diff options
Diffstat (limited to 'documentation/src')
| -rw-r--r-- | documentation/src/wayland.dox | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/documentation/src/wayland.dox b/documentation/src/wayland.dox index 331d8d79b..792363629 100644 --- a/documentation/src/wayland.dox +++ b/documentation/src/wayland.dox @@ -164,8 +164,22 @@ The rest of this chapter describes what happens when the Wayland leg has been ch \section wayland-connection Opening a Wayland connection -Function \c Fl_Wayland_Screen_Driver::open_display_platform() establishes the Wayland connection -calling \c wl_display_connect(NULL) which returns a <tt>struct wl_display</tt> object. +Establishing a Wayland connection requires environment variable \c XDG_RUNTIME_DIR to be +defined and to point to a directory containing a socket connected to a Wayland +compositor. This is usually done by the login procedure of Wayland-friendly desktops. +The name of the Wayland socket is determined as follows: +- the client may call Fl::display(const char *display_name) before \c fl_open_display() runs +or use the \c -display command line argument and transmit there the socket name; +- environment variable \c WAYLAND_DISPLAY can be defined to the socket name; +- otherwise, \c "wayland-0" is used. + +What socket is selected determines what compositor will be used by the client application. + +Function \c Fl_Wayland_Screen_Driver::open_display_platform() establishes the connection to the +Wayland socket identified above calling \c wl_display_connect(NULL) which returns a +<tt>struct wl_display</tt> pointer or NULL in case of failure. Such NULL return is the hint +that allows the FLTK display opening procedure of the Wayland/X11 hybrid to recognize when Wayland +access is not possible and to fallback to X11. Then, function \c wl_registry_add_listener() associates a 2-member listener, whose 1st member, \c registry_handle_global(), will be called by Wayland a number of times to indicate each time a protocol @@ -187,7 +201,8 @@ stored as member \c wl_compositor of the \c Fl_Wayland_Screen_Driver object. and stores this information in static member variable \c Fl_Wayland_Screen_Driver::compositor. Finally, function \c wl_display_get_fd() is called to obtain the file descriptor of the Wayland socket -and a call to Fl::add_fd() makes FLTK listen to this descriptor and associates function \c fd_callback() +and a call to Fl::add_fd() makes FLTK listen to this descriptor and associates function +\c wayland_socket_callback() from file \c Fl_Wayland_Screen_Driver.cxx with it. This function calls \c wl_display_dispatch() which asks the Wayland client library to process requests arrived in the socket. The \c wl_display_dispatch() call is repeated as long as data are available for reading. |