transmission/macosx/NSMutableArrayAdditions.m

/******************************************************************************
 * $Id$
 *
 * Copyright (c) 2011-2012 Transmission authors and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
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 * The above copyright notice and this permission notice shall be included in
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#import "NSMutableArrayAdditions.h"

@implementation NSMutableArray (NSMutableArrayAdditions)

/*
 Note: This assumes Apple implemented this as an array under the hood.
 If the underlying data structure is a linked-list, for example, then this might be less
 efficient than simply removing the object and re-adding it.
 */
- (void) moveObjectAtIndex: (NSUInteger) fromIndex toIndex: (NSUInteger) toIndex
{
    if (fromIndex == toIndex)
        return;
    
    id object = [[self objectAtIndex: fromIndex] retain];
    
    //shift objects - more efficient than simply removing the object and re-inserting the object
    if (fromIndex < toIndex)
    {
        for (NSUInteger i = fromIndex; i < toIndex; ++i)
            [self replaceObjectAtIndex: i withObject: [self objectAtIndex: i+1]];
    }
    else
    {
        for (NSUInteger i = fromIndex; i > toIndex; --i)
            [self replaceObjectAtIndex: i withObject: [self objectAtIndex: i-1]];
    }
    [self replaceObjectAtIndex: toIndex withObject: object];
    
    [object release];
}

@end