0
Not a bug

Can't click on client monitors when using Synergy

Road-hog123 7 years ago updated by Michael (Ramen Software) 7 years ago 8

I run a Windows 10 Desktop (10.0.14393) and a Windows 10 Laptop (10.0.10586), using Synergy to use my desktop's mouse and keyboard on my laptop for ease of use. Both machines have 7+TT installed.

While 7+TT is running on my desktop, click events through Synergy onto the laptop screen don't register at all, although keystrokes, mouse movement and hover events still go through. If I disable 7+TT on my desktop PC, the issue goes away, but then I don't get any of the nice features of 7+TT on my desktop.

My theory would be that the process to interrupt click events on the taskbar is preventing click events being passed to Synergy or through the program at all, perhaps only when the mouse is "off the screen" on another connected PC's screen? If it is in fact a problem with Synergy and not 7+TT, I'll take it to their bug tracker instead. :)

Under review
  • Is the issue about mouse clicks in general, or only about clicking the taskbar?
  • Does the issue happen when all of the tweaker's options are disabled? If not, can you find out which option causes the issue?
  • Is the free version enough to reproduce the issue?
  • Any clicks on the second PC's screen do not register, even on the lock screen when there is no taskbar.
  • The issue goes away when all the options are turned off, I'll try and find out which it is that's causing the issue.

Any of the options in the 'Other taskbar options > Mouse wheel' section display the issue, I use the basic paid version of Synergy, but I'll find out if the free one has the same issue. :)

These options cause 7+ Taskbar Tweaker to setup a global mouse hook, but it doesn't handle mouse clicks, only the mouse wheel. It seems like an issue of Synergy.


You can try the following example, which demonstrates a global mouse hook, and see whether it causes the same issue. If it does, it's definitely an issue of Synergy.

The example is here, use the Download demo application [Version 1] link.

So with some experimentation I discovered a couple of things:

  • Synergy starts well before 7+TT, with clicking only ceasing to work when 7+TT starts and enables the mouse wheel features (as would be expected).
  • Enabling the mouse wheel features after the PC starts with those features disabled results in the issue returning.
  • If Synergy is restarted, even if mouse wheel features remain enabled, the problem goes away.
  • Disabling and re-enabling the mouse wheel features causes the issue to return, even after Synergy has been restarted.
  • Any instance of "mouse wheel features" can be replaced with "global mouse hook demo" and the issue is the same.

Seems like Synergy can deal with existing mouse hooks, but if one is set up while Synergy's server is running, it doesn't notice and can't deal with it... Time to take this to Synergy. :)

Not a bug

Great investigation. I'm closing this due to the last bullet - it's not a bug of 7+ Taskbar Tweaker.

I am unfamiliar with global mouse hooks, but despite it intending only to capture the mouse wheel, is it perhaps preventing mouse click events from being passed further on down the chain to other mouse hooks?

I ran Synergy in Debug2 mode (as suggested by a member of the Synergy development team) and found that mouse clicks weren't being detected on the server. This brings up a possibility that the clicks are being blocked by 7TT, even if it is unintentional. As I understand it, such blocking would cause any other mouse hook app not to detect mouse clicks, not just Synergy.

I've replied in the GitHub issue.