lokdialog: Smoother mouse move on floating windows

Do away with an early hack to create the floating window with every
invalidate.

This gets rid of persistent blinking when moving the mouse over a
listbox, for example.

Change-Id: Ida9367156605edc9835529f83529363ad97beaee

libreofficekit/qa/gtktiledviewer/gtv-lok-dialog.cxx

@@ -598,34 +598,34 @@ void gtv_lok_dialog_child_invalidate(GtvLokDialog* dialog, int nX, int nY)
 
     GtvLokDialogPrivate* priv = getPrivate(dialog);
     // remove any existing floating windows, for now
-    if (priv->pFloatingWin)
-        gtk_widget_destroy(priv->pFloatingWin);
-
-    priv->pFloatingWin = gtk_window_new(GTK_WINDOW_POPUP);
-    GtkWidget* pDrawingArea = gtk_drawing_area_new();
-    gtk_container_add(GTK_CONTAINER(priv->pFloatingWin), pDrawingArea);
-
-    gtk_window_set_transient_for(GTK_WINDOW(priv->pFloatingWin), GTK_WINDOW(dialog));
-    gtk_window_set_destroy_with_parent(GTK_WINDOW(priv->pFloatingWin), true);
-
-    gtk_widget_add_events(pDrawingArea,
-                          GDK_BUTTON_PRESS_MASK
-                          |GDK_POINTER_MOTION_MASK
-                          |GDK_BUTTON_RELEASE_MASK
-                          |GDK_BUTTON_MOTION_MASK);
-
-    g_signal_connect(G_OBJECT(pDrawingArea), "draw", G_CALLBACK(gtv_lok_dialog_floating_win_draw), dialog);
-    g_signal_connect(G_OBJECT(pDrawingArea), "button-press-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_button), dialog);
-    g_signal_connect(G_OBJECT(pDrawingArea), "button-release-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_button), dialog);
-    g_signal_connect(G_OBJECT(pDrawingArea), "motion-notify-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_motion), dialog);
-
-    gtk_widget_set_size_request(priv->pFloatingWin, 1, 1);
-    gtk_window_set_type_hint(GTK_WINDOW(priv->pFloatingWin), GDK_WINDOW_TYPE_HINT_POPUP_MENU);
-    gtk_window_set_screen(GTK_WINDOW(priv->pFloatingWin), gtk_window_get_screen(GTK_WINDOW(dialog)));
-
-    gtk_widget_show_all(priv->pFloatingWin);
-    gtk_window_present(GTK_WINDOW(priv->pFloatingWin));
-    gtk_widget_grab_focus(pDrawingArea);
+    if (!priv->pFloatingWin)
+    {
+        priv->pFloatingWin = gtk_window_new(GTK_WINDOW_POPUP);
+        GtkWidget* pDrawingArea = gtk_drawing_area_new();
+        gtk_container_add(GTK_CONTAINER(priv->pFloatingWin), pDrawingArea);
+
+        gtk_window_set_transient_for(GTK_WINDOW(priv->pFloatingWin), GTK_WINDOW(dialog));
+        gtk_window_set_destroy_with_parent(GTK_WINDOW(priv->pFloatingWin), true);
+
+        gtk_widget_add_events(pDrawingArea,
+                              GDK_BUTTON_PRESS_MASK
+                              |GDK_POINTER_MOTION_MASK
+                              |GDK_BUTTON_RELEASE_MASK
+                              |GDK_BUTTON_MOTION_MASK);
+
+        g_signal_connect(G_OBJECT(pDrawingArea), "draw", G_CALLBACK(gtv_lok_dialog_floating_win_draw), dialog);
+        g_signal_connect(G_OBJECT(pDrawingArea), "button-press-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_button), dialog);
+        g_signal_connect(G_OBJECT(pDrawingArea), "button-release-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_button), dialog);
+        g_signal_connect(G_OBJECT(pDrawingArea), "motion-notify-event", G_CALLBACK(gtv_lok_dialog_floating_win_signal_motion), dialog);
+
+        gtk_widget_set_size_request(priv->pFloatingWin, 1, 1);
+        gtk_window_set_type_hint(GTK_WINDOW(priv->pFloatingWin), GDK_WINDOW_TYPE_HINT_POPUP_MENU);
+        gtk_window_set_screen(GTK_WINDOW(priv->pFloatingWin), gtk_window_get_screen(GTK_WINDOW(dialog)));
+
+        gtk_widget_show_all(priv->pFloatingWin);
+        gtk_window_present(GTK_WINDOW(priv->pFloatingWin));
+        gtk_widget_grab_focus(pDrawingArea);
+    }
 
     // Get the root coords of our new floating window
     GdkWindow* pGdkWin = gtk_widget_get_window(GTK_WIDGET(dialog));
@@ -633,6 +633,8 @@ void gtv_lok_dialog_child_invalidate(GtvLokDialog* dialog, int nX, int nY)
     int nrY = 0;
     gdk_window_get_root_coords(pGdkWin, nX, nY, &nrX, &nrY);
     gtk_window_move(GTK_WINDOW(priv->pFloatingWin), nrX, nrY);
+
+    gtk_widget_queue_draw(priv->pFloatingWin);
 }
 
 void gtv_lok_dialog_child_close(GtvLokDialog* dialog)