Category: Main

I find that a majority of the crash reports that come in for ReceiptWallet have the following for the description:

 

Yes, they are blank! While I appreciate people sending in crash reports (I read everyone of them and try to figure out the problem), having no description makes it much harder to figure out the problem. Today I received a blank description, but in reading the report, I was able to “reproduce it” (hard to reproduce when I wasn’t told what happened) and quickly fixed it. I’m contemplating making description a required field for the report; this could reduce the reports which I don’t want as it would give me a false view of how many crashes people are getting.

Thanks to Jim Correia of Bare Bones Software, I have a slightly different method for filtering NSTextFields based on an NSFormatter. While my older method worked, this is a bit cleaner.

Like my old filter, this also has three methods:

- (void) setAcceptableCharacterSet:(NSCharacterSet *) inCharacterSet;
- (void) setMaximumLength:(int) inLength;
- (void) setMaximumValue:(int) inValue;

However, they’re called differently. You’d do something like this:

NSMutableCharacterSet *characterSet = [[NSMutableCharacterSet alloc] init];
[characterSet addCharactersInString:@"0123456789"];
[secondaryTextField setFormatter:[[[PartialFormatter alloc] init] autorelease]];
[[secondaryTextField formatter] setMaximumValue:65535];
[[secondaryTextField formatter] setAcceptableCharacterSet:characterSet];
[characterSet release];

Note that the formatter is based on NSFormatter and not NSNumberFormatter. I actually am using this for a number field as I want the number field to give me back a string instead of a number, so that’s why I put in the setMaximumValue and didn’t base it on NSNumberFormatter.

As always, feedback is welcome.

The attached code can be freely used in commercial and non-commercial projects. While I’d like some credit in the about box, it isn’t necessary. This code has no warranty and you assume all risk for using it.

Download source

I love Cocoa, but it seems that some simple things are missing. For example, NSTextField doesn’t have the ability to filter text input as the user is typing. A friend reminded me that this is a feature that PowerPlant had ages ago. Cocoa has NSFormatters which allow the field to be validated after text is input, but in many cases, the right way to restrict input is to prevent it from being typed. I like NSFormatters and have created a very complex one to handle multiple currencies in ReceiptWallet, but I realized I needed something else.

So, I present FilteringTextField. The attached code can be freely used in commercial and non-commercial projects. While I’d like some credit in the about box, it isn’t necessary. This code has no warranty and you assume all risk for using it.

The subclass of NSTextField, has 3 methods.

- (void) setAcceptableCharacterSet:(NSCharacterSet *) inCharacterSet;
- (void) setMaximumLength:(int) inLength;
- (void) setMaximumValue:(int) inValue;

The first lets you set the characters that can be typed; anything that isn’t in the set is eaten. The second, only allows x characters to be typed and the last limits the value if the user is typing in a number. This class can easily be extended to handle other constraints. Pasting in text is also filtered.

If anyone finds problems with this code, please let me know.

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In my ongoing saga with PDFKit, a user had a crash that I couldn’t reproduce and generously sent me the PDF that caused the issue. I was immediately able to reproduce the problem and furthermore, managed to get Preview to crash on that PDF. The crash was occurring when I tried to generate the thumbnail for the PDF.

Here’s what doesn’t work on all PDFs:

PDFDocument *pdfDoc = [[PDFDocument alloc] initWithURL:[NSURL fileURLWithPath:fullPath]];
int thumbnailPage = [[self valueForKey:@"thumbnailpage"] intValue];
int pdfPageCount = [pdfDoc pageCount];
if (thumbnailPage < pdfPageCount && pdfPageCount > 0 && thumbnailPage >= 0)
{
	PDFPage *page = [pdfDoc pageAtIndex:thumbnailPage];
	if (page != nil)
	{
		NSData *data = [page dataRepresentation];
		if (data)
		{
			image = [[NSImage alloc] initWithData:data];
		}
	}
}

[pdfDoc release];

Here’s what works on all PDFs I’ve tested including the one in question:

NSPDFImageRep *pdfRep = [[NSPDFImageRep alloc] initWithData:
	[NSData dataWithContentsOfURL:[NSURL fileURLWithPath:fullPath]]];
if (pdfRep)
{
	int thumbnailPage = [[self valueForKey:@"thumbnailpage"] intValue];
	int pdfPageCount = [pdfRep pageCount];
	if (thumbnailPage < pdfPageCount && pdfPageCount >= 0 && thumbnailPage >= 0)
	{
		_DebugLog(@"thumbnail page count is valid");
		[pdfRep setCurrentPage:thumbnailPage];
		image = [[NSImage alloc] initWithSize:[pdfRep bounds].size];
		[image addRepresentation:pdfRep];
		[image setDataRetained:YES];
	}
	[pdfRep release];
}

So what does this tell me? It tells me that NSPDFImageRep handles PDFs better than PDFDocument/PDFPage does. I fixed that crash and optimized some other code while I was at it. This still doesn’t solve all my problems with PDFKit as the PDF in question crashes when I try to write metadata to it (it crashes Preview as well). Not much I can do about that, yet.

Update:Funny, when I put this code in a test application, it no longer crashes. I still believe something is wrong with PDFKit as the crash looks very suspicious:

Thread 0 Crashed:
0   libSystem.B.dylib             	0x93287474  
tiny_malloc_from_free_list +
548
1   libSystem.B.dylib             	0x93280ba8 szone_malloc + 200
2   com.apple.CoreFoundation      	0x92342414 __CFDictionaryGrow + 200
3   com.apple.CoreFoundation      	0x92342d64 CFDictionarySetValue + 252
4   libCGATS.A.dylib              	0x95265440  
get_name_with_name_code_nl + 532
5   libCGATS.A.dylib              	0x952654cc  
ats_name_handler_copy_full_name + 20
6   libCGATS.A.dylib              	0x95266ad0 copy_full_name + 36
7   com.apple.CoreGraphics        	0x919b1fd0 CGFontNameTableCreate +  
252
8   com.apple.CoreGraphics        	0x919b1e9c CGFontGetPostScriptName  
+ 36
9   libPDFRIP.A.dylib             	0x068fba64  
PDFFontType1EmitDefinition + 60
10  libPDFRIP.A.dylib             	0x068f8678 PDFFontEmitDefinitions +  
52
11  libPDFRIP.A.dylib             	0x068f9aa8 emitFontDefinition + 20
12  com.apple.CoreFoundation      	0x923743e0 CFSetApplyFunction + 284
13  libPDFRIP.A.dylib             	0x068f9b0c  
PDFFontSetEmitDefinitions + 68
14  libPDFRIP.A.dylib   
        	0x068f68e0 PDFDocumentFinalize + 312
15  libPDFRIP.A.dylib             	0x068f5314 pdf_Finalize + 24
16  com.apple.CoreGraphics        	0x919e5914  
CGContextDelegateFinalize + 72
17  com.apple.CoreFoundation      	0x92371840 _CFRelease + 216
18  com.apple.CoreGraphics        	0x919e58f4  
CGContextDelegateFinalize + 40
19  com.apple.PDFKit              	0x914f77d4 - 
[PDFPage(PDFPageInternal) writeToConsumer:] + 444
20  com.apple.PDFKit              	0x914f6a28 -[PDFPage  
dataRepresentation] + 84
21  ...gtenterprises.receiptwallet	0x0001b8dc -[ReceiptMO  
imageWithWritingThumbnail:] + 988