Implemented A anchor support.

When encountering a <a name="anchor">text</a> this causes a DTAnchorAttribute to be added to the text. DTAttributedTextView now has a method to scroll to thusly named anchors.

Core/Source/DTAttributedTextView.h

@@ -23,4 +23,12 @@
 
 @property (nonatomic, unsafe_unretained) IBOutlet id <DTAttributedTextContentViewDelegate> textDelegate;
 
+
+/**
+ Scrolls the receiver to the anchor with the given name to the top.
+ @param anchorName The name of the href anchor.
+ @param animated `YES` if the movement should be animated.
+ */
+- (void)scrollToAnchorNamed:(NSString *)anchorName animated:(BOOL)animated;
+
 @end

Core/Source/DTAttributedTextView.m

@@ -85,6 +85,25 @@ - (Class)classForContentView
 	return [DTAttributedTextContentView class];
 }
 
+#pragma mark External Methods
+- (void)scrollToAnchorNamed:(NSString *)anchorName animated:(BOOL)animated
+{
+	NSRange range = [self.contentView.attributedString rangeOfAnchorNamed:anchorName];
+
+	if (range.length != NSNotFound)
+	{
+		// get the line of the first index of the anchor range
+		DTCoreTextLayoutLine *line = [self.contentView.layoutFrame lineContainingIndex:range.location];
+
+		// make sure we don't scroll too far
+		CGFloat maxScrollPos = self.contentSize.height - self.bounds.size.height + self.contentInset.bottom + self.contentInset.top;
+		CGFloat scrollPos = MIN(line.frame.origin.y, maxScrollPos);
+
+		// scroll
+		[self setContentOffset:CGPointMake(0, scrollPos) animated:animated];
+	}
+}
+
 #pragma mark Notifications
 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
 {
@@ -95,7 +114,6 @@ - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(N
 	}
 }
 
-
 #pragma mark Properties
 - (DTAttributedTextContentView *)contentView
 {

Core/Source/DTCoreTextConstants.h

@@ -30,6 +30,7 @@ extern NSString *DTDefaultStyleSheet;
 extern NSString *DTTextListsAttribute;
 extern NSString *DTAttachmentParagraphSpacingAttribute;
 extern NSString *DTLinkAttribute;
+extern NSString *DTAnchorAttribute;
 extern NSString *DTGUIDAttribute;
 extern NSString *DTHeaderLevelAttribute;
 extern NSString *DTPreserveNewlinesAttribute;

Core/Source/DTCoreTextConstants.m

@@ -27,6 +27,7 @@
 NSString *DTTextListsAttribute = @"DTTextLists";
 NSString *DTAttachmentParagraphSpacingAttribute = @"DTAttachmentParagraphSpacing";
 NSString *DTLinkAttribute = @"DTLink";
+NSString *DTAnchorAttribute = @"DTAnchor";
 NSString *DTGUIDAttribute = @"DTGUID";
 NSString *DTHeaderLevelAttribute = @"DTHeaderLevel";
 NSString *DTPreserveNewlinesAttribute = @"DTPreserveNewlines";

Core/Source/DTHTMLAttributedStringBuilder.m

@@ -419,6 +419,10 @@ - (void)_registerTagStartHandlers
 		}
 
 		currentTag.link = link;
+
+
+		// the name attribute of A becomes an anchor
+		currentTag.anchorName = [currentTag attributeForKey:@"name"];
 	};
 
 	[_tagStartHandlers setObject:[aBlock copy] forKey:@"a"];

Core/Source/DTHTMLElement.h

@@ -41,6 +41,7 @@ typedef enum
 @property (nonatomic, copy) DTCoreTextParagraphStyle *paragraphStyle;
 @property (nonatomic, strong) DTTextAttachment *textAttachment;
 @property (nonatomic, copy) NSURL *link;
+@property (nonatomic, copy) NSString *anchorName;
 @property (nonatomic, strong) DTColor *textColor;
 @property (nonatomic, strong) DTColor *backgroundColor;
 @property (nonatomic, copy) NSString *tagName;

Core/Source/DTHTMLElement.m

@@ -29,6 +29,7 @@ @implementation DTHTMLElement
 	DTTextAttachment *_textAttachment;
 	DTTextAttachmentVerticalAlignment _textAttachmentAlignment;
 	NSURL *_link;
+	NSString *_anchorName;
 
