/*

     File: ISFAController.m 

 Abstract: Implements the main menu's controller.

 Opens a chat room in iChat when users click the "Joins Chat Room" button. 

 Watches for application switch events and updates iChat status using the Scripting Bridge framework. 

  Version: 1.2 

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 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION 

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 */

#import "ISFAController.h"

@interface ISFAController (PRIVATE) 

- (void)applicationSwitched;

- (void)applicationLaunched:(NSNotification *)notification;

- (void)applicationTerminated:(NSNotification *)notification;

- (void)registerForAppSwitchNotificationFor:(NSDictionary *)application;

@end

@implementation ISFAController

#pragma mark Watches for Application Switches

/*

    Updates the current status and icon of users in iChat and "iChatStatus" window.

    Sets the user's status and icon to the fronmost application's name and icon.  

*/ 

- (void)applicationSwitched

{

    /* Get information about the current active application */

    NSDictionary *applicationInfo = [[NSWorkspace sharedWorkspace] activeApplication];

    /* Get the application's process id  */

    pid_t switchedPid = (pid_t)[[applicationInfo valueForKey:@"NSApplicationProcessIdentifier"] integerValue];

    /* Do not do anything if we do not have new application in the front or if are in the front ourselves */

    if(switchedPid != _currentPid && switchedPid != getpid()) {

        /* Only update iChat's status if it is running and the current status is set to available */

        if([_iChatApp isRunning]) {

            if ([_iChatApp status] == iChatMyStatusAvailable) {

                /* Grab the icon of the running application as an NSImage */

                NSImage *iconImage = [[NSWorkspace sharedWorkspace] iconForFile:[applicationInfo valueForKey:@"NSApplicationPath"]];

                /* Set the buddy picture in iChat to the icon (using the bridged iChat application object) */

                [_iChatApp setImage:iconImage];

                /* Set the application's icon view in the "iChatStatus" window to the icon image */

                [_appIconView setImage:iconImage];

                NSString *statusString = [NSString stringWithFormat:@"Using %@", [applicationInfo objectForKey:@"NSApplicationName"]];

                /* Set the status message in iChat to the running application (using the bridged iChat application object) */

                [_iChatApp setStatusMessage:statusString];

                /* Set the status message in the "iChatStatus" window */

                [_appLabelField setStringValue:statusString];

            } else {

                /* Current status is not set to available */

                [_appIconView setImage:nil];

                [_appLabelField setStringValue:@"Status is not set to available"];

            }

        } else {

            /* iChat is not running  */

            [_appIconView setImage:nil];

            [_appLabelField setStringValue:@"iChat is not running"];

        }

        /* Store this application's process id so we can compare it with the process id of the next frontmost application */

        _currentPid = switchedPid;

    }

}

/*

    Called when a new application was launched. Registers for its notifications when the 

    application is activated.

*/ 

- (void)applicationLaunched:(NSNotification *)notification

{

    /* A new application has launched. Make sure we get notifications when it activates. */

    [self registerForAppSwitchNotificationFor:[notification userInfo]];

    [self applicationSwitched];

}

/*

    Called when an application was terminated. Stops watching for this application switch events.

*/

- (void)applicationTerminated:(NSNotification *)notification

{

    /* Get the application's process id  */

    NSNumber *pidNumber = [[notification userInfo] valueForKey:@"NSApplicationProcessIdentifier"];

    /* Get the observer associated to this application */

    AXObserverRef observer = (AXObserverRef)[_observers objectForKey:pidNumber];

    /* Check whether this observer is valid. If observer is valid, unregister for accessibility notifications 

       and display a descriptive message otherwise. */

    if(observer) {

        /* Stop listening to the accessibility notifications for the dead application */

        CFRunLoopRemoveSource(CFRunLoopGetCurrent(),

                              AXObserverGetRunLoopSource(observer),

                              kCFRunLoopDefaultMode);

        [_observers removeObjectForKey:pidNumber];

    } else {

        NSLog(@"Application \"%@\" that we didn't know about quit!", [[notification userInfo] valueForKey:@"NSApplicationName"]);

    }

}

/*

    Calls the applicationSwitched method. 

*/ 

static void applicationSwitched(AXObserverRef observer, AXUIElementRef element, CFStringRef notification, void *self)

{

    [(id)self applicationSwitched];

}

/*

    Creates an accessibility observer to watch an application switch events.

*/ 

- (void)registerForAppSwitchNotificationFor:(NSDictionary *)application

{

    NSNumber *pidNumber = [application valueForKey:@"NSApplicationProcessIdentifier"];

    /* Don't sign up for our own switch events (that will fail). */

    if([pidNumber intValue] != getpid()) {

        /* Check whether we are not already watching for this application's switch events */

        if(![_observers objectForKey:pidNumber]) {

            pid_t pid = (pid_t)[pidNumber integerValue];

            /* Create an Accessibility observer for the application */

            AXObserverRef observer;

            if(AXObserverCreate(pid, applicationSwitched, &observer) == kAXErrorSuccess) {

                /* Register for the application activated notification */

                CFRunLoopAddSource(CFRunLoopGetCurrent(),

                                   AXObserverGetRunLoopSource(observer), 

                                   kCFRunLoopDefaultMode);

