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 #include "config.h"
  28 #include "gtkbin.h"
  29 #include "gtkextendedlayout.h"
  30 #include "gtkintl.h"
  31 #include "gtkalias.h"
  32
  33 static void gtk_bin_add         (GtkContainer   *container,
  34                                  GtkWidget      *widget);
  35 static void gtk_bin_remove      (GtkContainer   *container,
  36                                  GtkWidget      *widget);
  37 static void gtk_bin_forall      (GtkContainer   *container,
  38                                  gboolean       include_internals,
  39                                  GtkCallback     callback,
  40                                  gpointer        callback_data);
  41 static GType gtk_bin_child_type (GtkContainer   *container);
  42
  43
  44 static void gtk_bin_extended_layout_init  (GtkExtendedLayoutIface *iface);
  45 static void gtk_bin_get_width_for_height  (GtkExtendedLayout      *layout,
  46                                            gint                    height,
  47                                            gint                   *minimum_width,
  48                                            gint                   *natural_width);
  49 static void gtk_bin_get_height_for_width  (GtkExtendedLayout      *layout,
  50                                            gint                    width,
  51                                            gint                   *minimum_height,
  52                                            gint                   *natural_height);
  53
  54
  55 static GtkExtendedLayoutIface *parent_extended_layout_iface;
  56
  57 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER,
  58                                   G_IMPLEMENT_INTERFACE (GTK_TYPE_EXTENDED_LAYOUT,
  59                                                          gtk_bin_extended_layout_init))
  60
  61 static void
  62 gtk_bin_class_init (GtkBinClass *class)
  63 {
  64   GtkContainerClass *container_class;
  65
  66   container_class = (GtkContainerClass*) class;
  67
  68   container_class->add = gtk_bin_add;
  69   container_class->remove = gtk_bin_remove;
  70   container_class->forall = gtk_bin_forall;
  71   container_class->child_type = gtk_bin_child_type;
  72 }
  73
  74 static void
  75 gtk_bin_init (GtkBin *bin)
  76 {
  77   gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);
  78
  79   bin->child = NULL;
  80 }
  81
  82
  83 static GType
  84 gtk_bin_child_type (GtkContainer *container)
  85 {
  86   if (!GTK_BIN (container)->child)
  87     return GTK_TYPE_WIDGET;
  88   else
  89     return G_TYPE_NONE;
  90 }
  91
  92 static void
  93 gtk_bin_add (GtkContainer *container,
  94              GtkWidget    *child)
  95 {
  96   GtkBin *bin = GTK_BIN (container);
  97
  98   if (bin->child != NULL)
  99     {
 100       g_warning ("Attempting to add a widget with type %s to a %s, "
 101                  "but as a GtkBin subclass a %s can only contain one widget at a time; "
 102                  "it already contains a widget of type %s",
 103                  g_type_name (G_OBJECT_TYPE (child)),
 104                  g_type_name (G_OBJECT_TYPE (bin)),
 105                  g_type_name (G_OBJECT_TYPE (bin)),
 106                  g_type_name (G_OBJECT_TYPE (bin->child)));
 107       return;
 108     }
 109
 110   gtk_widget_set_parent (child, GTK_WIDGET (bin));
 111   bin->child = child;
 112 }
 113
 114 static void
 115 gtk_bin_remove (GtkContainer *container,
 116                 GtkWidget    *child)
 117 {
 118   GtkBin *bin = GTK_BIN (container);
 119   gboolean widget_was_visible;
 120
 121   g_return_if_fail (bin->child == child);
 122
 123   widget_was_visible = gtk_widget_get_visible (child);
 124
 125   gtk_widget_unparent (child);
 126   bin->child = NULL;
 127
 128   /* queue resize regardless of gtk_widget_get_visible (container),
 129    * since that's what is needed by toplevels, which derive from GtkBin.
 130    */
 131   if (widget_was_visible)
 132     gtk_widget_queue_resize (GTK_WIDGET (container));
 133 }
 134
 135 static void
 136 gtk_bin_forall (GtkContainer *container,
 137                 gboolean      include_internals,
 138                 GtkCallback   callback,
 139                 gpointer      callback_data)
 140 {
 141   GtkBin *bin = GTK_BIN (container);
 142
 143   if (bin->child)
 144     (* callback) (bin->child, callback_data);
 145 }
 146
 147
 148 /* GtkBin widgets define the padding and borders independantly so
 149  * we cannot provide a generic get_desired_size() for the same reason
 150  * we never implemented size_request() here.
