/* GTK - The GIMP Toolkit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
#include <ctype.h>
#include "gdk/gdkkeysyms.h"
#include "gtkbindings.h"
#include "gtklabel.h"
#include "gtkmain.h"
#include "gtkmenu.h"
#include "gtkmenuitem.h"
#include "gtksignal.h"
#include "gtkwindow.h"


#define MENU_ITEM_CLASS(w)   GTK_MENU_ITEM_CLASS (GTK_OBJECT (w)->klass)
#define	MENU_NEEDS_RESIZE(m) GTK_MENU_SHELL (m)->menu_flag

typedef struct _GtkMenuAttachData	GtkMenuAttachData;

struct _GtkMenuAttachData
{
  GtkWidget *attach_widget;
  GtkMenuDetachFunc detacher;
};


static void gtk_menu_class_init	    (GtkMenuClass      *klass);
static void gtk_menu_init	    (GtkMenu	       *menu);
static void gtk_menu_destroy	    (GtkObject	       *object);
static void gtk_menu_realize	    (GtkWidget	       *widget);
static void gtk_menu_size_request   (GtkWidget	       *widget,
				     GtkRequisition    *requisition);
static void gtk_menu_size_allocate  (GtkWidget	       *widget,
				     GtkAllocation     *allocation);
static void gtk_menu_paint	    (GtkWidget	       *widget);
static void gtk_menu_draw	    (GtkWidget	       *widget,
				     GdkRectangle      *area);
static gint gtk_menu_expose	    (GtkWidget	       *widget,
				     GdkEventExpose    *event);
static gint gtk_menu_key_press	    (GtkWidget	       *widget,
				     GdkEventKey       *event);
static gint gtk_menu_motion_notify  (GtkWidget	       *widget,
				     GdkEventMotion    *event);
static void gtk_menu_deactivate	    (GtkMenuShell      *menu_shell);
static void gtk_menu_show_all       (GtkWidget         *widget);
static void gtk_menu_hide_all       (GtkWidget         *widget);
static void gtk_menu_position       (GtkMenu           *menu);
static void gtk_menu_reparent       (GtkMenu           *menu, 
				     GtkWidget         *new_parent, 
				     gboolean           unrealize);

static GtkMenuShellClass *parent_class = NULL;
static const gchar	*attach_data_key = "gtk-menu-attach-data";


GtkType
gtk_menu_get_type (void)
{
  static GtkType menu_type = 0;
  
  if (!menu_type)
    {
      static const GtkTypeInfo menu_info =
      {
	"GtkMenu",
	sizeof (GtkMenu),
	sizeof (GtkMenuClass),
	(GtkClassInitFunc) gtk_menu_class_init,
	(GtkObjectInitFunc) gtk_menu_init,
	/* reserved_1 */ NULL,
	/* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL,
      };
      
      menu_type = gtk_type_unique (gtk_menu_shell_get_type (), &menu_info);
    }
  
  return menu_type;
}

static void
gtk_menu_class_init (GtkMenuClass *class)
{
  GtkObjectClass *object_class;
  GtkWidgetClass *widget_class;
  GtkContainerClass *container_class;
  GtkMenuShellClass *menu_shell_class;

  GtkBindingSet *binding_set;
  
  object_class = (GtkObjectClass*) class;
  widget_class = (GtkWidgetClass*) class;
  container_class = (GtkContainerClass*) class;
  menu_shell_class = (GtkMenuShellClass*) class;
  parent_class = gtk_type_class (gtk_menu_shell_get_type ());
  
  object_class->destroy = gtk_menu_destroy;
  
  widget_class->realize = gtk_menu_realize;
  widget_class->draw = gtk_menu_draw;
  widget_class->size_request = gtk_menu_size_request;
  widget_class->size_allocate = gtk_menu_size_allocate;
  widget_class->expose_event = gtk_menu_expose;
  widget_class->key_press_event = gtk_menu_key_press;
  widget_class->motion_notify_event = gtk_menu_motion_notify;
  widget_class->show_all = gtk_menu_show_all;
  widget_class->hide_all = gtk_menu_hide_all;
  
