textfield not updating with bindings - Whats wrong?
Hi all
I have given up on doing anymore work on my current project until i
get this sorted
ok simply i have an interface with 2 textfields, one for a number and
one for a string.
Also there is a button which tells the controller to tell my class to
update the model vars.
I am using Obj-C 2.0 and properties and from all i have read
properties are fully KVO complient.
here is my app delegate.
#import Cocoa/Cocoa.h
@class someclass;
@interface bindingstestDelegate : NSObject{
someclass *fooClass;
}
- (IBAction)changeValues:(id)sender;
@end
#import someclass.h
@implementation bindingstestDelegate
- (id) init{
self = [super init];
if (self != nil) {
fooClass = [[someclass alloc] init];
}
return self;
}
- (IBAction)changeValues:(id)sender{
[fooClass updateValues];
}
@end
and the model class
@interface someclass : NSObject {
NSString *someString;
NSInteger someNumber;
}
@property (readwrite,retain) NSString *someString;
@property (readwrite) NSInteger someNumber;
- (void)updateValues;
@end
-
#import someclass.h
@implementation someclass
@synthesize someString, someNumber;
- (id) init{
self = [super init];
if (self != nil) {
self.someString = @ fred rocks;
self.someNumber = 6969;
}
return self;
}
- (void)updateValues
{
self.someString = [someString stringByAppendingString:@ YEP];
self.someNumber = self.someNumber + 5;
NSLog(@\n%d - %@,someNumber,someString);
}
@end
Right so in IB I have an object which is of class someClass and an
object controller which has the content outlet set to the someclass
object and the keys someString,someNumber.
The button calls the changeValues method in the delegate
The 2 textfields are bound to the controller with selection.someString
and selection.someNumber respectively.
upon application start the text fields are set with their respective
values as per the init of the model. which shows that the bindings are
working.
BUT pressing the button yields no change from the textfields. The
nslog shows the model values are changing but this is not propogated
to the UI.
Whats going on?
According to the Apple docs on troubleshooting bindings The model
class has automatic key-value observing enabled or implements manual
key-value observing for the property. its obviously not manual so huh?
Help and clarification or discussion much appreciated.
Kieren
Olearia - Talking Books on the Mac
http://olearia.googlecode.com/
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Re: textfield not updating with bindings - Whats wrong?
On Aug 23, 2008, at 12:41 AM, Kieren Eaton wrote: Right so in IB I have an object which is of class someClass and an object controller which has the content outlet set to the someclass object and the keys someString,someNumber. The button calls the changeValues method in the delegate The 2 textfields are bound to the controller with selection.someString and selection.someNumber respectively. upon application start the text fields are set with their respective values as per the init of the model. which shows that the bindings are working. BUT pressing the button yields no change from the textfields. The nslog shows the model values are changing but this is not propogated to the UI. Whats going on? According to the Apple docs on troubleshooting bindings The model class has automatic key-value observing enabled or implements manual key-value observing for the property. its obviously not manual so huh? Help and clarification or discussion much appreciated. One thing that I can think of is that you're not changing the fooClass/ someclass instance you think your controls are bound to. That would explain the log being correct while the UI does not update. How do you create the delegate and how do you create the fooClass/ someclass instance your object controller is bound to? Regards Markus -- __ Markus Spoettl smime.p7s Description: S/MIME cryptographic signature ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: NSMenuItem - setHidden
So I could use this method to enable/disable the menu item rather than hide it? That may look a bit more pleasing to the user. Will give it a go. Thanks. Regards, Stuart Sent from my iPhone On 23 Aug 2008, at 02:53, Jonathan Hess [EMAIL PROTECTED] wrote: On Aug 22, 2008, at 6:15 PM, Graham Cox wrote: On 23 Aug 2008, at 5:30 am, chaitanya pandit wrote: [itemToBeHidden setAutoEnablesItems:NO]; Don't call setAutoEnblesItems on the item you want to hide (NSMenuItem) call it on the menu to which the item belongs (or is gonna get added- NSMenu class) -setAutoEnablesItems: doesn't affect visible/hidden, it affects checked/unchecked. So it's unlikely to bear on this problem. I think you meant enabled/disabled, instead of checked/unchecked. Jon Hess hth, Graham ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/jhess%40apple.com This email sent to [EMAIL PROTECTED] ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/stuart%40sjgdigital.com This email sent to [EMAIL PROTECTED] ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: UTI Example
Reposted due to 25KB size limit. Sorry.
On 23 Aug 2008, at 06:42, Adam Thorsen wrote:
Are there any examples of using the UTI API to determine the UTI
given a path to a file?
Thanks,
-Adam
In my app I have a singleton UTI controller class that has an NSArray
property of UTIs supported by my application. There's also a
dictionary that maps the Core Data entities that I use to represent
each file type at runtime. Here are the methods of my UTI controller,
hope they help. I've replaced most of the string constants with
external declarations already but a couple are still constant
strings. They show how to use -[NSWorkspace type:conformsToType:] and
-[NSWorkspace typeOfFile:error:]
As for your info.plist file, and exported and imported declarations,
there's a good article here:
http://developer.apple.com/documentation/Carbon/Conceptual/understanding_utis/understand_utis_conc/chapter_2_section_4.html
- (id)init;
{
if (![super init])
return nil;
self.supportedUTIs = [NSArray arrayWithObjects:(NSString
*)kUTTypePlainText
,kUTTypeTex,kUTTypeTeXShopTex,kUTTypeBib,kUTTypeBibDeskBib,(NSString
*)kUTTypePDF,(NSString *)kUTTypeImage,kUTTypeEPS,nil];
self.utiEntityNameMap = [NSDictionary dictionaryWithObjects:[NSArray
arrayWithObjects:ESTexFileEntityName
,ESTexFileEntityName
,ESTexFileEntityName
,@BibTexFile
,@BibTexFile
,ESPDFFileEntityName,ESImageFileEntityName,@EPSFile,nil]
forKeys:self.supportedUTIs];
return self;
}
- (NSString *)isSupportedUTI:(NSString *)uti error:(NSError
**)errorPointer;
{
for (NSString *supportedUTI in self.supportedUTIs)
if ([[NSWorkspace sharedWorkspace] type:uti
conformsToType:supportedUTI])
return supportedUTI;
if (errorPointer != NULL)
*errorPointer = [NSError errorWithDomain:ESScribblerErrorDomain
code:ESUnsupportedUTIErrorCode userInfo:[NSDictionary
dictionaryWithObjectsAndKeys:NSLocalizedString
(@,@),NSLocalizedDescriptionKey
,NSLocalizedString
(@,@),NSLocalizedRecoverySuggestionErrorKey
,uti,ESUnsupportedUTIErrorKey,nil]];
return nil;
}
- (NSString *)isSupportedFile:(NSString *)filepath error:(NSError
**)errorPointer;
{
NSString *uti = [[NSWorkspace sharedWorkspace] typeOfFile:filepath
error:errorPointer];
if (!uti)
return nil;
return [self isSupportedUTI:uti error:errorPointer];
}
- (NSString *)entityNameForFile:(NSString *)filepath error:(NSError
**)errorPointer;
{
NSString *supportedUTI = [self isSupportedFile:filepath
error:errorPointer];
if (!supportedUTI)
return nil;
return [self.utiEntityNameMap valueForKey:supportedUTI]; // leave
this error as nil, if we've got this far then we can determine the UTI
}
/*
Maps the UTIs for the files and create a dictionary of entity name
values and filepath keys. All errros are put into an NSDictionary. It
is guaranteed to return a dictionary, so clients must inspect both the
errors dictionary and the count of the returned dictionary.
