grub-core/gfxmenu/gui_list.c - chromiumos/third_party/grub2 - Git at Google

 /* gui_list.c - GUI component to display a selectable list of items.  */
 /*
  *  GRUB  --  GRand Unified Bootloader
  *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  GRUB 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 General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <grub/mm.h>
 #include <grub/misc.h>
 #include <grub/gui.h>
 #include <grub/gui_string_util.h>
 #include <grub/gfxmenu_view.h>
 #include <grub/gfxwidgets.h>

 struct grub_gui_list_impl
 {
   struct grub_gui_list list;

   grub_gui_container_t parent;
   grub_video_rect_t bounds;
   char *id;
   int visible;

   int icon_width;
   int icon_height;
   int item_height;
   int item_padding;
   int item_icon_space;
   int item_spacing;
   grub_font_t item_font;
   grub_font_t selected_item_font;
   grub_video_rgba_color_t item_color;
   int selected_item_color_set;
   grub_video_rgba_color_t selected_item_color;

   int draw_scrollbar;
   int need_to_recreate_scrollbar;
   char *scrollbar_frame_pattern;
   char *scrollbar_thumb_pattern;
   grub_gfxmenu_box_t scrollbar_frame;
   grub_gfxmenu_box_t scrollbar_thumb;
   int scrollbar_width;

   int first_shown_index;

   int need_to_recreate_boxes;
   char *theme_dir;
   char *menu_box_pattern;
   char *selected_item_box_pattern;
   grub_gfxmenu_box_t menu_box;
   grub_gfxmenu_box_t selected_item_box;

   grub_gfxmenu_icon_manager_t icon_manager;

   grub_gfxmenu_view_t view;
 };

 typedef struct grub_gui_list_impl *list_impl_t;

 static void
 list_destroy (void *vself)
 {
   list_impl_t self = vself;

   grub_free (self->theme_dir);
   grub_free (self->menu_box_pattern);
   grub_free (self->selected_item_box_pattern);
   if (self->menu_box)
     self->menu_box->destroy (self->menu_box);
   if (self->selected_item_box)
     self->selected_item_box->destroy (self->selected_item_box);
   if (self->icon_manager)
     grub_gfxmenu_icon_manager_destroy (self->icon_manager);

   grub_free (self);
 }

 static int
 get_num_shown_items (list_impl_t self)
 {
   int boxpad = self->item_padding;
   int item_vspace = self->item_spacing;
   int item_height = self->item_height;

   grub_gfxmenu_box_t box = self->menu_box;
   int box_top_pad = box->get_top_pad (box);
   int box_bottom_pad = box->get_bottom_pad (box);

   return (self->bounds.height + item_vspace - 2 * boxpad
 	  - box_top_pad - box_bottom_pad) / (item_height + item_vspace);
 }

 static int
 check_boxes (list_impl_t self)
 {
   if (self->need_to_recreate_boxes)
     {
       grub_gui_recreate_box (&self->menu_box,
                              self->menu_box_pattern,
                              self->theme_dir);

       grub_gui_recreate_box (&self->selected_item_box,
                              self->selected_item_box_pattern,
                              self->theme_dir);

       self->need_to_recreate_boxes = 0;
     }

   return (self->menu_box != 0 && self->selected_item_box != 0);
 }

 static int
 check_scrollbar (list_impl_t self)
 {
   if (self->need_to_recreate_scrollbar)
     {
       grub_gui_recreate_box (&self->scrollbar_frame,
                              self->scrollbar_frame_pattern,
                              self->theme_dir);

       grub_gui_recreate_box (&self->scrollbar_thumb,
                              self->scrollbar_thumb_pattern,
                              self->theme_dir);

       self->need_to_recreate_scrollbar = 0;
     }

   return (self->scrollbar_frame != 0 && self->scrollbar_thumb != 0);
 }

 static const char *
 list_get_id (void *vself)
 {
   list_impl_t self = vself;
   return self->id;
 }

 static int
 list_is_instance (void *vself __attribute__((unused)), const char *type)
 {
   return (grub_strcmp (type, "component") == 0
           || grub_strcmp (type, "list") == 0);
 }

 static struct grub_video_bitmap *
 get_item_icon (list_impl_t self, int item_index)
 {
   grub_menu_entry_t entry;
   entry = grub_menu_get_entry (self->view->menu, item_index);
   if (! entry)
     return 0;

   return grub_gfxmenu_icon_manager_get_icon (self->icon_manager, entry);
 }

 static void
 make_selected_item_visible (list_impl_t self)
 {
   int selected_index = self->view->selected;
   if (selected_index < 0)
     return;   /* No item is selected.  */
   int num_shown_items = get_num_shown_items (self);
   int last_shown_index = self->first_shown_index + (num_shown_items - 1);
   if (selected_index < self->first_shown_index)
     self->first_shown_index = selected_index;
   else if (selected_index > last_shown_index)
     self->first_shown_index = selected_index - (num_shown_items - 1);
 }

