/src/wrappers/gtk/examples/gtk-demo/pixbufs.e

  1indexing
  2	description: "."
  3	copyright: "[
  4					Copyright (C) 2006 Paolo Redaelli, GTK+ team
  5					
  6					This library is free software; you can redistribute it and/or
  7					modify it under the terms of the GNU Lesser General Public License
  8					as published by the Free Software Foundation; either version 2.1 of
  9					the License, or (at your option) any later version.
 10					
 11					This library is distributed in the hope that it will be useful, but
 12					WITHOUT ANY WARRANTY; without even the implied warranty of
 13					MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14					Lesser General Public License for more details.
 15
 16					You should have received a copy of the GNU Lesser General Public
 17					License along with this library; if not, write to the Free Software
 18					Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 19					02110-1301 USA
 20			]"
 21
 22class PIXBUFS
 23
 24creation make
 25
 26feature
 27-- /* Pixbufs
 28--  *
 29--  * A GdkPixbuf represents an image, normally in RGB or RGBA format.
 30--  * Pixbufs are normally used to load files from disk and perform
 31--  * image scaling.
 32--  *
 33--  * This demo is not all that educational, but looks cool. It was written
 34--  * by Extreme Pixbuf Hacker Federico Mena Quintero. It also shows
 35--  * off how to use GtkDrawingArea to do a simple animation.
 36--  *
 37--  * Look at the Image demo for additional pixbuf usage examples.
 38--  *
 39--  */
 40
 41-- #include <stdlib.h>
 42-- #include <gtk/gtk.h>
 43-- #include <math.h>
 44
 45-- #include "demo-common.h"
 46
 47-- #define FRAME_DELAY 50
 48
 49-- #define BACKGROUND_NAME "background.jpg"
 50
 51-- static const char *image_names[] = {
 52--   "apple-red.png",
 53--   "gnome-applets.png",
 54--   "gnome-calendar.png",
 55--   "gnome-foot.png",
 56--   "gnome-gmush.png",
 57--   "gnome-gimp.png",
 58--   "gnome-gsame.png",
 59--   "gnu-keys.png"
 60-- };
 61
 62-- #define N_IMAGES G_N_ELEMENTS (image_names)
 63
 64-- /* demo window */
 65-- static GtkWidget *window = NULL;
 66
 67-- /* Current frame */
 68-- static GdkPixbuf *frame;
 69
 70-- /* Background image */
 71-- static GdkPixbuf *background;
 72-- static gint back_width, back_height;
 73
 74-- /* Images */
 75-- static GdkPixbuf *images[N_IMAGES];
 76
 77-- /* Widgets */
 78-- static GtkWidget *da;
 79
 80-- /* Loads the images for the demo and returns whether the operation succeeded */
 81-- static gboolean
 82-- load_pixbufs (GError **error)
 83-- {
 84--   gint i;
 85--   char *filename;
 86
 87--   if (background)
 88--     return TRUE; /* already loaded earlier */
 89
 90--   /* demo_find_file() looks in the the current directory first,
 91--    * so you can run gtk-demo without installing GTK, then looks
 92--    * in the location where the file is installed.
 93--    */
 94--   filename = demo_find_file (BACKGROUND_NAME, error);
 95--   if (!filename)
 96--     return FALSE; /* note that "error" was filled in and returned */
 97
 98--   background = gdk_pixbuf_new_from_file (filename, error);
 99--   g_free (filename);
100  
101--   if (!background)
102--     return FALSE; /* Note that "error" was filled with a GError */
103
104--   back_width = gdk_pixbuf_get_width (background);
105--   back_height = gdk_pixbuf_get_height (background);
106
107--   for (i = 0; i < N_IMAGES; i++)
108--     {
109--       filename = demo_find_file (image_names[i], error);
110--       if (!filename)
111-- 	return FALSE; /* Note that "error" was filled with a GError */
112		
113--       images[i] = gdk_pixbuf_new_from_file (filename, error);
114--       g_free (filename);
115		
116--       if (!images[i])
117-- 	return FALSE; /* Note that "error" was filled with a GError */
118--     }
119
120--   return TRUE;
121-- }
122
123-- /* Expose callback for the drawing area */
124-- static gint
125-- expose_cb (GtkWidget	  *widget,
126-- 	   GdkEventExpose *event,
127-- 	   gpointer	   data)
128-- {
129--   guchar *pixels;
130--   int rowstride;
131
132--   rowstride = gdk_pixbuf_get_rowstride (frame);
133
134--   pixels = gdk_pixbuf_get_pixels (frame) + rowstride * event->area.y + event->area.x * 3;
135
136--   gdk_draw_rgb_image_dithalign (widget->window,
137-- 				widget->style->black_gc,
138-- 				event->area.x, event->area.y,