This method can't reasonably return nil as the presence of errors
does not preclude the presence of supported files. To return nil if
there are errors is too simplistic.
*/
- (NSDictionary *)entityMapForFiles:(NSArray *)filepaths errors:
(NSDictionary **)dictionaryPtr;
{
NSMutableDictionary *mutableErrorsDictionary = [NSMutableDictionary
dictionary];
NSMutableDictionary *mutableEntityMap = [NSMutableDictionary
dictionary];
for (NSString *filepath in filepaths) {
NSError *entityError = nil;
NSString *entityName = [self entityNameForFile:filepath
error:entityError];
if (!entityName)
[mutableErrorsDictionary setObject:entityError
forKey:filepath];
else
[mutableEntityMap setObject:entityName forKey:filepath];
}
if ([mutableErrorsDictionary count] != 0 dictionaryPtr != NULL)
*dictionaryPtr = [[mutableErrorsDictionary copy] autorelease];
return [[mutableEntityMap copy] autorelease];
}
Jonathan
http://espresso-served-here.com
smime.p7s
Description: S/MIME cryptographic signature
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Implementing isEqual: and hash
I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? tia, Graham ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Sat, Aug 23, 2008 at 11:41 PM, Graham Cox [EMAIL PROTECTED] wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? If you're deferring both -isEqual: and -hash to an NSString, you'll be fine. Hash doesn't need to be anything complicated (although a good distribution is nice), just as long as two objects that return YES for -isEqual: return the same value for -hash (the inverse doesn't have to be true). Phil ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Sat, Aug 23, 2008 at 7:41 AM, Graham Cox [EMAIL PROTECTED] wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? The implementation of -hash should *always* match the implementation of -isEqual:. If you compare primitives in -isEqual:, you should combine them (using xor or the like) in -hash. If you compare objects by calling -isEqual: on them, you should combine their hashes (using xor or the like). If you do some of each, combine them all. If you compare only one thing for equality, return it (if it's a primitive) or its hash value (if you call isEqual: on it). Mike ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: textfield not updating with bindings - Whats wrong?
Right so in IB I have an object which is of class someClass and an object controller which has the content outlet set to the someclass object and the keys someString,someNumber. The button calls the changeValues method in the delegate The 2 textfields are bound to the controller with selection.someString and selection.someNumber respectively. upon application start the text fields are set with their respective values as per the init of the model. which shows that the bindings are working. BUT pressing the button yields no change from the textfields. The nslog shows the model values are changing but this is not propogated to the UI. Whats going on? According to the Apple docs on troubleshooting bindings The model class has automatic key-value observing enabled or implements manual key-value observing for the property. its obviously not manual so huh? Help and clarification or discussion much appreciated. One thing that I can think of is that you're not changing the fooClass/ someclass instance you think your controls are bound to. That would explain the log being correct while the UI does not update. How do you create the delegate and how do you create the fooClass/ someclass instance your object controller is bound to? Regards Markus -- Thanks Markus ok the delegate is set as an object in IB it is the delegate of Files owner and nsapplication (thats correct isnt it?) it has a class of bindtestdelegate which is where the button action is located. The button calls the changeValues method in the delegate class which then calls the updateValues in the fooClass instance of the someclass. should my filesOwner in IB (Currently it is NSApplication) be something different? the instance of someClass is just dragged straight out of the IB lib as a simple object and assigned the class someClass I dont actually have a nsobjectcontroller subclass .h/.m in my project but according to the apple docs I dont need one? Some things are harder than others. I can email you the entire project if you like if thats easier for your perusal. I would REALLY like to understand what I am not doing right? Thanks Kieren ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: textfield not updating with bindings - Whats wrong?
Right so in IB I have an object which is of class someClass and an object controller which has the content outlet set to the someclass object and the keys someString,someNumber. The button calls the changeValues method in the delegate The 2 textfields are bound to the controller with selection.someString and selection.someNumber respectively. upon application start the text fields are set with their respective values as per the init of the model. which shows that the bindings are working. BUT pressing the button yields no change from the textfields. The nslog shows the model values are changing but this is not propogated to the UI. Whats going on? According to the Apple docs on troubleshooting bindings The model class has automatic key-value observing enabled or implements manual key-value observing for the property. its obviously not manual so huh? Help and clarification or discussion much appreciated. One thing that I can think of is that you're not changing the fooClass/ someclass instance you think your controls are bound to. That would explain the log being correct while the UI does not update. How do you create the delegate and how do you create the fooClass/ someclass instance your object controller is bound to? Regards Markus -- Thanks Markus ok the delegate is set as an object in IB it is the delegate of Files owner and nsapplication (thats correct isnt it?) it has a class of bindtestdelegate which is where the button action is located. The button calls the changeValues method in the delegate class which then calls the updateValues in the fooClass instance of the someclass. should my filesOwner in IB (Currently it is NSApplication) be something different? the instance of someClass is just dragged straight out of the IB lib as a simple object and assigned the class someClass I dont actually have a nsobjectcontroller subclass .h/.m in my project but according to the apple docs I dont need one? Some things are harder than others. I can email you the entire project if you like if thats easier for your perusal. I would REALLY like to understand what I am not doing right? Thanks Kieren ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On 23 Aug 2008, at 10:13 pm, Michael Ash wrote: On Sat, Aug 23, 2008 at 7:41 AM, Graham Cox [EMAIL PROTECTED] wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? The implementation of -hash should *always* match the implementation of -isEqual:. If you compare primitives in -isEqual:, you should combine them (using xor or the like) in -hash. If you compare objects by calling -isEqual: on them, you should combine their hashes (using xor or the like). If you do some of each, combine them all. If you compare only one thing for equality, return it (if it's a primitive) or its hash value (if you call isEqual: on it). Thanks guys - works fine. cheers, Graham ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
Le 23 août 08 à 13:41, Graham Cox a écrit : I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? Yes, that the way to do it. To understand what an hash is and how it is used, I suggest you read the hash table article in wikipedia. http://en.wikipedia.org/wiki/Hash_table Hash tables are used in Cocoa in NSDictionary, NSSet, NSHashTable, NSHashMap and maybe more. When you understand how it works, choosing the implementation should be obvious. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On 23 Aug 2008, at 9:52 pm, Jean-Daniel Dupas wrote:
Le 23 août 08 à 13:41, Graham Cox a écrit :
I have a class for which equality can be defined as having the same
internal string value (which happens to be a UUID-turned-string). I
can easily implement isEqual: based on that but the docs say I also
need to implement -hash. Any pointers on what is a good way to do
that? Could I just safely defer to the -hash returned by the string
in question?
