Allow user to customize which key will cancel one-shot keys

Signed-off-by: Michael Richters <gedankenexperimenter@gmail.com>

plugins/Kaleidoscope-Escape-OneShot/README.md

@@ -27,7 +27,17 @@ The plugin only makes sense when using one-shot keys.
 
 ## Plugin methods
 
-The plugin provides the `EscapeOneShot` object, which has no public methods.
+The plugin provides the `EscapeOneShot` object, which has one public
+configuration method:
+
+### `.setCancelKey(key)`
+
+> Changes the `Key` value that will trigger deactivation of one-shot
+> (including sticky) keys. The default is to use `Key_Escape` (the
+> normal `Esc` key), but if you would rather have a dedicated key (so
+> that you can use `Key_Escape` in combination with one-shot
+> modifiers), there is the special `OneShotCancelKey`, which will not
+> have any side effects.
 
 ## Dependencies
 

plugins/Kaleidoscope-Escape-OneShot/src/kaleidoscope/plugin/Escape-OneShot.cpp

@@ -24,20 +24,22 @@
 namespace kaleidoscope {
 namespace plugin {
 
+Key EscapeOneShot::cancel_oneshot_key_{Key_Escape};
+
 EventHandlerResult EscapeOneShot::onKeyswitchEvent(
   Key &key, KeyAddr key_addr, uint8_t key_state) {
-  // We only act on an escape key that has just been pressed, and not
-  // generated by some other plugin. Also, only if at least one
-  // OneShot key is active and/or sticky. Last, only if there are no
-  // OneShot keys currently being held.
-  if (key == Key_Escape &&
+  // We only act on an escape key (or `cancel_oneshot_key_`, if that has been
+  // set) that has just been pressed, and not generated by some other
+  // plugin. Also, only if at least one OneShot key is active and/or
+  // sticky. Last, only if there are no OneShot keys currently being held.
+  if (key == cancel_oneshot_key_ &&
       keyToggledOn(key_state) &&
       !(key_state & INJECTED) &&
       ::OneShot.isActive()) {
     // Cancel all OneShot keys
     ::OneShot.cancel(true);
-    // Change the escape key to a blank key, and signal that event processing is
-    // complete.
+    // Change the cancellation key to a blank key, and signal that event
+    // processing is complete.
     key = Key_NoKey;
     return EventHandlerResult::EVENT_CONSUMED;
   }

plugins/Kaleidoscope-Escape-OneShot/src/kaleidoscope/plugin/Escape-OneShot.h

@@ -19,6 +19,8 @@
 
 #include "kaleidoscope/Runtime.h"
 
+constexpr Key OneShotCancelKey {kaleidoscope::ranges::OS_CANCEL};
+
 namespace kaleidoscope {
 namespace plugin {
 class EscapeOneShot : public kaleidoscope::Plugin {
@@ -26,6 +28,13 @@ class EscapeOneShot : public kaleidoscope::Plugin {
   EscapeOneShot(void) {}
 
   EventHandlerResult onKeyswitchEvent(Key &key, KeyAddr key_addr, uint8_t key_state);
+
+  void setCancelKey(Key cancel_key) {
+    cancel_oneshot_key_ = cancel_key;
+  }
+
+ private:
+  static Key cancel_oneshot_key_;
 };
 }
 }

plugins/Kaleidoscope-Ranges/src/Kaleidoscope-Ranges.h

@@ -56,6 +56,7 @@ enum : uint16_t {
   OSL_FIRST,
   OSL_LAST    = OSL_FIRST + 7,
   OS_LAST     = OSL_LAST,
+  OS_CANCEL,
   DU_FIRST,
   DUM_FIRST   = DU_FIRST,
   DUM_LAST    = DUM_FIRST + (8 << 8),