  menu_shell_class->submenu_placement = GTK_LEFT_RIGHT;
  menu_shell_class->deactivate = gtk_menu_deactivate;

  binding_set = gtk_binding_set_by_class (class);
  gtk_binding_entry_add_signal (binding_set,
				GDK_Up, 0,
				"move_current", 1,
				GTK_TYPE_MENU_DIRECTION_TYPE,
				GTK_MENU_DIR_PREV);
  gtk_binding_entry_add_signal (binding_set,
				GDK_Down, 0,
				"move_current", 1,
				GTK_TYPE_MENU_DIRECTION_TYPE,
				GTK_MENU_DIR_NEXT);
  gtk_binding_entry_add_signal (binding_set,
				GDK_Left, 0,
				"move_current", 1,
				GTK_TYPE_MENU_DIRECTION_TYPE,
				GTK_MENU_DIR_PARENT);
  gtk_binding_entry_add_signal (binding_set,
				GDK_Right, 0,
				"move_current", 1,
				GTK_TYPE_MENU_DIRECTION_TYPE,
				GTK_MENU_DIR_CHILD);
}

static void
gtk_menu_init (GtkMenu *menu)
{
  menu->parent_menu_item = NULL;
  menu->old_active_menu_item = NULL;
  menu->accel_group = NULL;
  menu->position_func = NULL;
  menu->position_func_data = NULL;

  menu->toplevel = gtk_window_new (GTK_WINDOW_POPUP);
  gtk_signal_connect_object (GTK_OBJECT (menu->toplevel),  "key_press_event",
			     GTK_SIGNAL_FUNC (gtk_menu_key_press), 
			     GTK_OBJECT (menu));
  gtk_window_set_policy (GTK_WINDOW (menu->toplevel),
			 FALSE, FALSE, TRUE);

  gtk_container_add (GTK_CONTAINER (menu->toplevel), GTK_WIDGET (menu));

  /* Refloat the menu, so that reference counting for the menu isn't
   * affected by it being a child of the toplevel
   */
  GTK_WIDGET_SET_FLAGS (menu, GTK_FLOATING);

  menu->tearoff_window = NULL;
  menu->torn_off = FALSE;

  MENU_NEEDS_RESIZE (menu) = TRUE;
}

static void
gtk_menu_destroy (GtkObject	    *object)
{
  GtkMenu *menu;
  GtkMenuAttachData *data;
  
  g_return_if_fail (object != NULL);
  g_return_if_fail (GTK_IS_MENU (object));

  menu = GTK_MENU (object);
  
  gtk_object_ref (object);
  
  data = gtk_object_get_data (object, attach_data_key);
  if (data)
    gtk_menu_detach (menu);
  
  gtk_menu_set_accel_group (menu, NULL);

  /* Add back the reference count for being a child */
  gtk_object_ref (object);
  
  gtk_widget_destroy (menu->toplevel);
  if (menu->tearoff_window)
    gtk_widget_destroy (menu->tearoff_window);

  if (GTK_OBJECT_CLASS (parent_class)->destroy)
    (* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
  
  gtk_object_unref (object);
}


void
gtk_menu_attach_to_widget (GtkMenu	       *menu,
			   GtkWidget	       *attach_widget,
			   GtkMenuDetachFunc	detacher)
{
  GtkMenuAttachData *data;
  
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  g_return_if_fail (attach_widget != NULL);
  g_return_if_fail (GTK_IS_WIDGET (attach_widget));
  g_return_if_fail (detacher != NULL);
  
  /* keep this function in sync with gtk_widget_set_parent()
   */
  
  data = gtk_object_get_data (GTK_OBJECT (menu), attach_data_key);
  if (data)
    {
      g_warning ("gtk_menu_attach_to_widget(): menu already attached to %s",
		 gtk_type_name (GTK_OBJECT_TYPE (data->attach_widget)));
      return;
    }
  
  gtk_object_ref (GTK_OBJECT (menu));
  gtk_object_sink (GTK_OBJECT (menu));
  
  data = g_new (GtkMenuAttachData, 1);
  data->attach_widget = attach_widget;
  data->detacher = detacher;
  gtk_object_set_data (GTK_OBJECT (menu), attach_data_key, data);
  
  if (GTK_WIDGET_STATE (menu) != GTK_STATE_NORMAL)
    gtk_widget_set_state (GTK_WIDGET (menu), GTK_STATE_NORMAL);
  