Yes, that the way to do it.
To understand what an hash is and how it is used, I suggest you read
the hash table article in wikipedia.
http://en.wikipedia.org/wiki/Hash_table
Hash tables are used in Cocoa in NSDictionary, NSSet, NSHashTable,
NSHashMap and maybe more. When you understand how it works, choosing
the implementation should be obvious.
Thanks for that. I'm pretty familiar with hash tables in general (and
in quite a bit of theory too) but I wasn't able to find out what Cocoa
uses for its hashing function or how good this needed to be to work
well with the built-in classes. However, by deferring to the string I
can avoid the issue altogether.
For curiosity's sake, I would be interested to know what sort of
hashing functions Cocoa does use. I haven't come across the need to
generate one for any of my custom classes before so it's not something
I need right now, but every bit of knowledge is worth having.
For example, here's a very crude hash function I used in a very simple
symbol table implementation from a long while ago. I imagine most hash
functions in Cocoa would be more sophisticated.
unsigned long ZHashTable::Hash( const char* name )
{
register unsigned long h = 1;
register char* p = (char*) name;
register char c;
while(( c = *p++ ) != 0 )
h *= (unsigned long) c;
return h % kHashTableSize;
}
cheers, Graham___
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Re: Implementing isEqual: and hash
Le 23 août 08 à 15:39, Graham Cox a écrit :
On 23 Aug 2008, at 9:52 pm, Jean-Daniel Dupas wrote:
Le 23 août 08 à 13:41, Graham Cox a écrit :
I have a class for which equality can be defined as having the
same internal string value (which happens to be a UUID-turned-
string). I can easily implement isEqual: based on that but the
docs say I also need to implement -hash. Any pointers on what is a
good way to do that? Could I just safely defer to the -hash
returned by the string in question?
Yes, that the way to do it.
To understand what an hash is and how it is used, I suggest you
read the hash table article in wikipedia.
http://en.wikipedia.org/wiki/Hash_table
Hash tables are used in Cocoa in NSDictionary, NSSet, NSHashTable,
NSHashMap and maybe more. When you understand how it works,
choosing the implementation should be obvious.
Thanks for that. I'm pretty familiar with hash tables in general
(and in quite a bit of theory too) but I wasn't able to find out
what Cocoa uses for its hashing function or how good this needed
to be to work well with the built-in classes. However, by deferring
to the string I can avoid the issue altogether.
For curiosity's sake, I would be interested to know what sort of
hashing functions Cocoa does use. I haven't come across the need to
generate one for any of my custom classes before so it's not
something I need right now, but every bit of knowledge is worth
having.
For example, here's a very crude hash function I used in a very
simple symbol table implementation from a long while ago. I imagine
most hash functions in Cocoa would be more sophisticated.
unsigned long ZHashTable::Hash( const char* name )
{
register unsigned long h = 1;
register char* p = (char*) name;
register char c;
while(( c = *p++ ) != 0 )
h *= (unsigned long) c;
return h % kHashTableSize;
}
Look into the CoreFoundation sources. as Cocoa primitive are tool free
bridged, they use the same hash functions. They is even a special case
for NSString into the CFString.c file.
http://www.opensource.apple.com/darwinsource/10.5.4/CF-476.14/
You can find Integer and double hash function into ForFoundationOnly.h.
And there is another generic hash function into CFData.c
According to the Leopard release notes, we can guess that thoses
function have been updated into Leopard:
Order of values in hashing-based collections
The CoreFoundation and Foundation framework-provided implementations
of hashing-based collections such as dictionaries have changed how
they store elements, so elements may be retrieved in a different order
than in previous releases. The order of elements in hashing-based
collections is undefined and can change at any time, so developers
must never rely on the order that elements are enumerated, or returned
from a function like CFDictionaryGetKeysAndValues(). This is true even
for cases where a developer may be trying to manipulate the hash codes
of the objects in order to achieve some particular ordering.
