Simplify the Focus commands

Instead of having a getter and a setter command, have one with an
optional argument instead. Less code, less docs, easier to use and
understand.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/Kaleidoscope/HostOS-Focus.cpp

@@ -23,28 +23,14 @@ namespace KaleidoscopePlugins {
   namespace HostOS {
     bool
     Focus (const char *command) {
-      enum {
-        GET,
-        SET,
-      } subCommand;
-
-      if (strncmp_P (command, PSTR ("hostos."), 7) != 0)
-        return false;
-      if (strcmp_P (command + 7, PSTR ("type")) == 0)
-        subCommand = GET;
-      else if (strcmp_P (command + 7, PSTR ("set")) == 0)
-        subCommand = SET;
-      else
+      if (strcmp_P (command, PSTR ("hostos.type")) != 0)
         return false;
 
-      switch (subCommand) {
-      case GET:
+      if (Serial.peek () == '\n') {
         Serial.println (::HostOS.os ());
-        break;
-      case SET:
+      } else {
         uint8_t os = Serial.parseInt ();
         ::HostOS.os ((KaleidoscopePlugins::HostOS::Type) os);
-        break;
       }
 
       Serial.read ();

src/Kaleidoscope/HostOS-Focus.h

@@ -28,9 +28,7 @@ namespace KaleidoscopePlugins {
 
 #define FOCUS_HOOK_HOSTOS                                       \
   FOCUS_HOOK(KaleidoscopePlugins::HostOS::Focus,                \
-             "hostos.type\n"                                    \
-             "-----------\n"                                    \
-             "Display the OS type, as known to the plugin.\n\n" \
-             "hostos.set type\n"                                \
-             "---------------\n"                                \
-             "Set the OS type.")
+             "hostos.type [TYPE]\n"                             \
+             "------------------\n"                             \
+             "Set the OS type to `TYPE`; or display the "       \
+             "type, when called without arguments.")