tdf#123956 Qt5 IM update cursor position

This sets the cursor position to the one provided by the
QInputMethodEvent::Cursor attribute.

Change-Id: I4a99f9939b53c69631e45d41102bf9c7f53f0ff5
Reviewed-on: https://gerrit.libreoffice.org/71782
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
(cherry picked from commit 110fd705)
Reviewed-on: https://gerrit.libreoffice.org/71955Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

vcl/qt5/Qt5Widget.cxx

@@ -469,10 +469,32 @@ void Qt5Widget::inputMethodEvent(QInputMethodEvent* pEvent)
     {
         aInputEvent.maText = toOUString(pEvent->preeditString());
         aInputEvent.mnCursorPos = 0;
-        sal_Int32 nLength = aInputEvent.maText.getLength();
+
+        const sal_Int32 nLength = aInputEvent.maText.getLength();
+        const QList<QInputMethodEvent::Attribute>& rAttrList = pEvent->attributes();
         std::vector<ExtTextInputAttr> aTextAttrs(nLength, ExtTextInputAttr::Underline);
+
+        for (int i = 0; i < rAttrList.size(); ++i)
+        {
+            const QInputMethodEvent::Attribute& rAttr = rAttrList.at(i);
+            switch (rAttr.type)
+            {
+                case QInputMethodEvent::Cursor:
+                {
+                    aInputEvent.mnCursorPos = rAttr.start;
+                    if (rAttr.length == 0)
+                        aInputEvent.mnCursorFlags |= EXTTEXTINPUT_CURSOR_INVISIBLE;
+                    break;
+                }
+                default:
+                    SAL_WARN("vcl.qt5", "Unhandled QInputMethodEvent attribute: "
+                                            << static_cast<int>(rAttr.type));
+                    break;
+            }
+        }
         if (nLength)
             aInputEvent.mpTextAttr = &aTextAttrs[0];
+
         m_pFrame->CallCallback(SalEvent::ExtTextInput, &aInputEvent);
         pEvent->accept();
     }