Hi, I have no problems using Alt+1 for opening Project tool window on Windows but I can't get Alt+1 to work on Ubuntu 18.04.1 LTS.
The issue is that Phpstorm doesn't recognize Alt+1 as Alt+1 but as Alt+Plus. The same for Ctrl+1 (Ctrl+Plus).
I found out by testing the shortcut with Phpstorm / Settings / Keymap / Find Actions by Shortcut.
I have English and Czech keyboards installed in Ubuntu, Alt+Plus is detected regardless of which keyboard layout is active.
I would expect Alt+Plus to be detected only with the Czech keyboard layout (Czech mapping for the numeric keys is 1=+, 2=ě, 3=š...). When I press Alt+2 with Czech layout, Phpstorm correctly shows Alt+ě. I switch to English layout and Phpstorm correctly shows Alt+2.
It's just key with number one that's stuck with +.
There's no system-wide shortcut for Alt+1 and the configuration app for system-wide shortcuts correctly recognizes Alt+1 or Alt++ when I try to create a new shortcut.
As a workaround, I added Alt+Plus as a secondary shortcut for the Project tool window. But still, I'd like to find the culprit in case it affects something else as well.