 /* Draw a scrollbar on the menu.  */
 static void
 draw_scrollbar (list_impl_t self,
                 int value, int extent, int min, int max,
                 int rightx, int topy, int height)
 {
   grub_gfxmenu_box_t frame = self->scrollbar_frame;
   grub_gfxmenu_box_t thumb = self->scrollbar_thumb;
   int frame_vertical_pad = (frame->get_top_pad (frame)
                             + frame->get_bottom_pad (frame));
   int frame_horizontal_pad = (frame->get_left_pad (frame)
                               + frame->get_right_pad (frame));
   int tracktop = topy + frame->get_top_pad (frame);
   int tracklen = height - frame_vertical_pad;
   frame->set_content_size (frame, self->scrollbar_width, tracklen);
   int thumby = tracktop + tracklen * (value - min) / (max - min);
   int thumbheight = tracklen * extent / (max - min) + 1;
   thumb->set_content_size (thumb,
                            self->scrollbar_width - frame_horizontal_pad,
                            thumbheight - (thumb->get_top_pad (thumb)
                                           + thumb->get_bottom_pad (thumb)));
   frame->draw (frame,
                rightx - (self->scrollbar_width + frame_horizontal_pad),
                topy);
   thumb->draw (thumb,
                rightx - (self->scrollbar_width - frame->get_right_pad (frame)),
                thumby);
 }

 /* Draw the list of items.  */
 static void
 draw_menu (list_impl_t self, int num_shown_items)
 {
   if (! self->menu_box || ! self->selected_item_box)
     return;

   int boxpad = self->item_padding;
   int icon_text_space = self->item_icon_space;
   int item_vspace = self->item_spacing;

   int ascent = grub_font_get_ascent (self->item_font);
   int descent = grub_font_get_descent (self->item_font);
   int item_height = self->item_height;

   make_selected_item_visible (self);

   grub_gfxmenu_box_t selbox = self->selected_item_box;
   int sel_leftpad = selbox->get_left_pad (selbox);
   int sel_toppad = selbox->get_top_pad (selbox);
   int item_top = sel_toppad;
   int menu_index;
   int visible_index;
   struct grub_video_rect oviewport;

   grub_video_get_viewport (&oviewport.x, &oviewport.y,
 			   &oviewport.width, &oviewport.height);
   grub_video_set_viewport (oviewport.x + boxpad,
 			   oviewport.y + boxpad,
 			   oviewport.width - 2 * boxpad,
 			   oviewport.height - 2 * boxpad);

   for (visible_index = 0, menu_index = self->first_shown_index;
        visible_index < num_shown_items && menu_index < self->view->menu->size;
        visible_index++, menu_index++)
     {
       int is_selected = (menu_index == self->view->selected);
       struct grub_video_bitmap *icon;

       if (is_selected)
         {
 	  int cwidth = oviewport.width - 2 * boxpad - 2;
 	  if (selbox->get_border_width)
 	    cwidth -= selbox->get_border_width (selbox);
 	  selbox->set_content_size (selbox, cwidth, item_height - 1);
           selbox->draw (selbox, 0,
                         item_top - sel_toppad);
         }

       icon = get_item_icon (self, menu_index);
       if (icon != 0)
         grub_video_blit_bitmap (icon, GRUB_VIDEO_BLIT_BLEND,
                                 sel_leftpad,
                                 item_top + (item_height - self->icon_height) / 2,
                                 0, 0, self->icon_width, self->icon_height);

       const char *item_title =
         grub_menu_get_entry (self->view->menu, menu_index)->title;
       grub_font_t font =
         (is_selected && self->selected_item_font
          ? self->selected_item_font
          : self->item_font);
       grub_video_rgba_color_t text_color =
         ((is_selected && self->selected_item_color_set)
          ? self->selected_item_color
          : self->item_color);
       grub_font_draw_string (item_title,
                              font,
                              grub_video_map_rgba_color (text_color),
                              sel_leftpad + self->icon_width + icon_text_space,
                              (item_top + (item_height - (ascent + descent))
                               / 2 + ascent));

       item_top += item_height + item_vspace;
     }
   grub_video_set_viewport (oviewport.x,
 			   oviewport.y,
 			   oviewport.width,
 			   oviewport.height);
 }

 static void
 list_paint (void *vself, const grub_video_rect_t *region)
 {
   list_impl_t self = vself;
   grub_video_rect_t vpsave;

   if (! self->visible)
     return;
   if (!grub_video_have_common_points (region, &self->bounds))
     return;

   check_boxes (self);

   if (! self->menu_box || ! self->selected_item_box)
     return;

