Use QMessageBox for toggleWarning if possible

[lyx.git] / src / frontends / qt4 / GuiWorkArea.cpp

diff --git a/src/frontends/qt4/GuiWorkArea.cpp b/src/frontends/qt4/GuiWorkArea.cpp
index 7a856ae90d24c4c6e6c11780fc9e81f8404a02f4..5835cbd9b63e061f4fa38025978fab506c460d41 100644 (file)
--- a/src/frontends/qt4/GuiWorkArea.cpp
+++ b/src/frontends/qt4/GuiWorkArea.cpp
@@ -1244,6 +1244,18 @@ void GuiWorkArea::Private::paintPreeditText(GuiPainter & pain)
 
 void GuiWorkArea::paintEvent(QPaintEvent * ev)
 {
+       // Do not trigger the painting machinery if we are not ready (see
+       // bug #10989). The second test triggers when in the middle of a
+       // dispatch operation.
+       if (view().busy() || d->buffer_view_->buffer().undo().activeUndoGroup()) {
+               // Since macOS has turned the screen black at this point, our
+               // backing store has to be copied to screen (this is a no-op
+               // except on macOS).
+               d->updateScreen(ev->rect());
+               ev->accept();
+               return;
+       }
+
        // LYXERR(Debug::PAINTING, "paintEvent begin: x: " << rc.x()
        //      << " y: " << rc.y() << " w: " << rc.width() << " h: " << rc.height());