Retired Document
Important: This sample code may not represent best practices for current development. The project may use deprecated symbols and illustrate technologies and techniques that are no longer recommended.
ImageClient4-proxy/ImageClient.m
/* |
File: ImageClient.m |
Abstract: CFNetwork ImageClient Sample |
Version: 1.0 |
Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple |
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"Apple Software"), to use, reproduce, modify and redistribute the Apple |
Software, with or without modifications, in source and/or binary forms; |
provided that if you redistribute the Apple Software in its entirety and |
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Neither the name, trademarks, service marks or logos of Apple Computer, |
Inc. may be used to endorse or promote products derived from the Apple |
Software without specific prior written permission from Apple. Except |
as expressly stated in this notice, no other rights or licenses, express |
or implied, are granted by Apple herein, including but not limited to |
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other works in which the Apple Software may be incorporated. |
The Apple Software is provided by Apple on an "AS IS" basis. APPLE |
MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION |
THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS |
FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND |
OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS. |
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Copyright (c) 2005 Apple Computer, Inc., All Rights Reserved |
*/ |
#import "ImageClient.h" |
#import "CFNetworkLoader.h" |
#import "NSURLLoader.h" |
#import <sys/socket.h> |
#import <netinet/in.h> |
const int kCFNetworkIndex = 0; |
const int kFoundationIndex = 1; |
const NSTimeInterval kRefetchInterval = 15.0; |
@implementation ImageClient |
- (id)init { |
if (self = [super init]) { |
cfnetworkLoader = [[CFNetworkLoader alloc] initWithImageClient:self]; |
nsurlLoader = [[NSURLLoader alloc] initWithImageClient:self]; |
useCFNetworkLoader = YES; |
srandomdev(); // Seed the random number generator |
} |
return self; |
} |
// Included for form's sake; our ImageClient object will be around for as long as the app is running |
- (void)dealloc { |
if (reloadTimer) { |
[reloadTimer invalidate]; |
[reloadTimer release]; |
} |
[cfnetworkLoader release]; |
[nsurlLoader release]; |
[super dealloc]; |
} |
// Create and start the timer that triggers a refetch every few seconds |
- (void)startTimer { |
[self stopTimer]; |
reloadTimer = [NSTimer scheduledTimerWithTimeInterval:kRefetchInterval target:self selector:@selector(refetch:) userInfo:nil repeats:YES]; |
[reloadTimer retain]; |
} |
// Stop the timer; prevent future loads until startTimer is called again |
- (void)stopTimer { |
if (reloadTimer) { |
[reloadTimer invalidate]; |
[reloadTimer release]; |
reloadTimer = nil; |
} |
} |
/* Called when the user enters a new URL in the textfield */ |
- (IBAction)newURL:(id)sender { |
// Clean up any loads in progress & restart the timer |
if (reloadTimer) { |
[self stopTimer]; |
[self cancelLoad]; |
} |
NSString *urlString = [urlField stringValue]; |
if (urlString && [urlString length]) { |
[self startTimer]; |
[self startLoad]; |
} |
} |
/* Triggered when the user chooses a different library for loading */ |
- (IBAction)libraryChanged:(id)sender { |
NSSegmentedControl *segControl = sender; |
int selectedLibrary = [segControl selectedSegment]; |
if ((selectedLibrary == kCFNetworkIndex && !useCFNetworkLoader) || (selectedLibrary == kFoundationIndex && useCFNetworkLoader)) { |
[self stopTimer]; |
[self cancelLoad]; |
useCFNetworkLoader = (selectedLibrary == kCFNetworkIndex); |
if ([urlField stringValue] && [[urlField stringValue] length]) { |
[self startTimer]; |
[self startLoad]; |
} |
} |
} |
/* The method called by our timer */ |
- (void)refetch:(NSTimer *)timer { |
[self startLoad]; |
} |
/* Starting and stopping loads */ |
- (void)startLoad { |
// choose a random picture from among 100 |
long randomNum = random(); |
int index = randomNum % 100; |
NSURL *url = [[NSURL alloc] initWithString:[NSString stringWithFormat:@"%@/%d.JPG", [[urlField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]], index]]; |
if (useCFNetworkLoader) { |
[cfnetworkLoader loadURL:url]; |
} else { |
[nsurlLoader loadURL:url]; |
} |
[url release]; |
} |
- (void)cancelLoad { |
if (useCFNetworkLoader) { |
[cfnetworkLoader cancelLoad]; |
} else { |
[nsurlLoader cancelLoad]; |
} |
[imageView setImage:nil]; |
} |
/* Called by the two loaders to report successful image loads */ |
- (void)setImageData:(NSData *)imageData { |
NSImage *image = [[NSImage alloc] initWithData:imageData]; |
[imageView setImage:image]; |
[image release]; |
} |
/* Called by the two loaders to report errors while loading images */ |
- (void)errorOccurredLoadingImage: (CFNetDiagnosticRef)diagnostics { |
[self stopTimer]; |
if (diagnostics) { |
NSBeginAlertSheet(@"Download failure", @"Network Diagnostics...", @"OK", nil, [imageView window], self, @selector(errorSheetDidEnd:returnCode:contextInfo:), NULL, (void*)diagnostics, @"Could not load an image from \"%@\"", [urlField stringValue]); |
} else { |
NSBeginAlertSheet(@"Download failure", @"OK", nil, nil, [imageView window], nil, NULL, NULL, NULL, @"Could not load an image from \"%@\"", [urlField stringValue]); |
} |
} |
// delegate call for the diagnostic sheet dropped in -errorOccurredLoadingImage: |
- (void)errorSheetDidEnd:(NSWindow *)sheet returnCode:(int)returnCode contextInfo:(void *)contextInfo { |
CFNetDiagnosticRef diagnostics = (CFNetDiagnosticRef)contextInfo; |
if (returnCode == NSAlertDefaultReturn) { |
(void)CFNetDiagnosticDiagnoseProblemInteractively(diagnostics); |
} |
CFRelease(diagnostics); |
} |
@end |
Copyright © 2005 Apple Computer, Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2005-06-01