Creative in Austria » Development

AudioSessionInitialize Workarounds

catlan — Thu, 25 Dec 2008 19:17:44 +0000

Yesterday I decided to go after one of my audio bugs by take a look how AVAudioPlayer does it right, and I discovered a little thing about Audio Session.

Here are two workarounds for AudioSessionInitialize.

I never liked AudioSessionInitialize because you can set the InterruptionListener and it’s ClientData just once:

/*

 * Discussion

 * Your application must call this function before making any other Audio

 * Session Services calls. You may activate and deactivate your audio session

 * as needed (see AudioSessionSetActive), but should initialize it only once.

 */

OSStatus AudioSessionInitialize (

   CFRunLoopRef                        inRunLoop,

   CFStringRef                         inRunLoopMode,

   AudioSessionInterruptionListener    inInterruptionListener,

   void                                *inClientData

);

So you need a helper class like this where you have to set the active AudioPlayer:

#import "AudioInterruptionListener.h"


voidinterruptionListenerCallback (
void *inUserData,
UInt32   interruptionState

) {

    AudioInterruptionListener *listener = (AudioInterruptionListener *) inUserData;

    DoItYourselfPlayer *player = listener.doItYourselfPlayer;

if (!player)
return;

if (interruptionState == kAudioSessionBeginInterruption) {

        [player performSelectorOnMainThread:@selector(audioStreamPlayerBeginInterruption)
withObject:nil
waitUntilDone:YES]; 

    } elseif ((interruptionState == kAudioSessionEndInterruption)) {

        [player performSelectorOnMainThread:@selector(audioStreamPlayerEndInterruption)
withObject:nil
waitUntilDone:YES]; 

    }

}
@implementation AudioInterruptionListener
static AudioInterruptionListener *sharedAudioInterruptionListener;
@synthesize doItYourselfPlayer;
+ (void)initialize {

    if (!sharedAudioInterruptionListener) {

        sharedAudioInterruptionListener = [[AudioInterruptionListener alloc] init];

        AudioSessionInitialize (

                                NULL,

                                NULL,

                                interruptionListenerCallback,

                                sharedAudioInterruptionListener

                                );

    }

}
+ (AudioInterruptionListener *)sharedAudioInterruptionListener 

{

    return sharedAudioInterruptionListener;

}
@end

This is fine, but I was no big fan of this helper class when I wrote it.

AVAudioPlayer works without such helper class, but how? Well don’t do this at home, because ‘intr’ is not documented in “Audio Session Services Property Identifiers.”, but you can also add an InterruptionListener with AudioSessionAddPropertyListener, the code should look something along this lines:

- (BOOL)prepareToPlay {
pthread_once(&interruptionListenerOneTimeInit, interruptionListenerInit);

    …
AudioSessionAddPropertyListener(‘intr’, interruptionListenerCallback, self);

}
- (void)stop {

    AudioSessionRemovePropertyListenerWithUserData(‘intr’, interruptionListenerCallback, self);

    …

}
#pragma mark -

#pragma mark Audio Session Implementations

pthread_once_t          interruptionListenerOneTimeInit = PTHREAD_ONCE_INIT;
void interruptionListenerInit(void)

{

    AudioSessionInitialize(NULL, NULL, NULL, NULL);

}
void interruptionListenerCallback (

                                    void                      *inClientData,

                                    AudioSessionPropertyID    inID,

                                    UInt32                    inDataSize,

                                    const void                *inData

) {

    DoItYourselfPlayer *player = inClientData;

    if (inID == ‘intr’) {

        UInt32 *interruptionState = (UInt32 *)inData;

        if (*interruptionState == kAudioSessionBeginInterruption) {

              [player performSelectorOnMainThread:@selector(audioStreamPlayerBeginInterruption)

                                 withObject:nil

                              waitUntilDone:YES]; 

        } else if (*interruptionState == kAudioSessionEndInterruption) {

              [player performSelectorOnMainThread:@selector(audioStreamPlayerEndInterruption)

                                 withObject:nil

                              waitUntilDone:YES]; 

            }

        }

    }

}

If you agree that Apple should expose this functionality to third parties, please submit a duplicate for Radar ID# 6467253.

