Prevents the key handler to see reserved keys like page up/down as BPMF keys.

Source/InputMethodController.swift

@@ -180,6 +180,9 @@ class McBopomofoInputMethodController: IMKInputController {
         }
 
         let input = KeyHandlerInput(event: event, isVerticalMode: useVerticalMode)
+
+        NSLog("input \(input)")
+
         let result = keyHandler.handle(input, state: state) { newState in
             self.handle(state: newState, client: client)
         } candidateSelectionCallback: {

Source/KeyHandler.mm

@@ -302,10 +302,12 @@ static NSString *const kGraphVizOutputfile = @"/tmp/McBopomofo-visualization.dot
     }
 
     bool composeReading = false;
+    BOOL skipBpmfHandling = [input isReservedKey] || [input isControlHold];
 
     // MARK: Handle BPMF Keys
+
     // see if it's valid BPMF reading
-    if (![input isControlHold] && _bpmfReadingBuffer->isValidKey((char) charCode)) {
+    if (!skipBpmfHandling && _bpmfReadingBuffer->isValidKey((char) charCode)) {
         _bpmfReadingBuffer->combineKey((char) charCode);
 
         // if we have a tone marker, we have to insert the reading to the

Source/KeyHandlerInput.swift

@@ -90,6 +90,10 @@ class KeyHandlerInput: NSObject {
         super.init()
     }
 
+    override var description: String {
+        return "<\(super.description) inputText:\(String(describing: inputText)), inputTextIgnoringModifiers:\(String(describing: inputTextIgnoringModifiers)) charCode:\(charCode), keyCode:\(keyCode), flags:\(flags), cursorForwardKey:\(cursorForwardKey), cursorBackwardKey:\(cursorBackwardKey), extraChooseCandidateKey:\(extraChooseCandidateKey), absorbedArrowKey:\(absorbedArrowKey),  verticalModeOnlyChooseCandidateKey:\(verticalModeOnlyChooseCandidateKey), emacsKey:\(emacsKey), useVerticalMode:\(useVerticalMode)>"
+    }
+
     @objc var isShiftHold: Bool {
         flags.contains([.shift])
     }
@@ -118,6 +122,13 @@ class KeyHandlerInput: NSObject {
         flags.contains([.numericPad])
     }
 
+    @objc var isReservedKey: Bool {
+        guard let code = KeyCode(rawValue: keyCode) else {
+            return false
+        }
+        return code.rawValue != KeyCode.none.rawValue
+    }
+
     @objc var isEnter: Bool {
         KeyCode(rawValue: keyCode) == KeyCode.enter
     }