Question

I’m trying to display an NSPopover with additional information to a selected row of an NSTableView. For that I need to get a reference to the view representation of the selected row so I can “attach” my popover to it:

    NSInteger row = [[self membersTableView] selectedRow];
    NSTableRowView *aView = [[self membersTableView] rowViewAtRow: row makeIfNecessary: YES];
    [self setQuickLookPopoverController: [QuickLookPopoverController showPopoverFor: anObject at: aView]];

In the above, the result of aView is always nil. According to Apple documentation, this is the method to obtain a view object, given a selected row. Especially the last sentence of the discussion is a bit weird:

Discussion This method will first attempt to return a currently
displayed view in the visible area. If there is no visible view, and
makeIfNecessary is YES, a prepared temporary view is returned. If
makeIfNecessary is NO, and the view is not visible, nil will be
returned.

In general, makeIfNecessary should be YES if you require a resulting
view, and NO if you only want to update properties on a view only if
it is available (generally this means it is visible).

An exception will be thrown if row is not within the numberOfRows. The
returned result should generally not be held onto for longer than the
current run loop cycle. It is better to call
rowViewAtRow:makeIfNecessary: whenever a view is required..

Why is this method always returning nil?

Answer 1

Solved it. I used NSTableView’s method (NSRect) rectOfRow: (NSInteger) rowIndex which will give the frame of the required row.