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 GtkSizeRequestMode gtk_bin_get_request_mode                (GtkWidget           *widget);
  63 static void               gtk_bin_get_preferred_width_for_height  (GtkWidget           *widget,
  64                                                                    gint                 height,
  65                                                                    gint                *minimum_width,
  66                                                                    gint                *natural_width);
  67 static void               gtk_bin_get_preferred_height_for_width  (GtkWidget           *widget,
  68                                                                    gint                 width,
  69                                                                    gint                *minimum_height,
  70                                                                    gint                *natural_height);
  71
  72 G_DEFINE_ABSTRACT_TYPE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER)
  73
  74 static void
  75 gtk_bin_class_init (GtkBinClass *class)
  76 {
  77   GtkWidgetClass *widget_class = (GtkWidgetClass*) class;
  78   GtkContainerClass *container_class = (GtkContainerClass*) class;
  79
  80   widget_class->get_request_mode               = gtk_bin_get_request_mode;
  81   widget_class->get_preferred_width_for_height = gtk_bin_get_preferred_width_for_height;
  82   widget_class->get_preferred_height_for_width = gtk_bin_get_preferred_height_for_width;
  83
  84   container_class->add = gtk_bin_add;
  85   container_class->remove = gtk_bin_remove;
  86   container_class->forall = gtk_bin_forall;
  87   container_class->child_type = gtk_bin_child_type;
  88
  89   g_type_class_add_private (class, sizeof (GtkBinPrivate));
  90 }
  91
  92 static void
  93 gtk_bin_init (GtkBin *bin)
  94 {
  95   GtkBinPrivate *priv;
  96
  97   bin->priv = G_TYPE_INSTANCE_GET_PRIVATE (bin,
  98                                            GTK_TYPE_BIN,
  99                                            GtkBinPrivate);
 100   priv = bin->priv;
 101
 102   gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);
 103
 104   priv->child = NULL;
 105 }
 106
 107
 108 static GType
 109 gtk_bin_child_type (GtkContainer *container)
 110 {
 111   GtkBinPrivate *priv = GTK_BIN (container)->priv;
 112
 113   if (!priv->child)
 114     return GTK_TYPE_WIDGET;
 115   else
 116     return G_TYPE_NONE;
 117 }
 118
 119 static void
 120 gtk_bin_add (GtkContainer *container,
 121              GtkWidget    *child)
 122 {
 123   GtkBin *bin = GTK_BIN (container);
 124   GtkBinPrivate *priv = bin->priv;
 125
 126   if (priv->child != NULL)
 127     {
 128       g_warning ("Attempting to add a widget with type %s to a %s, "
 129                  "but as a GtkBin subclass a %s can only contain one widget at a time; "
 130                  "it already contains a widget of type %s",
 131                  g_type_name (G_OBJECT_TYPE (child)),
 132                  g_type_name (G_OBJECT_TYPE (bin)),
 133                  g_type_name (G_OBJECT_TYPE (bin)),
 134                  g_type_name (G_OBJECT_TYPE (priv->child)));
 135       return;
 136     }
 137
 138   gtk_widget_set_parent (child, GTK_WIDGET (bin));
 139   priv->child = child;
 140 }
 141
 142 static void
 143 gtk_bin_remove (GtkContainer *container,
 144                 GtkWidget    *child)
 145 {
 146   GtkBin *bin = GTK_BIN (container);
 147   GtkBinPrivate *priv = bin->priv;
 148   gboolean widget_was_visible;
 149
 150   g_return_if_fail (priv->child == child);
 151
 152   widget_was_visible = gtk_widget_get_visible (child);
 153
 154   gtk_widget_unparent (child);
 155   priv->child = NULL;
 156
 157   /* queue resize regardless of gtk_widget_get_visible (container),
 158    * since that's what is needed by toplevels, which derive from GtkBin.
 159    */
 160   if (widget_was_visible)
 161     gtk_widget_queue_resize (GTK_WIDGET (container));
 162 }
 163
 164 static void
 165 gtk_bin_forall (GtkContainer *container,
 166                 gboolean      include_internals,
 167                 GtkCallback   callback,
 168                 gpointer      callback_data)
 169 {
 170   GtkBin *bin = GTK_BIN (container);
 171   GtkBinPrivate *priv = bin->priv;
 172
 173   if (priv->child)
 174     (* callback) (priv->child, callback_data);
 175 }
 176
 177
 178 /* GtkBin widgets define the padding and borders independantly so
 179  * we cannot provide a generic get_size() for the same reason
 180  * we never implemented size_request() here.
 181  *
 182  * But for cases where the GtkBin class's padding is constant and
 183  * does not vary based on allocation (most cases), we can at least
 184  * deduce a common code path for the get_width_for_height()/get_height_for_width()
 185  * cases by using the delta of the base size requsts.
