Open Radar

 
05-Apr-2013 04:33 PM Tim Ekl:
Summary: When specifying an array of NSLayoutConstraint instances using the visual format, a default Aqua space between a view and its immediate superview is unresolvable if the superview is referenced by name, instead of with the pipe (|) character.

Steps to Reproduce:
1. Create a new Cocoa application
2. Instantiate a button programmatically
3. Turn off translatesAutoresizingMaskIntoConstraints on the button
4. Add the button as a subview of the main window's content view
5. Add a constraint between the button and the main window's content view with the visual format: @"[contentView]-[button]"

Expected Results: The Auto Layout system interprets [contentView] as referring to the button's immediate superview and produces the appropriate Aqua space constraint.

Actual Results: The Auto Layout system logs an error:

2013-04-05 16:25:21.494 AquaSpaceSuperviewTest[97459:303] *** Assertion failure in -[NSLayoutConstraint constant], /SourceCache/Foundation/Foundation-945.16/Layout.subproj/NSLayoutConstraint.m:529
2013-04-05 16:25:21.495 AquaSpaceSuperviewTest[97459:303] Theme <NSAquaUserInterfaceTheme: 0x1021405d0> was unable to resolve symbolic constant <NSLayoutConstraint:0x10213eb90 H:[NSView:0x102124470]-(NSSpace(unresolvable))-[NSButton:0x10211d620'Button']> in constraint (null)

Regression: Unknown.

Notes: A sample app is forthcoming.




05-Apr-2013 04:38 PM Tim Ekl:
Sample app attached; to reproduce the problem, simply run the app, note the placement of the button, and observe the console output. A contrasting implementation is also provided that uses the superview | placeholder; to see the difference in behavior, change the value of CONSTRAIN_USING_SUPERVIEW_PLACEHOLDER to 1.

05-Apr-2013 04:38 PM Tim Ekl:
'AquaSpaceSuperviewTest.zip' was successfully uploaded