Happy Holidays hacking!

Apple Mail Plugins Developer Group

catlan — Fri, 12 Dec 2008 18:39:14 +0000

After talking with Scott Morrison of Indev Software at C4[2] about a mail list for Mail Plugin developers we finally started one.

If you are interested in this topic you are welcome to join us: Google Groups – Apple Mail Dev

Crash Reporter for iPhone Applications (Part 2)

catlan — Mon, 20 Oct 2008 22:07:43 +0000

In part one I describe how to set up an Exception Handler, Uli discovered as first one that this handles not all cases. The missing part is a signal handler to get information of SIGSEGV, SIGBUS, … signals.

I thought the hard part of this is getting the backtrace inside a signal handler. I already found code for this, but I couldn’t use it because it was GPL. I tried the easy way, offering the author money to release it under public domain, oh boy this was a waste of time. But now that I found my own solution for this I’m happy that I didn’t spend money on this. (1 line versus 20 lines of code)

Let’s start with setting up a signal handler, the good old man page helps.

/* GeSHi (C) 2004 – 2007 Nigel McNie (http://qbnz.com/highlighter) */
.objc .de1, .objc .de2 {font-family: ‘Courier New’, Courier, monospace; font-weight: normal; font-size: 11px; }
.objc {font-family: monospace;}
.objc .imp {font-weight: bold; color: red;}
.objc li {background: #f8f8f8;}
.objc li.li2 {background: #f8f8f8;}
.objc .kw1 {color: #0000ff;}
.objc .kw2 {color: #0000ff;}
.objc .kw3 {color: #0000dd;}
.objc .kw4 {color: #0000ff;}
.objc .kw5 {color: #0000ff;}
.objc .kw6 {color: #0000ff;}
.objc .co1 {color: #ff0000;}
.objc .co2 {color: #339900;}
.objc .coMULTI {color: #ff0000; font-style: italic;}
.objc .es0 {color: #666666; font-weight: bold;}
.objc .br0 {color: #002200;}
.objc .st0 {color: #666666;}
.objc .nu0 {color: #0000dd;}
html>body .entry .objc ol li { margin: 0 0 0 0; }
.syntax { padding-left: 15px; background-color: #E8E8E8; text-align:left; }

int main(int argc, char *argv[]) {
        struct sigaction mySigAction;
        mySigAction.sa_sigaction = mysighandler;
        mySigAction.sa_flags = SA_SIGINFO;
        sigemptyset(&mySigAction.sa_mask);
        sigaction(SIGQUIT, &mySigAction, NULL);
        sigaction(SIGILL, &mySigAction, NULL);
        sigaction(SIGTRAP, &mySigAction, NULL);
        sigaction(SIGABRT, &mySigAction, NULL);
        sigaction(SIGEMT, &mySigAction, NULL);
        sigaction(SIGFPE, &mySigAction, NULL);
        sigaction(SIGBUS, &mySigAction, NULL);
        sigaction(SIGSEGV, &mySigAction, NULL);
        sigaction(SIGSYS, &mySigAction, NULL);
        sigaction(SIGPIPE, &mySigAction, NULL);
        sigaction(SIGALRM, &mySigAction, NULL);
        sigaction(SIGXCPU, &mySigAction, NULL);
        sigaction(SIGXFSZ, &mySigAction, NULL);
        
        NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
        int retVal = UIApplicationMain(argc, argv, nil, nil);
        [pool release];
        return retVal;
}

And here the line of code I was searching for over two days: backtrace(3). You don’t find this little bastard if you search in Xcode Help with iPhone OS Library selected (there goes my two days)

void mysighandler(int sig, siginfo_t *info, void *context) {
        void *backtraceFrames[128];
        int frameCount = backtrace(backtraceFrames, 128);
 
        // report the error
}

Like in the Exception Handler you now just use backtrace_symbols(3). (Example)

Good luck with working down the crash reports you will get now

Crash Reporter for iPhone Applications (Part 1)
Crash Reporter for iPhone Applications (Part 2)

Crash Reporter for iPhone Applications (Part 1)

catlan — Sat, 18 Oct 2008 18:58:14 +0000

I’m getting ready to send my iPhone Application to the first beta testers and so I started thinking about crash reports.