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Re: Incorrect instance of custom view loading after unarchiving
Hi all, Thanks to Quincey's note and some back-referencing to one of the earlier RaiseMan projects, I was finally able to solve this. (as usual) The solution actually was simpler than I thought. I had to *effectively* override these two methods: - (NSData *)dataOfType:(NSString *)typeName error:(NSError **)outError; - (BOOL)readFromData:(NSData *)data ofType:(NSString *)typeName error: (NSError **)outError; I was doing *too much work* by making MyDocument conform to NSCoding. These two methods were doing the equivalent work of NSCoding for me. I just had to create a cleaner object model separation by only archiving my NSMutableArray to store my NSBezierPaths. This was a GINORMOUS breakthrough for me! I'd been afraid of doing graphical programming in Cocoa *FOREVER* (almost 10 years). Now I see how easy it is, esp. w/ all the new stuff in Leopard, and it's amazing. Thank you all! Live Playfully, Sam On Aug 23, 2008, at 12:12 AM, Quincey Morris wrote: On Aug 22, 2008, at 20:45, Sam Krishna wrote: OK, I've read all the email from the past month about Aaron's challenge in Ch. 18 of Cocoa Programming. I've got a custom view (OvalView) where the magic happens. I've got Undo working, but I can't get the app to load a saved document b/c it keeps loading the wrong instance of OvalView on unarchiving. [snip] Here's my Q: What do I need to do to fix it? Is there some simple IB3 gestalt that I'm missing? Some NSCoding voodoo that's completely obvious? what gives? Well, if it was completely obvious, you wouldn't have missed it. ;) What you're doing wrong is archiving your view (something that *draws* an oval). What you really need to do is archive your data model (something that *describes* an oval). That means you should keep the oval description separate from the view, and let the view refer to the separate description for the parameters it needs to draw the oval. Write on the blackboard 100 times: MVC MVC MVC ... ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/infinity%40mac.com This email sent to [EMAIL PROTECTED] ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Two questions about CoreData migration
On Aug 22, 2008, at 12:14, Timothy Larkin wrote: The first question is a simple one. After migration, the old persistent store is renamed sourceURL~.xml, and the document is supposed to open with a new persistent store with the old url, sourceURL.xml,. However, the document window that appears after migration has the title sourceURL~.xml, and saving this replaces the original, unmigrated document. Why doesn't the document open with sourceURL? I have examined the document at various stages during the open document process, and it consistently reports the URL without the tilde. And that is how the window initially appears. However, it switches to the form with the tilde as soon as the window is activated. I went so far as to subclass NSDocumentController, overriding openDocumentWithContentsOfURL:absoluteURL display:error:. I tried many ideas, including closing the document and having NSRunLoop send a message to reopen the document after openDocument had returned. Even with this desperate approach, the document opened as sourceURL~.xml, which was very perplexing. The resolution is quite strange. I had been setting a break point in the over-ride function, so that I could examine the state of the document after I called super openDocument. I discovered, quite by accident, that if I removed the breakpoint, the document opened as sourceURL, as expected. With the break point: sourceURL~.xml; without the break point: sourceURL.xml. This makes absolutely no sense to me, but it is certainly the case. -- Timothy Larkin Abstract Tools Caroline, NY PGP.sig Description: This is a digitally signed message part ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 7:41 AM, Graham Cox wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? Graham, Is your object mutable? (That is, is any attribute of the attribute which affects equality or hash mutable? In this case that sounds like the internal string value which is a UUID.) If so, that opens up another can of worms to consider. Jim ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 8:57 AM, Jean-Daniel Dupas wrote: Look into the CoreFoundation sources. as Cocoa primitive are tool free bridged, they use the same hash functions. They is even a special case for NSString into the CFString.c file. http://www.opensource.apple.com/darwinsource/10.5.4/CF-476.14/ Those are not the sources for CoreFoundation. Those are the sources for 'CFLite', which is a dumbed-down version of CoreFoundation used by IOKit. The real CoreFoundation is not open source. There is no guarantee that CFLite and CoreFoundation are the same. In fact, there are known differences. -Jeff ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
NSApplication _doOpenUntitled raises exception under Leopard, not Tiger
I have a document based app that does the right thing under Tiger.
Works great.
Under Leopard, NSApplication _doOpenUntitled is raising [NSCFArray
objectAtIndex:]: index (0) beyond bounds (0)
during the application opening sequence. There isn't a single routine
that is mine on the stack. So what array is _doOpenUntitled trying to
iterate on Leopard that it didn't on Tiger?
More clues:
I have a custom DocumentController that overrides newDocument: as
- (IBAction)newDocument:(id)sender
{
[self closeAllDocumentsWithDelegate:self
didCloseAllSelector
:@selector(documentController:didCloseAll:contextInfo:) contextInfo:0];
[super newDocument: sender];
}
because I only support one document open at a time. Oddly enough, if
I ignore the exception, this gets called twice during the opening
sequence on Leopard.
Anybody know what changed about the opening sequence or why this
should stop working on Leopard?
-Todd Blanchard
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Re: Implementing isEqual: and hash
On Aug 23, 2008, at 5:13 AM, Michael Ash wrote: On Sat, Aug 23, 2008 at 7:41 AM, Graham Cox [EMAIL PROTECTED] wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? The implementation of -hash should *always* match the implementation of -isEqual:. And as Jim alluded, -hash must not depend on mutable properties; if the hash changes while the object is in a hashing collection, you'll end up with random crashes. If you compare primitives in -isEqual:, you should combine them (using xor or the like) in -hash. If you compare objects by calling -isEqual: on them, you should combine their hashes (using xor or the like). If you do some of each, combine them all. What's the motivation for combining hashes in this case? I've wondered what is the best thing to do when isEqual: is based on comparing multiple ivars; I typically just use one of them for the hash. thanks, Adam smime.p7s Description: S/MIME cryptographic signature ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Two questions about CoreData migration
On Aug 23, 2008, at 08:00, Timothy Larkin wrote: I went so far as to subclass NSDocumentController, overriding openDocumentWithContentsOfURL:absoluteURL display:error:. I tried many ideas, including closing the document and having NSRunLoop send a message to reopen the document after openDocument had returned. Even with this desperate approach, the document opened as sourceURL~.xml, which was very perplexing. The resolution is quite strange. I had been setting a break point in the over-ride function, so that I could examine the state of the document after I called super openDocument. I discovered, quite by accident, that if I removed the breakpoint, the document opened as sourceURL, as expected. With the break point: sourceURL~.xml; without the break point: sourceURL.xml. This makes absolutely no sense to me, but it is certainly the case. If you can demonstrate this in a simple project, it would be a good candidate for a bug report to Apple. You actually have 3 things to report: 1. The above problem. 2. Your original problem, where the wrong file gets opened. 3. A documentation problem, where migration in a NSPersistentDocument context apparently requires some extra code that isn't documented. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: textfield not updating with bindings - Whats wrong?
