Allow tone key to revise prior reading (#753)

McBopomofoTests/KeyHandlerBopomofoTests.swift

@@ -2706,3 +2706,87 @@ extension KeyHandlerBopomofoTests {
         }
     }
 }
+
+extension KeyHandlerBopomofoTests {
+
+    func testChnagingReadingUsingToneKey1() {
+        let associatedPhrasesEnabled = Preferences.associatedPhrasesEnabled
+        Preferences.associatedPhrasesEnabled = false
+
+        defer {
+            Preferences.associatedPhrasesEnabled = associatedPhrasesEnabled
+        }
+
+        var state: InputState = InputState.Empty()
+        let keys = Array("vul3a943").map {
+            String($0)
+        }
+        for key in keys {
+            let input = KeyHandlerInput(
+                inputText: key, keyCode: 0, charCode: charCode(key), flags: [],
+                isVerticalMode: false)
+            handler.handle(input: input, state: state) { newState in
+                state = newState
+            } errorCallback: {
+            }
+        }
+        XCTAssertTrue(state is InputState.Inputting, "\(state)")
+        if let state = state as? InputState.Inputting {
+            XCTAssertEqual(state.composingBuffer, "小買")
+        }
+    }
+
+    func testChnagingReadingUsingToneKey2() {
+        let associatedPhrasesEnabled = Preferences.associatedPhrasesEnabled
+        Preferences.associatedPhrasesEnabled = false
+
+        defer {
+            Preferences.associatedPhrasesEnabled = associatedPhrasesEnabled
+        }
+
+        var state: InputState = InputState.Empty()
+        let keys = Array("vul3a946").map {
+            String($0)
+        }
+        for key in keys {
+            let input = KeyHandlerInput(
+                inputText: key, keyCode: 0, charCode: charCode(key), flags: [],
+                isVerticalMode: false)
+            handler.handle(input: input, state: state) { newState in
+                state = newState
+            } errorCallback: {
+            }
+        }
+        XCTAssertTrue(state is InputState.Inputting, "\(state)")
+        if let state = state as? InputState.Inputting {
+            XCTAssertEqual(state.composingBuffer, "小埋")
+        }
+    }
+
+    func testChnagingReadingUsingToneKey3() {
+        let associatedPhrasesEnabled = Preferences.associatedPhrasesEnabled
+        Preferences.associatedPhrasesEnabled = false
+
+        defer {
+            Preferences.associatedPhrasesEnabled = associatedPhrasesEnabled
+        }
+
+        var state: InputState = InputState.Empty()
+        let keys = Array("vul3a947").map {
+            String($0)
+        }
+        for key in keys {
+            let input = KeyHandlerInput(
+                inputText: key, keyCode: 0, charCode: charCode(key), flags: [],
+                isVerticalMode: false)
+            handler.handle(input: input, state: state) { newState in
+                state = newState
+            } errorCallback: {
+            }
+        }
+        XCTAssertTrue(state is InputState.Inputting, "\(state)")
+        if let state = state as? InputState.Inputting {
+            XCTAssertEqual(state.composingBuffer, "小麥˙")
+        }
+    }
+}

Source/Engine/Mandarin/Mandarin.h

@@ -458,6 +458,16 @@ class BopomofoReadingBuffer {
 
   const BPMF syllable() const { return syllable_; }
 
+  void setSyllableRemovingTone(BPMF syllable) {
+    BPMF::Component masked = (syllable.consonantComponent() |
+                               syllable.middleVowelComponent() |
+                               syllable.vowelComponent());
+    syllable_ = BPMF(masked);
+    if (pinyin_mode_) {
+      pinyin_sequence_ = syllable_.HanyuPinyinString(false, false);
+    }
+  }
+
   const std::string standardLayoutQueryString() const {
     return BopomofoKeyboardLayout::StandardLayout()->keySequenceFromSyllable(
         syllable_);
@@ -482,3 +492,4 @@ class BopomofoReadingBuffer {
 }  // namespace Formosa
 
 #endif  // SRC_ENGINE_MANDARIN_MANDARIN_H_
+

Source/KeyHandler.mm

@@ -450,7 +450,8 @@ - (BOOL)handleInput:(KeyHandlerInput *)input state:(InputState *)inState stateCa
     // MARK: Handle BPMF Keys
 
     // see if it's valid BPMF reading
-    if (!skipBpmfHandling && _bpmfReadingBuffer->isValidKey((char)charCode)) {
+    bool isValidKey = _bpmfReadingBuffer->isValidKey((char)charCode);
+    if (!skipBpmfHandling && isValidKey) {
         _bpmfReadingBuffer->combineKey((char)charCode);
         keyConsumedByReading = YES;
 
@@ -463,7 +464,32 @@ - (BOOL)handleInput:(KeyHandlerInput *)input state:(InputState *)inState stateCa
         }
     }
 
-    BOOL composeReading = _bpmfReadingBuffer->isValidKey((char)charCode) && _bpmfReadingBuffer->hasToneMarker() && !_bpmfReadingBuffer->hasToneMarkerOnly();
+    // Issue 753
+    //
+    // This allows users to use tone key to change an existing reading before
+    // the current cursor.
+    if (_bpmfReadingBuffer->hasToneMarkerOnly() && _grid->readings().size() > 0 && _grid->cursor() > 0) {
+        size_t cursor = _grid->cursor() - 1;
+        std::string reading = _grid->readings()[cursor];
+        if (!reading.empty() && reading[0] != '_') {
+            Formosa::Mandarin::BopomofoReadingBuffer tmpBuffer(_bpmfReadingBuffer->keyboardLayout());
+            Formosa::Mandarin::BopomofoSyllable syllable = Formosa::Mandarin::BopomofoSyllable::FromComposedString(reading);
+            tmpBuffer.setSyllableRemovingTone(syllable);
+            tmpBuffer.combineKey((char)charCode);
+            std::string newReading = tmpBuffer.syllable().composedString();
+            if (_languageModel->hasUnigrams(newReading)) {
+                _bpmfReadingBuffer->clear();
+                _grid->deleteReadingBeforeCursor();
+                _grid->insertReading(newReading);
+                [self _walk];
+                InputStateInputting *inputting = (InputStateInputting *)[self buildInputtingState];
+                stateCallback(inputting);
+                return YES;
+            }
+        }
+    }
+
+    BOOL composeReading = isValidKey && _bpmfReadingBuffer->hasToneMarker() && !_bpmfReadingBuffer->hasToneMarkerOnly();
 
     // see if we have composition if Enter/Space is hit and buffer is not empty
     // this is bit-OR'ed so that the tone marker key is also taken into account