Fl_Cairo_Window.H

//
// Main header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2018 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

/* \file
    Fl_Cairo_Window Handling transparently a FLTK window incorporating a cairo draw callback.
*/

#ifndef FL_CAIRO_WINDOW_H
# define FL_CAIRO_WINDOW_H
# ifdef FLTK_HAVE_CAIRO

// Cairo is currently supported for the following platforms:
// Win32, Apple Quartz, X11
#  include <FL/Fl.H>
#  include <FL/Fl_Double_Window.H>

class FL_EXPORT Fl_Cairo_Window : public Fl_Double_Window {

public:
  Fl_Cairo_Window(int W, int H, const char *L = 0)
    : Fl_Double_Window(W, H, L), draw_cb_(0) {}
  Fl_Cairo_Window(int X, int Y, int W, int H, const char *L = 0)
    : Fl_Double_Window(X, Y, W, H, L), draw_cb_(0) {}

protected:
  void draw() {
    Fl_Double_Window::draw();
    if (draw_cb_) { // call the Cairo draw callback
      // manual method ? if yes explicitly get a cairo_context here
      if (!Fl::cairo_autolink_context())
        Fl::cairo_make_current(this);
      draw_cb_(this, Fl::cairo_cc());
      // flush cairo drawings: necessary at least for Windows
      cairo_surface_t *s = cairo_get_target(Fl::cairo_cc());
      cairo_surface_flush(s);
    }
  }

public:
  typedef void (*cairo_draw_cb) (Fl_Cairo_Window* self, cairo_t* def);
  void set_draw_cb(cairo_draw_cb cb) { draw_cb_ = cb; }
private:
    cairo_draw_cb draw_cb_;
};


# endif // FLTK_HAVE_CAIRO
#endif // FL_CAIRO_WINDOW_H