   grub_gui_set_viewport (&self->bounds, &vpsave);
   {
     grub_gfxmenu_box_t box = self->menu_box;
     int box_left_pad = box->get_left_pad (box);
     int box_top_pad = box->get_top_pad (box);
     int box_right_pad = box->get_right_pad (box);
     int box_bottom_pad = box->get_bottom_pad (box);
     grub_video_rect_t vpsave2, content_rect;
     int num_shown_items = get_num_shown_items (self);
     int drawing_scrollbar = (self->draw_scrollbar
 			     && (num_shown_items < self->view->menu->size)
 			     && check_scrollbar (self));

     content_rect.x = box_left_pad;
     content_rect.y = box_top_pad;
     content_rect.width = self->bounds.width - box_left_pad - box_right_pad;
     content_rect.height = self->bounds.height - box_top_pad - box_bottom_pad;

     box->set_content_size (box, content_rect.width, content_rect.height);

     box->draw (box, 0, 0);

     grub_gui_set_viewport (&content_rect, &vpsave2);
     draw_menu (self, num_shown_items);
     grub_gui_restore_viewport (&vpsave2);

     if (drawing_scrollbar)
       draw_scrollbar (self,
 		      self->first_shown_index, num_shown_items,
 		      0, self->view->menu->size,
 		      self->bounds.width - box_right_pad
 		      + self->scrollbar_width,
 		      box_top_pad,
 		      self->bounds.height - box_top_pad - box_bottom_pad);
   }

   grub_gui_restore_viewport (&vpsave);
 }

 static void
 list_set_parent (void *vself, grub_gui_container_t parent)
 {
   list_impl_t self = vself;
   self->parent = parent;
 }

 static grub_gui_container_t
 list_get_parent (void *vself)
 {
   list_impl_t self = vself;
   return self->parent;
 }

 static void
 list_set_bounds (void *vself, const grub_video_rect_t *bounds)
 {
   list_impl_t self = vself;
   self->bounds = *bounds;
 }

 static void
 list_get_bounds (void *vself, grub_video_rect_t *bounds)
 {
   list_impl_t self = vself;
   *bounds = self->bounds;
 }

 static void
 list_get_minimal_size (void *vself, unsigned *width, unsigned *height)
 {
   list_impl_t self = vself;

   if (check_boxes (self))
     {
       int boxpad = self->item_padding;
       int item_vspace = self->item_spacing;
       int item_height = self->item_height;
       int num_items = 3;

       grub_gfxmenu_box_t box = self->menu_box;
       int box_left_pad = box->get_left_pad (box);
       int box_top_pad = box->get_top_pad (box);
       int box_right_pad = box->get_right_pad (box);
       int box_bottom_pad = box->get_bottom_pad (box);
       unsigned width_s;

       grub_gfxmenu_box_t selbox = self->selected_item_box;
       int sel_toppad = selbox->get_top_pad (selbox);

       *width = grub_font_get_string_width (self->item_font, "Typical OS");
       width_s = grub_font_get_string_width (self->selected_item_font,
 					    "Typical OS");
       if (*width < width_s)
 	*width = width_s;

       *width += 2 * boxpad + box_left_pad + box_right_pad;

       /* Set the menu box height to fit the items.  */
       *height = (item_height * num_items
                  + item_vspace * (num_items - 1)
                  + 2 * boxpad
                  + box_top_pad + box_bottom_pad + sel_toppad);
     }
   else
     {
       *width = 0;
       *height = 0;
     }
 }

