CharShift: Transition to using a function pointer instead of overridables

Instead of using overridable functions, use function pointers (+ setters) to
allow changing lookups and related things. This allows a bit more flexibility,
and makes the user sketch simpler, because there is no override necessary there.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

plugins/Kaleidoscope-CharShift/src/kaleidoscope/plugin/CharShift.cpp

@@ -34,6 +34,10 @@ namespace plugin {
 // CharShift class variables
 CharShift::KeyPair const * CharShift::progmem_keypairs_{nullptr};
 uint8_t CharShift::num_keypairs_{0};
+CharShift::GetNumKeyPairsFunction CharShift::numKeyPairs_ =
+    CharShift::numProgmemKeyPairs;
+CharShift::ReadKeyPairFunction CharShift::readKeyPair_ =
+    CharShift::readKeyPairFromProgmem;
 
 bool CharShift::reverse_shift_state_{false};
 
@@ -117,24 +121,12 @@ bool CharShift::isCharShiftKey(Key key) {
 
 CharShift::KeyPair CharShift::decodeCharShiftKey(Key key) {
   uint8_t i = key.getRaw() - ranges::CS_FIRST;
-  if (i < numKeyPairs()) {
-    return readKeyPair(i);
+  if (i < numKeyPairs_()) {
+    return readKeyPair_(i);
   }
   return {Key_NoKey, Key_NoKey};
 }
 
-// This should be overridden if the KeyPairs array is stored in EEPROM
-__attribute__((weak))
-uint8_t CharShift::numKeyPairs() {
-  return numProgmemKeyPairs();
-}
-
-// This should be overridden if the KeyPairs array is stored in EEPROM
-__attribute__((weak))
-CharShift::KeyPair CharShift::readKeyPair(uint8_t n) {
-  return readKeyPairFromProgmem(n);
-}
-
 uint8_t CharShift::numProgmemKeyPairs() {
   return num_keypairs_;
 }

plugins/Kaleidoscope-CharShift/src/kaleidoscope/plugin/CharShift.h

@@ -76,12 +76,25 @@ class CharShift : public Plugin {
     num_keypairs_ = _num_keypairs;
   }
 
+  typedef uint8_t (*GetNumKeyPairsFunction)();
+  typedef KeyPair (*ReadKeyPairFunction)(uint8_t n);
+
+  static void setNumKeyPairsFunction(GetNumKeyPairsFunction f) {
+    numKeyPairs_ = f;
+  }
+  static void setReadKeyPairFunction(ReadKeyPairFunction f) {
+    readKeyPair_ = f;
+  }
+
  private:
   // A pointer to an array of `KeyPair` objects in PROGMEM
   static KeyPair const * progmem_keypairs_;
   // The size of the PROGMEM array of `KeyPair` objects
   static uint8_t num_keypairs_;
 
+  static GetNumKeyPairsFunction numKeyPairs_;
+  static ReadKeyPairFunction readKeyPair_;
+
   // If a `shift` key needs to be suppressed in `beforeReportingState()`
   static bool reverse_shift_state_;
 
@@ -91,18 +104,6 @@ class CharShift : public Plugin {
   /// Look up the `KeyPair` specified by the given keymap entry
   static KeyPair decodeCharShiftKey(Key key);
 
-  /// Get the total number of KeyPairs defined
-  ///
-  /// This function can be overridden in order to store the `KeyPair` array in
-  /// EEPROM instead of PROGMEM.
-  static uint8_t numKeyPairs();
-
-  /// Get the `KeyPair` at the specified index from the defined `KeyPair` array
-  ///
-  /// This function can be overridden in order to store the `KeyPair` array in
-  /// EEPROM instead of PROGMEM.
-  static KeyPair readKeyPair(uint8_t n);
-
   // Default for `keypairsCount()`: size of the PROGMEM array
   static uint8_t numProgmemKeyPairs();
   // Default for `readKeypair(i)`: fetch the value from PROGMEM