[gegl-gtk] Examples: Add simple example for transformations

[Jon Nordby <jonnor src gnome org>]

commit 8935c6be2191f50e519f770bfb9fd304cb997c23
Author: Jon Nordby <jononor gmail com>
Date:   Thu Jun 23 23:17:57 2011 +0200

    Examples: Add simple example for transformations

 examples/c/.gitignore           |    1 +
 examples/c/gegl-gtk-transform.c |  100 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+), 0 deletions(-)
---
diff --git a/examples/c/.gitignore b/examples/c/.gitignore
index 54e0920..81c2fa4 100644
--- a/examples/c/.gitignore
+++ b/examples/c/.gitignore
@@ -1 +1,2 @@
 gegl-gtk-scroll
+gegl-gtk-transform
diff --git a/examples/c/gegl-gtk-transform.c b/examples/c/gegl-gtk-transform.c
new file mode 100644
index 0000000..a1f380c
--- /dev/null
+++ b/examples/c/gegl-gtk-transform.c
@@ -0,0 +1,100 @@
+/* This file is part of GEGL-GTK
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2011 Jon Nordby <jononor gmail com>
+ */
+
+#include <string.h>
+#include <glib.h>
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gegl-gtk.h>
+
+static gboolean motion_event (GtkWidget      *widget,
+                              GdkEventMotion *event,
+			      GeglGtkView    *view)
+{
+
+  static gboolean has_last_pos = FALSE;
+  static gfloat last_x, last_y;
+
+  if (event->state & GDK_BUTTON1_MASK) {
+    if (has_last_pos) { 
+      
+      g_object_set (view, "x", -last_x, "y", -last_y, NULL);
+    }
+
+    last_x = event->x;
+    last_y = event->y;
+    has_last_pos = TRUE;
+  }
+
+
+  return FALSE;
+}
+
+gint
+main (gint    argc,
+      gchar **argv)
+{
+  GtkWidget *window = NULL;
+  GtkWidget *view = NULL;
+  GtkWidget *eventbox = NULL;
+  GeglNode *graph = NULL;
+  GeglNode *node = NULL;
+
+  g_thread_init (NULL);
+  gtk_init (&argc, &argv);
+  gegl_init (&argc, &argv);
+
+  if (argc != 2) {
+    g_print ("Usage: %s <FILENAME>\n", argv[0]);
+    exit(1);
+  }
+
+  /* Build graph that loads an image */
+  graph = gegl_node_new ();
+  node = gegl_node_new_child (graph,
+    "operation", "gegl:load", 
+    "path", argv[1], NULL);
+
+  gegl_node_process (node);
+
+  /* Setup */
+  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+  gtk_window_set_title (GTK_WINDOW (window), "GEGL-GTK transformation example");
+
+  eventbox = gtk_event_box_new ();
+  view = g_object_new (GEGL_GTK_TYPE_VIEW, "node", node, NULL);
+
+  g_signal_connect (G_OBJECT (eventbox), "motion-notify-event",
+                    (GCallback) motion_event, (gpointer)view);
+
+  gtk_container_add (GTK_CONTAINER (eventbox), view);
+  gtk_container_add (GTK_CONTAINER (window), eventbox);
+
+  g_signal_connect (G_OBJECT (window), "delete-event",
+                    G_CALLBACK (gtk_main_quit), window);
+  gtk_widget_show_all (window);
+
+  /* Run */
+  gtk_main ();
+
+  /* Cleanup */
+  g_object_unref (graph);
+  gtk_widget_destroy (window);
+  gegl_exit ();
+  return 0;
+}