Add xhandler hook

Boiler plate code to intercept system events from FLTK so that
we can generate proper keyboard messages.

1 files changed, 31 insertions, 0 deletions

diff --git a/vncviewer/Viewport.cxx b/vncviewer/Viewport.cxx
index 16b34e6c..2b22a973 100644
--- a/vncviewer/Viewport.cxx
+++ b/vncviewer/Viewport.cxx
@@ -100,6 +100,11 @@ Viewport::Viewport(int w, int h, const rfb::PixelFormat& serverPF, CConn* cc_)
   Fl::add_clipboard_notify(handleClipboardChange, this);
 #endif
 
+#ifdef HAVE_FLTK_XHANDLERS
+  // We need to intercept keyboard events early
+  Fl::add_xhandler(handleXEvent, this);
+#endif
+
   frameBuffer = createFramebuffer(w, h);
   assert(frameBuffer);
 
@@ -132,6 +137,10 @@ Viewport::~Viewport()
   // again later when this object is already gone.
   Fl::remove_timeout(handlePointerTimeout, this);
 
+#ifdef HAVE_FLTK_XHANDLERS
+  Fl::remove_xhandler(handleXEvent);
+#endif
+
 #ifdef HAVE_FLTK_CLIPBOARD
   Fl::remove_clipboard_notify(handleClipboardChange);
 #endif
@@ -620,6 +629,28 @@ void Viewport::handleKeyRelease(int keyCode)
 }
 
 
+bool Viewport::handleXEvent(void *event, void *data)
+{
+  Viewport *self = (Viewport *)data;
+  Fl_Widget *focus;
+
+  assert(self);
+
+  focus = Fl::grab();
+  if (!focus)
+    focus = Fl::focus();
+  if (!focus)
+    return false;
+
+  if (focus != self)
+    return false;
+
+  assert(event);
+
+  return false;
+}
+
+
 rdr::U32 Viewport::translateKeyEvent(void)
 {
   unsigned ucs;