Plug-in Architectures in Cocoa

第51回 Cocoa勉強会関西 『Cocoaのプラグインアーキテクチャ』 by @questbeat

Transcript

1. Plug-in Architectures in Cocoa Katsuma Tanaka
2. @questbeat
3. Plug-in Architectures in Cocoa - Sample program is available on GitHub. https://github.com/questbeat/PlugInSample
4. Introduction: Creating Xcode Plug-in
5. - github.com/questbeat/Lin Creating Xcode Plug-in
6. Creating Xcode Plug-in - Create a new project.
7. + (void)pluginDidLoad:(NSBundle *)plugin { [self sharedPlugin]; } + (id)sharedPlugin { static id sharedPlugin = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ sharedPlugin = [[self alloc] init]; }); } Creating Xcode Plug-in - Lin.m
8. - Info.plist Creating Xcode Plug-in - Build settings
9. - Install the plug-in in the appropriate folder. Creating Xcode Plug-in
10. - Installation can be easier by Installation Directory settings. Creating Xcode Plug-in
11. - Plug-in works on the same process as Xcode. Creating Xcode Plug-in
12. What is a plug-in? - A plug-in is a loadable bundle that adds functionality to an application. MyBundle.bundle/ Contents/ Info.plist Frameworks/ MacOS/ Resources/ ...
13. - Application (.app) - Framework (.framework) - Preference Pane (.prefPane) - Screen Saver (.saver) - Xcode Plug-in (.xcplugin) Loadable Bundles are used in ...
14. Loading Bundles
15. 1. Locate the bundle 2. Load the bundle’s executable code 3. Instantiate an object of the principal class Loading Bundles Basic Three Steps
16. MyApp.app/ Contents/ PlugIns/ MyPlugin.bundle Resources/ Frameworks/ ... Locating Bundles Standard Location
17. NSBundle *appBundle = [NSBundle mainBundle]; NSString *plugInsPath = [appBundle builtInPlugInsPath]; “/Applications/MyApp.app/Contents/PlugIns” Standard Location Locating Bundles
18. MyApp.app/ Contents/ Resources/ PlugIns/ MyPlugin.bundle Frameworks/ ... Nonstandard Location Locating Bundles
19. NSBundle *appBundle = [NSBundle mainBundle]; NSArray *bundlePaths = [appBundle pathsForResourcesOfType:@"bundle" inDirectory:@"PlugIns"]; Nonstandard Location Locating Bundles
20. /Users/questbeat/Library/Application Support/MyApp/PlugIns User-speci c /Library/Application Support/MyApp/PlugIns /Network/Library/Application Support/MyApp/PlugIns System-wide Network Support Library Directories Locating Bundles
21. NSString *appSupportSubpath = @"Application Support/MyApp/PlugIns"; NSMutableArray *bundleSearchPaths = [NSMutableArray array]; NSArray *librarySearchPaths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSAllDomainsMask - NSSystemDomainMask, YES); for (NSString *path in librarySearchPaths) { [bundleSearchPaths addObject:[path stringByAppendingPathComponent:appSupportSubpath]]; } Support Library Directories Locating Bundles
22. 1. Locate the bundle 2. Load the bundle’s executable code 3. Instantiate an object of the principal class Loading Bundles Basic Three Steps
23. NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; Creating a NSBundle Object
24. NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; if ([bundle load]) { NSLog(@"Bundle was successfully loaded."); } Loading Code
25. Loading Code and Get Errors NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; NSError *error = nil; if (![bundle loadAndReturnError:&error]) { NSLog(@"Error: %@", [error localizedDescription]); }
26. Checking Code without Loading NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; NSError *error = nil; if (![bundle preflightAndReturnError:&error]) { NSLog(@"Error: %@", [error localizedDescription]); }
27. Unloading Code NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; [bundle load]; if ([bundle isLoaded] && [bundle unload]) { NSLog(@"Bundle was successfully unloaded."); }
28. 1. Locate the bundle 2. Load the bundle’s executable code 3. Instantiate an object of the principal class Loading Bundles Basic Three Steps
29. Retrieving the Principal Class
30. NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; Class principalClass = [bundle principalClass]; Retrieving the Principal Class
31. NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; Class someClass = [bundle classNamed:@"MyAppController"]; Retrieving the Principal Class
32. NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; Class principalClass = [bundle principalClass]; id instance = [[principalClass alloc] init]; Instantiating the Principal Class
33. Instantiating the Principal Class NSString *bundlePath = ...; NSBundle *bundle = [NSBundle bundleWithPath:bundlePath]; Class principalClass = [bundle principalClass]; id instance<MyPlugIn> = [[principalClass alloc] init]; [instance greet]; @protocol MyPlugIn <NSObject> - (void)greet; @end ... - Host application should provide an interface.
34. Creating Plug-in Architectures
35. - Use a formal protocol - Use an informal protocol - Use an abstract base class Creating Plug-in Architectures Three Ways to Provide Interface
36. #import <Cocoa/Cocoa.h> @protocol MyAppBitmapGraphicsFiltering <NSObject> @required // Returns the version of the interface you're implementing. - (unsigned)interfaceVersion; // Filters the bitmap and returns a modified version. - (NSBitmapImageRep *)filteredImageRep:(NSBitmapImageRep *)imageRep; @optional // Returns what to display in the Filter menu. - (NSString *)menuItemString; // Returns the window controller for the settings configuration window. - (NSWindowController *)configurationWindowController; @end Use a Formal Protocol
37. #import <Cocoa/Cocoa.h> @interface NSObject (MyAppBitmapGraphicsFiltering) // REQUIRED // Returns the version of the interface you're implementing. - (unsigned)interfaceVersion; // REQUIRED // Filters the bitmap and returns a modified version. - (NSBitmapImageRep *)filteredImageRep:(NSBitmapImageRep *)imageRep; // OPTIONAL // Returns what to display in the Filter menu. - (NSString *)menuItemString; // OPTIONAL // Returns the window controller for the settings configuration window. - (NSWindowController *)configurationWindowController; @end Use an Informal Protocol
38. #import <Cocoa/Cocoa.h> @interface MyAppEmbeddingView : NSView { @private NSURL *_URL; void *_reserved1; void *_reserved2; void *_reserved3; } - (id)initWithFrame:(NSRect)frameRect URL:(NSURL)URL; - (unsigned)interfaceVersion; - (NSURL *)URL; - (void)setURL:(NSURL *)URL; @end Use an Abstract Base Class
39. #import "MyAppEmbeddingView.h" @implementation MyAppEmbeddingView - (id)initWithFrame:(NSRect)frameRect URL:(NSURL)URL { self = [self initWithFrame:frameRect]; if (self) { self.URL = URL; } return self; } - (unsigned)interfaceVersion { return 0; } ... Use an Abstract Base Class
40. - (void)drawRect:(NSRect)rect { NSEraseRect(rect); } - (NSURL *)URL { return _URL; } - (void)setURL:(NSURL *)URL { _URL = URL; } @end ... Use an Abstract Base Class
41. - (BOOL)plugInClassIsValid:(Class)plugInClass { if ([plugInClass conformsToProtocol:@protocol(MyAppBitmapGraphicsFiltering)]) { if ([plugInClass instancesRespondToSelector:@selector(interfaceVersion)] && [plugInClass instancesRespondToSelector:@selector(filteredImageRep)]) { return YES; } } return NO; } Formal Protocol Validating Plug-ins
42. - (BOOL)plugInClassIsValid:(Class)plugInClass { if ([plugInClass instancesRespondToSelector:@selector(interfaceVersion)] && [plugInClass instancesRespondToSelector:@selector(filteredImageRep)]) { return YES; } return NO; } Validating Plug-ins Informal Protocol
43. - (BOOL)plugInClassIsValid:(Class)plugInClass { if ([plugInClass isSubclassOfClass:[MyAppEmbeddingView class]]) { return YES; } return NO; } Abstract Base Class Validating Plug-ins
44. Sample Program
45. Summary - Plug-in is a loadable bundle. - Bundle is easily accessible through NSBundle. - There are three choices for plug-in architecture in Cocoa: - Formal protocol - Informal protocol - Abstract base class
46. References - Code Loading Programming Topics https://developer.apple.com/library/mac/ #documentation/Cocoa/Conceptual/LoadingCode/ LoadingCode.html https://developer.apple.com/library/mac/ #documentation/Cocoa/Reference/Foundation/Classes/ NSBundle_Class/Reference/Reference.html - NSBundle Class Reference
47. Thank you