 	DTColor *_textColor;
 	DTColor *backgroundColor;
@@ -149,6 +150,12 @@ - (NSDictionary *)attributesDictionary
 		[tmpDict setObject:_linkGUID forKey:DTGUIDAttribute];
 	}
 
+	// add anchor
+	if (_anchorName)
+	{
+		[tmpDict setObject:_anchorName forKey:DTAnchorAttribute];
+	}
+
 	// add strikout if applicable
 	if (strikeOut)
 	{
@@ -899,6 +906,7 @@ - (id)copyWithZone:(NSZone *)zone
 	newObject.shadows = self.shadows;
 
 	newObject.link = self.link; // copy
+	newObject.anchorName = self.anchorName; // copy
 	newObject.linkGUID = _linkGUID; // transfer the GUID
 
 	newObject.preserveNewlines = self.preserveNewlines;
@@ -1010,6 +1018,7 @@ - (void)setLink:(NSURL *)link
 @synthesize tagName;
 @synthesize text;
 @synthesize link = _link;
+@synthesize anchorName = _anchorName;
 @synthesize underlineStyle;
 @synthesize textAttachment = _textAttachment;
 @synthesize tagContentInvisible;

Core/Source/NSAttributedString+DTCoreText.h

@@ -65,9 +65,17 @@
 - (NSRange)rangeOfTextBlock:(DTTextBlock *)textBlock atIndex:(NSUInteger)location;
 
 /**
- @name Converting to Other Representations
+ Returns the range of the given href anchor.
+ 
+ @param list The text block.
+ @param anchorName The name of the anchor.
+ @returns The range of the given anchor.
  */
+- (NSRange)rangeOfAnchorNamed:(NSString *)anchorName;
 
+/**
+ @name Converting to Other Representations
+ */
 
 /**
  Encodes the receiver into a generic HTML prepresentation.

Core/Source/NSAttributedString+DTCoreText.m

@@ -197,6 +197,21 @@ - (NSRange)rangeOfTextBlock:(DTTextBlock *)textBlock atIndex:(NSUInteger)locatio
 	return [self _rangeOfObject:textBlock inArrayBehindAttribute:DTTextBlocksAttribute atIndex:location];
 }
 
+- (NSRange)rangeOfAnchorNamed:(NSString *)anchorName
+{
+	__block NSRange foundRange = NSMakeRange(0, NSNotFound);
+
+	[self enumerateAttribute:DTAnchorAttribute inRange:NSMakeRange(0, [self length]) options:0 usingBlock:^(NSString *value, NSRange range, BOOL *stop) {
+		if ([value isEqualToString:anchorName])
+		{
+			*stop = YES;
+			foundRange = range;
+		}
+	}];
+
+	return foundRange;
+}
+
 #pragma mark HTML Encoding
 
 

Demo/Resources/CurrentTest.html

@@ -1,3 +1,29 @@
-<p style="font-family:'Times New Roman';font-size:20px;">Hello</p>
-<p style="font-family:'Times New Roman';font-size:20px;"></p>
-<p style="font-family:'Times New Roman';font-size:20px;">World</p>
+<a href="#kapitel2">Go To Chapter2</a>
+<a name="kapitel1" href="#kapitel1">Kapitel 1</a>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<a name="kapitel2">Chapter2</a>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>
+<p>text</p>

Demo/Source/DemoTextViewController.m

@@ -396,7 +396,26 @@ - (BOOL)attributedTextContentView:(DTAttributedTextContentView *)attributedTextC
 
 - (void)linkPushed:(DTLinkButton *)button
 {
-	[[UIApplication sharedApplication] openURL:[button.URL absoluteURL]];
+	NSURL *URL = button.URL;
+
+	if ([[UIApplication sharedApplication] canOpenURL:[URL absoluteURL]])
+	{
+		[[UIApplication sharedApplication] openURL:[URL absoluteURL]];
+	}
+	else 
+	{
+		if (![URL host] && ![URL path])
+		{
+
+			// possibly a local anchor link
+			NSString *fragment = [URL fragment];
+
+			if (fragment)
+			{
+				[_textView scrollToAnchorNamed:fragment animated:NO];
+			}
+		}
+	}
 }
 
 - (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex