[gdal-dev] Usage of styles in C API

[Nik Sands]

Thanks Even,

Yes, deleting the spaces seems to get it working correctly.  Is this expected?  Are spaces an illegal part of a style string?

The documentation includes spaces in the example .ofs file there, so I had copied that format when creating my text file.

Cheers,
Nik.


On 3 Aug 2014, at 8:45 pm, Even Rouault <even.rouault at mines-paris.org> wrote:

> Le dimanche 03 août 2014 12:41:56, Nik Sands a écrit :
>> Sorry, my mistake... I had my logging in the wrong place.  styleChars is
>> actually of the form (including the leading space):
>> 
>> 	' PEN(c:#A08080,w:2pt); LABEL(c:#000000,s:18pt,t:{title})'
> 
> The issue must be the leading space before PEN, and potentially LABEL too.
> 
>> 
>> On 3 Aug 2014, at 8:35 pm, Nik Sands <nixanz at nixanz.com> wrote:
>>> On one of the iterations through this code, styleChars is:
>>> 	'vegetation_low: BRUSH(fc:#A0F0A0); LABEL(c:#004000,s:18pt,t:{title})'
>>> 
>>> So perhaps the inclusion of the style name is the problem?
>>> 
>>> This was read into a style table from a text file using
>>> 'OGR_STBL_LoadStyleTable()'.  I had assumed that a similar format to
>>> .ofs was suitable.  If this is not the case, how should I read a style
>>> table from a text file in such a way that I can distinguish the various
>>> styles by name?
>>> 
>>> In guess my more general question is:  What is the correct way to read
>>> styles from an arbitrary text file into a style table, and then use a
>>> style manager to get the various parts/tools?
>>> 
>>> On 3 Aug 2014, at 8:26 pm, Even Rouault <even.rouault at mines-paris.org> 
> wrote:
>>>> Le dimanche 03 août 2014 12:11:42, Nik Sands a écrit :
>>>>> I'm just starting out using the styles features of OGR (using the C
>>>>> API) but at struggling with a few elements of it.
>>>>> 
>>>>> My code (copied below) fails to get any OGRStyleToolH.  Ie, the "if (
>>>>> tool )" block never gets run, because 'tool' is always NULL at the
>>>>> point indicated by the comment.  But the execution does reach that
>>>>> point in the code which indicates that the OGRStyleMrgH does in fact
>>>>> include at least one part (tool).
>>>>> 
>>>>> I'd be grateful if somebody could point out what I'm doing wrong.
>>>> 
>>>> Nothing strikes me as wrong. A potential explanation is that styleChars
>>>> doesn't contain a valid OGR Feature Style string.
>>>> GetPartCount() counts the number of ";" separating style parts, but it
>>>> doens't check that each style part actually begins by a recognized tool
>>>> name (PEN, BRUSH, SYMBOL, LABEL). OGR_SM_GetPart() does this check
>>>> however and if it cannot recognize it it returns a NULL tool.
>>>> 
>>>>> Thanks,
>>>>> Nik.
>>>>> 
>>>>> 
>>>>> -------------------------------------------
>>>>> 
>>>>> 	const char *styleChars = OGR_STBL_GetNextStyle(table) ) )
>>>>> 	NSString *styleName = [NSString
>>>>> 
>>>>> stringWithUTF8String:OGR_STBL_GetLastStyleName(table)]; OGRStyleMgrH
>>>>> styleMgr = OGR_SM_Create(NULL);
>>>>> 
>>>>> 	OGR_SM_InitStyleString(styleMgr, styleChars);
>>>>> 	
>>>>> 	
>>>>> 	for ( int i = 0; i < OGR_SM_GetPartCount(styleMgr, NULL); i++ )
>>>>> 	{
>>>>> 	
>>>>> 		OGRStyleToolH tool = OGR_SM_GetPart(styleMgr, i, NULL);
>>>>> 		
>>>>> 		if ( tool )  //  'tool' always NULL here
>>>>> 		{
>>>>> 		
>>>>> 			switch ( OGR_ST_GetType(tool) )
>>>>> 			{
>>>>> 			
>>>>> 				case OGRSTCPen:
>>>>> 					self.pen = tool;
>>>>> 					break;
>>>>> 				
>>>>> 				case OGRSTCBrush:
>>>>> 					self.brush = tool;
>>>>> 					break;
>>>>> 				
>>>>> 				case OGRSTCSymbol:
>>>>> 					self.symbol = tool;
>>>>> 					break;
>>>>> 				
>>>>> 				case OGRSTCLabel:
>>>>> 					self.label = tool;
>>>>> 					break;
>>>>> 				
>>>>> 				default:
>>>>> 					NSLog(@"Unknown style tool type!");
>>>>> 					break;
>>>>> 			
>>>>> 			}
>>>>> 		
>>>>> 		}
>>>>> 	
>>>>> 	}
>>>>> 
>>>>> -------------------------------------------
>>>>> 
>>>>> 
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>>> 
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> 
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