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, 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 /**
  28  * SECTION:gtkbin
  29  * @Short_description: A container with just one child
  30  * @Title: GtkBin
  31  *
  32  * The #GtkBin widget is a container with just one child.
  33  * It is not very useful itself, but it is useful for deriving subclasses,
  34  * since it provides common code needed for handling a single child widget.
  35  *
  36  * Many GTK+ widgets are subclasses of #GtkBin, including #GtkWindow,
  37  * #GtkButton, #GtkFrame, #GtkHandleBox or #GtkScrolledWindow.
  38  */
  39
  40 #include "config.h"
  41 #include "gtkbin.h"
  42 #include "gtksizerequest.h"
  43 #include "gtkintl.h"
  44
  45
  46 struct _GtkBinPrivate
  47 {
  48   GtkWidget *child;
  49 };
  50
  51 static void gtk_bin_add         (GtkContainer   *container,
  52                                  GtkWidget      *widget);
  53 static void gtk_bin_remove      (GtkContainer   *container,
  54                                  GtkWidget      *widget);
  55 static void gtk_bin_forall      (GtkContainer   *container,
  56                                  gboolean       include_internals,
  57                                  GtkCallback     callback,
  58                                  gpointer        callback_data);
  59 static GType gtk_bin_child_type (GtkContainer   *container);
  60
  61
  62 static void               gtk_bin_get_preferred_width_for_height  (GtkWidget           *widget,
  63                                                                    gint                 height,
  64                                                                    gint                *minimum_width,
  65                                                                    gint                *natural_width);
  66 static void               gtk_bin_get_preferred_height_for_width  (GtkWidget           *widget,
  67                                                                    gint                 width,
  68                                                                    gint                *minimum_height,
  69                                                                    gint                *natural_height);
  70
  71 G_DEFINE_ABSTRACT_TYPE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER)
  72
  73 static void
  74 gtk_bin_class_init (GtkBinClass *class)
  75 {
  76   GtkWidgetClass *widget_class = (GtkWidgetClass*) class;
  77   GtkContainerClass *container_class = (GtkContainerClass*) class;
  78
  79   widget_class->get_preferred_width_for_height = gtk_bin_get_preferred_width_for_height;
  80   widget_class->get_preferred_height_for_width = gtk_bin_get_preferred_height_for_width;
  81
  82   container_class->add = gtk_bin_add;
  83   container_class->remove = gtk_bin_remove;
  84   container_class->forall = gtk_bin_forall;
  85   container_class->child_type = gtk_bin_child_type;
  86
  87   g_type_class_add_private (class, sizeof (GtkBinPrivate));
  88 }
  89
  90 static void
  91 gtk_bin_init (GtkBin *bin)
  92 {
  93   GtkBinPrivate *priv;
  94
  95   bin->priv = G_TYPE_INSTANCE_GET_PRIVATE (bin,
  96                                            GTK_TYPE_BIN,
  97                                            GtkBinPrivate);
  98   priv = bin->priv;
  99
 100   gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);
 101
 102   priv->child = NULL;
 103 }
 104
 105
 106 static GType
 107 gtk_bin_child_type (GtkContainer *container)
 108 {
 109   GtkBinPrivate *priv = GTK_BIN (container)->priv;
 110
 111   if (!priv->child)
 112     return GTK_TYPE_WIDGET;
 113   else
 114     return G_TYPE_NONE;
 115 }
 116
 117 static void
 118 gtk_bin_add (GtkContainer *container,
 119              GtkWidget    *child)
 120 {
 121   GtkBin *bin = GTK_BIN (container);
 122   GtkBinPrivate *priv = bin->priv;
 123
 124   if (priv->child != NULL)
 125     {
 126       g_warning ("Attempting to add a widget with type %s to a %s, "
 127                  "but as a GtkBin subclass a %s can only contain one widget at a time; "
 128                  "it already contains a widget of type %s",
 129                  g_type_name (G_OBJECT_TYPE (child)),
 130                  g_type_name (G_OBJECT_TYPE (bin)),
 131                  g_type_name (G_OBJECT_TYPE (bin)),
 132                  g_type_name (G_OBJECT_TYPE (priv->child)));
 133       return;
 134     }
 135
 136   gtk_widget_set_parent (child, GTK_WIDGET (bin));
 137   priv->child = child;
 138 }
 139
 140 static void
 141 gtk_bin_remove (GtkContainer *container,
 142                 GtkWidget    *child)
 143 {
 144   GtkBin *bin = GTK_BIN (container);
 145   GtkBinPrivate *priv = bin->priv;
 146   gboolean widget_was_visible;
 147
 148   g_return_if_fail (priv->child == child);
 149
 150   widget_was_visible = gtk_widget_get_visible (child);
 151
 152   gtk_widget_unparent (child);
 153   priv->child = NULL;
 154
 155   /* queue resize regardless of gtk_widget_get_visible (container),
 156    * since that's what is needed by toplevels, which derive from GtkBin.
