You all know the menu bar (or better said NSStatusBar) in Mac OS X.
There are some items which I can move and other which not.
I would like to be able to drag the NSStatusItem of my app.
Any idea how to implement this?
Although NSStatusItems appear near Apple's internal "menu extras", they are distinct and behave differently. It would be nice if Apple unified the items that can appear in the right-hand area of the menu bar, but for now the section is split into distinct "apple internal" (on the right), and "app-provided (NSStatusItem)" on the left.
You can visualize the distinction by putting your computer into screen capture mode (cmd-shift-4), and pressing the space bar to switch to "capture whole window". When you hover over Apple's menu icons, you'll see that they all live in a single window. This explains their ability to be easily managed and dragged about. Hovering over the other items reveals that each NSStatusItem is in fact living in a single window of its own (which happens to be owned by the application that installed it).
It's best to stick with NSStatusItem even though you can't drag them. It's a shortcoming from Apple which most users will understand, even if it's annoying. Emphasizing the positive tradeoffs of offering a more stable application for the long term will usually soften the opinions of your customers (or managers?) who are pushing for the draggability.