Display partial updates on slow transfers

Normally we only display screen changes once we have the updates for
the entire screen. This may give the impression that the viewer is
hung though. So display the partial data if the update is taking to
long to arrive.

vncviewer/CConn.cxx

@@ -133,6 +133,7 @@ CConn::CConn(const char* vncServerName, network::Socket* socket=NULL)
 CConn::~CConn()
 {
   OptionsDialog::removeCallback(handleOptions);
+  Fl::remove_timeout(handleUpdateTimeout, this);
 
   for (size_t i = 0; i < sizeof(decoders)/sizeof(decoders[0]); i++)
     delete decoders[i];
@@ -344,6 +345,9 @@ void CConn::framebufferUpdateStart()
   pendingUpdate = false;
 
   requestNewUpdate();
+
+  // Update the screen prematurely for very slow updates
+  Fl::add_timeout(1.0, handleUpdateTimeout, this);
 }
 
 // framebufferUpdateEnd() is called at the end of an update.
@@ -352,6 +356,7 @@ void CConn::framebufferUpdateStart()
 // appropriately, and then request another incremental update.
 void CConn::framebufferUpdateEnd()
 {
+  Fl::remove_timeout(handleUpdateTimeout, this);
   desktop->updateWindow();
 
   if (firstUpdate) {
@@ -692,3 +697,14 @@ void CConn::handleOptions(void *data)
       self->requestNewUpdate();
   }
 }
+
+void CConn::handleUpdateTimeout(void *data)
+{
+  CConn *self = (CConn *)data;
+
+  assert(self);
+
+  self->desktop->updateWindow();
+
+  Fl::repeat_timeout(1.0, handleUpdateTimeout, data);
+}

vncviewer/CConn.h

@@ -81,6 +81,8 @@ private:
 
   static void handleOptions(void *data);
 
+  static void handleUpdateTimeout(void *data);
+
 private:
   char* serverHost;
   int serverPort;

vncviewer/Viewport.cxx

@@ -170,7 +170,6 @@ const rfb::PixelFormat &Viewport::getPreferredPF()
 
 // Copy the areas of the framebuffer that have been changed (damaged)
 // to the displayed window.
-// FIXME: Make sure this gets called on slow updates
 
 void Viewport::updateWindow()
 {