On the Mac you have two options to get the crash report of your application. The first one is to check on startup if there is a new crash report file in ~/Library/Logs/CrashReporter for your application and simply send it. (Example: HDCrashReporter , UKCrashReporter)

The other option is to use NSExceptionHandler, which let you report the problem as it happens. (Example: A simple debugging tool for Cocoa)

On the iPhone you can’t access the crash report file form your application because it’s running in a sandbox (rdar://problem/6296554). iTunes synchronizes the crash reports of all applications, so although a user could in theory send it to you, this seems rather complicated to me (Locations of Crash Logs).

So what about NSExceptionHandler? Well, there isn’t a NSExceptionHandler in the iPhone SDK. But wait, there is a NSUncaughtExceptionHandler!

void MyUncaughtExceptionHandler(NSException *exception) {
    NSArray *callStackArray = [exception callStackReturnAddresses];
    int frameCount = [callStackArray count];
    void *backtraceFrames[frameCount];
    
    for (int i=0; i) {
        backtraceFrames[i] = (void *)[[callStackArray objectAtIndex:i] unsignedIntegerValue];
    }
    
    // report the exception
}
 
@implementation AppDelegate
 
- (void)applicationDidFinishLaunching:(UIApplication *)application {
    NSSetUncaughtExceptionHandler(&MyUncaughtExceptionHandler);
}
 
@end

Now you can get the backtrace in MyUncaughtExceptionHandler with backtrace_symbols(3). (Example)
You still have to symbolicate the crash reports.

As a big fan of Fogbugz, I also wanted to use BugzScout. It’s just a HTTP POST, but here is the code:

void bugzScout(NSString *description, NSString *extra) {
        NSMutableString *post = [NSMutableString string];
        [post appendString:@"ScoutUserName="];
        [post appendString:urlEncodeValue(@"Your BugzScout User")];
        
        [post appendString:@"&ScoutProject="];
        [post appendString:urlEncodeValue(@"Your Project")];
        
        [post appendString:@"&ScoutArea="];
        [post appendString:urlEncodeValue(@"Your Area")];
        
        [post appendString:@"&Description="];
        [post appendString:urlEncodeValue(description)];
        
        [post appendString:@"&Extra="];
        [post appendString:urlEncodeValue(extra)];
        
        [post appendString:@"&ScoutDefaultMessage=&FriendlyResponse=0&ForceNewBug=0"];
        
        //NSLog(post);
        
        NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
        NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];
        
        NSURL *webServiceURL = [NSURL URLWithString:@"https://yourcompany.fogbugz.com/ScoutSubmit.asp"];
        NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:webServiceURL];
        
        [req setHTTPMethod:@"POST"];
        [req addValue:@"application/x-www-form-urlencoded" forHTTPHeaderField: @"Content-Type"];
        [req addValue:postLength forHTTPHeaderField: @"Content-Length"];
        [req setHTTPBody:postData];
        
        [NSURLConnection sendSynchronousRequest:req returningResponse:nil error:nil];   
}
 
NSString *urlEncodeValue(NSString *str) {
        CFStringRef urlString = CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                (CFStringRef)str, NULL, CFSTR(";/?:@&=+$,"), kCFStringEncodingUTF8);
        return [(NSString *)urlString autorelease];
}

Crash Reporter for iPhone Applications (Part 1)
Crash Reporter for iPhone Applications (Part 2)

Microsoft Entourage 2008 Plug-in development

catlan — Tue, 15 Jan 2008 20:25:50 +0000

Today is the release day of Microsoft Office for Mac 2008. Let’s take a look if it is possible to develop a Plug-in for Entourage 2008.

As far as I know, there was no way in Entourage 2004 for a Third Party Developer, and there is still no support from Microsoft. But after four years, things a little different now…

In the Entourage application bundle I discovered a Plugins folder, which contain a Plug-in named EntouragePrintPDE. So what is EntouragePrintPDE? This is an Extending Printing Dialogs Plug-in, I found a example for such a Plug-in at mozilla.

