LinkedImageFetcher.h

/*
    File:       LinkedImageFetcher.h
 
    Contains:   Downloads an HTML page and then downloads all of the referenced images.
 
    Written by: DTS
 
    Copyright:  Copyright (c) 2011-2013 Apple Inc. All Rights Reserved.
 
    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.
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                not use, install, modify or redistribute this Apple software.
 
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                original Apple software (the "Apple Software"), to use,
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*/
 
#import <Foundation/Foundation.h>
 
#import "QWatchedOperationQueue.h"
 
@protocol LinkedImageFetcherDelegate;
 
@interface LinkedImageFetcher : NSObject
{
    NSURL *                         _URL;
    NSUInteger                      _maximumDepth;
    NSString *                      _imagesDirPath;
    id<LinkedImageFetcherDelegate>  _delegate;
    QWatchedOperationQueue *        _queue;
    BOOL                            _done;
    NSError *                       _error;
    NSMutableSet *                  _foundPageURLs;
    NSMutableDictionary *           _foundImageURLToPathMap;
    NSUInteger                      _runningOperationCount;
}
 
+ (BOOL)isSupportedURL:(NSURL *)url;
 
- (id)initWithURL:(NSURL *)url;
    // Initialises the object to start by downloading the HTML at the 
    // specified URL.
 
// Things that are configured by the init method and can't be changed.
 
@property (nonatomic, copy,   readonly ) NSURL *        URL;
 
// Things you can change before calling -start.
 
@property (nonatomic, assign, readwrite) NSUInteger     maximumDepth;       // defaults to 0
@property (nonatomic, copy,   readwrite) NSString *     imagesDirPath;      // defaults to the "images" directory within the temporary directory
                                                                            // don't change this after calling -startWithURLString:
@property (nonatomic, assign, readwrite) id<LinkedImageFetcherDelegate> delegate;
 
// Things that are meaningful after you've called -start.
 
@property (nonatomic, assign, readwrite) BOOL           done;               // observable
@property (nonatomic, copy,   readonly ) NSError *      error;              // nil if no error
 
@property (nonatomic, copy,   readonly ) NSDictionary * imageURLToPathMap;  // NSURL -> NSNull (in progress), NSError (failed), NSString (downloaded)
 
// Methods to start and stop the fetch.  Note that this is a one-shot thing; 
// you can't call -stop and then call -start again.
 
- (BOOL)start;
- (void)stop;
 
+ (id)fetcherWithURLString:(const char *)urlCStr maximumDepth:(int)maximumDepth;
    // Convenience method for the command line test program.
    // Handles urlStr being nil.  Handles the URL scheme being unsupported.  
    // Handles maximum depth being negative.
 
@end
 
@protocol LinkedImageFetcherDelegate <NSObject>
 
@optional
 
- (void)linkedImageFetcher:(LinkedImageFetcher *)fetcher logText:(NSString *)text URL:(NSURL *)url depth:(NSUInteger)depth error:(NSError *)error;
    // You can implement this delegate method to do your own logging.
    // You're called with some text, the URL that the text relates to, 
    // the depth of that URL (0 if the it relates to the main page, 1 
    // if it relates to resource directly linked to from the main page, 
    // and so on) and an optional error.
 
@end