Add option to adjust power consumption format replacement field precision

[ajgae]

current behavior

the {power} (power in watts) format replacement can take up a variable amount of characters, which sometimes leads to a shorter or longer character count for the battery module on my waybar:

better behavior

allow the user to specify the amount of decimal places so that character count stays constant (essentially something like %4.2f in printf)

[jramrath]

I think making an option to configure the number of decimals is not necessary.

I'll make a PR to always shows two decimals.

[alebastr]

essentially something like %4.2f in printf

That should translate to {power:4.2f}. Does it do what you wanted?

[phonetic112]

You could use padright() from the string library in Lua, but that might have some limitations if your generated text is larger than your field width so choose wisely.

[ajgae]

That should translate to {power:4.2f}. Does it do what you wanted?

@alebastr sadly it does not, this seems to have no effect at all.

I think making an option to configure the number of decimals is not necessary.

I'll make a PR to always shows two decimals.

@jramrath i think it might be good to have the option, as some people may be short on waybar space and want to only show one or even no decimals. But I think showing only two by default may still be an improvement. Do you know where in the codebase the format string interpolation is done, and whether it would be reasonably easy to implement an option for number of decimals? (something like {power:4.2f} like suggested above, or via an additional key-value pair in the json config file)?

[ajgae]

I see now that waybar uses the {fmt} library for label formatting. Given the official example for how fmt::arg works, and the way it is used in the battery module, it seems the {power:4.2f} suggestion should work. Why does it not?

[ajgae]

Nevermind this. I was simply changing the value of the format key in my config file while having unchanged format-discharging and format-charging values. The {power:4.2f} suggestion does work. I now also realize that this is mentioned in the FAQ, so my bad for opening the issue. I think it may be useful to mention that {fmt} is used as the formatting library in the configuration section of the wiki, but it's up to the people who maintain the documentation to see if it they think it fit to be mentioned there as well.