  /* we don't need to set the style here, since
   * we are a toplevel widget.
   */
}

GtkWidget*
gtk_menu_get_attach_widget (GtkMenu		*menu)
{
  GtkMenuAttachData *data;
  
  g_return_val_if_fail (menu != NULL, NULL);
  g_return_val_if_fail (GTK_IS_MENU (menu), NULL);
  
  data = gtk_object_get_data (GTK_OBJECT (menu), attach_data_key);
  if (data)
    return data->attach_widget;
  return NULL;
}

void
gtk_menu_detach (GtkMenu	     *menu)
{
  GtkMenuAttachData *data;
  
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  
  /* keep this function in sync with gtk_widget_unparent()
   */
  data = gtk_object_get_data (GTK_OBJECT (menu), attach_data_key);
  if (!data)
    {
      g_warning ("gtk_menu_detach(): menu is not attached");
      return;
    }
  gtk_object_remove_data (GTK_OBJECT (menu), attach_data_key);
  
  data->detacher (data->attach_widget, menu);
  
  if (GTK_WIDGET_REALIZED (menu))
    gtk_widget_unrealize (GTK_WIDGET (menu));
  
  g_free (data);
  
  gtk_widget_unref (GTK_WIDGET (menu));
}

GtkWidget*
gtk_menu_new (void)
{
  return GTK_WIDGET (gtk_type_new (gtk_menu_get_type ()));
}

void
gtk_menu_append (GtkMenu   *menu,
		 GtkWidget *child)
{
  gtk_menu_shell_append (GTK_MENU_SHELL (menu), child);
}

void
gtk_menu_prepend (GtkMenu   *menu,
		  GtkWidget *child)
{
  gtk_menu_shell_prepend (GTK_MENU_SHELL (menu), child);
}

void
gtk_menu_insert (GtkMenu   *menu,
		 GtkWidget *child,
		 gint	    position)
{
  gtk_menu_shell_insert (GTK_MENU_SHELL (menu), child, position);
}

void
gtk_menu_popup (GtkMenu		    *menu,
		GtkWidget	    *parent_menu_shell,
		GtkWidget	    *parent_menu_item,
		GtkMenuPositionFunc  func,
		gpointer	     data,
		guint		     button,
		guint32		     activate_time)
{
  GtkWidget *widget;
  GtkWidget *xgrab_shell;
  GtkWidget *parent;
  GdkEvent *current_event;
  GtkMenuShell *menu_shell;
  
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  
  widget = GTK_WIDGET (menu);
  menu_shell = GTK_MENU_SHELL (menu);
  
  menu_shell->parent_menu_shell = parent_menu_shell;
  menu_shell->active = TRUE;
  menu_shell->button = button;

  /* If we are popping up the menu from something other than, a button
   * press then, as a heuristic, we ignore enter events for the menu
   * until we get a MOTION_NOTIFY.  
   */

  current_event = gtk_get_current_event();
  if (current_event)
    {
      if ((current_event->type != GDK_BUTTON_PRESS) &&
	  (current_event->type != GDK_ENTER_NOTIFY))
	menu_shell->ignore_enter = TRUE;
      gdk_event_free(current_event);
    }

  if (menu->torn_off)
    {
      GdkPixmap *pixmap;
      GdkGC *gc;
      GdkGCValues gc_values;
      
      gc_values.subwindow_mode = GDK_INCLUDE_INFERIORS;
      gc = gdk_gc_new_with_values (widget->window,
				   &gc_values, GDK_GC_SUBWINDOW);
      
      pixmap = gdk_pixmap_new (widget->window,
			       widget->requisition.width,
			       widget->requisition.height,
			       -1);
      
      gdk_draw_pixmap (pixmap, gc,
		       widget->window,
		       0, 0, 0, 0, -1, -1);
      gdk_gc_unref(gc);

      gtk_widget_set_usize (menu->tearoff_window,
			    widget->requisition.width,
			    widget->requisition.height);
		    
      gdk_window_set_back_pixmap (menu->tearoff_window->window, pixmap, FALSE);
      gdk_pixmap_unref (pixmap);

