NSSplitViewDelegate splitView:shouldCollapseSubview:forDoubleClickOnDividerAtIndex: never called in 10.11

Number:rdar://22675408 Date Originated:12-Sep-2015 07:30 PM
Status:Duplicate/22537402 Resolved:
Product:OS X SDK Product Version:
Classification: Reproducible:
My app includes a split view which, up until OS X 10.11, would let you double click its divider/split bar in order to collapse it. This no longer works and the corresponding method is never invoked.

Steps to Reproduce:
1. Compile the attached project with Xcode 7.
2. Run the project on OS X 10.10 and OS X 10.11.
3. Drag the split bar to the left and right of the window.
4. Double-click the split bar.

Expected Results:
The split bar snaps from 50 pixels from the left side of the window to the left edge of the window; it cannot be pulled closer than 50 pixels to the right edge of the window.

Double-clicking the split bar causes it to collapse to the left edge of the window, and a corresponding message is logged.

Actual Results:
Snapping works similarly on 10.10 and 10.11.

Nothing happens when I double-click on the split bar in 10.11, whereas it collapses on 10.10.

Xcode Version 7.0 (7A218) / OS X 10.11 (15A282b)


Broken on: OS X 10.11 (15A282b)
Works on: OS X 10.10.5 (14F27)

'SplitTest.zip' was successfully uploaded.


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!