On Aug 23, 2008, at 5:16 AM, Kieren Eaton wrote: ok the delegate is set as an object in IB it is the delegate of Files owner and nsapplication (thats correct isnt it?) it has a class of bindtestdelegate which is where the button action is located. The button calls the changeValues method in the delegate class which then calls the updateValues in the fooClass instance of the someclass. should my filesOwner in IB (Currently it is NSApplication) be something different? Well, that depends, in most cases it's good to have a NSWindowController or NSViewController as file owner since those take care of memory management of the nib file. But I believe it's irrelevant to the problem at hand. the instance of someClass is just dragged straight out of the IB lib as a simple object and assigned the class someClass I dont actually have a nsobjectcontroller subclass .h/.m in my project but according to the apple docs I dont need one? No, you don't, you just mentioned you used one. As far as I can tell from your explanation, you have 1 bindingstestDelegate object (the file's owner) and one extra someClass object. The problem is that your delegate class creates its own someClass instance and when you press the button that instance get changed, not the other instance you created in the nib file. I would change the code so that the bindingstestDelegate class exposes a readonly property named fooClass. You then remove the extra someClass object from your nib and bind the NSTextFields to the file's owner fooClass.someString and fooClass.someNumber keys. I would also suggest you change the naming slightly, using uppercase first characters for class names. This makes it easier to distinguish classes from instances, methods and properties. More details here: http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC/Articles/chapter_950_section_12.html#/ /apple_ref/doc/uid/TP30001163-CH3-TPXREF108 Markus -- __ Markus Spoettl smime.p7s Description: S/MIME cryptographic signature ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: NSApplication _doOpenUntitled raises exception under Leopard, not Tiger
On Aug 23, 2008, at 9:26 AM, Todd Blanchard wrote:
- (IBAction)newDocument:(id)sender
{
[self closeAllDocumentsWithDelegate:self
didCloseAllSelector
:@selector(documentController:didCloseAll:contextInfo:) contextInfo:
0];
[super newDocument: sender];
}
because I only support one document open at a time. Oddly enough,
if I ignore the exception, this gets called twice during the opening
sequence on Leopard.
Anybody know what changed about the opening sequence or why this
should stop working on Leopard?
No idea, but it seems really odd to be closing all other documents
when a new document is being opened.
It sounds like what might be happening is:
- app launches
- app requests untitled document
- untitled document is opened
- newDocument: is invoked
- newDocument: closes the freshly opened untitled document
- something a-splodes in super's newDocument: because it was doing
something funky w/the untitled document
Do you need an untitled document? If not, kill it.
Otherwise, I'd need more context to understand the issue.
- what is the backtrace when the exception is tossed?
- what are the backtraces when -newDocument: is invoked twice?
... etc ...
b.bum
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Re: Implementing isEqual: and hash
On Aug 23, 2008, at 11:38 AM, Adam R. Maxwell wrote: On Aug 23, 2008, at 5:13 AM, Michael Ash wrote: On Sat, Aug 23, 2008 at 7:41 AM, Graham Cox [EMAIL PROTECTED] wrote: I have a class for which equality can be defined as having the same internal string value (which happens to be a UUID-turned-string). I can easily implement isEqual: based on that but the docs say I also need to implement -hash. Any pointers on what is a good way to do that? Could I just safely defer to the -hash returned by the string in question? The implementation of -hash should *always* match the implementation of -isEqual:. And as Jim alluded, -hash must not depend on mutable properties; if the hash changes while the object is in a hashing collection, you'll end up with random crashes. Right. Thus, it's a bad idea to use mutable properties in isEqual:. If you find yourself tempted to do that, impement an isEqualToMyClass: method rather than isEqual:. If you compare primitives in -isEqual:, you should combine them (using xor or the like) in -hash. If you compare objects by calling - isEqual: on them, you should combine their hashes (using xor or the like). If you do some of each, combine them all. What's the motivation for combining hashes in this case? I've wondered what is the best thing to do when isEqual: is based on comparing multiple ivars; I typically just use one of them for the hash. It's a documented requirement of the isEqual: and hash methods that the hash must be the same when isEqual: returns YES. Thus, whatever logic that returns YES in isEqual: must have some kind of match in hash. -Jeff ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 12:26 PM, Jeff Johnson wrote: If you compare primitives in -isEqual:, you should combine them (using xor or the like) in -hash. If you compare objects by calling - isEqual: on them, you should combine their hashes (using xor or the like). If you do some of each, combine them all. What's the motivation for combining hashes in this case? I've wondered what is the best thing to do when isEqual: is based on comparing multiple ivars; I typically just use one of them for the hash. It's a documented requirement of the isEqual: and hash methods that the hash must be the same when isEqual: returns YES. Thus, whatever logic that returns YES in isEqual: must have some kind of match in hash. -Jeff Also, you're probably less likely to have collisions by combining. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
error codes
Is there a convenience function (or method) foo() with int arg and NSString* value for converting an error code to a string? For example, given error code errcode = 560227702 = 0x21646576, foo(errcode) = @!idev? --RS ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: error codes
On Sat, Aug 23, 2008 at 2:09 PM, Roland Silver [EMAIL PROTECTED] wrote:
Is there a convenience function (or method) foo() with int arg and NSString*
value for converting an error code to a string?
This program:
#include stdio.h
int main(int argc, char **argv)
{
int a = 560227702;
char *b = (char*)(a);
printf(%c%c%c%c%c, b[0], b[1], b[2], b[3], b[4]);
return 0;
}
Produces this output:
$ ./a.out
ved!?
It's close... dunno what magic is going on, but it shouldn't be that
hard to do yourself. What bothers me is that you have a five
character error code (!idev) whereas an int is only 4 bytes wide. I
wrote my code with 5 characters, but it's an obvious out-of-bounds
access.
--Kyle Sluder
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Re: error codes
On Aug 23, 2008, at 11:44 AM, Kyle Sluder wrote:
On Sat, Aug 23, 2008 at 2:09 PM, Roland Silver
[EMAIL PROTECTED] wrote:
Is there a convenience function (or method) foo() with int arg and
NSString*
value for converting an error code to a string?
This program:
#include stdio.h
int main(int argc, char **argv)
{
int a = 560227702;
char *b = (char*)(a);
printf(%c%c%c%c%c, b[0], b[1], b[2], b[3], b[4]);
return 0;
}
Produces this output:
$ ./a.out
ved!?
It's close... dunno what magic is going on, but it shouldn't be that
hard to do yourself. What bothers me is that you have a five
character error code (!idev) whereas an int is only 4 bytes wide. I
wrote my code with 5 characters, but it's an obvious out-of-bounds
access.
Huh? There is no reason why accessing b[4] should crash. Produce a
random value? Sure, but not crash. You are just accessing one byte
past a stack based array and, thus, reading a random byte off the stack.
If you want to crash, try:
((char *)0x1) = 'a';
Or the like.
Is there a convenience function (or method) foo() with int arg and
NSString* value for converting an error code to a string?
For example, given error code errcode = 560227702 = 0x21646576,
foo(errcode) = @!idev?
Actually, I'm not even sure what the OP is asking for. Where did the
error code come from and why do you think converting it to the string
'!idev' is going to be useful?