      /* We force an unrealize here so that we don't trigger redrawing/
       * clearing code - we just want to reveal our backing pixmap.
       */
      gtk_menu_reparent (menu, menu->toplevel, TRUE);
    }
  
  menu->parent_menu_item = parent_menu_item;
  menu->position_func = func;
  menu->position_func_data = data;
  menu_shell->activate_time = activate_time;

  gtk_menu_position (menu);

  /* We need to show the menu _here_ because code expects to be
   * able to tell if the menu is onscreen by looking at the
   * GTK_WIDGET_VISIBLE (menu)
   */
  gtk_widget_show (GTK_WIDGET (menu));
  gtk_widget_show (menu->toplevel);
  
  /* Find the last viewable ancestor, and make an X grab on it
   */
  parent = GTK_WIDGET (menu);
  xgrab_shell = NULL;
  while (parent)
    {
      gboolean viewable = TRUE;
      GtkWidget *tmp = parent;
      
      while (tmp)
	{
	  if (!GTK_WIDGET_MAPPED (tmp))
	    {
	      viewable = FALSE;
	      break;
	    }
	  tmp = tmp->parent;
	}
      
      if (viewable)
	xgrab_shell = parent;
      
      parent = GTK_MENU_SHELL (parent)->parent_menu_shell;
    }
  
  if (xgrab_shell && (!GTK_MENU_SHELL (xgrab_shell)->have_xgrab))
    {
      GdkCursor *cursor = gdk_cursor_new (GDK_ARROW);

      if ((gdk_pointer_grab (xgrab_shell->window, TRUE,
			     GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
			     GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK |
			     GDK_POINTER_MOTION_MASK,
			     NULL, cursor, activate_time) == 0))
	{
	  if (gdk_keyboard_grab (xgrab_shell->window, TRUE,
			      activate_time) == 0)
	    GTK_MENU_SHELL (xgrab_shell)->have_xgrab = TRUE;
	  else
	    {
	      gdk_pointer_ungrab (activate_time);
	    }
	}

      gdk_cursor_destroy (cursor);
    }
  
  gtk_grab_add (GTK_WIDGET (menu));
}

void
gtk_menu_popdown (GtkMenu *menu)
{
  GtkMenuShell *menu_shell;
  
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  
  menu_shell = GTK_MENU_SHELL (menu);
  
  menu_shell->parent_menu_shell = NULL;
  menu_shell->active = FALSE;
  menu_shell->ignore_enter = FALSE;
  
  if (menu_shell->active_menu_item)
    {
      menu->old_active_menu_item = menu_shell->active_menu_item;
      gtk_menu_item_deselect (GTK_MENU_ITEM (menu_shell->active_menu_item));
      menu_shell->active_menu_item = NULL;
    }
  
  /* The X Grab, if present, will automatically be removed when we hide
   * the window */
  gtk_widget_hide (menu->toplevel);

  if (menu->torn_off)
    {
      if (GTK_BIN (menu->toplevel)->child) 
	{
	  gtk_menu_reparent (menu, menu->tearoff_window, FALSE);
	} 
      else
	{
	  /* We popped up the menu from the tearoff, so we need to 
	   * release the grab - we aren't actually hiding the menu.
	   */
	  if (menu_shell->have_xgrab)
	    {
	      gdk_pointer_ungrab (GDK_CURRENT_TIME);
	      gdk_keyboard_ungrab (GDK_CURRENT_TIME);
	    }
	}
    }
  else
    gtk_widget_hide (GTK_WIDGET (menu));
        
  menu_shell->have_xgrab = FALSE;
  gtk_grab_remove (GTK_WIDGET (menu));
}

GtkWidget*
gtk_menu_get_active (GtkMenu *menu)
{
  GtkWidget *child;
  GList *children;
  
  g_return_val_if_fail (menu != NULL, NULL);
  g_return_val_if_fail (GTK_IS_MENU (menu), NULL);
  
  if (!menu->old_active_menu_item)
    {
      child = NULL;
      children = GTK_MENU_SHELL (menu)->children;
      
      while (children)
	{
	  child = children->data;
	  children = children->next;
	  
	  if (GTK_BIN (child)->child)
	    break;
	  child = NULL;
	}
      
      menu->old_active_menu_item = child;
    }
  
  return menu->old_active_menu_item;
}

void
gtk_menu_set_active (GtkMenu *menu,
		     guint    index)
{
  GtkWidget *child;
  GList *tmp_list;
  
