X11: fix extraneous (undefined) event state bits

- Restrict FL_BUTTONS mask to only three valic mouse buttons.
  Pseudo mouse buttons 4-7 are used for FL_MOUSEWHEEL events and
  are no longer reflected in Fl::event_buttons().
- Return only state of mouse buttons 1-3 in Fl::event_buttons().
  Buttons 4-7 are not "sticky" (used for FL_MOUSEWHEEL).
- Keep undefined keyboard related bits in Fl::event_state() for
  backwards compatibility and transparency. These bits may be masked
  out in a later release.
- Document Fl::event_state() bits for X11 in src/Fl_x.cxx.

Note: this is a bug fix for X11 only, Wayland and other platforms are
not affected.

2 files changed, 14 insertions, 14 deletions

diff --git a/FL/Enumerations.H b/FL/Enumerations.H
index ff2f163e1..d944a13a2 100644
--- a/FL/Enumerations.H
+++ b/FL/Enumerations.H
@@ -562,8 +562,8 @@ enum Fl_Callback_Reason {
 
 /**@{*/          // group: Event States
 
-// FIXME: it would be nice to have the modifiers in the upper 8 bit so that
-//        a unicode key (24bit) can be sent as an unsigned with the modifiers.
+// FIXME: it would be nice to have the modifiers in the upper 8 bits so that
+//        a unicode key (21 bits) can be sent as an unsigned with the modifiers.
 
 #define FL_SHIFT        0x00010000      ///< One of the shift keys is down
 #define FL_CAPS_LOCK    0x00020000      ///< The caps lock is on
@@ -575,14 +575,14 @@ enum Fl_Callback_Reason {
                                         // correct for XFree86
 #define FL_SCROLL_LOCK  0x00800000      ///< The scroll lock is on
                                         // correct for XFree86
-#define FL_BUTTON1      0x01000000      ///< Mouse button 1 is pushed
-#define FL_BUTTON2      0x02000000      ///< Mouse button 2 is pushed
-#define FL_BUTTON3      0x04000000      ///< Mouse button 3 is pushed
-#define FL_BUTTONS      0x7f000000      ///< Any mouse button is pushed
-#define FL_BUTTON(n)    (0x00800000<<(n)) ///< Mouse button n (n > 0) is pushed
-
-#define FL_KEY_MASK 0x0000ffff          ///< All keys are 16 bit for now
-                                        //   FIXME: Unicode needs 24 bits!
+#define FL_BUTTON1      0x01000000      ///< Mouse button 1 is pushed (L)
+#define FL_BUTTON2      0x02000000      ///< Mouse button 2 is pushed (M)
+#define FL_BUTTON3      0x04000000      ///< Mouse button 3 is pushed (R)
+#define FL_BUTTONS      0x07000000      ///< Any mouse button (1-3) is pushed
+#define FL_BUTTON(n)   (0x00800000<<(n)) ///< Mouse button n (n > 0) is pushed
+
+#define FL_KEY_MASK     0x0000ffff      ///< All keys are 16 bit for now
+                                        //   FIXME: Unicode needs 21 bits!
 
 /**@}*/          // group: Event States
 
diff --git a/FL/Fl.H b/FL/Fl.H
index 8d86370f3..796843d75 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -1263,22 +1263,22 @@ public:
     caused an FL_RELEASE event, you can use Fl::event_button() instead.
     \return a bit mask value like { [FL_BUTTON1] | [FL_BUTTON2] | [FL_BUTTON3] }
   */
-  static int event_buttons() {return e_state&0x7f000000;}
+  static int event_buttons() {return e_state & FL_BUTTONS;}
   /**
     Returns non-zero if mouse button 1 is currently held down.
     For more details, see Fl::event_buttons().
   */
-  static int event_button1() {return e_state&FL_BUTTON1;}
+  static int event_button1() {return e_state & FL_BUTTON1;}
   /**
     Returns non-zero if button 2 is currently held down.
     For more details, see Fl::event_buttons().
   */
-  static int event_button2() {return e_state&FL_BUTTON2;}
+  static int event_button2() {return e_state & FL_BUTTON2;}
   /**
     Returns non-zero if button 3 is currently held down.
     For more details, see Fl::event_buttons().
   */
-  static int event_button3() {return e_state&FL_BUTTON3;}
+  static int event_button3() {return e_state & FL_BUTTON3;}
   /**   @} */
 
   /**