Mouseover in NSTableView

Question

I'm having trouble creating a mouseover function with an NSTableView. The idea is that (if the feature is selected in prefs) placing the mouse pointer above a particular row in an NSTabelView will display a small popup window with additional information regarding the entry in that particular row. The effect should not be immediate (as e.g. highliting a button when rolling over it), but come with a delay of a few seconds.

So far, I have implemented this functionality using the tooltip delegate method, but this does not allow for customization of the window and does not work well (layout wise) if more than 1-3 rows of info need to be displayed.

In Hillegass' book it is suggested that one uses the mouseEntered/mouseExited methods for rollovers, but as far as I can tell this works with pre-defined areas of a window and not rows in a table view.

Does anyone have any suggestions?

Gregor Tomasevic, Sweden

Answer 1

You're on the right track with -mouseEntered: and -mouseExited:.

Look into NSView's -addTrackingRect:owner:userData:assumeInside: and -removeTrackingRect: methods. You can either set up your tableView to create trackingRects for every row that's in there whenever the contents of the tableView change, or alternatively, set up/update one tracking area on the entire tableView whenever -tile or another layout related method is called.