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  
  tmp_list = g_list_nth (GTK_MENU_SHELL (menu)->children, index);
  if (tmp_list)
    {
      child = tmp_list->data;
      if (GTK_BIN (child)->child)
	menu->old_active_menu_item = child;
    }
}

void
gtk_menu_set_accel_group (GtkMenu	*menu,
			  GtkAccelGroup *accel_group)
{
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));
  
  if (menu->accel_group != accel_group)
    {
      if (menu->accel_group)
	gtk_accel_group_unref (menu->accel_group);
      menu->accel_group = accel_group;
      if (menu->accel_group)
	gtk_accel_group_ref (menu->accel_group);
    }
}


void
gtk_menu_reposition (GtkMenu *menu)
{
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));

  if (GTK_WIDGET_DRAWABLE (menu) && !menu->torn_off)
    gtk_menu_position (menu);
}


void       
gtk_menu_set_tearoff_state (GtkMenu  *menu,
			    gboolean  torn_off)
{
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));

  if (menu->torn_off != torn_off)
    {
      menu->torn_off = torn_off;
      
      if (menu->torn_off)
	{
	  if (GTK_WIDGET_VISIBLE (menu))
	    gtk_menu_popdown (menu);

	  if (!menu->tearoff_window)
	    {
	      GtkWidget *attach_widget;
	      
	      menu->tearoff_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
	      gtk_widget_set_app_paintable (menu->tearoff_window, TRUE);
	      gtk_signal_connect_object (GTK_OBJECT (menu->tearoff_window),  
					 "key_press_event",
					 GTK_SIGNAL_FUNC (gtk_menu_key_press), 
					 GTK_OBJECT (menu));
	      gtk_widget_realize (menu->tearoff_window);
	      
	      attach_widget = gtk_menu_get_attach_widget (menu);
	      if (GTK_IS_MENU_ITEM (attach_widget))
		{
		  GtkWidget *child = GTK_BIN (attach_widget)->child;
		  if (GTK_IS_LABEL (child))
		    {
		      gchar *ret;
		      gtk_label_get (GTK_LABEL (child), &ret);
		      gdk_window_set_title (menu->tearoff_window->window, ret);
		    }
		}

	      gdk_window_set_decorations (menu->tearoff_window->window, 
					  GDK_DECOR_ALL |
					  GDK_DECOR_RESIZEH |
					  GDK_DECOR_MINIMIZE |
					  GDK_DECOR_MAXIMIZE);
	      gtk_window_set_policy (GTK_WINDOW (menu->tearoff_window),
				     FALSE, FALSE, TRUE);
	    }
	  gtk_menu_reparent (menu, menu->tearoff_window, FALSE);

	  gtk_menu_position (menu);
	  
	  gtk_widget_show (GTK_WIDGET (menu));
	  gtk_widget_show (menu->tearoff_window);
	}
      else
	{
	  gtk_widget_hide (menu->tearoff_window);
	  gtk_menu_reparent (menu, menu->toplevel, FALSE);
	}
    }
}

static void
gtk_menu_realize (GtkWidget *widget)
{
  GdkWindowAttr attributes;
  gint attributes_mask;
  
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));
  
