[SOLVED] Launch only one instance of KCalc

[kayvee]

My keyboard has a button to launch calculator and I often use it to launch KCalc. However, if I forget that I already have KCalc running and hit that key again, I end up with two instances of KCalc. Is there a way to switch to the running instance of KCalc instead of launching a new one? I don't need to use KCalc, I am open to any other calculator app.

[jlittle]

xdotool can do that sort of thing. I don't have a calculator key on my keyboard, so I don't know if it can be remapped.

But I have mapped a key to do what you want:

1. Install xdotool using your favourite method; f.ex. muon package manager.
2. Right-click the K-menu, select Edit applications, to start the KDE Menu Editor.
3. In some place you find sensible, maybe Utilities, make a new item, give it a name, and for the command use
   

   if ! xdotool search --classname --onlyvisible KCalc windowactivate; then kcalc;fi

4. On the advanced tab, set up a shortcut key by clicking the button that says "None".
5. Save the menu changes; maybe by clicking Save on the toolbar, or File->Save.

A big caveat is that I find xdotool can be capricious, illogical or inexplicable. Another caveat is that this is using the X window system, and with Wayland I imagine there'll be problems.

[chimak111]

I use wmctrl for this purpose.

Example: wmctrl -xa Konsole || konsole

I too don't have a Calculator key and so don't know whether this will work ...

[kayvee]

Thank you @jlittle and @chimak111
I am using wmctrl and it works perfectly!

[chimak111]

A big caveat is that I find xdotool can be capricious, illogical or inexplicable. Another caveat is that this is using the X window system, and with Wayland I imagine there'll be problems.

There's ydotool over at GitHub but it looks like the developer is facing some constraints.