So here we go, lets learn more about CFPlugIn, which is little uncommon for us Cocoa guys who use NSBundle. BasicPlugIn is a good example to start with.

And yeah, after setting up a Xcode project with this I was able get the Plug-in loaded:

This is not all good news. Because it is based on a Extending Printing Dialogs Plug-in, it gets only loaded when you open the print dialog. The CFPlugInTypes UUID in the Info.plist is BCB07250-E57F-11D3-8CA6-0050E4603277 which described as “Application pane for the Print dialog” Interface type:

Is this the end of the story? Almost, without Interface descriptions and the UUIDs we are out of luck here. I searched for standard UUIDs, but didn’t find any “load on start of host app” UUIDs.

But wait, I don’t like to close this with a “it’s impossible, don’t even dream of it”. Here the class-dump output of Entourage 2008. It is pretty short for such a big application because it is mostly a Carbon application, never mind, I like what it shows.

/* GeSHi (C) 2004 – 2007 Nigel McNie (http://qbnz.com/highlighter) */
.objc .de1, .objc .de2 {font-family: ‘Courier New’, Courier, monospace; font-weight: normal;}
.objc {font-family: monospace;}
.objc .imp {font-weight: bold; color: red;}
.objc li {background: #f8f8f8;}
.objc li.li2 {background: #f8f8f8;}
.objc .kw1 {color: #0000ff;}
.objc .kw2 {color: #0000ff;}
.objc .kw3 {color: #0000dd;}
.objc .kw4 {color: #0000ff;}
.objc .kw5 {color: #0000ff;}
.objc .kw6 {color: #0000ff;}
.objc .co1 {color: #ff0000;}
.objc .co2 {color: #339900;}
.objc .coMULTI {color: #ff0000; font-style: italic;}
.objc .es0 {color: #666666; font-weight: bold;}
.objc .br0 {color: #002200;}
.objc .st0 {color: #666666;}
.objc .nu0 {color: #0000dd;}
html>body .entry .objc ol li { margin: 0 0 0 0; }
.syntax { padding-left: 15px; background-color: #E8E8E8; text-align:left; }

/*
 *     Generated by class-dump 3.1.1.
 *
 *     class-dump is Copyright (C) 1997-1998, 2000-2001, 2004-2006 by Steve Nygard.
 */
 
struct CToolTip;
 
struct CURLToolTip {
    struct CToolTip *_field1;
};
 
struct OpaqueMenuRef;
 
struct _NSPoint {
    float _field1;
    float _field2;
};
 
struct _NSZone;
 
struct __CFString;
 
/*
 * File: /Applications/Microsoft Office 2008/Microsoft Entourage.app/Contents/MacOS/Microsoft Entourage
 * Arch: Intel 80×86 (i386)
 */
 
@protocol NSObject
- (BOOL)isEqual:(id)fp8;
- (unsigned int)hash;
- (Class)superclass;
- (Class)class;
- (id)self;
- (struct _NSZone *)zone;
- (id)performSelector:(SEL)fp8;
- (id)performSelector:(SEL)fp8 withObject:(id)fp12;
- (id)performSelector:(SEL)fp8 withObject:(id)fp12 withObject:(id)fp16;
- (BOOL)isProxy;
- (BOOL)isKindOfClass:(Class)fp8;
- (BOOL)isMemberOfClass:(Class)fp8;
- (BOOL)conformsToProtocol:(id)fp8;
- (BOOL)respondsToSelector:(SEL)fp8;
- (id)retain;
- (oneway void)release;
- (id)autorelease;
- (unsigned int)retainCount;
- (id)description;
@end
 
@protocol WebDocumentText 
- (BOOL)supportsTextEncoding;
- (id)string;
- (id)attributedString;
- (id)selectedString;
- (id)selectedAttributedString;
- (void)selectAll;
- (void)deselectAll;
@end
 
@interface NSView (Undocumented)
- (void)preparePageForPrinting:(float)fp8;
@end
 
@interface MessagePrintoutController : NSObject
{
    BOOL loading;
}
 
- (BOOL)isLoading;
- (void)setLoading:(BOOL)fp8;
- (void)webView:(id)fp8 didStartProvisionalLoadForFrame:(id)fp12;
- (void)webView:(id)fp8 didFinishLoadForFrame:(id)fp12;
- (void)webView:(id)fp8 didFailProvisionalLoadWithError:(id)fp12 forFrame:(id)fp16;
- (void)webView:(id)fp8 didFailLoadWithError:(id)fp12 forFrame:(id)fp16;
 
