (G_OBJECT_TYPE (child)),
 138                  g_type_name (G_OBJECT_TYPE (bin)),
 139                  g_type_name (G_OBJECT_TYPE (bin)),
 140                  g_type_name (G_OBJECT_TYPE (priv->child)));
 141       return;
 142     }
 143
 144   gtk_widget_set_parent (child, GTK_WIDGET (bin));
 145   priv->child = child;
 146 }
 147
 148 static void
 149 gtk_bin_remove (GtkContainer *container,
 150                 GtkWidget    *child)
 151 {
 152   GtkBin *bin = GTK_BIN (container);
 153   GtkBinPrivate *priv = bin->priv;
 154   gboolean widget_was_visible;
 155
 156   g_return_if_fail (priv->child == child);
 157
 158   widget_was_visible = gtk_widget_get_visible (child);
 159
 160   gtk_widget_unparent (child);
 161   priv->child = NULL;
 162
 163   /* queue resize regardless of gtk_widget_get_visible (container),
 164    * since that's what is needed by toplevels, which derive from GtkBin.
 165    */
 166   if (widget_was_visible)
 167     gtk_widget_queue_resize (GTK_WIDGET (container));
 168 }
 169
 170 static void
 171 gtk_bin_forall (GtkContainer *container,
 172                 gboolean      include_internals,
 173                 GtkCallback   callback,
 174                 gpointer      callback_data)
 175 {
 176   GtkBin *bin = GTK_BIN (container);
 177   GtkBinPrivate *priv = bin->priv;
 178
 179   if (priv->child)
 180     (* callback) (priv->child, callback_data);
 181 }
 182
 183 static int
 184 gtk_bin_get_effective_border_width (GtkBin *bin)
 185 {
 186   if (GTK_CONTAINER_CLASS (GTK_BIN_GET_CLASS (bin))->_handle_border_width)
 187     return 0;
 188
 189   return gtk_container_get_border_width (GTK_CONTAINER (bin));
 190 }
 191
 192 static void
 193 gtk_bin_get_preferred_width (GtkWidget *widget,
 194                              gint      *minimum_width,
 195                              gint      *natural_width)
 196 {
 197   GtkBin *bin = GTK_BIN (widget);
 198   GtkBinPrivate *priv = bin->priv;
 199   gint border_width;
 200
 201   *minimum_width = 0;
 202   *natural_width = 0;
 203
 204   if (priv->child && gtk_widget_get_visible (priv->child))
 205     {
 206       gint child_min, child_nat;
 207       gtk_widget_get_preferred_width (priv->child,
 208                                       &child_min, &child_nat);
 209       *minimum_width = child_min;
 210       *natural_width = child_nat;
 211     }
 212
 213   border_width = gtk_bin_get_effective_border_width (bin);
 214   *minimum_width += 2 * border_width;
 215   *natural_width += 2 * border_width;
 216 }
 217
 218 static void
 219 gtk_bin_get_preferred_height (GtkWidget *widget,
 220                               gint      *minimum_height,
 221                               gint      *natural_height)
 222 {
 223   GtkBin *bin = GTK_BIN (widget);
 224   GtkBinPrivate *priv = bin->priv;
 225   gint border_width;
 226
 227   *minimum_height = 0;
 228   *natural_height = 0;
 229
 230   if (priv->child && gtk_widget_get_visible (priv->child))
 231     {
 232       gint child_min, child_nat;
 233       gtk_widget_get_preferred_height (priv->child,
 234                                        &child_min, &child_nat);
 235       *minimum_height = child_min;
 236       *natural_height = child_nat;
 237     }
 238
 239   border_width = gtk_bin_get_effective_border_width (bin);
 240   *minimum_height += 2 * border_width;
 241   *natural_height += 2 * border_width;
 242 }
 243
 244 static void
 245 gtk_bin_get_preferred_width_for_height (GtkWidget *widget,
 246                                         gint       height,
 247                                         gint      *minimum_width,
 248                                         gint      *natural_width)
 249 {
 250   GtkBin *bin = GTK_BIN (widget);
 251   GtkBinPrivate *priv = bin->priv;
 252   gint border_width;
 253
 254   *minimum_width = 0;
 255   *natural_width = 0;
 256
 257   border_width = gtk_bin_get_effective_border_width (bin);
 258
 259   if (priv->child && gtk_widget_get_visible (priv->child))
 260     {
 261       gint child_min, child_nat;
 262       gtk_widget_get_preferred_width_for_height (priv->child, height - 2 * border_width,
 263                                                  &child_min, &child_nat);
 264
 265       *minimum_width = child_min;
 266       *natural_width = child_nat;
 267     }
 268
 269   *minimum_width += 2 * border_width;
 270   *natural_width += 2 * border_width;
 271 }
 272
 273 static void
 274 gtk_bin_get_preferred_height_for_width  (GtkWidget *widget,
 275                                          gint       width,
 276                                          gint      *minimum_height,
 277                                          gint      *natural_height)
 278 {
 279   GtkBin *bin = GTK_BIN (widget);
 280   GtkBinPrivate *priv = bin->priv;
 281   gint border_width;
 282
 283   *minimum_height = 0;
 284   *natural_height = 0;
 285
 286   border_width = gtk_bin_get_effective_border_width (bin);
 287
 288   if (priv->child && gtk_widget_get_visible (priv->child))
 289     {
 290       gint child_min, child_nat;
 291       gtk_widget_get_preferred_height_for_width (priv->child, width - 2 * border_width,
 292                                                  &child_min, &child_nat);
 293
 294       *minimum_height = child_min;
 295       *natural_height = child_nat;
 296     }
 297
 298   *minimum_height += 2 * border_width;
 299   *natural_height += 2 * border_width;
 300 }
 301
 302 static void
 303 gtk_bin_size_allocate (GtkWidget     *widget,
 304                        GtkAllocation *allocation)
 305 {
 306   GtkBin *bin = GTK_BIN (widget);
 307   GtkBinPrivate *priv = bin->priv;
 308
 309   gtk_widget_set_allocation (widget, allocation);
 310
 311   if (priv->child && gtk_widget_get_visible (priv->child))
 312     {
 313       GtkAllocation child_allocation;
 314       gint border_width = gtk_bin_get_effective_border_width (bin);
 315
 316       child_allocation.x = allocation->x + border_width;
 317       child_allocation.y = allocation->y + border_width;
 318       child_allocation.width = allocation->width - 2 * border_width;
 319       child_allocation.height = allocation->height - 2 * border_width;
 320
 321       gtk_widget_size_allocate (priv->child, &child_allocation);
 322     }
 323 }
 324
 325 /**
 326  * gtk_bin_get_child:
 327  * @bin: a #GtkBin
 328  *
 329  * Gets the child of the #GtkBin, or %NULL if the bin contains
 330  * no child widget. The returned widget does not have a reference
 331  * added, so you do not need to unref it.
 332  *
 333  * Return value: (transfer none): pointer to child of the #GtkBin
 334  **/
 335 GtkWidget*
 336 gtk_bin_get_child (GtkBin *bin)
 337 {
 338   g_return_val_if_fail (GTK_IS_BIN (bin), NULL);
 339
 340   return bin->priv->child;
 341 }
 342
 343 void
 344 _gtk_bin_set_child (GtkBin    *bin,
 345                     GtkWidget *widget)
 346 {
 347   bin->priv->child = widget;
 348 }