139-- 				event->area.width, event->area.height,
140-- 				GDK_RGB_DITHER_NORMAL,
141-- 				pixels, rowstride,
142-- 				event->area.x, event->area.y);
143
144--   return TRUE;
145-- }
146
147-- #define CYCLE_LEN 60
148
149-- static int frame_num;
150
151-- /* Timeout handler to regenerate the frame */
152-- static gint
153-- timeout (gpointer data)
154-- {
155--   double f;
156--   int i;
157--   double xmid, ymid;
158--   double radius;
159
160--   gdk_pixbuf_copy_area (background, 0, 0, back_width, back_height,
161-- 			frame, 0, 0);
162
163--   f = (double) (frame_num % CYCLE_LEN) / CYCLE_LEN;
164
165--   xmid = back_width / 2.0;
166--   ymid = back_height / 2.0;
167
168--   radius = MIN (xmid, ymid) / 2.0;
169
170--   for (i = 0; i < N_IMAGES; i++)
171--     {
172--       double ang;
173--       int xpos, ypos;
174--       int iw, ih;
175--       double r;
176--       GdkRectangle r1, r2, dest;
177--       double k;
178
179--       ang = 2.0 * G_PI * (double) i / N_IMAGES - f * 2.0 * G_PI;
180
181--       iw = gdk_pixbuf_get_width (images[i]);
182--       ih = gdk_pixbuf_get_height (images[i]);
183
184--       r = radius + (radius / 3.0) * sin (f * 2.0 * G_PI);
185
186--       xpos = floor (xmid + r * cos (ang) - iw / 2.0 + 0.5);
187--       ypos = floor (ymid + r * sin (ang) - ih / 2.0 + 0.5);
188
189--       k = (i & 1) ? sin (f * 2.0 * G_PI) : cos (f * 2.0 * G_PI);
190--       k = 2.0 * k * k;
191--       k = MAX (0.25, k);
192
193--       r1.x = xpos;
194--       r1.y = ypos;
195--       r1.width = iw * k;
196--       r1.height = ih * k;
197
198--       r2.x = 0;
199--       r2.y = 0;
200--       r2.width = back_width;
201--       r2.height = back_height;
202
203--       if (gdk_rectangle_intersect (&r1, &r2, &dest))
204-- 	gdk_pixbuf_composite (images[i],
205-- 			      frame,
206-- 			      dest.x, dest.y,
207-- 			      dest.width, dest.height,
208-- 			      xpos, ypos,
209-- 			      k, k,
210-- 			      GDK_INTERP_NEAREST,
211-- 			      ((i & 1)
212-- 			       ? MAX (127, fabs (255 * sin (f * 2.0 * G_PI)))
213-- 			       : MAX (127, fabs (255 * cos (f * 2.0 * G_PI)))));
214--     }
215
216--   gtk_widget_queue_draw (da);
217
218--   frame_num++;
219--   return TRUE;
220-- }
221
222-- static guint timeout_id;
223
224-- static void
225-- cleanup_callback (GtkObject *object,
226-- 		  gpointer   data)
227-- {
228--   g_source_remove (timeout_id);
229--   timeout_id = 0;
230-- }
231
232-- GtkWidget *
233-- do_pixbufs (GtkWidget *do_widget)
234-- {
235--   if (!window)
236--     {
237--       GError *error;
238
239--       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
240--       gtk_window_set_screen (GTK_WINDOW (window),
241-- 			     gtk_widget_get_screen (do_widget));
242--       gtk_window_set_title (GTK_WINDOW (window), "Pixbufs");
243--       gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
244
245--       g_signal_connect (window, "destroy", G_CALLBACK (gtk_widget_destroyed), &window);
246--       g_signal_connect (window, "destroy", G_CALLBACK (cleanup_callback), NULL);
247
248
249--       error = NULL;
250--       if (!load_pixbufs (&error))
251-- 	{
252-- 	  GtkWidget *dialog;
253
254-- 	  dialog = gtk_message_dialog_new (GTK_WINDOW (window),
255-- 					   GTK_DIALOG_DESTROY_WITH_PARENT,
256-- 					   GTK_MESSAGE_ERROR,
257-- 					   GTK_BUTTONS_CLOSE,
258-- 					   "Failed to load an image: %s",
259-- 					   error->message);
260
261-- 	  g_error_free (error);
262
263-- 	  g_signal_connect (dialog, "response",
264-- 			    G_CALLBACK (gtk_widget_destroy), NULL);
265
266-- 	  gtk_widget_show (dialog);
267-- 	}
268--       else
269-- 	{
270-- 	  gtk_widget_set_size_request (window, back_width, back_height);
271
272-- 	  frame = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, back_width, back_height);
273
274-- 	  da = gtk_drawing_area_new ();
275
276-- 	  g_signal_connect (da, "expose_event",
277-- 			    G_CALLBACK (expose_cb), NULL);
278
279-- 	  gtk_container_add (GTK_CONTAINER (window), da);
280
281-- 	  timeout_id = g_timeout_add (FRAME_DELAY, timeout, NULL);
282-- 	}
283--     }
284
285--   if (!GTK_WIDGET_VISIBLE (window))
286--     {
287--       gtk_widget_show_all (window);
288--     }
289--   else
290--     {
291--       gtk_widget_destroy (window);
292--       window = NULL;
293--       g_object_unref (frame);
294--     }
295
296--   return window;
297-- }
298end