I've installed (sudo apt-get install indicator-synapse), and I see the icon on the wingpanel. However, I can't activate it with any shortcut (ctrl-space doesn't work, which I though was the default), and can't find the entry in dconf-editor (net/launchpad/indicator-synapse) to change the shortcut!
This solution worked for me originally posted by Karut on Launchpad:
Manually installing a newer (sucessfully built) build of synapse (529) actually solves this problem. Once you update synapse via package manager the problem of course will reappear.
Download it here.
There is a work around for this, using xdotool. This tool lets you simulate keyboard input and mouse activity, move and resize windows, etc. It does this using X11's XTEST extension and other Xlib functions.
Here, we are going to find the coordinates of the mouse, and emulate a mouse click on the synapse indicator using a command and set a shortcut key for the command.
Step 1: Install xdotool.
sudo apt-get install xdotool
Step 2: Move your mouse over the synapse icon and get mouse location
You should get output like this:
x:1105 y:14 screen:0 window:39845936
Step 3: Add keyboard shortcut for indicator
System Settings -> Keyboard -> Shortcuts -> Custom Shortcuts.
Click the + and enter the below command:
xdotool mousemove x y click 1 mousemove restore
y with the values you got. Set the shortcut as
Ctrl + Space Logout and Login again.