@end
 
@interface MessageViewController : NSObject
{
    WebView *webView;
    void *view;
    id messageRecordID;
    BOOL networkBlocked;
    BOOL networkResources;
    NSURL *hrefURL;
    NSString *currentURL;
    NSString *currentHRef;
    struct CURLToolTip *toolTip;
}
 
+ (void)initialize;
- (void)dealloc;
- (id)init;
- (id)webView;
- (void)setWebView:(id)fp8;
- (void *)view;
- (void)setView:(void *)fp8;
- (void *)message;
- (void)setMessage:(void *)fp8;
- (BOOL)isNetworkBlocked;
- (void)setNetworkBlocked:(BOOL)fp8;
- (BOOL)hasNetworkResources;
- (void)buildExecuteScriptMenu:(struct OpaqueMenuRef *)fp8 withParent:(id)fp12;
- (void)openLink:(id)fp8;
- (void)copyImage:(id)fp8;
- (void)openImage:(id)fp8;
- (void)executeScriptCommand:(id)fp8;
- (struct __CFString *)getSelectedText;
- (void)selectAllCommand:(id)fp8;
- (void)decreaseFontSizeCommand:(id)fp8;
- (void)increaseFontSizeCommand:(id)fp8;
- (void)translateCommand:(id)fp8;
- (void)dictionaryCommand:(id)fp8;
- (void)synonymCommand:(id)fp8;
- (void)encyclopediaCommand:(id)fp8;
- (void)webSearchCommand:(id)fp8;
- (void)helpCommand:(id)fp8;
- (void)download:(id)fp8 decideDestinationWithSuggestedFilename:(id)fp12;
- (void)webView:(id)fp8 didStartProvisionalLoadForFrame:(id)fp12;
- (void)webView:(id)fp8 decidePolicyForNewWindowAction:(id)fp12 request:(id)fp16 newFrameName:(id)fp20 decisionListener:(id)fp24;
- (void)webView:(id)fp8 decidePolicyForNavigationAction:(id)fp12 request:(id)fp16 frame:(id)fp20 decisionListener:(id)fp24;
- (id)webView:(id)fp8 resource:(id)fp12 willSendRequest:(id)fp16 redirectResponse:(id)fp20 fromDataSource:(id)fp24;
- (void)webView:(id)fp8 willPerformDragSourceAction:(int)fp12 fromPoint:(struct _NSPoint)fp16 withPasteboard:(id)fp24;
- (void)webView:(id)fp8 mouseDidMoveOverElement:(id)fp12 modifierFlags:(unsigned int)fp16;
- (id)webView:(id)fp8 contextMenuItemsForElement:(id)fp12 defaultMenuItems:(id)fp16;
 
@end
 
@interface MessageViewController (Private)
- (void)decidePolicyForAction:(id)fp8 request:(id)fp12 decisionListener:(id)fp16;
- (struct _NSPoint)mouseLocation;
@end
 
@interface MHTMLProtocol : NSURLProtocol
{
}
 
+ (BOOL)canInitWithRequest:(id)fp8;
+ (id)canonicalRequestForRequest:(id)fp8;
- (id)initWithRequest:(id)fp8 cachedResponse:(id)fp12 client:(id)fp16;
- (void)startLoading;
- (void)stopLoading;
 
@end
 
@interface NetworkBlock : NSURLProtocol
{
}
 
+ (BOOL)canInitWithRequest:(id)fp8;
+ (id)canonicalRequestForRequest:(id)fp8;
- (id)initWithRequest:(id)fp8 cachedResponse:(id)fp12 client:(id)fp16;
- (void)startLoading;
- (void)stopLoading;
 
@end

Sparkle in large deployments

catlan — Sat, 10 Nov 2007 17:12:51 +0000

I’m happy that I have some customer which have large enough deployments that they use Apple Remote Desktop (ARD) to install OMiC. In such a deployment the administrator don’t want that a update dialog pop up by his users, which has most the time not the rights to perform the update.

