Updated Area's KeyEvent documentation to talk about some window managers on Unix intercepting some events; also updated the keyboard test program to make a note of behaviors related to that.

area.go

@@ -124,6 +124,11 @@ func (e MouseEvent) HeldBits() (h uintptr) {
 // unconditionally, which may result in unwanted behavior like
 // global task-switching keystrokes not being processed.)
 // 
+// Note that even given the above, some systems might intercept
+// some keystrokes (like Alt-F4 on various Unix systems) before
+// Area will ever see them (and the Area might get an incorrect
+// KeyEvent in this case, but this is not guaranteed); be wary.
+// 
 // If a key is pressed that is not supported by Key, ExtKey,
 // or Modifiers, no KeyEvent will be produced, and package
 // ui will act as if false was returned for handled.

test/kbtest.go

@@ -80,7 +80,7 @@ func kbTest() {
 	w := NewWindow("Hi", wid, ht)
 	err := w.Open(a)
 	if err != nil { panic(err) }
-	<-w.Closing
+	select {}		// some X11-based systems intercept Alt-F4 and various other keys; this is to find out if we get the key event anyway after ignoring the other requests (it has the effect of requiring us to abort the keyboard test though)
 }
 
 var (