add devterm_keyboard_mini init code

Code/devterm_keyboard_mini/state.h

@@ -0,0 +1,37 @@
+#ifndef STATE_H
+#define STATE_H
+
+#include <bitset>
+#include <array>
+#include <USBComposite.h>
+
+#include "debouncer.h"
+
+enum class TrackballMode : uint8_t {
+  Wheel,
+  Mouse,
+};
+
+class State
+{
+  public:
+    static const uint16_t MIDDLE_CLICK_TIMEOUT_MS = 0;
+
+    State();
+
+    void tick(uint8_t delta);
+
+    bool fn;
+
+    void pressMiddleClick();
+    bool releaseMiddleClick();
+    bool getScrolled();
+    void setScrolled();
+    TrackballMode moveTrackball();
+  private:
+    bool middleClick;
+    bool scrolled;
+    Timeout<uint16_t, MIDDLE_CLICK_TIMEOUT_MS> middleClickTimeout;
+};
+
+#endif