discover keybindings "when" conditionals

[r2evans]

I recently met with some fantastic Positron helpers (at posit::conf) and they were helping me discover various components for defining keybindings. One of the tricks was using Developer Tools to discover what was currently defined and/or available for "when".

In my case, I'm trying to determine if the text editor currently has a range of text highlighted/selected to differentiate certain action. Namely, on the first keypress I'd like to highlight between the previous and the next occurrence of ^ *$, effectively a block of code.

I've started with

{
    "key":"cmd+. q", "command":"runCommands",
    "when": "editorTextFocus",
    "args": {
        "commands": [
            {
                "command": "editor.actions.findWithArgs",
                "args": {
                    "searchString": "^ *$",
                    "isRegex": true
                 }
            },
            "editor.action.previousMatchFindAction",
            "closeFindWidget",
        ]
    }
}

This is imperfect (it wraps in its search), but it starts the process. The next step would be to start a selection and go to the next occurrence of ^ *$ (or EOF, though that may be too far).

All of that is one condition, when nothing is currently selected. When something is selected, I think I need to extend "when" so that not only is the editor in focus, but there is currently a selection, where the intended action is now to extend the selection end until the next pattern, not change the selection begin, and repeated cmd+. q presses will iteratively expand the selection end.

(I'm learning how to learn this, though if you can also help with the list of commands to do this, that would also be appreciated. But please teach me to fish too :-)

[juliasilge]

Thank you for the kind words, and for chatting with us at posit::conf!

There are some context keys documented here:
https://code.visualstudio.com/api/references/when-clause-contexts#available-context-keys

You might see if using editorHasSelection gets you what you need.

[r2evans]

Thanks! Something Sam showed me was the ability to go into DevTools and either activate something or type in a variable name that listed all of the current contexts. I suspect that's not intended for general consumption/use, but I found it particularly enlightening as I learn this new ecosystem. In addition to showing what is possible (your link), I think it showed what was currently active. Did I misinterpret what he was exploring?

[juliasilge]

Ah yep, that is a super cool thing to be able to do! I think I didn't understand what you were asking about. First you run Developer: Toggle Developer Tools to bring up the Developer Tools console. Then you run Developer: Inspect Context Keys to set up the special functionality for seeing all the context keys. At this point you will have a special cursor that highlights exactly the part of the UI where you can explore it. Click where you are interested in, and then in the Developer Tools console you will see something like:

Click to expand that, and you will see all the context keys from the spot you clicked your cursor. You can read a bit more about this here:
https://code.visualstudio.com/api/references/when-clause-contexts#inspect-context-keys-utility

[r2evans]

That is precisely what I was going for, thank you @juliasilge !

It did take me a moment to recognize that Developer: Inspect Context Keys was in the command palette. While that seems obvious, I had started by selecting the Help > Toggle Developer Tools menu item instead of using the command palette, not realizing it was in both.

(And I think I have confirmed the behavior of editorHasSelection that I was looking for.)