Cleaner declaration of public function fl_wl_cairo().

FL/wayland.H

@@ -26,7 +26,8 @@ struct flCairoRegion {
 }; // a region is the union of a series of rectangles
 
 #include <stdint.h>
+typedef struct _cairo cairo_t;
 
 FL_EXPORT struct wl_display *fl_wl_display();
 FL_EXPORT struct wl_surface *fl_wl_surface(Window xid);
-FL_EXPORT struct _cairo *fl_wl_cairo();
+FL_EXPORT cairo_t *fl_wl_cairo();

documentation/src/osissues.dox

@@ -964,13 +964,13 @@ struct wl_surface *fl_wl_surface(Window wld_win)
 Returns a pointer to the struct wl_surface corresponding to a show()'n
 top-level window or subwindow.
 
-struct _cairo *fl_wl_cairo(void)
+cairo_t *fl_wl_cairo(void)
 \par
 Drawing natively to a Wayland window : Within an overridden Fl_Widget::draw() method,
 or after a call to Fl_Window::make_current(), it's possible to draw
 <u>using the Cairo library</u>. Function \c fl_wl_cairo() returns the adequate
-\c cairo_t* (equivalent to <tt>struct _cairo*</tt>) value. All FLTK-defined
-drawing functions (e.g., fl_rect(), fl_draw()) can be used too.
+\c cairo_t* value. Regular FLTK coordinates, with top-left origin, are to be used.
+All FLTK-defined drawing functions (e.g., fl_rect(), fl_draw()) can be used too.
 
 void fl_close_display()
 \par

src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx

@@ -1543,7 +1543,7 @@ struct wl_surface *fl_wl_surface(Window xid) {
 }
 
 
-struct _cairo *fl_wl_cairo() {
+cairo_t *fl_wl_cairo() {
   return ((Fl_Cairo_Graphics_Driver*)fl_graphics_driver)->cr();
 }