在JavaFX中构建代码编辑器控件

private final ListView<String> listView = new ListView<String>();
private final ListView<String> gutterListView = new ListView<String>();

private void setupVerticalScrollSync() {
    ScrollBar mainVBar = findVerticalScrollBar(listView);
    ScrollBar gutterVBar = findVerticalScrollBar(gutterListView);
    mainVBar.valueProperty().bind(gutterVBar.valueProperty());
    gutterVBar.setValue(mainVBar.getValue());
}

private class GutterCell extends ListCell<String> {
    private final Label lineNumberLabel = new Label();
    private final HBox gutterIconBox = new HBox(2);

    @Override
    protected void updateItem(String item, boolean empty) {
        super.updateItem(item, empty);
        if (empty || item == null) {
            setGraphic(null);
            return;
        }
        setGraphic(rowBox);
        int idx = getIndex();
        lineNumberLabel.setText(String.valueOf(idx + 1));
        gutterIconBox.getChildren().setAll(buildGutterIcons(idx, item));
        boolean isCaretLine = idx == caretLine();
        rowBox.setStyle(isCaretLine
            ? "-fx-background-color: " + toWeb(getSkinnable().getCurrentLineColor())
            : "-fx-background-color: " + toWeb(getSkinnable().getLineColor()));
    }
}

private List<Text> buildHighlightedFlowChildren(String lineText) {
    Map<String, Color> keywords = getSkinnable().getKeywordColors();
    Matcher m = WORD_PATTERN.matcher(lineText);
    int last = 0;
    List<Text> parts = new ArrayList<Text>();
    while (m.find()) {
        if (m.start() > last) {
            parts.add(plainText(lineText.substring(last, m.start())));
        }
        String word = m.group();
        Text wordText = plainText(word);
        Color c = keywords.get(word);
        if (c != null) {
            wordText.setFill(c);
        }
        parts.add(wordText);
        last = m.end();
    }
    if (last < lineText.length()) {
        parts.add(plainText(lineText.substring(last)));
    }
    return parts;
}

editor.addKeywords(Color.web("#CC7832"), "public", "class", "return", "if", "else");

private void updateBracketMatch() {
    getSkinnable().matchBracketAProperty().set(-1);
    getSkinnable().matchBracketBProperty().set(-1);
    String text = getSkinnable().getText();
    if (text.isEmpty()) {
        return;
    }
    int checkPos = -1;
    if (isBracket(text.charAt(caretIndex))) {
        checkPos = caretIndex;
    } else if (isBracket(text.charAt(caretIndex - 1))) {
        checkPos = caretIndex - 1;
    }
    if (checkPos < 0) {
        return;
    }
    char c = text.charAt(checkPos);
    int match = OPEN_BRACKETS.indexOf(c) >= 0
        ? findMatchingForward(text, checkPos, c, closeFor(c))
        : findMatchingBackward(text, checkPos, c, openFor(c));
    if (match >= 0) {
        getSkinnable().matchBracketAProperty().set(checkPos);
        getSkinnable().matchBracketBProperty().set(match);
    }
}

private void handleMousePressed(MouseEvent e) {
    if (e.isAltDown()) {
        // Might become a click (new cursor) or a drag (column selection) — resolved later.
        getSkinnable().altDragOccurredProperty().set(false);
        getSkinnable().columnSelectingProperty().set(true);
        // ...
        return;
    }
    // A plain click always collapses back to a single caret.
    extraCarets.clear();
}

private void handleMouseReleased(MouseEvent e) {
    if (columnSelecting && !altDragOccurred) {
        // No drag happened — treat this as a plain Alt+Click: add a cursor.
        int offset = offsetForMouse(e.getX(), e.getY());
        extraCarets.add(new CaretState(caretIndex, selectionAnchor));
        getSkinnable().caretIndexProperty().set(offset);
    }
    getSkinnable().columnSelectingProperty().set(false);
}

private void pushUndoState() {
    if (getSkinnable().isIsUndoRedoOperation()) return; // don't record undo/redo as new edits
    getSkinnable().getUndoStack().push(new EditorState(
        getSkinnable().getText(),
        getSkinnable().caretIndexProperty().get(),
        getSkinnable().selectionAnchorProperty().get()
    ));
    getSkinnable().getRedoStack().clear();
    if (getSkinnable().getUndoStack().size() > getSkinnable().getMAX_UNDO_STEPS()) {
        getSkinnable().getUndoStack().removeLast();
    }
}

private void undo() {
    if (getSkinnable().getUndoStack().isEmpty()) return;
    getSkinnable().getRedoStack().push(currentState());
    applyState(getSkinnable().getUndoStack().pop());
}

private void updateAutocomplete() {
    String currentWord = wordAt(getSkinnable().caretIndexProperty().get());
    if (currentWord.isEmpty()) { 
        autocompletePopup.hide();
         return;
    }
    List<String> matches = new ArrayList<>();
    for (String s : getSkinnable().getAutocompleteSuggestions()) {
        if (s.toLowerCase().startsWith(currentWord.toLowerCase())
                && !s.equalsIgnoreCase(currentWord)) {
            matches.add(s);
        }
    }
    if (matches.isEmpty()) { 
        autocompletePopup.hide();
        return;
    }
    autocompleteListView.setItems(FXCollections.observableArrayList(matches));
    autocompleteListView.getSelectionModel().selectFirst();
    // Find the on-screen cell for the caret's line, then position the popup under it.
    VirtualFlow<IndexedCell<String>> flow = getVirtualFlow();
    IndexedCell<String> cell = null;
    if(flow != null){
        cell=flow.getCell(caretLine());
    }
    if (cell == null) {
        return;
    }
    Bounds cellBounds = cell.localToScreen(cell.getBoundsInLocal());
    autocompletePopup.show(listView, cellBounds.getMinX() + x, cellBounds.getMaxY());
}