 151  *
 152  * But for cases where the GtkBin class's padding is constant and
 153  * does not vary based on allocation (most cases), we can at least
 154  * deduce a common code path for the get_width_for_height()/get_height_for_width()
 155  * cases by using the delta of the base size requsts.
 156  */
 157 static void
 158 gtk_bin_extended_layout_init (GtkExtendedLayoutIface *iface)
 159 {
 160   parent_extended_layout_iface = g_type_interface_peek_parent (iface);
 161
 162   iface->get_width_for_height  = gtk_bin_get_width_for_height;
 163   iface->get_height_for_width  = gtk_bin_get_height_for_width;
 164 }
 165
 166 static void
 167 get_child_padding_delta (GtkBin         *bin,
 168                          gint           *delta_h,
 169                          gint           *delta_v)
 170 {
 171   GtkRequisition min_req, child_min;
 172
 173   gtk_extended_layout_get_desired_size (GTK_EXTENDED_LAYOUT (bin),
 174                                         &min_req, NULL);
 175
 176   gtk_extended_layout_get_desired_size (GTK_EXTENDED_LAYOUT (bin->child),
 177                                         &child_min, NULL);
 178
 179
 180   *delta_h = min_req.width  - child_min.width;
 181   *delta_v = min_req.height - child_min.height;
 182 }
 183
 184 static void
 185 gtk_bin_get_width_for_height (GtkExtendedLayout      *layout,
 186                               gint                    height,
 187                               gint                   *minimum_width,
 188                               gint                   *natural_width)
 189 {
 190   GtkBin *bin = GTK_BIN (layout);
 191   gint    hdelta, vdelta, child_min, child_nat;
 192
 193   if (bin->child)
 194     {
 195       get_child_padding_delta (bin, &hdelta, &vdelta);
 196
 197       gtk_extended_layout_get_width_for_height (GTK_EXTENDED_LAYOUT (bin->child),
 198                                                 height - vdelta,
 199                                                 &child_min, &child_nat);
 200
 201       if (minimum_width)
 202         *minimum_width = child_min + hdelta;
 203
 204       if (natural_width)
 205         *natural_width = child_nat + hdelta;
 206     }
 207   else
 208     parent_extended_layout_iface->get_height_for_width (layout, height, minimum_width, natural_width);
 209 }
 210
 211 static void
 212 gtk_bin_get_height_for_width  (GtkExtendedLayout      *layout,
 213                                gint                    width,
 214                                gint                   *minimum_height,
 215                                gint                   *natural_height)
 216 {
 217   GtkBin *bin = GTK_BIN (layout);
 218   gint    hdelta, vdelta, child_min, child_nat;
 219
 220   if (bin->child)
 221     {
 222       get_child_padding_delta (bin, &hdelta, &vdelta);
 223
 224       gtk_extended_layout_get_height_for_width (GTK_EXTENDED_LAYOUT (bin->child),
 225                                                 width - hdelta,
 226                                                 &child_min, &child_nat);
 227
 228       if (minimum_height)
 229         *minimum_height = child_min + vdelta;
 230
 231       if (natural_height)
 232         *natural_height = child_nat + vdelta;
 233     }
 234   else
 235     parent_extended_layout_iface->get_height_for_width (layout, width, minimum_height, natural_height);
 236 }
 237
 238
 239 /**
 240  * gtk_bin_get_child:
 241  * @bin: a #GtkBin
 242  *
 243  * Gets the child of the #GtkBin, or %NULL if the bin contains
 244  * no child widget. The returned widget does not have a reference
 245  * added, so you do not need to unref it.
 246  *
 247  * Return value: (transfer none): pointer to child of the #GtkBin
 248  **/
 249 GtkWidget*
 250 gtk_bin_get_child (GtkBin *bin)
 251 {
 252   g_return_val_if_fail (GTK_IS_BIN (bin), NULL);
 253
 254   return bin->child;
 255 }
 256
 257 #define __GTK_BIN_C__
 258 #include "gtkaliasdef.c"