#3590 noteedit: fix IME candidate window overlapping text when typing with a Japanese IME

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

CHANGELOG.md

@@ -1,5 +1,12 @@
 # QOwnNotes Changelog
 
+## 26.5.1
+
+- Fixed IME candidate window overlapping text when typing with a Japanese (or
+  other CJK) IME on Windows by overriding `inputMethodQuery()` in
+  `QOwnNotesMarkdownTextEdit` to offset the reported cursor rectangle by the
+  current viewport margins (for [#3590](https://github.com/pbek/QOwnNotes/issues/3590))
+
 ## 26.5.0
 
 - Added **Note Bookmarks** sub-menus to the _Note / Navigation_ menu

src/widgets/qownnotesmarkdowntextedit.cpp

@@ -3438,6 +3438,30 @@ void QOwnNotesMarkdownTextEdit::focusInEvent(QFocusEvent *e) {
     QMarkdownTextEdit::focusInEvent(e);
 }
 
+/**
+ * Override inputMethodQuery to fix IME candidate window position on Windows.
+ * When viewport margins are set (e.g. for paper margins), the cursor rectangle
+ * returned to the IME must be offset by the top/left margin so that the
+ * candidate window appears adjacent to the cursor rather than overlapping it.
+ */
+QVariant QOwnNotesMarkdownTextEdit::inputMethodQuery(Qt::InputMethodQuery property) const {
+    QVariant result = QPlainTextEdit::inputMethodQuery(property);
+
+    const bool isCursorQuery =
+        (property == Qt::ImCursorRectangle || property == Qt::ImAnchorRectangle);
+    if (isCursorQuery) {
+        // viewportMargins() is non-const in this class, so cast away const to call it
+        const QMargins vm = const_cast<QOwnNotesMarkdownTextEdit *>(this)->viewportMargins();
+        if (vm.top() != 0 || vm.left() != 0) {
+            if (result.userType() == QMetaType::QRectF) {
+                result = result.toRectF().translated(qreal(vm.left()), qreal(vm.top()));
+            }
+        }
+    }
+
+    return result;
+}
+
 /**
  * Register this editor as the active one for AI autocomplete
  */

src/widgets/qownnotesmarkdowntextedit.h

@@ -162,6 +162,7 @@ class QOwnNotesMarkdownTextEdit : public QMarkdownTextEdit {
     int sidebarAdditionalWidth() const override;
     void paintSidebar(QPainter *painter, const QRect &eventRect) override;
     bool sidebarMousePressEvent(QMouseEvent *event) override;
+    QVariant inputMethodQuery(Qt::InputMethodQuery property) const override;
 
    private:
     struct FoldRegion {