Use a timer instead of a loop counter

Loop counters are not a reliable way to track time, use a proper timer instead.

Fixes #2.

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

README.md

@@ -74,13 +74,13 @@ void setup () {
 
 ### `.timeOut`
 
-> The number of loop iterations to wait before considering a held key in
-> isolation as its secondary role. That is, we'd have to hold a `Shift` key
-> this long, by itself, to trigger the `Shift` role in itself.
+> The number of milliseconds to wait before considering a held key in isolation
+> as its secondary role. That is, we'd have to hold a `Shift` key this long, by
+> itself, to trigger the `Shift` role in itself.
 >
 > Not strictly a method, it is a variable one can assign a new value to.
 >
-> Defaults to 40.
+> Defaults to 1000.
 
 ## Further reading
 

src/Akela/SpaceCadet.cpp

@@ -21,8 +21,8 @@
 namespace Akela {
 
   uint8_t SpaceCadetShift::parenNeeded;
-  uint8_t SpaceCadetShift::timer;
-  uint8_t SpaceCadetShift::timeOut = 40;
+  uint32_t SpaceCadetShift::startTime;
+  uint16_t SpaceCadetShift::timeOut = 1000;
   Key SpaceCadetShift::leftParen, SpaceCadetShift::rightParen;
 
   SpaceCadetShift::SpaceCadetShift () {
@@ -67,15 +67,13 @@ namespace Akela {
     if (key_toggled_on (keyState)) {
       if (mappedKey.raw == Key_LShift.raw) { // if it is LShift, remember it
         bitWrite (parenNeeded, 0, 1);
-        if (timer < timeOut)
-          timer++;
+        startTime = millis ();
       } else if (mappedKey.raw == Key_RShift.raw) { // if it is RShift, remember it
         bitWrite (parenNeeded, 1, 1);
-        if (timer < timeOut)
-          timer++;
+        startTime = millis ();
       } else { // if it is something else, we do not need a paren at the end.
         parenNeeded = 0;
-        timer = 0;
+        startTime = 0;
       }
 
       // this is all we need to do on keypress, let the next handler do its thing too.
@@ -87,15 +85,10 @@ namespace Akela {
     if (!parenNeeded)
       return mappedKey;
 
-    // if we did not time out yet, up the timer
-    if (timer < timeOut)
-      timer++;
-
     // if we timed out, that means we need to keep pressing shift, but won't
     // need the parens in the end.
-    if (timer >= timeOut) {
+    if ((millis () - startTime) >= timeOut) {
       parenNeeded = 0;
-      timer = 0;
       return mappedKey;
     }
 
@@ -118,7 +111,6 @@ namespace Akela {
       Keyboard.sendReport ();
 
       parenNeeded = 0;
-      timer = 0;
     }
 
     return mappedKey;

src/Akela/SpaceCadet.h

@@ -28,13 +28,13 @@ namespace Akela {
     virtual void begin (void) final;
 
     static void configure (Key left, Key right);
-    static uint8_t timeOut;
+    static uint16_t timeOut;
 
     void on (void);
     void off (void);
   private:
     static uint8_t parenNeeded;
-    static uint8_t timer;
+    static uint32_t startTime;
     static Key leftParen, rightParen;
 
     static Key eventHandlerHook (Key mappedKey, byte row, byte col, uint8_t keyState);