  GTK_WIDGET_SET_FLAGS (widget, GTK_REALIZED);
  
  attributes.window_type = GDK_WINDOW_CHILD;
  attributes.x = widget->allocation.x;
  attributes.y = widget->allocation.y;
  attributes.width = widget->allocation.width;
  attributes.height = widget->allocation.height;
  attributes.wclass = GDK_INPUT_OUTPUT;
  attributes.visual = gtk_widget_get_visual (widget);
  attributes.colormap = gtk_widget_get_colormap (widget);
  attributes.event_mask = gtk_widget_get_events (widget);
  attributes.event_mask |= (GDK_EXPOSURE_MASK | GDK_KEY_PRESS_MASK);
  
  attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
  widget->window = gdk_window_new (gtk_widget_get_parent_window (widget), &attributes, attributes_mask);
  gdk_window_set_user_data (widget->window, widget);
  
  widget->style = gtk_style_attach (widget->style, widget->window);
  gtk_style_set_background (widget->style, widget->window, GTK_STATE_NORMAL);
  gtk_menu_paint(widget);
}

static void
gtk_menu_size_request (GtkWidget      *widget,
		       GtkRequisition *requisition)
{
  GtkMenu *menu;
  GtkMenuShell *menu_shell;
  GtkWidget *child;
  GList *children;
  guint max_toggle_size;
  guint max_accel_width;
  
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));
  g_return_if_fail (requisition != NULL);
  
  menu = GTK_MENU (widget);
  menu_shell = GTK_MENU_SHELL (widget);
  
  requisition->width = 0;
  requisition->height = 0;
  
  max_toggle_size = 0;
  max_accel_width = 0;
  
  children = menu_shell->children;
  while (children)
    {
      child = children->data;
      children = children->next;
      
      if (GTK_WIDGET_VISIBLE (child))
	{
	  GTK_MENU_ITEM (child)->show_submenu_indicator = TRUE;
	  gtk_widget_size_request (child, &child->requisition);
	  
	  requisition->width = MAX (requisition->width, child->requisition.width);
	  requisition->height += child->requisition.height;
	  
	  max_toggle_size = MAX (max_toggle_size, MENU_ITEM_CLASS (child)->toggle_size);
	  max_accel_width = MAX (max_accel_width, GTK_MENU_ITEM (child)->accelerator_width);
	}
    }
  
  requisition->width += max_toggle_size + max_accel_width;
  requisition->width += (GTK_CONTAINER (menu)->border_width +
			 widget->style->klass->xthickness) * 2;
  requisition->height += (GTK_CONTAINER (menu)->border_width +
			  widget->style->klass->ythickness) * 2;
  
  children = menu_shell->children;
  while (children)
    {
      child = children->data;
      children = children->next;
      
      GTK_MENU_ITEM (child)->toggle_size = max_toggle_size;
    }
}

static void
gtk_menu_size_allocate (GtkWidget     *widget,
			GtkAllocation *allocation)
{
  GtkMenu *menu;
  GtkMenuShell *menu_shell;
  GtkWidget *child;
  GtkAllocation child_allocation;
  GList *children;
  
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));
  g_return_if_fail (allocation != NULL);
  
  menu = GTK_MENU (widget);
  menu_shell = GTK_MENU_SHELL (widget);
  
  widget->allocation = *allocation;
  if (GTK_WIDGET_REALIZED (widget))
    gdk_window_move_resize (widget->window,
			    allocation->x, allocation->y,
			    allocation->width, allocation->height);


  if (menu_shell->children)
    {
      child_allocation.x = (GTK_CONTAINER (menu)->border_width +
			    widget->style->klass->xthickness);
      child_allocation.y = (GTK_CONTAINER (menu)->border_width +
			    widget->style->klass->ythickness);
      child_allocation.width = MAX (1, (gint)allocation->width - child_allocation.x * 2);
      
      children = menu_shell->children;
      while (children)
	{
	  child = children->data;
	  children = children->next;
	  
	  if (GTK_WIDGET_VISIBLE (child))
	    {
	      child_allocation.height = child->requisition.height;
	      
	      gtk_widget_size_allocate (child, &child_allocation);
	      gtk_widget_queue_draw (child);
	      
	      child_allocation.y += child_allocation.height;
	    }
	}
    }
}

static void
gtk_menu_paint (GtkWidget *widget)
{
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));
  
  if (GTK_WIDGET_DRAWABLE (widget))
    {
      gtk_paint_box (widget->style,
		     widget->window,
		     GTK_STATE_NORMAL,
		     GTK_SHADOW_OUT,
		     NULL, widget, "menu",
		     0, 0, -1, -1);
    }
}

static void
gtk_menu_draw (GtkWidget    *widget,
	       GdkRectangle *area)
{
  GtkMenuShell *menu_shell;
  GtkWidget *child;
  GdkRectangle child_area;
  GList *children;
  
