This is one of the three classes that define the overall architecture of the Application Kit, as well as the general behavior of Cocoa applications. The other two classes are NSView and NSResponder. Every AppKit-based application has an instance of NSApplication that is accessible through the global variable NSApp.

@interface NSApplication : NSResponder
// Accessor Methods
- (void)setMainMenu:(NSMenu *)aMenu;
- (NSMenu *)mainMenu;
- (void)setDelegate:(id)anObject;
- (id)delegate;
- (void)setWindowsNeedUpdate:(BOOL)needUpdate;
- (void)setAppleMenu:(NSMenu *)menu;
- (void)setApplicationIconImage:(NSImage *)image;
- (NSImage *)applicationIconImage;
- (void)setWindowsMenu:(NSMenu *)aMenu;
- (NSMenu *)windowsMenu;
- (void)setServicesMenu:(NSMenu *)aMenu;
- (NSMenu *)servicesMenu;
- (void)setServicesProvider:(id)provider;
- (id)servicesProvider;
// Class Methods
+ (void)detachDrawingThread:(SEL)selector toTarget:(id)target withObject:(id)argument;
+ (NSApplication *)sharedApplication;
// Instance Methods
- (NSModalSession)beginModalSessionForWindow:(NSWindow *)theWindow;
- (void)activateContextHelpMode:(id)sender;
- (void)abortModal;
- (void)activateIgnoringOtherApps:(BOOL)flag;
- (void)addWindowsItem:(NSWindow *)win title:(NSString *)aString filename:(BOOL)isFilename;
- (void)arrangeInFront:(id)sender;
- (NSModalSession)beginModalSessionForWindow:(NSWindow *)theWindow relativeToWindow:(NSWindow *)docWindow;
- (void)beginSheet:(NSWindow *)sheet modalForWindow:(NSWindow *)docWindow modalDelegate:(id)modalDelegate didEndSelector:(SEL)didEndSelector contextInfo:(void *)contextInfo;
- (void)cancelUserAttentionRequest:(int)request;
- (void)changeColor:(id)sender;
- (void)changeWindowsItem:(NSWindow *)win title:(NSString *)aString filename:(BOOL)isFilename;
- (NSGraphicsContext*)context;
- (NSEvent *)currentEvent;
- (void)deactivate;
- (void)discardEventsMatchingMask:(unsigned int)mask beforeEvent:(NSEvent *)lastEvent;
- (void)endModalSession:(NSModalSession)session;
- (void)endSheet:(NSWindow *)sheet;
- (void)endSheet:(NSWindow *)sheet returnCode:(int)returnCode;
- (void)finishLaunching;
- (void)hide:(id)sender;
- (void)hideOtherApplications:(id)sender;
- (BOOL)isActive;
- (BOOL)isHidden;
- (BOOL)isRunning;
- (NSWindow *)keyWindow;
- (NSWindow *)mainWindow;
- (NSWindow *)makeWindowsPerform:(SEL)aSelector inOrder:(BOOL)flag;
- (void)miniaturizeAll:(id)sender;
- (NSWindow *)modalWindow;
- (NSEvent *)nextEventMatchingMask:(unsigned int)mask untilDate:(NSDate *)expiration inMode:(NSString *)mode dequeue:(BOOL)deqFlag;
- (void)orderFrontColorPanel:(id)sender;
- (void)orderFrontStandardAboutPanel:(id)sender;
- (void)orderFrontStandardAboutPanelWithOptions:(NSDictionary *)optionsDictionary;
- (void)postEvent:(NSEvent *)event atStart:(BOOL)flag;
- (void)preventWindowOrdering;
- (void)registerServicesMenuSendTypes:(NSArray *)sendTypes returnTypes:(NSArray *)returnTypes;
- (void)removeWindowsItem:(NSWindow *)win;
- (void)replyToApplicationShouldTerminate:(BOOL)shouldTerminate;
- (void)reportException:(NSException *)theException;
- (int)requestUserAttention:(NSRequestUserAttentionType)requestType;
- (void)run;
- (int)runModalForWindow:(NSWindow *)theWindow;