 186  */
 187 static GtkSizeRequestMode
 188 gtk_bin_get_request_mode (GtkWidget           *widget)
 189 {
 190   GtkBin *bin = GTK_BIN (widget);
 191   GtkBinPrivate *priv = bin->priv;
 192
 193   if (priv->child)
 194     return gtk_widget_get_request_mode (priv->child);
 195
 196   return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;
 197 }
 198
 199 static void
 200 get_child_padding_delta (GtkBin *bin,
 201                          gint   *delta_h,
 202                          gint   *delta_v)
 203 {
 204   GtkBinPrivate *priv = bin->priv;
 205   gint hmin, vmin, hnat, vnat, child_hmin, child_vmin;
 206
 207   /* we can't use gtk_widget_get_preferred_width() wrapper
 208    * because we want our "original" request, not any external
 209    * adjustments from set_size_request() or whatever.  we have
 210    * to ask for natural also because NULL isn't allowed for the
 211    * direct vfuncs
 212    */
 213   GTK_WIDGET_GET_CLASS (bin)->get_preferred_width (GTK_WIDGET (bin), &hmin, &hnat);
 214   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 215                                                    GTK_ORIENTATION_HORIZONTAL, &hmin, &hnat);
 216
 217   GTK_WIDGET_GET_CLASS (bin)->get_preferred_height (GTK_WIDGET (bin), &vmin, &vnat);
 218   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 219                                                    GTK_ORIENTATION_VERTICAL, &vmin, &vnat);
 220
 221   gtk_widget_get_preferred_width (priv->child, &child_hmin, NULL);
 222   gtk_widget_get_preferred_height (priv->child, &child_vmin, NULL);
 223
 224   *delta_h = hmin - child_hmin;
 225   *delta_v = vmin - child_vmin;
 226 }
 227
 228 static void
 229 gtk_bin_get_preferred_width_for_height (GtkWidget *widget,
 230                                         gint       height,
 231                                         gint      *minimum_width,
 232                                         gint      *natural_width)
 233 {
 234   GtkBin *bin = GTK_BIN (widget);
 235   GtkBinPrivate *priv = bin->priv;
 236   gint    hdelta, vdelta, child_min, child_nat;
 237
 238   if (priv->child)
 239     {
 240       get_child_padding_delta (bin, &hdelta, &vdelta);
 241
 242       gtk_widget_get_preferred_width_for_height (priv->child,
 243                                                  height - vdelta,
 244                                                  &child_min, &child_nat);
 245
 246       if (minimum_width)
 247         *minimum_width = child_min + hdelta;
 248
 249       if (natural_width)
 250         *natural_width = child_nat + hdelta;
 251     }
 252   else
 253     GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, minimum_width, natural_width);
 254 }
 255
 256 static void
 257 gtk_bin_get_preferred_height_for_width  (GtkWidget *widget,
 258                                          gint       width,
 259                                          gint      *minimum_height,
 260                                          gint      *natural_height)
 261 {
 262   GtkBin *bin = GTK_BIN (widget);
 263   GtkBinPrivate *priv = bin->priv;
 264   gint    hdelta, vdelta, child_min, child_nat;
 265
 266   if (priv->child)
 267     {
 268       get_child_padding_delta (bin, &hdelta, &vdelta);
 269
 270       gtk_widget_get_preferred_height_for_width (priv->child,
 271                                                  width - hdelta,
 272                                                  &child_min, &child_nat);
 273
 274       if (minimum_height)
 275         *minimum_height = child_min + vdelta;
 276
 277       if (natural_height)
 278         *natural_height = child_nat + vdelta;
 279     }
 280   else
 281     GTK_WIDGET_GET_CLASS (widget)->get_preferred_height (widget, minimum_height, natural_height);
 282 }
 283
 284
 285 /**
 286  * gtk_bin_get_child:
 287  * @bin: a #GtkBin
 288  *
 289  * Gets the child of the #GtkBin, or %NULL if the bin contains
 290  * no child widget. The returned widget does not have a reference
 291  * added, so you do not need to unref it.
 292  *
 293  * Return value: (transfer none): pointer to child of the #GtkBin
 294  **/
 295 GtkWidget*
 296 gtk_bin_get_child (GtkBin *bin)
 297 {
 298   g_return_val_if_fail (GTK_IS_BIN (bin), NULL);
 299
 300   return bin->priv->child;
 301 }
 302
 303 void
 304 _gtk_bin_set_child (GtkBin    *bin,
 305                     GtkWidget *widget)
 306 {
 307   bin->priv->child = widget;
 308 }