Ahh... it is kAudioHardwareBadDeviceError from Core Audio. That is,
there is a constant defined and you can do comparisons to see which
error you have. Converting to the four+ character gobbledy-gook
really isn't going to help much. A quick search reveals this bit of
code which might be quite helpful:
http://www.martux.org/qemu_old/qemu-0.8.2-solaris__20061010x11/audio/coreaudio.c
b.bum
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Re: Implementing isEqual: and hash
On Aug 23, 2008, at 10:26 AM, Jeff Johnson wrote:
On Aug 23, 2008, at 11:38 AM, Adam R. Maxwell wrote:
On Aug 23, 2008, at 5:13 AM, Michael Ash wrote:
On Sat, Aug 23, 2008 at 7:41 AM, Graham Cox
[EMAIL PROTECTED] wrote:
I have a class for which equality can be defined as having the
same internal
string value (which happens to be a UUID-turned-string). I can
easily
implement isEqual: based on that but the docs say I also need to
implement
-hash. Any pointers on what is a good way to do that? Could I
just safely
defer to the -hash returned by the string in question?
The implementation of -hash should *always* match the implementation
of -isEqual:.
And as Jim alluded, -hash must not depend on mutable properties; if
the hash changes while the object is in a hashing collection,
you'll end up with random crashes.
Right. Thus, it's a bad idea to use mutable properties in isEqual:.
If you find yourself tempted to do that, impement an
isEqualToMyClass: method rather than isEqual:.
CF collection callbacks are also handy in cases like this, since you
can use equality functions that may not be correct for the general
case of isEqual:.
If you compare primitives in -isEqual:, you should combine them
(using
xor or the like) in -hash. If you compare objects by calling -
isEqual:
on them, you should combine their hashes (using xor or the like). If
you do some of each, combine them all.
What's the motivation for combining hashes in this case? I've
wondered what is the best thing to do when isEqual: is based on
comparing multiple ivars; I typically just use one of them for the
hash.
It's a documented requirement of the isEqual: and hash methods that
the hash must be the same when isEqual: returns YES. Thus, whatever
logic that returns YES in isEqual: must have some kind of match in
hash.
If I have
@interface Test : NSObject
{
id ivar1;
id ivar2;
}
@end
@implementation Test
- (BOOL)isEqual:(id)other
{
if ([other isKindOfClass:[self class]] == NO) return NO;
return ([ivar1 isEqual:(Test *)other-ivar1] [ivar2 isEqual:
(Test *)other-ivar2]);
}
- (unsigned)hash { return [ivar1 hash]; }
@end
I believe it's sufficient to use [ivar1 hash], since the object is
only equal if ivar1 is equal in both objects. I was just curious to
know what you gain by using ([ivar1 hash] ^ [ivar2 hash]); is it
possible to know in general if it reduces collisions? Presumably that
depends on the hash table implementation as well.
--
Adam
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How to read pixel values of monochrome images
I'm trying to read individual pixel values in a monochrome image using NSReadPixel, but I haven't been able to. I would much appreciate anyone's help ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: error codes
On Sat, Aug 23, 2008 at 2:54 PM, Bill Bumgarner [EMAIL PROTECTED] wrote: Huh? There is no reason why accessing b[4] should crash. Produce a random value? Sure, but not crash. You are just accessing one byte past a stack based array and, thus, reading a random byte off the stack. I'm not looking for a crash. The OP presented an error string !idev, which has five characters. An int is only four bytes wide, so I was concerned about how the OP had gotten the !idev == 560227702 relationship in the first place. I thought it was perhaps a typo, especially given the OS's history of FourCC's. --Kyle Sluder ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 2:05 PM, Adam R. Maxwell wrote:
If I have
@interface Test : NSObject
{
id ivar1;
id ivar2;
}
@end
@implementation Test
- (BOOL)isEqual:(id)other
{
if ([other isKindOfClass:[self class]] == NO) return NO;
return ([ivar1 isEqual:(Test *)other-ivar1] [ivar2 isEqual:
(Test *)other-ivar2]);
}
- (unsigned)hash { return [ivar1 hash]; }
@end
I believe it's sufficient to use [ivar1 hash], since the object is
only equal if ivar1 is equal in both objects. I was just curious
to know what you gain by using ([ivar1 hash] ^ [ivar2 hash]); is it
possible to know in general if it reduces collisions? Presumably
that depends on the hash table implementation as well.
--
Adam
Right, it depends on the hash table implementation, which we don't
know. Theoretically, it seems likely to reduce collisions. This could
only be confirmed by real-world performance tests, though.
-Jeff
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Re: NSApplication _doOpenUntitled raises exception under Leopard, not Tiger
I found it. CoreAudio being flakey again while being initialized.
Changed order of initialization a bit and it stopped giving me the no
such property error. It is different in Tiger and Leopard despite
sticking to the 10.4 api.
Is it me or is the debugger becoming progressively more useless? I
often find that it can't show me variables in the current scope and
setting a breakpoint on NSException raise doesn't really reveal the
point of error like it used to (lots of stack frames are omitted -
even when they're mine).
Anyhow, thanks for noticing me.
-Todd Blanchard
On Aug 23, 2008, at 10:08 AM, Bill Bumgarner wrote:
On Aug 23, 2008, at 9:26 AM, Todd Blanchard wrote:
- (IBAction)newDocument:(id)sender
{
[self closeAllDocumentsWithDelegate:self
didCloseAllSelector
:@selector(documentController:didCloseAll:contextInfo:) contextInfo:
0];
[super newDocument: sender];
}
because I only support one document open at a time. Oddly enough,
if I ignore the exception, this gets called twice during the
opening sequence on Leopard.
Anybody know what changed about the opening sequence or why this
should stop working on Leopard?
No idea, but it seems really odd to be closing all other documents
when a new document is being opened.
It sounds like what might be happening is:
- app launches
- app requests untitled document
- untitled document is opened
- newDocument: is invoked
- newDocument: closes the freshly opened untitled document
- something a-splodes in super's newDocument: because it was doing
something funky w/the untitled document
Do you need an untitled document? If not, kill it.
Otherwise, I'd need more context to understand the issue.
- what is the backtrace when the exception is tossed?
- what are the backtraces when -newDocument: is invoked twice?