 static grub_err_t
 list_set_property (void *vself, const char *name, const char *value)
 {
   list_impl_t self = vself;
   if (grub_strcmp (name, "item_font") == 0)
     {
       self->item_font = grub_font_get (value);
     }
   else if (grub_strcmp (name, "selected_item_font") == 0)
     {
       if (! value || grub_strcmp (value, "inherit") == 0)
         self->selected_item_font = 0;
       else
         self->selected_item_font = grub_font_get (value);
     }
   else if (grub_strcmp (name, "item_color") == 0)
     {
       grub_video_parse_color (value, &self->item_color);
     }
   else if (grub_strcmp (name, "selected_item_color") == 0)
     {
       if (! value || grub_strcmp (value, "inherit") == 0)
         {
           self->selected_item_color_set = 0;
         }
       else
         {
           if (grub_video_parse_color (value, &self->selected_item_color)
               == GRUB_ERR_NONE)
             self->selected_item_color_set = 1;
         }
     }
   else if (grub_strcmp (name, "icon_width") == 0)
     {
       self->icon_width = grub_strtol (value, 0, 10);
       grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
                                                self->icon_width,
                                                self->icon_height);
     }
   else if (grub_strcmp (name, "icon_height") == 0)
     {
       self->icon_height = grub_strtol (value, 0, 10);
       grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
                                                self->icon_width,
                                                self->icon_height);
     }
   else if (grub_strcmp (name, "item_height") == 0)
     {
       self->item_height = grub_strtol (value, 0, 10);
     }
   else if (grub_strcmp (name, "item_padding") == 0)
     {
       self->item_padding = grub_strtol (value, 0, 10);
     }
   else if (grub_strcmp (name, "item_icon_space") == 0)
     {
       self->item_icon_space = grub_strtol (value, 0, 10);
     }
   else if (grub_strcmp (name, "item_spacing") == 0)
     {
       self->item_spacing = grub_strtol (value, 0, 10);
     }
   else if (grub_strcmp (name, "visible") == 0)
     {
       self->visible = grub_strcmp (value, "false") != 0;
     }
   else if (grub_strcmp (name, "menu_pixmap_style") == 0)
     {
       self->need_to_recreate_boxes = 1;
       grub_free (self->menu_box_pattern);
       self->menu_box_pattern = value ? grub_strdup (value) : 0;
     }
   else if (grub_strcmp (name, "selected_item_pixmap_style") == 0)
     {
       self->need_to_recreate_boxes = 1;
       grub_free (self->selected_item_box_pattern);
       self->selected_item_box_pattern = value ? grub_strdup (value) : 0;
     }
   else if (grub_strcmp (name, "scrollbar_frame") == 0)
     {
       self->need_to_recreate_scrollbar = 1;
       grub_free (self->scrollbar_frame_pattern);
       self->scrollbar_frame_pattern = value ? grub_strdup (value) : 0;
     }
   else if (grub_strcmp (name, "scrollbar_thumb") == 0)
     {
       self->need_to_recreate_scrollbar = 1;
       grub_free (self->scrollbar_thumb_pattern);
       self->scrollbar_thumb_pattern = value ? grub_strdup (value) : 0;
     }
   else if (grub_strcmp (name, "scrollbar_width") == 0)
     {
       self->scrollbar_width = grub_strtol (value, 0, 10);
     }
   else if (grub_strcmp (name, "scrollbar") == 0)
     {
       self->draw_scrollbar = grub_strcmp (value, "false") != 0;
     }
   else if (grub_strcmp (name, "theme_dir") == 0)
     {
       self->need_to_recreate_boxes = 1;
       grub_free (self->theme_dir);
       self->theme_dir = value ? grub_strdup (value) : 0;
     }
   else if (grub_strcmp (name, "id") == 0)
     {
       grub_free (self->id);
       if (value)
         self->id = grub_strdup (value);
       else
         self->id = 0;
     }
   return grub_errno;
 }

 /* Set necessary information that the gfxmenu view provides.  */
 static void
 list_set_view_info (void *vself,
                     grub_gfxmenu_view_t view)
 {
   list_impl_t self = vself;
   grub_gfxmenu_icon_manager_set_theme_path (self->icon_manager,
 					    view->theme_path);
   self->view = view;
 }

 static struct grub_gui_component_ops list_comp_ops =
   {
     .destroy = list_destroy,
     .get_id = list_get_id,
     .is_instance = list_is_instance,
     .paint = list_paint,
     .set_parent = list_set_parent,
     .get_parent = list_get_parent,
     .set_bounds = list_set_bounds,
     .get_bounds = list_get_bounds,
     .get_minimal_size = list_get_minimal_size,
     .set_property = list_set_property
   };

 static struct grub_gui_list_ops list_ops =
 {
   .set_view_info = list_set_view_info
 };

 grub_gui_component_t
 grub_gui_list_new (void)
 {
   list_impl_t self;
   grub_font_t default_font;
   grub_video_rgba_color_t default_fg_color;

   self = grub_zalloc (sizeof (*self));
   if (! self)
     return 0;

   self->list.ops = &list_ops;
   self->list.component.ops = &list_comp_ops;

   self->visible = 1;

   default_font = grub_font_get ("Unknown Regular 16");
   default_fg_color = grub_video_rgba_color_rgb (0, 0, 0);

   self->icon_width = 32;
   self->icon_height = 32;
   self->item_height = 42;
   self->item_padding = 14;
   self->item_icon_space = 4;
   self->item_spacing = 16;
   self->item_font = default_font;
   self->selected_item_font = 0;    /* Default to using the item_font.  */
   self->item_color = default_fg_color;
   self->selected_item_color_set = 0;  /* Default to using the item_color.  */
   self->selected_item_color = default_fg_color;

   self->draw_scrollbar = 1;
   self->need_to_recreate_scrollbar = 1;
   self->scrollbar_frame = 0;
   self->scrollbar_thumb = 0;
   self->scrollbar_frame_pattern = 0;
   self->scrollbar_thumb_pattern = 0;
   self->scrollbar_width = 16;

   self->first_shown_index = 0;

   self->need_to_recreate_boxes = 0;
   self->theme_dir = 0;
   self->menu_box_pattern = 0;
   self->selected_item_box_pattern = 0;
   self->menu_box = grub_gfxmenu_create_box (0, 0);
   self->selected_item_box = grub_gfxmenu_create_box (0, 0);