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));
  g_return_if_fail (area != NULL);
  
  if (GTK_WIDGET_DRAWABLE (widget))
    {
      gtk_menu_paint (widget);
      
      menu_shell = GTK_MENU_SHELL (widget);
      
      children = menu_shell->children;
      while (children)
	{
	  child = children->data;
	  children = children->next;
	  
	  if (gtk_widget_intersect (child, area, &child_area))
	    gtk_widget_draw (child, &child_area);
	}
    }
}

static gint
gtk_menu_expose (GtkWidget	*widget,
		 GdkEventExpose *event)
{
  GtkMenuShell *menu_shell;
  GtkWidget *child;
  GdkEventExpose child_event;
  GList *children;
  
  g_return_val_if_fail (widget != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_MENU (widget), FALSE);
  g_return_val_if_fail (event != NULL, FALSE);
  
  if (GTK_WIDGET_DRAWABLE (widget))
    {
      gtk_menu_paint (widget);
      
      menu_shell = GTK_MENU_SHELL (widget);
      child_event = *event;
      
      children = menu_shell->children;
      while (children)
	{
	  child = children->data;
	  children = children->next;
	  
	  if (GTK_WIDGET_NO_WINDOW (child) &&
	      gtk_widget_intersect (child, &event->area, &child_event.area))
	    gtk_widget_event (child, (GdkEvent*) &child_event);
	}
    }
  
  return FALSE;
}

static gint
gtk_menu_key_press (GtkWidget	*widget,
		    GdkEventKey *event)
{
  GtkMenuShell *menu_shell;
  gboolean delete = FALSE;
  
  g_return_val_if_fail (widget != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_MENU (widget), FALSE);
  g_return_val_if_fail (event != NULL, FALSE);
      
  menu_shell = GTK_MENU_SHELL (widget);

  if (GTK_WIDGET_CLASS (parent_class)->key_press_event (widget, event))
    return TRUE;

  switch (event->keyval)
    {
    case GDK_Delete:
    case GDK_KP_Delete:
    case GDK_BackSpace:
      delete = TRUE;
      break;
    default:
      break;
    }

  /* Modify the accelerators */
  if (delete || gtk_accelerator_valid (event->keyval, event->keyval))
    {
      if (menu_shell->active_menu_item &&
	  GTK_BIN (menu_shell->active_menu_item)->child &&
	  GTK_MENU_ITEM (menu_shell->active_menu_item)->submenu == NULL)
	{
	  GtkMenuItem *menu_item;
	  GtkAccelGroup *accel_group;
	  
	  menu_item = GTK_MENU_ITEM (menu_shell->active_menu_item);
	  
	  if (!GTK_MENU (widget)->accel_group)
	    accel_group = gtk_accel_group_get_default ();
	  else
	    accel_group = GTK_MENU (widget)->accel_group;

	  gtk_widget_remove_accelerators (GTK_WIDGET (menu_item),
					  gtk_signal_name (menu_item->accelerator_signal),
					  TRUE);
	  
	  if (!delete &&
	      0 == gtk_widget_accelerator_signal (GTK_WIDGET (menu_item),
						  accel_group,
						  event->keyval,
						  event->state))
	    {
	      GSList *slist;
	      
	      slist = gtk_accel_group_entries_from_object (GTK_OBJECT (menu_item));
	      while (slist)
		{
		  GtkAccelEntry *ac_entry;
		  
		  ac_entry = slist->data;
		  
		  if (ac_entry->signal_id == menu_item->accelerator_signal)
		    break;
		  
		  slist = slist->next;
		}

	      if (!slist)
		gtk_widget_add_accelerator (GTK_WIDGET (menu_item),
					    gtk_signal_name (menu_item->accelerator_signal),
					    accel_group,
					    event->keyval,
					    event->state,
					    GTK_ACCEL_VISIBLE);
	    }
	}
    }
  