 157    */
 158   if (widget_was_visible)
 159     gtk_widget_queue_resize (GTK_WIDGET (container));
 160 }
 161
 162 static void
 163 gtk_bin_forall (GtkContainer *container,
 164                 gboolean      include_internals,
 165                 GtkCallback   callback,
 166                 gpointer      callback_data)
 167 {
 168   GtkBin *bin = GTK_BIN (container);
 169   GtkBinPrivate *priv = bin->priv;
 170
 171   if (priv->child)
 172     (* callback) (priv->child, callback_data);
 173 }
 174
 175
 176 /* GtkBin widgets define the padding and borders independantly so
 177  * we cannot provide a generic get_size() for the same reason
 178  * we never implemented size_request() here.
 179  *
 180  * But for cases where the GtkBin class's padding is constant and
 181  * does not vary based on allocation (most cases), we can at least
 182  * deduce a common code path for the get_width_for_height()/get_height_for_width()
 183  * cases by using the delta of the base size requsts.
 184  */
 185 static void
 186 get_child_padding_delta (GtkBin *bin,
 187                          gint   *delta_h,
 188                          gint   *delta_v)
 189 {
 190   GtkBinPrivate *priv = bin->priv;
 191   gint hmin, vmin, hnat, vnat, child_hmin, child_vmin;
 192
 193   /* we can't use gtk_widget_get_preferred_width() wrapper
 194    * because we want our "original" request, not any external
 195    * adjustments from set_size_request() or whatever.  we have
 196    * to ask for natural also because NULL isn't allowed for the
 197    * direct vfuncs
 198    */
 199   GTK_WIDGET_GET_CLASS (bin)->get_preferred_width (GTK_WIDGET (bin), &hmin, &hnat);
 200   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 201                                                    GTK_ORIENTATION_HORIZONTAL, &hmin, &hnat);
 202
 203   GTK_WIDGET_GET_CLASS (bin)->get_preferred_height (GTK_WIDGET (bin), &vmin, &vnat);
 204   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 205                                                    GTK_ORIENTATION_VERTICAL, &vmin, &vnat);
 206
 207   gtk_widget_get_preferred_width (priv->child, &child_hmin, NULL);
 208   gtk_widget_get_preferred_height (priv->child, &child_vmin, NULL);
 209
 210   *delta_h = hmin - child_hmin;
 211   *delta_v = vmin - child_vmin;
 212 }
 213
 214 static void
 215 gtk_bin_get_preferred_width_for_height (GtkWidget *widget,
 216                                         gint       height,
 217                                         gint      *minimum_width,
 218                                         gint      *natural_width)
 219 {
 220   GtkBin *bin = GTK_BIN (widget);
 221   GtkBinPrivate *priv = bin->priv;
 222   gint    hdelta, vdelta, child_min, child_nat;
 223
 224   if (priv->child)
 225     {
 226       get_child_padding_delta (bin, &hdelta, &vdelta);
 227
 228       gtk_widget_get_preferred_width_for_height (priv->child,
 229                                                  height - vdelta,
 230                                                  &child_min, &child_nat);
 231
 232       if (minimum_width)
 233         *minimum_width = child_min + hdelta;
 234
 235       if (natural_width)
 236         *natural_width = child_nat + hdelta;
 237     }
 238   else
 239     GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, minimum_width, natural_width);
 240 }
 241
 242 static void
 243 gtk_bin_get_preferred_height_for_width  (GtkWidget *widget,
 244                                          gint       width,
 245                                          gint      *minimum_height,
 246                                          gint      *natural_height)
 247 {
 248   GtkBin *bin = GTK_BIN (widget);
 249   GtkBinPrivate *priv = bin->priv;
 250   gint    hdelta, vdelta, child_min, child_nat;
 251
 252   if (priv->child)
 253     {
 254       get_child_padding_delta (bin, &hdelta, &vdelta);
 255
 256       gtk_widget_get_preferred_height_for_width (priv->child,
 257                                                  width - hdelta,
 258                                                  &child_min, &child_nat);
 259
 260       if (minimum_height)
 261         *minimum_height = child_min + vdelta;
 262
 263       if (natural_height)
 264         *natural_height = child_nat + vdelta;
 265     }
 266   else
 267     GTK_WIDGET_GET_CLASS (widget)->get_preferred_height (widget, minimum_height, natural_height);
 268 }
 269
 270
 271 /**
 272  * gtk_bin_get_child:
 273  * @bin: a #GtkBin
 274  *
 275  * Gets the child of the #GtkBin, or %NULL if the bin contains
 276  * no child widget. The returned widget does not have a reference
 277  * added, so you do not need to unref it.
 278  *
 279  * Return value: (transfer none): pointer to child of the #GtkBin
 280  **/
 281 GtkWidget*
 282 gtk_bin_get_child (GtkBin *bin)
 283 {
 284   g_return_val_if_fail (GTK_IS_BIN (bin), NULL);
 285
 286   return bin->priv->child;
 287 }
 288
 289 void
 290 _gtk_bin_set_child (GtkBin    *bin,
 291                     GtkWidget *widget)
 292 {
 293   bin->priv->child = widget;
 294 }