   self->icon_manager = grub_gfxmenu_icon_manager_new ();
   if (! self->icon_manager)
     {
       self->list.component.ops->destroy (self);
       return 0;
     }
   grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
                                            self->icon_width,
                                            self->icon_height);
   return (grub_gui_component_t) self;
 }
	/* gui_list.c - GUI component to display a selectable list of items. */
	/*
	* GRUB -- GRand Unified Bootloader
	* Copyright (C) 2008,2009 Free Software Foundation, Inc.
	*
	* GRUB is free software: you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation, either version 3 of the License, or
	* (at your option) any later version.
	*
	* GRUB 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 General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <grub/mm.h>
	#include <grub/misc.h>
	#include <grub/gui.h>
	#include <grub/gui_string_util.h>
	#include <grub/gfxmenu_view.h>
	#include <grub/gfxwidgets.h>

	struct grub_gui_list_impl
	{
	struct grub_gui_list list;

	grub_gui_container_t parent;
	grub_video_rect_t bounds;
	char *id;
	int visible;

	int icon_width;
	int icon_height;
	int item_height;
	int item_padding;
	int item_icon_space;
	int item_spacing;
	grub_font_t item_font;
	grub_font_t selected_item_font;
	grub_video_rgba_color_t item_color;
	int selected_item_color_set;
	grub_video_rgba_color_t selected_item_color;

	int draw_scrollbar;
	int need_to_recreate_scrollbar;
	char *scrollbar_frame_pattern;
	char *scrollbar_thumb_pattern;
	grub_gfxmenu_box_t scrollbar_frame;
	grub_gfxmenu_box_t scrollbar_thumb;
	int scrollbar_width;

	int first_shown_index;

	int need_to_recreate_boxes;
	char *theme_dir;
	char *menu_box_pattern;
	char *selected_item_box_pattern;
	grub_gfxmenu_box_t menu_box;
	grub_gfxmenu_box_t selected_item_box;

	grub_gfxmenu_icon_manager_t icon_manager;

	grub_gfxmenu_view_t view;
	};

	typedef struct grub_gui_list_impl *list_impl_t;

	static void
	list_destroy (void *vself)
	{
	list_impl_t self = vself;

	grub_free (self->theme_dir);
	grub_free (self->menu_box_pattern);
	grub_free (self->selected_item_box_pattern);
	if (self->menu_box)
	self->menu_box->destroy (self->menu_box);
	if (self->selected_item_box)
	self->selected_item_box->destroy (self->selected_item_box);
	if (self->icon_manager)
	grub_gfxmenu_icon_manager_destroy (self->icon_manager);

	grub_free (self);
	}

	static int
	get_num_shown_items (list_impl_t self)
	{
	int boxpad = self->item_padding;
	int item_vspace = self->item_spacing;
	int item_height = self->item_height;

	grub_gfxmenu_box_t box = self->menu_box;
	int box_top_pad = box->get_top_pad (box);
	int box_bottom_pad = box->get_bottom_pad (box);

	return (self->bounds.height + item_vspace - 2 * boxpad
	- box_top_pad - box_bottom_pad) / (item_height + item_vspace);
	}

	static int
	check_boxes (list_impl_t self)
	{
	if (self->need_to_recreate_boxes)
	{
	grub_gui_recreate_box (&self->menu_box,
	self->menu_box_pattern,
	self->theme_dir);

	grub_gui_recreate_box (&self->selected_item_box,
	self->selected_item_box_pattern,
	self->theme_dir);

	self->need_to_recreate_boxes = 0;
	}

	return (self->menu_box != 0 && self->selected_item_box != 0);
	}

	static int
	check_scrollbar (list_impl_t self)
	{
	if (self->need_to_recreate_scrollbar)
	{
	grub_gui_recreate_box (&self->scrollbar_frame,
	self->scrollbar_frame_pattern,
	self->theme_dir);

	grub_gui_recreate_box (&self->scrollbar_thumb,
	self->scrollbar_thumb_pattern,
	self->theme_dir);

	self->need_to_recreate_scrollbar = 0;
	}

	return (self->scrollbar_frame != 0 && self->scrollbar_thumb != 0);
	}

	static const char *
	list_get_id (void *vself)
	{
	list_impl_t self = vself;
	return self->id;
	}

	static int
	list_is_instance (void vself __attribute__((unused)), const char type)
	{
	return (grub_strcmp (type, "component") == 0
	\|\| grub_strcmp (type, "list") == 0);
	}

	static struct grub_video_bitmap *
	get_item_icon (list_impl_t self, int item_index)
	{
	grub_menu_entry_t entry;
	entry = grub_menu_get_entry (self->view->menu, item_index);
	if (! entry)
	return 0;

	return grub_gfxmenu_icon_manager_get_icon (self->icon_manager, entry);
	}

	static void
	make_selected_item_visible (list_impl_t self)
	{
	int selected_index = self->view->selected;
	if (selected_index < 0)
	return; /* No item is selected. */
	int num_shown_items = get_num_shown_items (self);
	int last_shown_index = self->first_shown_index + (num_shown_items - 1);
	if (selected_index < self->first_shown_index)
	self->first_shown_index = selected_index;
	else if (selected_index > last_shown_index)
	self->first_shown_index = selected_index - (num_shown_items - 1);
	}

