cog/Spotlight/SpotlightTransformers.m

//
//  SpotlightTransformers.m
//  Cog
//
//  Created by Matthew Grinshpun on 11/02/08.
//  Copyright 2008 Matthew Leon Grinshpun. All rights reserved.
//

#import "SpotlightTransformers.h"
#import "SpotlightWindowController.h"

// This is what we use instead of an outlet for PausingQueryTransformer
static SpotlightWindowController * searchController;

@implementation PausingQueryTransformer
+ (Class)transformedValueClass { return [NSArray class]; }
+ (BOOL)allowsReverseTransformation { return NO; }

+ (void)setSearchController:(SpotlightWindowController *)aSearchController
{
    searchController = aSearchController;
}

- (id)transformedValue:(id)value {
    // Rather unintuitively, this piece of code eliminates the "flicker"
    // when searching for new results, which resulted from a pause when the
    // search query stops gathering and sends an empty results array through KVO.
    if(([value count] > 0) || ([searchController.query isGathering]))
    {
        self.oldResults = (NSArray *)value;
    }
    return self.oldResults;
}

- (void)dealloc
{
    self.oldResults = nil;
}

@synthesize oldResults;

@end

@implementation AuthorToArtistTransformer
+ (Class)transformedValueClass { return [NSString class]; }
+ (BOOL)allowsReverseTransformation { return NO; }
- (id)transformedValue:(id)value {
    return [value objectAtIndex:0];
}
@end

@implementation PathToURLTransformer

+ (Class)transformedValueClass { return [NSURL class]; }
+ (BOOL)allowsReverseTransformation { return YES; }

// Convert from path to NSURL
- (id)transformedValue:(id)value {
    if (value == nil) return nil;

    return [NSURL fileURLWithPath:value];
}

// Convert from NSURL to path
- (id)reverseTransformedValue:(id)value {
    if (value == nil) return nil;
    
    return [value path];
}

@end

@implementation StringToSearchScopeTransformer

+ (Class)transformedValueClass { return [NSArray class]; }
+ (BOOL)allowsReverseTransformation { return NO; }

// Convert from URL string to Search Scope
- (id)transformedValue:(id)value {
    if (value == nil) return nil;
    
    NSURL *scope = [NSURL URLWithString:value];
    return @[scope];
}

@end

@implementation NumberToStringTransformer

+ (Class)transformedValueClass { return [NSString class]; }
+ (BOOL)allowsReverseTransformation { return NO; }

// Convert from NSNumber to NSString
- (id)transformedValue:(id)value {
    if (value == nil) return nil;
    
    // If there's an NS/CFNumber hiding in here...
    if([value respondsToSelector:@selector(stringValue)])
    {
        return [value stringValue];
    }
    
    return value; 
}

@end