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 ROTATED_TEXT

creation make

feature
-- /* Rotated Text
--  *
--  * This demo shows how to use GDK and Pango to draw rotated and transformed
--  * text. The use of GdkPangoRenderer in this example is a somewhat advanced
--  * technique; most applications can simply use gdk_draw_layout(). We use
--  * it here mostly because that allows us to work in user coordinates - that is,
--  * coordinates prior to the application of the transformation matrix, rather
--  * than device coordinates.
--  *
--  * As of GTK+-2.6, the ability to draw transformed and anti-aliased graphics
--  * as shown in this example is only present for text. With GTK+-2.8, a new
--  * graphics system called "Cairo" will be introduced that provides these
--  * capabilities and many more for all types of graphics.
--  */
-- #include <math.h>
-- #include <gtk/gtk.h>

-- static GtkWidget *window = NULL;

-- static gboolean
-- rotated_text_expose_event (GtkWidget      *widget,
-- 			   GdkEventExpose *event,
-- 			   gpointer	   data)
-- {
-- #define RADIUS 150
-- #define N_WORDS 10
-- #define FONT "Sans Bold 27"
  
--   PangoRenderer *renderer;
--   PangoMatrix matrix = PANGO_MATRIX_INIT;
--   PangoContext *context;
--   PangoLayout *layout;
--   PangoFontDescription *desc;

--   int width = widget->allocation.width;
--   int height = widget->allocation.height;
--   double device_radius;
--   int i;

--   /* Get the default renderer for the screen, and set it up for drawing  */
--   renderer = gdk_pango_renderer_get_default (gtk_widget_get_screen (widget));
--   gdk_pango_renderer_set_drawable (GDK_PANGO_RENDERER (renderer), widget->window);
--   gdk_pango_renderer_set_gc (GDK_PANGO_RENDERER (renderer), widget->style->black_gc);

--   /* Set up a transformation matrix so that the user space coordinates for
--    * the centered square where we draw are [-RADIUS, RADIUS], [-RADIUS, RADIUS]
--    * We first center, then change the scale */
--   device_radius = MIN (width, height) / 2.;
--   pango_matrix_translate (&matrix,
-- 			  device_radius + (width - 2 * device_radius) / 2,
-- 			  device_radius + (height - 2 * device_radius) / 2);
--   pango_matrix_scale (&matrix, device_radius / RADIUS, device_radius / RADIUS);

--   /* Create a PangoLayout, set the font and text */
--   context = gtk_widget_create_pango_context (widget);
--   layout = pango_layout_new (context);
--   pango_layout_set_text (layout, "Text", -1);
--   desc = pango_font_description_from_string (FONT);
--   pango_layout_set_font_description (layout, desc);
--   pango_font_description_free (desc);

--   /* Draw the layout N_WORDS times in a circle */
--   for (i = 0; i < N_WORDS; i++)
--     {
--       GdkColor color;
--       PangoMatrix rotated_matrix = matrix;
--       int width, height;
--       double angle = (360. * i) / N_WORDS;

--       /* Gradient from red at angle == 60 to blue at angle == 300 */
--       color.red   = 65535 * (1 + cos ((angle - 60) * G_PI / 180.)) / 2;
--       color.green = 0;
--       color.blue  = 65535  - color.red;
	
--       gdk_pango_renderer_set_override_color (GDK_PANGO_RENDERER (renderer),
-- 					     PANGO_RENDER_PART_FOREGROUND, &color);
															
--       pango_matrix_rotate (&rotated_matrix, angle);

--       pango_context_set_matrix (context, &rotated_matrix);
	
--       /* Inform Pango to re-layout the text with the new transformation matrix */
--       pango_layout_context_changed (layout);
	
--       pango_layout_get_size (layout, &width, &height);
--       pango_renderer_draw_layout (renderer, layout,
-- 				  - width / 2, - RADIUS * PANGO_SCALE);
--     }

--   /* Clean up default renderer, since it is shared */
--   gdk_pango_renderer_set_override_color (GDK_PANGO_RENDERER (renderer),
-- 					 PANGO_RENDER_PART_FOREGROUND, NULL);
--   gdk_pango_renderer_set_drawable (GDK_PANGO_RENDERER (renderer), NULL);
--   gdk_pango_renderer_set_gc (GDK_PANGO_RENDERER (renderer), NULL);

--   /* free the objects we created */
--   g_object_unref (layout);
--   g_object_unref (context);
  
--   return FALSE;
-- }

-- GtkWidget *
-- do_rotated_text (GtkWidget *do_widget)
-- {
--   GtkWidget *drawing_area;
  
--   if (!window)
--     {
--       const GdkColor white = { 0, 0xffff, 0xffff, 0xffff };
		
--       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
--       gtk_window_set_screen (GTK_WINDOW (window),
-- 			     gtk_widget_get_screen (do_widget));
--       gtk_window_set_title (GTK_WINDOW (window), "Rotated Text");

--       g_signal_connect (window, "destroy", G_CALLBACK (gtk_widget_destroyed), &window);

--       drawing_area = gtk_drawing_area_new ();
--       gtk_container_add (GTK_CONTAINER (window), drawing_area);

--       /* This overrides the background color from the theme */
--       gtk_widget_modify_bg (drawing_area, GTK_STATE_NORMAL, &white);

--       g_signal_connect (drawing_area, "expose-event",
-- 			G_CALLBACK (rotated_text_expose_event), NULL);

--       gtk_window_set_default_size (GTK_WINDOW (window), 2 * RADIUS, 2 * RADIUS);
--     }

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

--   return window;
-- }
end