	/* Draw a scrollbar on the menu. */
	static void
	draw_scrollbar (list_impl_t self,
	int value, int extent, int min, int max,
	int rightx, int topy, int height)
	{
	grub_gfxmenu_box_t frame = self->scrollbar_frame;
	grub_gfxmenu_box_t thumb = self->scrollbar_thumb;
	int frame_vertical_pad = (frame->get_top_pad (frame)
	+ frame->get_bottom_pad (frame));
	int frame_horizontal_pad = (frame->get_left_pad (frame)
	+ frame->get_right_pad (frame));
	int tracktop = topy + frame->get_top_pad (frame);
	int tracklen = height - frame_vertical_pad;
	frame->set_content_size (frame, self->scrollbar_width, tracklen);
	int thumby = tracktop + tracklen * (value - min) / (max - min);
	int thumbheight = tracklen * extent / (max - min) + 1;
	thumb->set_content_size (thumb,
	self->scrollbar_width - frame_horizontal_pad,
	thumbheight - (thumb->get_top_pad (thumb)
	+ thumb->get_bottom_pad (thumb)));
	frame->draw (frame,
	rightx - (self->scrollbar_width + frame_horizontal_pad),
	topy);
	thumb->draw (thumb,
	rightx - (self->scrollbar_width - frame->get_right_pad (frame)),
	thumby);
	}

	/* Draw the list of items. */
	static void
	draw_menu (list_impl_t self, int num_shown_items)
	{
	if (! self->menu_box \|\| ! self->selected_item_box)
	return;

	int boxpad = self->item_padding;
	int icon_text_space = self->item_icon_space;
	int item_vspace = self->item_spacing;

	int ascent = grub_font_get_ascent (self->item_font);
	int descent = grub_font_get_descent (self->item_font);
	int item_height = self->item_height;

	make_selected_item_visible (self);

	grub_gfxmenu_box_t selbox = self->selected_item_box;
	int sel_leftpad = selbox->get_left_pad (selbox);
	int sel_toppad = selbox->get_top_pad (selbox);
	int item_top = sel_toppad;
	int menu_index;
	int visible_index;
	struct grub_video_rect oviewport;

	grub_video_get_viewport (&oviewport.x, &oviewport.y,
	&oviewport.width, &oviewport.height);
	grub_video_set_viewport (oviewport.x + boxpad,
	oviewport.y + boxpad,
	oviewport.width - 2 * boxpad,
	oviewport.height - 2 * boxpad);

	for (visible_index = 0, menu_index = self->first_shown_index;
	visible_index < num_shown_items && menu_index < self->view->menu->size;
	visible_index++, menu_index++)
	{
	int is_selected = (menu_index == self->view->selected);
	struct grub_video_bitmap *icon;

	if (is_selected)
	{
	int cwidth = oviewport.width - 2 * boxpad - 2;
	if (selbox->get_border_width)
	cwidth -= selbox->get_border_width (selbox);
	selbox->set_content_size (selbox, cwidth, item_height - 1);
	selbox->draw (selbox, 0,
	item_top - sel_toppad);
	}

	icon = get_item_icon (self, menu_index);
	if (icon != 0)
	grub_video_blit_bitmap (icon, GRUB_VIDEO_BLIT_BLEND,
	sel_leftpad,
	item_top + (item_height - self->icon_height) / 2,
	0, 0, self->icon_width, self->icon_height);

	const char *item_title =
	grub_menu_get_entry (self->view->menu, menu_index)->title;
	grub_font_t font =
	(is_selected && self->selected_item_font
	? self->selected_item_font
	: self->item_font);
	grub_video_rgba_color_t text_color =
	((is_selected && self->selected_item_color_set)
	? self->selected_item_color
	: self->item_color);
	grub_font_draw_string (item_title,
	font,
	grub_video_map_rgba_color (text_color),
	sel_leftpad + self->icon_width + icon_text_space,
	(item_top + (item_height - (ascent + descent))
	/ 2 + ascent));

	item_top += item_height + item_vspace;
	}
	grub_video_set_viewport (oviewport.x,
	oviewport.y,
	oviewport.width,
	oviewport.height);
	}

	static void
	list_paint (void vself, const grub_video_rect_t region)
	{
	list_impl_t self = vself;
	grub_video_rect_t vpsave;

	if (! self->visible)
	return;
	if (!grub_video_have_common_points (region, &self->bounds))
	return;

	check_boxes (self);

	if (! self->menu_box \|\| ! self->selected_item_box)
	return;

