indexing
	description: "."
	copyright: "[
					Copyright (C) 2006 Paolo Redaelli, GTK+ team
					
					This library is free software; you can redistribute it and/or
					modify it under the terms of the GNU Lesser General Public License
					as published by the Free Software Foundation; either version 2.1 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
					Lesser General Public License for more details.

					You should have received a copy of the GNU Lesser General Public
					License along with this library; if not, write to the Free Software
					Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
					02110-1301 USA
			]"

class HYPERTEXT

creation make

feature
-- /* Text Widget/Hypertext
--  *
--  * Usually, tags modify the appearance of text in the view, e.g. making it 
--  * bold or colored or underlined. But tags are not restricted to appearance. 
--  * They can also affect the behavior of mouse and key presses, as this demo 
--  * shows.
--  */

-- #include <gtk/gtk.h>
-- #include <gdk/gdkkeysyms.h>

-- /* Inserts a piece of text into the buffer, giving it the usual
--  * appearance of a hyperlink in a web browser: blue and underlined.
--  * Additionally, attaches some data on the tag, to make it recognizable
--  * as a link. 
--  */
-- static void 
-- insert_link (GtkTextBuffer *buffer, 
-- 	     GtkTextIter   *iter, 
-- 	     gchar         *text, 
-- 	     gint           page)
-- {
--   GtkTextTag *tag;
  
--   tag = gtk_text_buffer_create_tag (buffer, NULL, 
-- 				    "foreground", "blue", 
-- 				    "underline", PANGO_UNDERLINE_SINGLE, 
-- 				    NULL);
--   g_object_set_data (G_OBJECT (tag), "page", GINT_TO_POINTER (page));
--   gtk_text_buffer_insert_with_tags (buffer, iter, text, -1, tag, NULL);
-- }

-- /* Fills the buffer with text and interspersed links. In any real
--  * hypertext app, this method would parse a file to identify the links.
--  */
-- static void
-- show_page (GtkTextBuffer *buffer, 
-- 	   gint           page)
-- {
--   GtkTextIter iter;

--   gtk_text_buffer_set_text (buffer, "", 0);
--   gtk_text_buffer_get_iter_at_offset (buffer, &iter, 0);
--   if (page == 1)
--     {
--       gtk_text_buffer_insert (buffer, &iter, "Some text to show that simple ", -1);
--       insert_link (buffer, &iter, "hypertext", 3);
--       gtk_text_buffer_insert (buffer, &iter, " can easily be realized with ", -1);
--       insert_link (buffer, &iter, "tags", 2);
--       gtk_text_buffer_insert (buffer, &iter, ".", -1);
--     }
--   else if (page == 2)
--     {
--       gtk_text_buffer_insert (buffer, &iter, 
-- 			      "A tag is an attribute that can be applied to some range of text. "
-- 			      "For example, a tag might be called \"bold\" and make the text inside "
-- 			      "the tag bold. However, the tag concept is more general than that; "
-- 			      "tags don't have to affect appearance. They can instead affect the "
-- 			      "behavior of mouse and key presses, \"lock\" a range of text so the "
-- 			      "user can't edit it, or countless other things.\n", -1);
--       insert_link (buffer, &iter, "Go back", 1);
--     }
--   else if (page == 3) 
--     {
--       GtkTextTag *tag;
  
--       tag = gtk_text_buffer_create_tag (buffer, NULL, 
-- 					"weight", PANGO_WEIGHT_BOLD, 
-- 					NULL);
--       gtk_text_buffer_insert_with_tags (buffer, &iter, "hypertext:\n", -1, tag, NULL);
--       gtk_text_buffer_insert (buffer, &iter, 
-- 			      "machine-readable text that is not sequential but is organized "
-- 			      "so that related items of information are connected.\n", -1);
--       insert_link (buffer, &iter, "Go back", 1);
--     }
-- }

-- /* Looks at all tags covering the position of iter in the text view, 
--  * and if one of them is a link, follow it by showing the page identified
--  * by the data attached to it.
--  */
-- static void
-- follow_if_link (GtkWidget   *text_view, 
-- 		GtkTextIter *iter)
-- {
--   GSList *tags = NULL, *tagp = NULL;

--   tags = gtk_text_iter_get_tags (iter);
--   for (tagp = tags;  tagp != NULL;  tagp = tagp->next)
--     {
--       GtkTextTag *tag = tagp->data;
--       gint page = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (tag), "page"));

--       if (page != 0)
--         {
-- 	  show_page (gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view)), page);
-- 	  break;
--         }
--     }

--   if (tags) 
--     g_slist_free (tags);
-- }

-- /* Links can be activated by pressing Enter.
--  */
-- static gboolean
-- key_press_event (GtkWidget *text_view,
-- 		 GdkEventKey *event)
-- {
--   GtkTextIter iter;
--   GtkTextBuffer *buffer;

--   switch (event->keyval)
--     {
--       case GDK_Return: 
--       case GDK_KP_Enter:
--         buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));
--         gtk_text_buffer_get_iter_at_mark (buffer, &iter, 
--                                           gtk_text_buffer_get_insert (buffer));
--         follow_if_link (text_view, &iter);
--         break;

--       default:
--         break;
--     }

--   return FALSE;
-- }

-- /* Links can also be activated by clicking.
--  */
-- static gboolean
-- event_after (GtkWidget *text_view,
-- 	     GdkEvent  *ev)
-- {
--   GtkTextIter start, end, iter;
--   GtkTextBuffer *buffer;
--   GdkEventButton *event;
--   gint x, y;

--   if (ev->type != GDK_BUTTON_RELEASE)
--     return FALSE;

