[LyX/master] Regularly check if preview is modified when visible on screen

[Guillaume Munch]

commit ac6d3ffb6a5c8b007d198681b169e1d68b0971e9
Author: Guillaume Munch <g...@lyx.org>
Date:   Sun Mar 19 14:41:54 2017 +0100

    Regularly check if preview is modified when visible on screen
    
    In case one cannot rely on QFileSystemWatcher.
---
 src/insets/RenderPreview.cpp |    3 ++-
 src/insets/RenderPreview.h   |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/insets/RenderPreview.cpp b/src/insets/RenderPreview.cpp
index 99abca9..e29ccc4 100644
--- a/src/insets/RenderPreview.cpp
+++ b/src/insets/RenderPreview.cpp
@@ -292,6 +292,7 @@ void RenderMonitoredPreview::draw(PainterInfo & pi, int x, 
int y) const
 {
        RenderPreview::draw(pi, x, y);
        startMonitoring();
+       monitor_->checkModifiedAsync();
 }
 
 
@@ -311,7 +312,7 @@ bool RenderMonitoredPreview::monitoring() const
 void RenderMonitoredPreview::startMonitoring() const
 {
        if (!monitoring()) {
-               monitor_ = FileSystemWatcher::monitor(filename_);
+               monitor_ = FileSystemWatcher::activeMonitor(filename_);
                monitor_->connect(changed_);
        }
 }
diff --git a/src/insets/RenderPreview.h b/src/insets/RenderPreview.h
index c6dd74d..42d944d 100644
--- a/src/insets/RenderPreview.h
+++ b/src/insets/RenderPreview.h
@@ -134,7 +134,7 @@ private:
        /// This signal is emitted if the file is modified
        ChangedSig changed_;
        ///
-       mutable support::FileMonitorPtr monitor_;
+       mutable support::ActiveFileMonitorPtr monitor_;
        ///
        support::FileName filename_;
 };