  return FALSE;
}

static gint 
gtk_menu_motion_notify  (GtkWidget	   *widget,
			 GdkEventMotion    *event)
{
  g_return_val_if_fail (widget != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_MENU (widget), FALSE);

  if (GTK_MENU_SHELL (widget)->ignore_enter)
    GTK_MENU_SHELL (widget)->ignore_enter = FALSE;
  else
    {
      GdkEvent send_event;

      send_event.crossing.type = GDK_ENTER_NOTIFY;
      send_event.crossing.window = event->window;
      send_event.crossing.time = event->time;

      gtk_widget_event (widget, &send_event);
    }
      
  return FALSE;
}

static void
gtk_menu_deactivate (GtkMenuShell *menu_shell)
{
  GtkWidget *parent;
  
  g_return_if_fail (menu_shell != NULL);
  g_return_if_fail (GTK_IS_MENU (menu_shell));
  
  parent = menu_shell->parent_menu_shell;
  
  menu_shell->activate_time = 0;
  gtk_menu_popdown (GTK_MENU (menu_shell));
  
  if (parent)
    gtk_menu_shell_deactivate (GTK_MENU_SHELL (parent));
}


static void
gtk_menu_position (GtkMenu *menu)
{
  GtkWidget *widget;
  gint x, y;
 
  g_return_if_fail (menu != NULL);
  g_return_if_fail (GTK_IS_MENU (menu));

  widget = GTK_WIDGET (menu);

  gdk_window_get_pointer (NULL, &x, &y, NULL);

  /* We need the requisition to figure out the right place to
   * popup the menu. In fact, we always need to ask here, since
   * if one a size_request was queued while we weren't popped up,
   * the requisition won't have been recomputed yet.
   */
  gtk_widget_size_request (widget, &widget->requisition);
      
  if (menu->position_func)
    (* menu->position_func) (menu, &x, &y, menu->position_func_data);
  else
    {
      gint screen_width;
      gint screen_height;
      
      screen_width = gdk_screen_width ();
      screen_height = gdk_screen_height ();
	  
      x -= 2;
      y -= 2;
      
      if ((x + widget->requisition.width) > screen_width)
	x -= ((x + widget->requisition.width) - screen_width);
      if (x < 0)
	x = 0;
      if ((y + widget->requisition.height) > screen_height)
	y -= ((y + widget->requisition.height) - screen_height);
      if (y < 0)
	y = 0;
    }
  
  gtk_widget_set_uposition (GTK_MENU_SHELL (menu)->active ?
			        menu->toplevel : menu->tearoff_window, 
			    x, y);
}

/* Reparent the menu, taking care of the refcounting
 */
static void 
gtk_menu_reparent (GtkMenu      *menu, 
		   GtkWidget    *new_parent, 
		   gboolean      unrealize)
{
  GtkObject *object = GTK_OBJECT (menu);
  GtkWidget *widget = GTK_WIDGET (menu);
  gboolean was_floating = GTK_OBJECT_FLOATING (object);

  gtk_object_ref (object);
  gtk_object_sink (object);

  if (unrealize)
    {
      gtk_object_ref (object);
      gtk_container_remove (GTK_CONTAINER (widget->parent), widget);
      gtk_container_add (GTK_CONTAINER (new_parent), widget);
      gtk_object_unref (object);
    }
  else
    gtk_widget_reparent (GTK_WIDGET (menu), new_parent);
  
  if (was_floating)
    GTK_OBJECT_SET_FLAGS (object, GTK_FLOATING);
  else
    gtk_object_unref (object);
}

static void
gtk_menu_show_all (GtkWidget *widget)
{
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));

  /* Show children, but not self. */
  gtk_container_foreach (GTK_CONTAINER (widget), (GtkCallback) gtk_widget_show_all, NULL);
}


static void
gtk_menu_hide_all (GtkWidget *widget)
{
  g_return_if_fail (widget != NULL);
  g_return_if_fail (GTK_IS_MENU (widget));

  /* Hide children, but not self. */
  gtk_container_foreach (GTK_CONTAINER (widget), (GtkCallback) gtk_widget_hide_all, NULL);
}