I'm using an application on a remote desktop served by Guacamole 0.9.14 (Remote side: CentOS 7.5, MATE Desktop, TurboVNC 2.2, VirtualGL 2.6). The application uses the following workflow: If pressing the Spacebar (and holding it down) it shows an overlay on an OpenGL window it renders. This overlay has three buttons. Each button selects a different action for the 3D view (rotate, zoom, pan). So while the spacebar is pressed, I'm moving the mouse to this overlay, press the left mouse button to select the action, and then move the mouse (spacebar and left mouse button still pressed at the same time) to perform the action on the 3D view.
While a normal TurboVNC+VirtualGL connection works for this workflow, the behavior gets weird when guacamole is on top of it. The overlay flickers once I start moving the mouse (mouse button and spacebar pressed) and the 3D view doesn't perform the expected action. I suppose that guacamole has some difficulty passing the events to the remote session. It seems like it sends a series of key-down and key-release events instead of a single key-down event at the start and a key-release event at the end (at least the behavior of the remote application looks like this). Has anyone seen such a behavior?
