Gui: add WaitCursor API

src/Gui/ApplicationPy.cpp

@@ -430,6 +430,12 @@ PyMethodDef ApplicationPy::Methods[] = {
    "Remove all children from a group node.\n"
    "\n"
    "node : object"},
+  {"suspendWaitCursor", (PyCFunction) ApplicationPy::sSuspendWaitCursor, METH_VARARGS,
+   "suspendWaitCursor() -> None\n\n"
+   "Temporarily suspends the application's wait cursor and event filter."},
+  {"resumeWaitCursor",  (PyCFunction) ApplicationPy::sResumeWaitCursor, METH_VARARGS,
+   "resumeWaitCursor() -> None\n\n"
+   "Resumes the application's wait cursor and event filter."},
   {nullptr, nullptr, 0, nullptr}    /* Sentinel */
 };
 
@@ -1813,3 +1819,23 @@ PyObject* ApplicationPy::sSetUserEditMode(PyObject * /*self*/, PyObject *args)
 
     return Py::new_reference_to(Py::Boolean(ok));
 }
+
+PyObject* ApplicationPy::sSuspendWaitCursor(PyObject * /*self*/, PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, "")) {
+        return nullptr;
+    }
+
+    WaitCursor::suspend();
+    Py_RETURN_NONE;
+}
+
+PyObject* ApplicationPy::sResumeWaitCursor(PyObject * /*self*/, PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, "")) {
+        return nullptr;
+    }
+
+    WaitCursor::resume();
+    Py_RETURN_NONE;
+}

src/Gui/ApplicationPy.h

@@ -111,6 +111,9 @@ public:
     static PyObject* sGetUserEditMode          (PyObject *self,PyObject *args);
     static PyObject* sSetUserEditMode          (PyObject *self,PyObject *args);
 
+    static PyObject* sSuspendWaitCursor        (PyObject *self, PyObject *args);
+    static PyObject* sResumeWaitCursor         (PyObject *self, PyObject *args);
+
     static PyMethodDef    Methods[];
     // clang-format on
 };

src/Gui/WaitCursor.cpp

@@ -189,3 +189,16 @@ void WaitCursor::setIgnoreEvents(FilterEventsFlags flags)
 {
     WaitCursorP::getInstance()->setIgnoreEvents(flags);
 }
+
+void WaitCursor::suspend()
+{
+    // Calling setBusy(false) will restore the cursor and remove the event filter.
+    WaitCursorP::getInstance()->setBusy(false);
+}
+
+void WaitCursor::resume()
+{
+    // Calling setBusy(true) will set the wait cursor and reinstall the event filter.
+    // The WaitCursorP's internal state `isOn` correctly handles this call.
+    WaitCursorP::getInstance()->setBusy(true);
+}

src/Gui/WaitCursor.h

@@ -75,6 +75,19 @@ public:
     FilterEventsFlags ignoreEvents() const;
     void setIgnoreEvents(FilterEventsFlags flags = AllEvents);
 
+    /**
+     * @brief Suspends the wait cursor state by restoring the normal cursor
+     * and removing the event filter. To be used before showing an interactive
+     * dialog during a long operation.
+     */
+    static void suspend();
+
+    /**
+     * @brief Resumes the wait cursor state by setting the wait cursor
+     * and reinstalling the event filter, if a WaitCursor is active.
+     */
+    static void resume();
+
 private:
     FilterEventsFlags filter;
     static int instances;