/*

     File: LoadOperation.m 

 Abstract: NSOperation code for examining image files.

  Version: 1.3 

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 */

#import "LoadOperation.h"

// key for obtaining the current scan count

NSString *kScanCountKey = @"scanCount";

// key for obtaining the path of an image fiel

NSString *kPathKey = @"path";

// key for obtaining the size of an image file

NSString *kSizeKey = @"size";

// key for obtaining the name of an image file

NSString *kNameKey = @"name";

// key for obtaining the mod date of an image file

NSString *kModifiedKey = @"modified";

// NSNotification name to tell the Window controller an image file as found

NSString *kLoadImageDidFinish = @"LoadImageDidFinish";

@interface LoadOperation ()

{

    NSURL *loadURL;

    NSInteger ourScanCount;

}

@property (retain) NSURL *loadURL;

@end

@implementation LoadOperation

@synthesize loadURL;

// -------------------------------------------------------------------------------

//  initWithPath:path

// -------------------------------------------------------------------------------

- (id)initWithURL:(NSURL *)url scanCount:(NSInteger)scanCount

{

    self = [super init];

    if (self)

    {

        self.loadURL = url;

        ourScanCount = scanCount;

    }

    return self;

}

// -------------------------------------------------------------------------------

//  isImageFile:filePath

//

//  Uses LaunchServices and UTIs to detect if a given file path is an image file.

// -------------------------------------------------------------------------------

- (BOOL)isImageFile:(NSURL *)url

{

    BOOL isImageFile = NO;

    NSString *utiValue;

    [url getResourceValue:&utiValue forKey:NSURLTypeIdentifierKey error:nil];

    if (utiValue)

    {

        isImageFile = UTTypeConformsTo((__bridge CFStringRef)utiValue, kUTTypeImage);

    }

    return isImageFile;

}

// -------------------------------------------------------------------------------

//  main:

//

//  Examine the given file (from the NSURL "loadURL") to see it its an image file.

//  If an image file examine further and report its file attributes.

//

//  We could use NSFileManager, but to be on the safe side we will use the

//  File Manager APIs to get the file attributes.

// -------------------------------------------------------------------------------

- (void)main

{

    if (![self isCancelled])

    {

        // test to see if it's an image file

        if ([self isImageFile:loadURL])

        {

            // in this example, we just get the file's info (mod date, file size) and report it to the table view

            //

            NSNumber *fileSize;

            [self.loadURL getResourceValue:&fileSize forKey:NSURLFileSizeKey error:nil];

            NSDate *fileCreationDate;

            [self.loadURL getResourceValue:&fileCreationDate forKey:NSURLCreationDateKey error:nil];

            NSDateFormatter* formatter = [[NSDateFormatter alloc] init];

            [formatter setTimeStyle:NSDateFormatterNoStyle];

            [formatter setDateStyle:NSDateFormatterShortStyle];

            NSString *modDateStr = [formatter stringFromDate:fileCreationDate];

            NSDictionary *info = [NSDictionary dictionaryWithObjectsAndKeys:

                                  [self.loadURL lastPathComponent], kNameKey,

                                  [self.loadURL absoluteString], kPathKey,

                                  modDateStr, kModifiedKey,

                                  [NSString stringWithFormat:@"%ld", [fileSize integerValue]], kSizeKey,

                                  [NSNumber numberWithInteger:ourScanCount], kScanCountKey,  // pass back to check if user cancelled/started a new scan

                                  nil];

            if (![self isCancelled])

            {

                // for the purposes of this sample, we're just going to post the information

                // out there and let whoever might be interested receive it (in our case its MyWindowController).

                //

                [[NSNotificationCenter defaultCenter] postNotificationName:kLoadImageDidFinish object:nil userInfo:info];

            }

        }

    }

}

@end