... etc ...
b.bum
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Re: NSApplication _doOpenUntitled raises exception under Leopard, not Tiger
On Sat, Aug 23, 2008 at 4:40 PM, Todd Blanchard [EMAIL PROTECTED] wrote: Is it me or is the debugger becoming progressively more useless? I often find that it can't show me variables in the current scope and setting a breakpoint on NSException raise doesn't really reveal the point of error like it used to (lots of stack frames are omitted - even when they're mine). On Leopard, you should be breaking on objc_exception_throw. Use +[NSException raise] for Tiger exception debugging. --Kyle Sluder ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: NSApplication _doOpenUntitled raises exception under Leopard, not Tiger
On Sat, Aug 23, 2008 at 4:55 PM, Todd Blanchard [EMAIL PROTECTED] wrote: I had no idea - I'm still catering to the Tiger world mostly. Is there a good document that just tells me what is new? The Leopard release notes are a great start: http://developer.apple.com/releasenotes/Cocoa/Foundation.html By the way, I was mistaken in suggesting breaking on +[NSException raise]. No such method exists. You want to break on -[NSException raise] instead. --Kyle Sluder ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: How to read pixel values of monochrome images
On Fri, Aug 22, 2008 at 2:54 AM, Eduardo Areitio [EMAIL PROTECTED] wrote: I'm trying to read individual pixel values in a monochrome image using NSReadPixel, but I haven't been able to. I would much appreciate anyone's help It is usually best to post some code or better explain what you tried and what is going wrong otherwise we have to guess at the difficulty you are having. Anyway... http://developer.apple.com/samplecode/Color_Sampler/listing5.html -Shawn ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Basic Window Management
I am trying to add a log window to an otherwise single window application and have come across a couple of basic window management issues. Firstly, if the log window is closed by clicking the close button and then I subsequently call makeKeyAndOrderFront then I get a crash. I presume there is a window life cycle issue here I don't understand. How do I correctly bring back a closed window? Secondly, since this is a log window I want to write log info whenever I have some. I also get a crash if I attempt to write to the textView when the window has been closed. Can I keep the window alive, even if not on screen, so I can continue to write to the textView? thanks, Andrew ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Basic Window Management
--- On Sat, 8/23/08, Andrew Zahra [EMAIL PROTECTED] wrote: I am trying to add a log window to an otherwise single window application and have come across a couple of basic window management issues. Firstly, if the log window is closed by clicking the close button and then I subsequently call makeKeyAndOrderFront then I get a crash. I presume there is a window life cycle issue here I don't understand. How do I correctly bring back a closed window? The window is being released. Uncheck Release when closed in Interface Builder if you want it to stick around. Cheers, Chuck ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
renaming a project
hi, I have a project which has MyTest as the project name, so the executable has the same name, now I'd like to rename it to MyProg, I renamed the Xoce's project file to MyProg, but the executable still has the previous name, any idea how to rename ? thanks Angelo 為了不斷提升Yahoo! Mail，雅虎香港誠邀你參與意見調查。請前往http://surveylink.yahoo.com/wix/p5429076.aspx 發表你的意見! ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 9:43 PM, Jeff Johnson wrote:
On Aug 23, 2008, at 2:05 PM, Adam R. Maxwell wrote:
If I have
@interface Test : NSObject
{
id ivar1;
id ivar2;
}
@end
@implementation Test
- (BOOL)isEqual:(id)other
{
if ([other isKindOfClass:[self class]] == NO) return NO;
return ([ivar1 isEqual:(Test *)other-ivar1] [ivar2 isEqual:
(Test *)other-ivar2]);
}
- (unsigned)hash { return [ivar1 hash]; }
@end
I believe it's sufficient to use [ivar1 hash], since the object is
only equal if ivar1 is equal in both objects. I was just curious
to know what you gain by using ([ivar1 hash] ^ [ivar2 hash]); is it
possible to know in general if it reduces collisions? Presumably
that depends on the hash table implementation as well.
--
Adam
Right, it depends on the hash table implementation, which we don't
know. Theoretically, it seems likely to reduce collisions. This
could only be confirmed by real-world performance tests, though.
-Jeff
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I think theoretically, it seems likely to increase collisions. If
ivar1 and ivar2 aren't independent of each other, xor can cluster
different values causing lots of collisions. Consider what happens if
ivars are laid out serially say 0x0100 and 0x0200, xor and you
get 0x300, and let's say that another completely different object's
ivars are 0xff000600 and 0xff000700, and you still get 0x300,
collision.
The hash table implementation has nothing to do with this, the problem
occurs before the hash table has any chance to make it even worse. (If
you always return the same hash value, the hash table has nothing to
work with in spreading the stored objects.)
/Pierre
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Re: Implementing isEqual: and hash
Date: Sat, 23 Aug 2008 12:05:44 -0700
From: Adam R. Maxwell [EMAIL PROTECTED]
[...]
- (BOOL)isEqual:(id)other
{
if ([other isKindOfClass:[self class]] == NO) return NO;
return ([ivar1 isEqual:(Test *)other-ivar1] [ivar2 isEqual:
(Test *)other-ivar2]);
}
- (unsigned)hash { return [ivar1 hash]; }
@end
I believe it's sufficient to use [ivar1 hash], since the object is
only equal if ivar1 is equal in both objects. I was just curious to
know what you gain by using ([ivar1 hash] ^ [ivar2 hash]); is it
possible to know in general if it reduces collisions?
If you combine the hash values correctly, it will reduce collisions.
Note that the previously mentioned xor technique is not generally
considered correct and can in fact lead to increased collisions,
not fewer.
One reasonably common technique for combining hash values into a new
hash value is to multiply and accumulate using a prime number.
There's probably some good math theory as to what a nice prime number
to pick might be, but I've seen enough examples that use 37 that
that's what I usually use. :)
For example:
- (unsigned) hash
{
unsigned ret = 0;
ret += ret * 37 + [ivar1 hash];
ret += ret * 37 + [ivar2 hash];
return ret;
}
Note the redundant multiply and add in the first line. Writing the
code that way makes it easy to add/remove members if for some reason
the data structure should change in the future. But it would be just
as correct to simply initialize ret to the first hash value, of course.
Presumably that
depends on the hash table implementation as well.
Well, if your hash values collide, they collide regardless of the
hash table. As long as you've got a well-distributed hash function,
any collisions generated by the hash table implementation should be
well-distributed as well.
Pete
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specify a NSPredicate for jpeg file names?
