NSAttributedString+HTML-IM.m

//
//  NSAttributedString+HTML-IM.m
//  Jabber
//
//  Created by David Chisnall on 27/08/2007.
//  Copyright 2007 __MyCompanyName__. All rights reserved.
//

#import "NSAttributedString+HTML-IM.h"
#import <EtoileFoundation/EtoileFoundation.h>
#import <EtoileXML/ETXMLWriter.h>
// Work around some GSBreakage
#define NSFontFamiliyClassMask NSFontFamilyClassMask
#import <AppKit/NSFontDescriptor.h>
#undef NSFontFamiliyClassMask

static NSMapTable * STYLE_HANDLERS = NULL;

typedef NSString*(*styleHandler)(id);

NSString * foregroundColor(NSColor * aColour)
{
	CGFloat r,g,b,a;
	[[aColour colorUsingColorSpaceName:NSCalibratedRGBColorSpace]
                                getRed:&r
                                 green:&g
                                  blue:&b
                                 alpha:&a];
	return [NSString stringWithFormat:@"color: #%.2x%.2x%.2x;",
	(int) (r * 255),
	(int) (g * 255),
	(int) (b * 255)];
}
NSString * cssGenericFontFamily(NSFontSymbolicTraits traits)
{
	if(traits & NSFontMonoSpaceTrait)
	{
		return @"monospace";
	}
	
	switch(traits & NSFontFamilyClassMask)
	{
#define FONT_FAMILY(value, name) case value: return name; break;
		case NSFontOldStyleSerifsClass:
		case NSFontTransitionalSerifsClass:
		case NSFontModernSerifsClass:
		case NSFontClarendonSerifsClass:
		case NSFontSlabSerifsClass:
		case NSFontOrnamentalsClass:
		FONT_FAMILY(NSFontFreeformSerifsClass, @"serif")
		FONT_FAMILY(NSFontSansSerifClass, @"sans-serif")
		FONT_FAMILY(NSFontScriptsClass, @"cursive")
		FONT_FAMILY(NSFontSymbolicClass, @"fantasy")
#undef FONT_FAMILY
	}
	return nil;
}
NSString * fontAttributes(NSFont * aFont)
{
	NSFontSymbolicTraits traits = [[aFont fontDescriptor] symbolicTraits];
#ifndef DNDEBUG
	ETLog(@"Traits: %x", traits);
#endif
	NSString * genericFamily = cssGenericFontFamily(traits);
	NSMutableString * style;
	if(genericFamily == nil)
	{
		style = [NSMutableString stringWithFormat:@"font-family: %@;",
		[aFont familyName]];
	}
	else
	{
		style = [NSMutableString stringWithFormat:@"font-family: %@, %@;",
		[aFont familyName],
		genericFamily];
	}
	if(traits & NSFontItalicTrait)
		{
			[style appendString:@"font-style: oblique;"];
		}
	if(traits & NSFontBoldTrait)
	{
		[style appendString:@"font-weight: bold;"];
	}
	NSDictionary * attributes = [[aFont fontDescriptor] fontAttributes];
	NSString * attribute;
	if((attribute = [attributes objectForKey:NSFontSizeAttribute]))
	{
		[style appendFormat:@"font-size: %.1fpt;", [attribute floatValue]];
	}
	if((attribute = [attributes objectForKey:NSUnderlineStyleAttributeName]))
	{
		[style appendString:@"text-decoration: underline;"];
	}
	return style;
}


NSString * styleFromAttributes(NSDictionary * attributes)
{
	NSMutableString * style = [NSMutableString string];
	if(STYLE_HANDLERS == nil)
	{
		STYLE_HANDLERS = NSCreateMapTable(NSNonRetainedObjectMapKeyCallBacks,NSNonOwnedPointerMapValueCallBacks,10);
		NSMapInsert(STYLE_HANDLERS,(__bridge const void*)NSForegroundColorAttributeName,(void*)foregroundColor);
		NSMapInsert(STYLE_HANDLERS,(__bridge const void*)NSFontAttributeName,(void*)fontAttributes);
	}
	NSEnumerator * enumerator = [attributes keyEnumerator];
	id key;
	while(nil != (key = [enumerator nextObject]))
	{
		styleHandler handler = NSMapGet(STYLE_HANDLERS,(__bridge const void*)key);
		if(handler != NULL)
		{
			[style appendString:handler([attributes objectForKey:key])];
		}
	}
	return style;
}

void addCdataWithLineBreaksToNode(ETXMLWriter *xmlWriter, NSString *cdata)
{
	NSArray * segments = [cdata componentsSeparatedByString:@"\n"];
	if([segments count] > 1)
	{
		int i;
		for(i=0 ; i < [segments count] -1 ; i++)
		{
			[xmlWriter characters: [segments objectAtIndex:i]];
			[xmlWriter startElement: @"br"];
			[xmlWriter endElement];
		}
		[xmlWriter characters: [segments objectAtIndex:i]];                
	}
	else
	{
		[xmlWriter characters: cdata];
	}
}

@implementation NSAttributedString (XHTML_IM)
- (void)writeXHTMLIMToXMLWriter: (ETXMLWriter*)xmlWriter
{
#ifndef DNDEBUG
	ETLog(@"Writing XHTML...");
#endif
	[xmlWriter startElement: @"html"
                 attributes: D(@"http://jabber.org/protocol/xhtml-im", @"xmlns")];
	[xmlWriter startElement: @"body" 
                 attributes: D(@"http://www.w3.org/1999/xhtml", @"xmlns")];
	NSString * plainText = [self string];
	NSRange attributeRange;
	NSUInteger start = 0;
	NSInteger end = [self length];
	while(start < end)
	{
		//Get the range and attributes:
		NSDictionary * attributes = [self attributesAtIndex:start effectiveRange:&attributeRange];
		NSString * css = styleFromAttributes(attributes);
		NSURL * linkTarget = [attributes objectForKey:NSLinkAttributeName];
		NSMutableDictionary *tagAttributes = [NSMutableDictionary dictionary];
		if (![css isEqualToString:@""] || linkTarget != nil)
		{
			if (![css isEqualToString:@""])
			{
				[tagAttributes setObject: styleFromAttributes(attributes) forKey: @"style"];
			}
			if (linkTarget != nil)
			{
				[tagAttributes setObject: linkTarget forKey: @"href"];
				[xmlWriter startElement: @"a" attributes: tagAttributes];
			}
			else
			{
				[xmlWriter startElement: @"span" attributes: tagAttributes];
			}
			addCdataWithLineBreaksToNode(xmlWriter, [plainText substringWithRange:attributeRange]);
			[xmlWriter endElement];
		}
		else
		{
			addCdataWithLineBreaksToNode(xmlWriter, [plainText substringWithRange:attributeRange]);
		}
		start = attributeRange.location + attributeRange.length;
	}
	[xmlWriter endElement];
	[xmlWriter endElement];
}

- (NSString*) stringValueWithExpandedLinks
{
		NSMutableString * string = [NSMutableString stringWithString:[self string]];
		NSUInteger length = [self length];
		int offset = 0;
		for(int i = 0 ; i<length ; i++)
		{
			NSRange range;
			NSString * href;
			if((href = [self attribute:NSLinkAttributeName
                               atIndex:i
                        effectiveRange:&range]))
			{
				i += range.length;
				NSString * link = [NSString stringWithFormat:@" (%@)", href];
				[string insertString:link
                             atIndex:i + offset];
				offset += [link length];
			}
		}
		return string;
}
@end