doc/tutorial/src/include/cairo-tutorial-gtk.h

   1 /* cairo-tutorial-gtk.h - a tutorial framework for cairo with gtk+
   2  *
   3  * Copyright © 2005, Carl Worth
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA.
  17  */
  18
  19 #include <gtk/gtk.h>
  20 #include <gdk/gdkkeysyms.h>
  21
  22 #include <cairo.h>
  23
  24 #ifndef WIDTH
  25 #define WIDTH 400
  26 #endif
  27
  28 #ifndef HEIGHT
  29 #define HEIGHT 400
  30 #endif
  31
  32 static void
  33 draw (cairo_t *cr, int width, int height);
  34
  35 #if ! GTK_CHECK_VERSION(2,7,0)
  36 /* copied from gtk+/gdk/gdkcairo.c and gtk+/gdk/x11/gdkdrawable-x11.c
  37  * gdk_cairo_create() which is available in 2.7.0 and later.
  38  */
  39 static cairo_t *
  40 gdk_cairo_create (GdkDrawable *drawable)
  41 {
  42     int width, height;
  43     cairo_t *cr = NULL;
  44     cairo_surface_t *surface = NULL;
  45     GdkVisual *visual = gdk_drawable_get_visual (drawable);
  46
  47     gdk_drawable_get_size (drawable, &width, &height);
  48     if (visual)
  49         surface = cairo_xlib_surface_create (GDK_DRAWABLE_XDISPLAY (drawable),
  50                                              GDK_DRAWABLE_XID (drawable),
  51                                              GDK_VISUAL_XVISUAL (visual),
  52                                              width, height);
  53     else if (gdk_drawable_get_depth (drawable) == 1)
  54         surface = cairo_xlib_surface_create_for_bitmap
  55             (GDK_PIXMAP_XDISPLAY (drawable),
  56              GDK_PIXMAP_XID (drawable),
  57              GDK_SCREEN_XSCREEN (gdk_drawable_get_screen (drawable)),
  58              width, height);
  59     else {
  60         g_warning ("Using Cairo rendering requires the drawable argument to\n"
  61                    "have a specified colormap. All windows have a colormap,\n"
  62                    "however, pixmaps only have colormap by default if they\n"
  63                    "were created with a non-NULL window argument. Otherwise\n"
  64                    "a colormap must be set on them with "
  65                    "gdk_drawable_set_colormap");
  66         return NULL;
  67     }
  68     if (surface) {
  69         cr = cairo_create (surface);
  70         cairo_surface_destroy (surface);
  71     }
  72     return cr;
  73 }
  74 #endif
  75
  76 static gboolean
  77 handle_expose (GtkWidget      *widget,
  78                GdkEventExpose *event,
  79                gpointer        data)
  80 {
  81     cairo_t *cr;
  82
  83     cr = gdk_cairo_create (widget->window);
  84
  85     draw (cr, widget->allocation.width, widget->allocation.height);
  86
  87     cairo_destroy (cr);
  88
  89     return FALSE;
  90 }
  91
  92 static gboolean
  93 handle_key_press (GtkWidget *widget,
  94                   GdkEventKey *event,
  95                   gpointer data)
  96 {
  97     if ((event->keyval == GDK_Q ||
  98          event->keyval == GDK_q) && (event->state & GDK_CONTROL_MASK))
  99         gtk_main_quit ();
 100
 101     return FALSE;
 102 }
 103
 104 int
 105 main (int argc, char **argv)
 106 {
 107     GtkWidget *window, *drawing_area;
 108
 109     gtk_init (&argc, &argv);
 110
 111     window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 112
 113     gtk_window_set_default_size (GTK_WINDOW (window), WIDTH, HEIGHT);
 114     gtk_window_set_title (GTK_WINDOW (window), "cairo demo");
 115
 116     g_signal_connect (window, "destroy",
 117                       G_CALLBACK (gtk_main_quit), NULL);
 118
 119     drawing_area = gtk_drawing_area_new ();
 120     gtk_container_add (GTK_CONTAINER (window), drawing_area);
 121
 122     g_signal_connect (drawing_area, "expose-event",
 123                       G_CALLBACK (handle_expose), NULL);
 124
 125     g_signal_connect (window, "key-press-event",
 126                       G_CALLBACK (handle_key_press), NULL);
 127
 128     gtk_widget_show_all (window);
 129
 130     gtk_main ();
 131
 132     return 0;
 133 }