Make it possible again to choose between variants

Fixes #1.

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

README.md

@@ -39,6 +39,7 @@ the `HostOS` library header.
 
 #include <Kaleidoscope.h>
 #include <Kaleidoscope-HostOS.h>
+#include <Kaleidoscope/HostOS-select.h>
 
 void someFunction (void) {
   if (HostOS.os() == Kaleidoscope::HostOS::LINUX) {
@@ -55,6 +56,9 @@ void setup (void) {
 }
 ```
 
+To be able to choose between the two variants, one must also include the
+`Kaleidoscope/HostOS-select.h` header.
+
 ## Extension methods
 
 The extension provides the following methods on the `HostOS` singleton:

examples/HostOS/HostOS.ino

@@ -17,6 +17,7 @@
  */
 
 #include <Kaleidoscope-HostOS.h>
+#include <Kaleidoscope/HostOS-select.h>
 
 const Key keymaps[][ROWS][COLS] PROGMEM = {
   [0] = KEYMAP_STACKED

src/Kaleidoscope-HostOS.h

@@ -18,12 +18,7 @@
 
 #pragma once
 
-#include <Kaleidoscope/HostOS.h>
-#include <Kaleidoscope/HostOS-Tracker.h>
+#include <Kaleidoscope/HostOS-Base.h>
 #include <Kaleidoscope/HostOS-Guesser.h>
 
-#ifdef KALEIDOSCOPE_HOSTOS_GUESSER
-extern KaleidoscopePlugins::HostOS::Guesser HostOS;
-#else
-extern KaleidoscopePlugins::HostOS::Tracker HostOS;
-#endif
+extern KaleidoscopePlugins::HostOS::Base HostOS;

src/Kaleidoscope/HostOS-Base.cpp

@@ -16,7 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <Kaleidoscope/HostOS.h>
+#include <Kaleidoscope/HostOS-Base.h>
 #include <Kaleidoscope-EEPROM-Settings.h>
 
 #include <EEPROM.h>

src/Kaleidoscope/HostOS-Base.h

@@ -39,7 +39,7 @@ namespace KaleidoscopePlugins {
       void os (Type osType);
 
     protected:
-      virtual void autoDetect (void) = 0;
+      virtual void autoDetect (void) {};
       Type osType;
 
     private:

src/Kaleidoscope/HostOS-Guesser.cpp

@@ -48,5 +48,3 @@ namespace KaleidoscopePlugins {
     }
   };
 };
-
-KaleidoscopePlugins::HostOS::Guesser HostOS;

src/Kaleidoscope/HostOS-Guesser.h

@@ -18,7 +18,7 @@
 
 #pragma once
 
-#include <Kaleidoscope/HostOS.h>
+#include <Kaleidoscope/HostOS-Base.h>
 
 namespace KaleidoscopePlugins {
   namespace HostOS {

src/Kaleidoscope/HostOS-Tracker.cpp

@@ -1,21 +0,0 @@
-/* -*- mode: c++ -*-
- * Kaleidoscope-HostOS -- Host OS detection and tracking for Kaleidoscope
- * Copyright (C) 2016, 2017  Gergely Nagy
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <Kaleidoscope/HostOS-Tracker.h>
-
-KaleidoscopePlugins::HostOS::Tracker HostOS;

src/Kaleidoscope/HostOS-select.h

@@ -18,16 +18,11 @@
 
 #pragma once
 
-#include <Kaleidoscope/HostOS.h>
+#include <Kaleidoscope/HostOS-Base.h>
+#include <Kaleidoscope/HostOS-Guesser.h>
 
-namespace KaleidoscopePlugins {
-  namespace HostOS {
-    class Tracker : public Base {
-    public:
-      Tracker (void) {};
-
-    protected:
-      virtual void autoDetect (void) final {};
-    };
-  };
-};
+#if KALEIDOSCOPE_HOSTOS_GUESSER
+KaleidoscopePlugins::HostOS::Base HostOS = KaleidoscopePlugins::HostOS::Guesser();
+#else
+KaleidoscopePlugins::HostOS::Base HostOS;
+#endif