--   event = (GdkEventButton *)ev;

--   if (event->button != 1)
--     return FALSE;

--   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));

--   /* we shouldn't follow a link if the user has selected something */
--   gtk_text_buffer_get_selection_bounds (buffer, &start, &end);
--   if (gtk_text_iter_get_offset (&start) != gtk_text_iter_get_offset (&end))
--     return FALSE;

--   gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
--                                          GTK_TEXT_WINDOW_WIDGET,
--                                          event->x, event->y, &x, &y);

--   gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (text_view), &iter, x, y);

--   follow_if_link (text_view, &iter);

--   return FALSE;
-- }

-- gboolean hovering_over_link = FALSE;
-- GdkCursor *hand_cursor = NULL;
-- GdkCursor *regular_cursor = NULL;

-- /* Looks at all tags covering the position (x, y) in the text view, 
--  * and if one of them is a link, change the cursor to the "hands" cursor
--  * typically used by web browsers.
--  */
-- static void
-- set_cursor_if_appropriate (GtkTextView    *text_view,
--                            gint            x,
--                            gint            y)
-- {
--   GSList *tags = NULL, *tagp = NULL;
--   GtkTextBuffer *buffer;
--   GtkTextIter iter;
--   gboolean hovering = FALSE;

--   buffer = gtk_text_view_get_buffer (text_view);

--   gtk_text_view_get_iter_at_location (text_view, &iter, x, y);
  
--   tags = gtk_text_iter_get_tags (&iter);
--   for (tagp = tags;  tagp != NULL;  tagp = tagp->next)
--     {
--       GtkTextTag *tag = tagp->data;
--       gint page = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (tag), "page"));

--       if (page != 0) 
--         {
--           hovering = TRUE;
--           break;
--         }
--     }

--   if (hovering != hovering_over_link)
--     {
--       hovering_over_link = hovering;

--       if (hovering_over_link)
--         gdk_window_set_cursor (gtk_text_view_get_window (text_view, GTK_TEXT_WINDOW_TEXT), hand_cursor);
--       else
--         gdk_window_set_cursor (gtk_text_view_get_window (text_view, GTK_TEXT_WINDOW_TEXT), regular_cursor);
--     }

--   if (tags) 
--     g_slist_free (tags);
-- }

-- /* Update the cursor image if the pointer moved. 
--  */
-- static gboolean
-- motion_notify_event (GtkWidget      *text_view,
-- 		     GdkEventMotion *event)
-- {
--   gint x, y;

--   gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
--                                          GTK_TEXT_WINDOW_WIDGET,
--                                          event->x, event->y, &x, &y);

--   set_cursor_if_appropriate (GTK_TEXT_VIEW (text_view), x, y);

--   gdk_window_get_pointer (text_view->window, NULL, NULL, NULL);
--   return FALSE;
-- }

-- /* Also update the cursor image if the window becomes visible
--  * (e.g. when a window covering it got iconified).
--  */
-- static gboolean
-- visibility_notify_event (GtkWidget          *text_view,
-- 			 GdkEventVisibility *event)
-- {
--   gint wx, wy, bx, by;
  
--   gdk_window_get_pointer (text_view->window, &wx, &wy, NULL);
  
--   gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (text_view), 
--                                          GTK_TEXT_WINDOW_WIDGET,
--                                          wx, wy, &bx, &by);

--   set_cursor_if_appropriate (GTK_TEXT_VIEW (text_view), bx, by);

--   return FALSE;
-- }

-- GtkWidget *
-- do_hypertext (GtkWidget *do_widget)
-- {
--   static GtkWidget *window = NULL;

--   if (!window)
--     {
--       GtkWidget *view;
--       GtkWidget *sw;
--       GtkTextBuffer *buffer;

--       hand_cursor = gdk_cursor_new (GDK_HAND2);
--       regular_cursor = gdk_cursor_new (GDK_XTERM);
		
--       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
--       gtk_window_set_screen (GTK_WINDOW (window),
-- 			     gtk_widget_get_screen (do_widget));
--       gtk_window_set_default_size (GTK_WINDOW (window),
-- 				   450, 450);
		
--       g_signal_connect (window, "destroy",
-- 			G_CALLBACK (gtk_widget_destroyed), &window);

--       gtk_window_set_title (GTK_WINDOW (window), "Hypertext");
--       gtk_container_set_border_width (GTK_CONTAINER (window), 0);

--       view = gtk_text_view_new ();
--       gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
--       g_signal_connect (view, "key-press-event", 
-- 			G_CALLBACK (key_press_event), NULL);
--       g_signal_connect (view, "event-after", 
-- 			G_CALLBACK (event_after), NULL);
--       g_signal_connect (view, "motion-notify-event", 
-- 			G_CALLBACK (motion_notify_event), NULL);
--       g_signal_connect (view, "visibility-notify-event", 
-- 			G_CALLBACK (visibility_notify_event), NULL);

--       buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
		
--       sw = gtk_scrolled_window_new (NULL, NULL);
--       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
-- 				      GTK_POLICY_AUTOMATIC,
-- 				      GTK_POLICY_AUTOMATIC);
--       gtk_container_add (GTK_CONTAINER (window), sw);
--       gtk_container_add (GTK_CONTAINER (sw), view);

--       show_page (buffer, 1);

--       gtk_widget_show_all (sw);
--     }

--   if (!GTK_WIDGET_VISIBLE (window))
--     {
--       gtk_widget_show (window);
--     }
--   else
--     {
--       gtk_widget_destroy (window);
--       window = NULL;
--     }

--   return window;
-- }

end