Javascript Question

[Camerinthus]

This is for a friend who's making an addition to his computer which is running Linux Mint (12, I believe). Basically, he's making a little mod with a messaging popup (hover over an icon on taskbar, menu pops up) with a "Mail" option, along with several others. However, he wants it to not show up (only the Mail one) when the program it uses isn't installed.

How would you do that?


(To try to clarify: hover over icon in taskbar -> menu with ~5 options (looks sort of like mini start menu) -> mail icon + link at top)

[OneTripleZero]

This is a desktop application he's making? Do you mean Java, not Javascript? (They're two completely different things) If you mean Java, you might want to edit your title to bring in more traffic :)

[Elensaar]

No matter which one he's actually using, his app needs to check at startup if the third-party mail app is available. Worst-case scenario: try to run it and handle the error as an "available = false" ;) But most APIs used for coding these kinds of things have some call you can make to check the existence of files and such.

[OneTripleZero]

Right. There's really too little info here to give meaningful help without running the risk that we'll steer you both in the wrong direction. However, things such as popups typically initialize their contents when they are opened, not when their containing application is initialized, so they're probably going to need to look into the method(s)/routine(s) where the popup is generated, and make a check there to see if the mail app is installed. How will this be done? There's a lot of possibilities here so I won't speculate, but if your friend is knowledgeable enough to be writing Linux app extensions/mods they'll probably know where/how to do that.

edit: It sounds at first like I'm disagreeing with Elensaar re: proper time to check for the mail app, so I should clarify: checking for the mail app at the startup for your friend's app is probably best, and then they should store that result somewhere. When changing the contents of the popup, your friend will probably check his previously stored reference, and set the contents of the popup that way.