Hi, I'd like to filter an array to return only jpeg file names like DSC0001.jpg, DSC0002.jpg, etc. could anybody help me modify the jpegPredicate for that mater? thanks NSPredicate *jpegPredicate = [NSPredicate predicateWithFormat:@SELF [c] 'b']; NSArray *lst = [[[NSFileManager defaultManager] directoryContentsAtPath:aDir] filteredArrayUsingPredicate:jpegPredicate]; 為了不斷提升Yahoo! Mail，雅虎香港誠邀你參與意見調查。請前往http://surveylink.yahoo.com/wix/p5429076.aspx 發表你的意見! ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
On Aug 23, 2008, at 5:20 PM, Peter Duniho wrote: Date: Sat, 23 Aug 2008 12:05:44 -0700 From: Adam R. Maxwell [EMAIL PROTECTED] [...] Note the redundant multiply and add in the first line. Writing the code that way makes it easy to add/remove members if for some reason the data structure should change in the future. But it would be just as correct to simply initialize ret to the first hash value, of course. Thanks for the example...I need to find time to do some profiling with this. Presumably that depends on the hash table implementation as well. Well, if your hash values collide, they collide regardless of the hash table. As long as you've got a well-distributed hash function, any collisions generated by the hash table implementation should be well-distributed as well. My understanding was that the table might not use all bits of the hash value, so even differing hash values could be placed in the same bucket; that may be a misinterpretation of [1]. I find CFSet/CFBag/ CFDictionary to be one of the more confusing implementations in CF-Lite. thanks, Adam [1] http://www.mulle-kybernetik.com/artikel/Optimization/opti-7.html smime.p7s Description: S/MIME cryptographic signature ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: textfield not updating with bindings - Whats wrong?
On Aug 23, 2008, at 5:16 AM, Kieren Eaton wrote: ok the delegate is set as an object in IB it is the delegate of Files owner and nsapplication (thats correct isnt it?) it has a class of bindtestdelegate which is where the button action is located. The button calls the changeValues method in the delegate class which then calls the updateValues in the fooClass instance of the someclass. should my filesOwner in IB (Currently it is NSApplication) be something different? Well, that depends, in most cases it's good to have a NSWindowController or NSViewController as file owner since those take care of memory management of the nib file. But I believe it's irrelevant to the problem at hand. the instance of someClass is just dragged straight out of the IB lib as a simple object and assigned the class someClass I dont actually have a nsobjectcontroller subclass .h/.m in my project but according to the apple docs I dont need one? No, you don't, you just mentioned you used one. As far as I can tell from your explanation, you have 1 bindingstestDelegate object (the file's owner) and one extra someClass object. The problem is that your delegate class creates its own someClass instance and when you press the button that instance get changed, not the other instance you created in the nib file. Thats correct. I was not realising that the instance created in code and the one from the nib were not the same. I would change the code so that the bindingstestDelegate class exposes a readonly property named fooClass. You then remove the extra someClass object from your nib and bind the NSTextFields to the file's owner fooClass.someString and fooClass.someNumber keys. I did that and it worked! thanks very much. This has increased my comprehension of bindings a lot. just for my own benefit i also tried adding an instance on an object controller to the nib and set its content outlet to the bindingstestDelegate. Then I bound one of the textfields to the object controller with controller Key = selection model Key = fooClass.someString this also worked. YAyY :) I have one minor question now that I am understanding bindings more. Is is good policy to add an object controller instead of just binding directly to the class? I would also suggest you change the naming slightly, using uppercase first characters for class names. This makes it easier to distinguish classes from instances, methods and properties. More details here: http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC/Articles/chapter_950_section_12.html#/ /apple_ref/doc/uid/TP30001163-CH3-TPXREF108 Thanks and I do always use these conventions, except in this case where I just wanted a quick and dirty test case for my own learning. I did not expect to be posting it on this list, so apologies for the bad form on class and instance names etc. Thanks very much for your help. Now its onto much bigger things. Kieren ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: How to read pixel values of monochrome images
On Aug 23, 2008, at 2:51 PM, Shawn Erickson wrote: On Fri, Aug 22, 2008 at 2:54 AM, Eduardo Areitio [EMAIL PROTECTED] wrote: I'm trying to read individual pixel values in a monochrome image using NSReadPixel, but I haven't been able to. I would much appreciate anyone's help It is usually best to post some code or better explain what you tried and what is going wrong otherwise we have to guess at the difficulty you are having. Anyway... http://developer.apple.com/samplecode/Color_Sampler/listing5.html You'll notice from the comments in that sample, that NSReadPixel() gets a value from the graphics context that has the current drawing focus. If you're trying to read a value from an image, you've got to have somewhere to draw it first. -jcr ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: ObjC 2.0, properties, KVC, special _ hacks etc.
On Aug 21, 2008, at 7:59 PM, Thomas Engelmeier wrote: Am 22.08.2008 um 00:59 schrieb Dave MacLachlan: Also, are the _ in front of member variables for Apple only (so we don't stomp on each other with member var names) or are they using them for the readability reason mentioned above? There is documentation where they have claimed _ at the beginning of method names as being Apple only, but nothing about method vars, and the KVC compliance docs seem to imply that it is fine to do. Officially it is Apple only, but everybody and his dog uses it - in consistency to quite some Apple-provided samples. Please file bugs when you see a sample that does so. A single leading underscore is an Apple internal coding convention, which should not be used for code samples. I did what I could to get those kinds of things fixed when I was there, but someone's got to file a bug for it to get noticed. -jcr ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
Re: Implementing isEqual: and hash
Date: Sat, 23 Aug 2008 17:52:21 -0700 From: Adam R. Maxwell [EMAIL PROTECTED] Well, if your hash values collide, they collide regardless of the hash table. As long as you've got a well-distributed hash function, any collisions generated by the hash table implementation should be well-distributed as well. My understanding was that the table might not use all bits of the hash value, so even differing hash values could be placed in the same bucket; [...] Sure. Unless you've got a table that has as many entries as can be indexed by the full size of your hash value, it _has_ throw some sort of information away. With a 32-bit hash value, you'd need a 4 billion entry table, which obviously doesn't happen in practice. I don't know the Cocoa hash table implementations, so I can't speak for how they work. And any hash table implementation will have some particular worst-case input that could lead to pathological cases. But, it seems likely that the Cocoa hash table implementations perform reasonably well given reasonable, well-distributed hash value inputs. Basically, don't worry about it until it's actually a problem. Just make sure you're generating well-distributed hash values, and let Cocoa worry about how to apply those values with respect to its own hash table implementations. Pete ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