For this cases I add to Sparkle the SUIgnoreChecks key, which the administrator can set over Apple Remote Desktop (ARD) in the application preferences file.

Sparkle for Plug-ins

catlan — Fri, 09 Nov 2007 14:48:31 +0000

OMiC use Sparkle for updating since version 1.7.2, but you can’t use Sparkle do update Plug-ins out of the box. So I spend the last days do turn my home cooked solution into something which work for other Plug-ins as well. If you are interested, checkout the Sparkle subversion repository.

PackageMaker 3.0

catlan — Thu, 01 Nov 2007 18:17:24 +0000

Yesterday I switched to PackageMaker 3.0 to generate packages. My Plug-in OMiC is build separate for Mac OS X 10.3 and 10.4 to support the different features.

So the simplest solution maybe offer two downloads and give user the choice which version he needs. But thanks to Metapackages and Distribution Packages the installer choice which version is needed.

So let us start PackageMaker (/Developer/Applications/Utilities/PackageMaker) …

Add the two releases for my project build folder:

Enter the name and description in each Choice:

Now the interesting part, the Requirements for each Choice. Add the two the requirements “is greater than or equal to ’10.3′” and “is less than ’10.4′” for the Panther Choice and just “is greater than or equal to ’10.4′” for Tiger:

In Package Configuration is one important thing, the Package Identifier. The two packages must have a different identifier, I first try it with the same and PackageMaker gave me no error. But when you save and reopen it with the same identifier, PackageMaker is confused because it can’t make the relation between choices and packages.

So when you now build the package you get this warnings:

/* GeSHi (C) 2004 – 2007 Nigel McNie (http://qbnz.com/highlighter) */
.bash .de1, .bash .de2 {font-family: ‘Courier New’, Courier, monospace; font-weight: normal;}
.bash {font-family: monospace;}
.bash .imp {font-weight: bold; color: red;}
.bash li {background: #f8f8f8; /* DEDEDE;*/}
.bash li.li2 {background: #f8f8f8;}
.bash .kw1 {color: #000000; font-weight: bold;}
.bash .kw2 {color: #c20cb9; font-weight: bold;}
.bash .kw3 {color: #7a0874; font-weight: bold;}
.bash .es0 {color: #000099; font-weight: bold;}
.bash .br0 {color: #000000; font-weight: bold;}
.bash .st0 {color: #ff0000;}
.bash .nu0 {color: #000000;}
.bash .re0 {color: #007800;}
.bash .re1 {color: #007800;}
.bash .re2 {color: #007800;}
.bash .re3 {color: #808080; font-style: italic;}
.bash .re4 {color: #007800;}
html>body .entry .bash ol li { margin: 0 0 0 0; }
.syntax { margin: 10px 0; background-color: #E8E8E8; text-align:left; }

Warning: Requirement "System OS Version (e.g. 10.x.x)" of choice "OMiC for Mac OS X v10.3 (Panther)" is not supported prior to Mac OS X v10.4.

To support Panther we need some tricks, we need a InstallationCheck script. Here as example my script:

#!/bin/sh
 
MAJOR=`sw_vers -productVersion | awk -F "." ‘{ print $2 }’`
if [ "${MAJOR}" = "3" ];
then
    exit 0
else
    exit 64
fi

You need to copy the InstallationCheck scripts into the Resources folder of each package. Copy this by hand is very error-prone, so I use a script for building and copying:

#!/bin/sh
PACKAGEMAKER="/Developer/usr/bin/packagemaker"
 
$PACKAGEMAKER –doc PackageMaker/OMiC.pmdoc –out ./build/OMiC.mpkg
 
echo "Patch OMiC.mpkg with InstallationCheck"
cp PackageMaker/10.3/Resources/InstallationCheck build/OMiC.mpkg/Contents/Packages/omic.pkg/Contents/Resources
cp PackageMaker/10.4/Resources/InstallationCheck build/OMiC.mpkg/Contents/Packages/omic-1.pkg/Contents/Resources

That’s it, overall I like the improvements of new PackageMaker.