	grub_gui_set_viewport (&self->bounds, &vpsave);
	{
	grub_gfxmenu_box_t box = self->menu_box;
	int box_left_pad = box->get_left_pad (box);
	int box_top_pad = box->get_top_pad (box);
	int box_right_pad = box->get_right_pad (box);
	int box_bottom_pad = box->get_bottom_pad (box);
	grub_video_rect_t vpsave2, content_rect;
	int num_shown_items = get_num_shown_items (self);
	int drawing_scrollbar = (self->draw_scrollbar
	&& (num_shown_items < self->view->menu->size)
	&& check_scrollbar (self));

	content_rect.x = box_left_pad;
	content_rect.y = box_top_pad;
	content_rect.width = self->bounds.width - box_left_pad - box_right_pad;
	content_rect.height = self->bounds.height - box_top_pad - box_bottom_pad;

	box->set_content_size (box, content_rect.width, content_rect.height);

	box->draw (box, 0, 0);

	grub_gui_set_viewport (&content_rect, &vpsave2);
	draw_menu (self, num_shown_items);
	grub_gui_restore_viewport (&vpsave2);

	if (drawing_scrollbar)
	draw_scrollbar (self,
	self->first_shown_index, num_shown_items,
	0, self->view->menu->size,
	self->bounds.width - box_right_pad
	+ self->scrollbar_width,
	box_top_pad,
	self->bounds.height - box_top_pad - box_bottom_pad);
	}

	grub_gui_restore_viewport (&vpsave);
	}

	static void
	list_set_parent (void *vself, grub_gui_container_t parent)
	{
	list_impl_t self = vself;
	self->parent = parent;
	}

	static grub_gui_container_t
	list_get_parent (void *vself)
	{
	list_impl_t self = vself;
	return self->parent;
	}

	static void
	list_set_bounds (void vself, const grub_video_rect_t bounds)
	{
	list_impl_t self = vself;
	self->bounds = *bounds;
	}

	static void
	list_get_bounds (void vself, grub_video_rect_t bounds)
	{
	list_impl_t self = vself;
	*bounds = self->bounds;
	}

	static void
	list_get_minimal_size (void vself, unsigned width, unsigned *height)
	{
	list_impl_t self = vself;

	if (check_boxes (self))
	{
	int boxpad = self->item_padding;
	int item_vspace = self->item_spacing;
	int item_height = self->item_height;
	int num_items = 3;

	grub_gfxmenu_box_t box = self->menu_box;
	int box_left_pad = box->get_left_pad (box);
	int box_top_pad = box->get_top_pad (box);
	int box_right_pad = box->get_right_pad (box);
	int box_bottom_pad = box->get_bottom_pad (box);
	unsigned width_s;

	grub_gfxmenu_box_t selbox = self->selected_item_box;
	int sel_toppad = selbox->get_top_pad (selbox);

	*width = grub_font_get_string_width (self->item_font, "Typical OS");
	width_s = grub_font_get_string_width (self->selected_item_font,
	"Typical OS");
	if (*width < width_s)
	*width = width_s;

	width += 2 boxpad + box_left_pad + box_right_pad;

	/* Set the menu box height to fit the items. */
	height = (item_height num_items
	+ item_vspace * (num_items - 1)
	+ 2 * boxpad
	+ box_top_pad + box_bottom_pad + sel_toppad);
	}
	else
	{
	*width = 0;
	*height = 0;
	}
	}

