This work is based on PR 1068 (patch by @CendioHalim) and
extended to store button status (4,5) in Fl::event_state() like
it's done for other mouse buttons (1-3).
Changes:
- new symbol: FL_BUTTON4 = side button 1 = "back"
- new symbol: FL_BUTTON5 = side button 2 = "forward"
- modified : FL_BUTTONS now includes bits for two side buttons
Note: the status of these new buttons is not maintained by X11,
therefore we need to maintain them in internal variables for
this platform.
The Fast Light Tool Kit is a cross-platform C++ GUI toolkit for
UNIX®/Linux® (X11 or Wayland), Microsoft® Windows®, and macOS®.
FLTK provides modern GUI functionality without the bloat and
supports 3D graphics via OpenGL® and its built-in GLUT
emulation. It was originally developed by Mr. Bill Spitzak
and is currently maintained by a small group of developers
across the world with a central repository on GitHub.
For more information see README.txt:
https://github.com/fltk/fltk/blob/master/README.txt