- (int)runModalForWindow:(NSWindow *)theWindow relativeToWindow:(NSWindow *)docWindow;
- (int)runModalSession:(NSModalSession)session;
- (void)runPageLayout:(id)sender;
- (BOOL)sendAction:(SEL)theAction to:(id)theTarget from:(id)sender;
- (void)sendEvent:(NSEvent *)theEvent;
- (void)showHelp:(id)sender;
- (void)stop:(id)sender;
- (void)stopModal;
- (void)stopModalWithCode:(int)returnCode;
- (id)targetForAction:(SEL)theAction;
- (id)targetForAction:(SEL)theAction to:(id)theTarget from:(id)sender;
- (void)terminate:(id)sender;
- (BOOL)tryToPerform:(SEL)anAction with:(id)anObject;
- (void)unhide:(id)sender;
- (void)unhideAllApplications:(id)sender;
- (void)unhideWithoutActivation;
- (void)updateWindows;
- (void)updateWindowsItem:(NSWindow *)win;
- (id)validRequestorForSendType:(NSString *)sendType
returnType:(NSString *)returnType;
- (NSWindow *)windowWithWindowNumber:(int)windowNum;
- (NSArray *)windows;
// Methods Implemented by the Delegate
- (BOOL)application:(NSApplication *)sender delegateHandlesKey:(NSString *)key;
- (BOOL)application:(NSApplication *)sender openFile:(NSString *)filename;
- (BOOL)application:(NSApplication *)sender openTempFile:(NSString *)filename;
- (BOOL)application:(NSApplication *)sender printFile:(NSString *)filename;
- (BOOL)application:(id)sender openFileWithoutUI:(NSString *)filename;
- (void)applicationDidBecomeActive:(NSNotification *)notification;
- (void)applicationDidChangeScreenParameters:(NSNotification *)notification;
- (void)applicationDidFinishLaunching:(NSNotification *)notification;
- (void)applicationDidHide:(NSNotification *)notification;
- (void)applicationDidResignActive:(NSNotification *)notification;
- (void)applicationDidUnhide:(NSNotification *)notification;
- (void)applicationDidUpdate:(NSNotification *)notification;
- (NSMenu *)applicationDockMenu:(NSApplication *)sender;
- (BOOL)applicationOpenUntitledFile:(NSApplication *)sender;
- (BOOL)applicationShouldHandleReopen:(NSApplication *)sender hasVisibleWindows:(BOOL)flag;
- (BOOL)applicationShouldOpenUntitledFile:(NSApplication *)sender;
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender;
- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)sender;
- (void)applicationWillBecomeActive:(NSNotification *)notification;
- (void)applicationWillFinishLaunching:(NSNotification *)notification;
- (void)applicationWillHide:(NSNotification *)notification;
- (void)applicationWillResignActive:(NSNotification *)notification;
- (void)applicationWillTerminate:(NSNotification *)notification;
- (void)applicationWillUnhide:(NSNotification *)notification;
- (void)applicationWillUpdate:(NSNotification *)notification;
// Notifications
NSApplicationDidBecomeActiveNotification;
NSApplicationDidChangeScreenParametersNotification;
NSApplicationDidFinishLaunchingNotification;
NSApplicationDidHideNotification;
NSApplicationDidResignActiveNotification;
NSApplicationDidUnhideNotification;
NSApplicationDidUpdateNotification;
NSApplicationWillBecomeActiveNotification;
NSApplicationWillFinishLaunchingNotification;
NSApplicationWillHideNotification;
NSApplicationWillResignActiveNotification;
NSApplicationWillTerminateNotification;
NSApplicationWillUnhideNotification;
NSApplicationWillUpdateNotification;