tools/mopen/CompositeHelper.cs

   1 //
   2 // CompositeHelper.cs
   3 //
   4 // Simple helper methods for doing rgba drawing
   5 //
   6 // Author: Larry Ewing <lewing@novell.com>
   7 //
   8 //
   9 using System;
  10 using System.Runtime.InteropServices;
  11 using Cairo;
  12 using Gtk;
  13 using Gdk;
  14
  15 static class CompositeHelper {
  16                 [DllImport("libgdk-win32-2.0-0.dll")]
  17                 static extern IntPtr gdk_cairo_create (IntPtr raw);
  18
  19                 [DllImport("libgdk-win32-2.0-0.dll")]
  20                 static extern IntPtr gdk_screen_get_rgba_colormap (IntPtr screen);
  21
  22                 [DllImport("libgdk-win32-2.0-0.dll")]
  23                 static extern void gdk_cairo_region (IntPtr ctx, IntPtr region);
  24
  25                 public static Cairo.Context Create (Gdk.Drawable drawable)
  26                 {
  27                         Cairo.Context ctx = new Cairo.Context (gdk_cairo_create (drawable.Handle));
  28                         if (ctx == null)
  29                                 throw new Exception ("Couldn't create Cairo Graphics!");
  30
  31                         return ctx;
  32                 }
  33
  34                 public static void Region (Cairo.Context ctx, Gdk.Region region)
  35                 {
  36                         gdk_cairo_region (ctx.Handle, region.Handle);
  37                 }
  38
  39                 public static Colormap GetRgbaColormap (Screen screen)
  40                 {
  41                         try {
  42                                 IntPtr raw_ret = gdk_screen_get_rgba_colormap (screen.Handle);
  43                                 Gdk.Colormap ret = GLib.Object.GetObject(raw_ret) as Gdk.Colormap;
  44                                 return ret;
  45                         } catch {
  46                                 Gdk.Visual visual = Gdk.Visual.GetBestWithDepth (32);
  47                                 if (visual != null) {
  48                                         Gdk.Colormap cmap = new Gdk.Colormap (visual, false);
  49                                         System.Console.WriteLine ("fallback");
  50                                         return cmap;
  51                                 }
  52                         }
  53                         return null;
  54                 }
  55
  56                 public static bool SetRgbaColormap (Widget w)
  57                 {
  58                         Gdk.Colormap cmap = GetRgbaColormap (w.Screen);
  59
  60                         if (cmap != null) {
  61                                 w.Colormap = cmap;
  62                                 return true;
  63                         }
  64
  65                         return false;
  66                 }
  67 }