	static grub_err_t
	list_set_property (void vself, const char name, const char *value)
	{
	list_impl_t self = vself;
	if (grub_strcmp (name, "item_font") == 0)
	{
	self->item_font = grub_font_get (value);
	}
	else if (grub_strcmp (name, "selected_item_font") == 0)
	{
	if (! value \|\| grub_strcmp (value, "inherit") == 0)
	self->selected_item_font = 0;
	else
	self->selected_item_font = grub_font_get (value);
	}
	else if (grub_strcmp (name, "item_color") == 0)
	{
	grub_video_parse_color (value, &self->item_color);
	}
	else if (grub_strcmp (name, "selected_item_color") == 0)
	{
	if (! value \|\| grub_strcmp (value, "inherit") == 0)
	{
	self->selected_item_color_set = 0;
	}
	else
	{
	if (grub_video_parse_color (value, &self->selected_item_color)
	== GRUB_ERR_NONE)
	self->selected_item_color_set = 1;
	}
	}
	else if (grub_strcmp (name, "icon_width") == 0)
	{
	self->icon_width = grub_strtol (value, 0, 10);
	grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
	self->icon_width,
	self->icon_height);
	}
	else if (grub_strcmp (name, "icon_height") == 0)
	{
	self->icon_height = grub_strtol (value, 0, 10);
	grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
	self->icon_width,
	self->icon_height);
	}
	else if (grub_strcmp (name, "item_height") == 0)
	{
	self->item_height = grub_strtol (value, 0, 10);
	}
	else if (grub_strcmp (name, "item_padding") == 0)
	{
	self->item_padding = grub_strtol (value, 0, 10);
	}
	else if (grub_strcmp (name, "item_icon_space") == 0)
	{
	self->item_icon_space = grub_strtol (value, 0, 10);
	}
	else if (grub_strcmp (name, "item_spacing") == 0)
	{
	self->item_spacing = grub_strtol (value, 0, 10);
	}
	else if (grub_strcmp (name, "visible") == 0)
	{
	self->visible = grub_strcmp (value, "false") != 0;
	}
	else if (grub_strcmp (name, "menu_pixmap_style") == 0)
	{
	self->need_to_recreate_boxes = 1;
	grub_free (self->menu_box_pattern);
	self->menu_box_pattern = value ? grub_strdup (value) : 0;
	}
	else if (grub_strcmp (name, "selected_item_pixmap_style") == 0)
	{
	self->need_to_recreate_boxes = 1;
	grub_free (self->selected_item_box_pattern);
	self->selected_item_box_pattern = value ? grub_strdup (value) : 0;
	}
	else if (grub_strcmp (name, "scrollbar_frame") == 0)
	{
	self->need_to_recreate_scrollbar = 1;
	grub_free (self->scrollbar_frame_pattern);
	self->scrollbar_frame_pattern = value ? grub_strdup (value) : 0;
	}
	else if (grub_strcmp (name, "scrollbar_thumb") == 0)
	{
	self->need_to_recreate_scrollbar = 1;
	grub_free (self->scrollbar_thumb_pattern);
	self->scrollbar_thumb_pattern = value ? grub_strdup (value) : 0;
	}
	else if (grub_strcmp (name, "scrollbar_width") == 0)
	{
	self->scrollbar_width = grub_strtol (value, 0, 10);
	}
	else if (grub_strcmp (name, "scrollbar") == 0)
	{
	self->draw_scrollbar = grub_strcmp (value, "false") != 0;
	}
	else if (grub_strcmp (name, "theme_dir") == 0)
	{
	self->need_to_recreate_boxes = 1;
	grub_free (self->theme_dir);
	self->theme_dir = value ? grub_strdup (value) : 0;
	}
	else if (grub_strcmp (name, "id") == 0)
	{
	grub_free (self->id);
	if (value)
	self->id = grub_strdup (value);
	else
	self->id = 0;
	}
	return grub_errno;
	}

	/* Set necessary information that the gfxmenu view provides. */
	static void
	list_set_view_info (void *vself,
	grub_gfxmenu_view_t view)
	{
	list_impl_t self = vself;
	grub_gfxmenu_icon_manager_set_theme_path (self->icon_manager,
	view->theme_path);
	self->view = view;
	}

	static struct grub_gui_component_ops list_comp_ops =
	{
	.destroy = list_destroy,
	.get_id = list_get_id,
	.is_instance = list_is_instance,
	.paint = list_paint,
	.set_parent = list_set_parent,
	.get_parent = list_get_parent,
	.set_bounds = list_set_bounds,
	.get_bounds = list_get_bounds,
	.get_minimal_size = list_get_minimal_size,
	.set_property = list_set_property
	};

	static struct grub_gui_list_ops list_ops =
	{
	.set_view_info = list_set_view_info
	};

	grub_gui_component_t
	grub_gui_list_new (void)
	{
	list_impl_t self;
	grub_font_t default_font;
	grub_video_rgba_color_t default_fg_color;

	self = grub_zalloc (sizeof (*self));
	if (! self)
	return 0;

	self->list.ops = &list_ops;
	self->list.component.ops = &list_comp_ops;

	self->visible = 1;

	default_font = grub_font_get ("Unknown Regular 16");
	default_fg_color = grub_video_rgba_color_rgb (0, 0, 0);

	self->icon_width = 32;
	self->icon_height = 32;
	self->item_height = 42;
	self->item_padding = 14;
	self->item_icon_space = 4;
	self->item_spacing = 16;
	self->item_font = default_font;
	self->selected_item_font = 0; /* Default to using the item_font. */
	self->item_color = default_fg_color;
	self->selected_item_color_set = 0; /* Default to using the item_color. */
	self->selected_item_color = default_fg_color;

	self->draw_scrollbar = 1;
	self->need_to_recreate_scrollbar = 1;
	self->scrollbar_frame = 0;
	self->scrollbar_thumb = 0;
	self->scrollbar_frame_pattern = 0;
	self->scrollbar_thumb_pattern = 0;
	self->scrollbar_width = 16;

	self->first_shown_index = 0;

	self->need_to_recreate_boxes = 0;
	self->theme_dir = 0;
	self->menu_box_pattern = 0;
	self->selected_item_box_pattern = 0;
	self->menu_box = grub_gfxmenu_create_box (0, 0);
	self->selected_item_box = grub_gfxmenu_create_box (0, 0);

	self->icon_manager = grub_gfxmenu_icon_manager_new ();
	if (! self->icon_manager)
	{
	self->list.component.ops->destroy (self);
	return 0;
	}
	grub_gfxmenu_icon_manager_set_icon_size (self->icon_manager,
	self->icon_width,
	self->icon_height);
	return (grub_gui_component_t) self;
	}