                AXUIElementRef element = AXUIElementCreateApplication(pid);

                if(AXObserverAddNotification(observer, element, kAXApplicationActivatedNotification, self) != kAXErrorSuccess) {

                    NSLog(@"Failed to create observer for application \"%@\".", [application valueForKey:@"NSApplicationName"]);

                } else {

                    /* Remember the observer so that we can unregister later */

                    [_observers setObject:(id)observer forKey:pidNumber];

                }

                /* The observers dictionary wil hold on to the observer for us */

                CFRelease(observer); 

                 /* We do not need the element any more */

                CFRelease(element); 

            } else {

                /* We could not create an observer to watch this application's switch events */

                NSLog(@"Failed to create observer for application \"%@\".", [application valueForKey:@"NSApplicationName"]);

            }  

        } else {

            /* We are already observing this application */

            NSLog(@"Attempted to observe application \"%@\" twice.", [application valueForKey:@"NSApplicationName"]);

        }

    }

}

#pragma mark iChat

/*

    Attempts to retrieve an instance of the iChat application and returns it

    if successful.

*/

- (void)getiChatApp

{

    /* This will use the Scripting Bridge to get a reference to the main application class

        for iChat, as defined in the iChat.h header (see ReadMe.txt for more information). */

    _iChatApp = (iChatApplication *)[[SBApplication applicationWithBundleIdentifier:@"com.apple.iChat"] retain];

    if (!_iChatApp)

        NSLog(@"Unable to create an instance of SBApplication.");

}

/*

   Launches a chat room in iChat when users click the "Join Chat Room" button in the "iChat Status" window. 

   Uses bridged objects to make iChat join (or create) an AIM chat room named @"ichatStatus".

*/ 

- (IBAction)joinChatRoom:(id)sender

{

    /* Get the list of all active services in iChat */

    SBElementArray *services = [_iChatApp services];

    /* We're looking for any AIM service */

    iChatService *aimService = nil;

    /* Iterate through the available services */

    for (iChatService * svc in services) {

        /* Use the first connected AIM service we find */

        if (svc.serviceType == iChatServiceTypeAIM && svc.status == iChatConnectionStatusConnected) {

            aimService = svc;

            break;

        }

    }

    /* Join the chat room if we found an aim service */

    if (aimService) {

        /* Go to the chat room named "ichatStatus" on the AIM service we found */

        NSDictionary *chatProperties = [NSDictionary dictionaryWithObjectsAndKeys:aimService, @"service", 

                                                                                  @"ichatStatus", @"name", nil];

        /* Get the class for the text chat AppleScript class */

        Class textChatClass = [_iChatApp classForScriptingClass:@"text chat"];

        /* Create the text chat object */

        iChatTextChat *myChat = [[textChatClass alloc] initWithProperties:chatProperties];

        /* Add the text chat to the app's list of open chats */

        [[_iChatApp textChats] addObject:myChat];

        /* iChat will now send out the request to create chat room (not synchronous) */

        /* Realeasing iChatTextChat here is not necessary and will result in a crash.

           This is because it was not actually allocated until it was used (by adding it 

           to the SBElementArray) and was autoreleased afterwards. */

    }

}

#pragma mark Initialization

- (void)awakeFromNib

{   

    /* Check if 'Enable access for assistive devices' is enabled. */

    if(!AXAPIEnabled()) {

        /* 

         'Enable access for assistive devices' is not enabled, so we will alert the user,

         then quit because we can't update the users status on app switch as we are meant to

         (because we can't get notifications of application switches).

         */

        NSRunCriticalAlertPanel(@"'Enable access for assistive devices' is not enabled.", @"iChatStatusFromApplication requires that 'Enable access for assistive devices' in the 'Universal Access' preferences panel be enabled in order to monitor application switching.", @"Quit", nil, nil);

        [NSApp terminate:self];

    }

    [self getiChatApp];

    NSWorkspace *workspace = [NSWorkspace sharedWorkspace];

    _observers = [[NSMutableDictionary alloc] init];

    /* Register for application launch notifications */

    [[workspace notificationCenter] addObserver:self 

                                       selector:@selector(applicationLaunched:) 

                                           name:NSWorkspaceDidLaunchApplicationNotification 

                                         object:workspace];

    /* Register for application termination notifications */

    [[workspace notificationCenter] addObserver:self 

                                       selector:@selector(applicationTerminated:) 

                                           name:NSWorkspaceDidTerminateApplicationNotification 

                                         object:workspace];

    /* Register for activation notifications for all currently running applications */

    for(NSDictionary *application in [workspace launchedApplications]) {

        [self registerForAppSwitchNotificationFor:application];

    }

    [self applicationSwitched];

}

#pragma mark Deallocate Resources

- (void)dealloc

{

    /* Stop listening to all the notifications */

    [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:self];

    for(NSNumber *pidNumber in _observers) {

        AXObserverRef observer = (AXObserverRef)[_observers objectForKey:pidNumber];

        CFRunLoopRemoveSource(CFRunLoopGetCurrent(), AXObserverGetRunLoopSource(observer),kCFRunLoopDefaultMode);

    }

    /* This will also release the observers in the dictionary */

    [_observers release];

    [super dealloc];

}

@end