Status toolbar item like Xcode 4 and iTunes about xit

[Uncommon]

Apparently Xcode uses some trickery to achieve its full-height toolbar item.

http://stackoverflow.com/questions/6169255/is-it-possible-to-draw-in-the-label-area-of-nstoolbar

[Uncommon]

Since I'm working on this now, my plans:

• Show info about user-initialed git operations: load history, all write operations (commit, merge, etc)
• Updates for in-progress and complete
• A button will open a popover with the raw output from the last (or in-progress) operation

Technical challenges:

• As mentioned above, Xcode uses some hack to get around the limitation that there's no standard way for a toolbar item to draw in the label area. I may go with Xcode 4.1's overlay window approach.
• A custom flexible space item will be needed to keep the status item centered.

[Uncommon]

On the output popover: what if the output is really long, like the history of a very large repository? Truncate? Is it even useful to show output for that case?

[laullon]

put the output only on errors.

[Uncommon]

That's a good idea, at least for loading the history. I think I still want to put the successful output for cases where it will always be short.

[Uncommon]

Basic version is done in 66ba8e4. Refine it more when we hit other features that use it.