also build with older Qt versions

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@32612 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index 9e51f708ae913b67cdc2f635bed27b7a4dc6fe12..862870c7f973ba7f97e0ceed8ef3905b1e7598b8 100644 (file)
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -107,6 +107,7 @@
 
 #define EXPORT_in_THREAD 1
 
+
 // QtConcurrent was introduced in Qt 4.4
 #if (QT_VERSION >= 0x040400)
 #include <QFuture>
@@ -270,6 +271,7 @@ struct GuiView::GuiViewPrivate
                return tabWorkArea(0);
        }
 
+#if (QT_VERSION >= 0x040400)
        void setPreviewFuture(QFuture<docstring> const & f)
        {
                if (preview_watcher_.isRunning())
@@ -278,6 +280,7 @@ struct GuiView::GuiViewPrivate
                connect(&preview_watcher_, SIGNAL(finished()), gv_,
                        SLOT(threadFinished()));
        }
+#endif
 
 public:
        GuiView * gv_;
@@ -320,6 +323,9 @@ public:
        ///
        QFutureWatcher<docstring> autosave_watcher_;
        QFutureWatcher<docstring> preview_watcher_;
+#else
+       struct DummyWatcher { bool isRunning(){return false;} }; 
+       DummyWatcher preview_watcher_;
 #endif
 };