FileSystemNode.m

/*

     File: FileSystemNode.m

 Abstract: An abstract wrapper node around the file system.

  Version: 1.2

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 */

#import "FileSystemNode.h"

@implementation FileSystemNode

- (id)initWithURL:(NSURL *)url {

    if (self = [super init]) {

        _url = [url retain];

    }

    return self;

}

- (void)dealloc {

    // We have to release the underlying ivars associated with our properties

    [_url release];

    [_children release];

    [super dealloc];

}

- (NSString *)description {

    return [NSString stringWithFormat:@"%@ - %@", super.description, _url];

}

@synthesize URL = _url;

@dynamic displayName, children, isDirectory, icon, labelColor;

- (NSString *)displayName {

    id value = nil;

    NSError *error;

    if ([_url getResourceValue:&value forKey:NSURLLocalizedNameKey error:&error]) {

        return [value retain]; // hack work around the crash

    } else {

        return [error localizedDescription];

    }

}

- (NSImage *)icon {

    return [[NSWorkspace sharedWorkspace] iconForFile:[_url path]];

}

- (BOOL)isDirectory {

    id value = nil;

    [_url getResourceValue:&value forKey:NSURLIsDirectoryKey error:nil];

    return [value boolValue];

}

- (NSColor *)labelColor {

    id value = nil;

    [_url getResourceValue:&value forKey:NSURLLabelColorKey error:nil];

    return value;

}

// We are equal if we represent the same URL. This allows children to reuse the same instances.

- (BOOL)isEqual:(id)object {

    if ([object isKindOfClass:[FileSystemNode class]]) {

        FileSystemNode *other = (FileSystemNode *)object;

        return [other.URL isEqual:self.URL];

    } else {

        return NO;

    }

}

- (NSUInteger)hash {

    return self.URL.hash;

}

- (NSArray *)children {

    if (_children == nil || _childrenDirty) {

        // This logic keeps the same pointers around, if possible.

        NSMutableArray *newChildren = [NSMutableArray array];

        CFURLEnumeratorRef enumerator = CFURLEnumeratorCreateForDirectoryURL(NULL, (CFURLRef)_url, kCFURLEnumeratorSkipInvisibles, (CFArrayRef)[NSArray array]);

        NSURL *childURL = nil;

    CFURLEnumeratorResult enumeratorResult;

    do {

            enumeratorResult = CFURLEnumeratorGetNextURL(enumerator, (CFURLRef *)&childURL, NULL);

            if (enumeratorResult == kCFURLEnumeratorSuccess) {

                FileSystemNode *node = [[[FileSystemNode alloc] initWithURL:childURL] autorelease];

                if (_children != nil) {

                    NSInteger oldIndex = [_children indexOfObject:childURL];

                    if (oldIndex != NSNotFound) {

                        // Use the same pointer value, if possible

                        node = [_children objectAtIndex:oldIndex];

                    }

                }

                [newChildren addObject:node];

            } else if (enumeratorResult == kCFURLEnumeratorError) {

                // A possible enhancement would be to present error-based items to the user.

            }

    } while (enumeratorResult != kCFURLEnumeratorEnd);

        CFRelease(enumerator);

        [_children release];

        _childrenDirty = NO;

        // Now sort them

        _children = [[newChildren sortedArrayUsingComparator:^(id obj1, id obj2) {

            NSString *objName = [obj1 displayName];

            NSString *obj2Name = [obj2 displayName];

            NSComparisonResult result = [objName compare:obj2Name options:NSNumericSearch | NSCaseInsensitiveSearch | NSWidthInsensitiveSearch | NSForcedOrderingSearch range:NSMakeRange(0, [objName length]) locale:[NSLocale currentLocale]];

            return result;

        }] retain];

    }

    return _children;

}

- (void)invalidateChildren {

    _childrenDirty = YES;

    for (FileSystemNode *child in _children) {

        [child invalidateChildren];

    }

}

@end