CocoaDev

I’m using bindings to set up an NSBrowser with an NSTreeController. My app reliably crashes (runs out of stack space due to an infinite loop) when the window it is in is resized as narrowly as possible.

Here is the stack trace:

#0 0x958aa970 in tiny_malloc_from_free_list #1 0x958a382d in szone_malloc #2 0x958a3738 in malloc_zone_malloc #3 0x95f28cec in mem_heap_malloc #4 0x95f2ec26 in shape_union #5 0x95f2eb5b in shape_union_with_bounds #6 0x95f2ea32 in CGSUnionRegionWithRect #7 0x94bf631e in -[NSRegion addRect:] #8 0x94bf6211 in -[NSWindow _setNeedsDisplayInRect:] #9 0x94c9d77a in -[NSView _setKeyboardFocusRingNeedsDisplayInRect:force:] #10 0x94c9d48d in -[NSView setKeyboardFocusRingNeedsDisplayInRect:] #11 0x94db7d2c in -[NSScrollView setKeyboardFocusRingNeedsDisplayInRect:] #12 0x94c2bb7e in -[NSScrollView setNeedsDisplayInRect:] #13 0x94c9d48d in -[NSView setKeyboardFocusRingNeedsDisplayInRect:] #14 0x94db7d2c in -[NSScrollView setKeyboardFocusRingNeedsDisplayInRect:] … (ad infinitum)

Is there anything that I’m doing wrong here, in this VERY simple app, that could be causing this NSBrowser crash? Here is where the action is in the app:

#import “AppController.h”

@implementation AppController -(void)awakeFromNib {

rootArray = [NSMutableArray new];
treeController = [NSTreeController new];
NSTreeNode *root1 = [NSTreeNode treeNodeWithRepresentedObject:@"Root Node 1 "];
NSTreeNode *root2 = [NSTreeNode treeNodeWithRepresentedObject:@"Root Node 2 "];
NSTreeNode *child1 = [NSTreeNode treeNodeWithRepresentedObject:@"first child"];
NSTreeNode *child2 = [NSTreeNode treeNodeWithRepresentedObject:@"first child"];

root1 mutableChildNodes] addObject:child1];
[[root2 mutableChildNodes] addObject:child2];
[rootArray addObject:root1];
[rootArray addObject:root2];

[[NSLog(@"Awake from Nib called!!!");

[treeController setChildrenKeyPath:@"childNodes"];

//Without the following two lines, the app will not crash.
[treeController bind:@"contentArray" toObject:self withKeyPath:@"rootArray" options:nil];
[browser bind:@"content" toObject:treeController withKeyPath:@"arrangedObjects" options:nil];

[browser bind:@"contentValues" toObject:treeController withKeyPath:@"arrangedObjects.representedObject" options:nil];
NSLog(@"browser: %@", browser);

}

@end

The issue turns out to be unrelated to bindings. As narrowly as I’ve been able to define it thus far, infinite recursion is cause when an NSBrowser displaying more than one column of data is touching the edges of an NSWindow on all sides.

A simple solution could be to set the minimum size of the window and the minimum column width of the browser to reasonable values. Might make this go away completely. –JediKnil