DTTextAttachment Class Reference
| Inherits from | NSObject |
| Conforms to | NSCoding |
| Declared in | DTTextAttachment.h |
Tasks
Creating Text Attachments
Vertical Alignment
Retrieving Information about Attachments
-
originalSizeproperty -
displaySizeproperty -
– setDisplaySize:withMaxDisplaySize: -
contentURLproperty -
hyperLinkURLproperty -
hyperLinkGUIDproperty -
attributesproperty
Customizing Attachments
Properties
attributes
The attributes dictionary of the attachment.
@property (nonatomic, strong) NSDictionary *attributesDiscussion
If initialized from HTML, the values of this dictionary are transferred from the give HTML element. If you wish to add custom attribute values to be written to and read from HTML, be aware that the attribute name will be lowercased in compliance with W3C recommendations. Therefore, you may set a camel-case name and persist to HTML, but you will receive a lowercase name when the HTML is transformed into an attributed string.
Declared In
DTTextAttachment.hcontentURL
The URL representing the content
@property (nonatomic, strong) NSURL *contentURLDeclared In
DTTextAttachment.hdisplaySize
The size to use for displaying/layouting the receiver
@property (nonatomic, assign) CGSize displaySizeDeclared In
DTTextAttachment.hhyperLinkGUID
The GUID of the hyperlink that this is a part of. All parts of a hyperlink have the same GUID so that they can highlight together.
@property (nonatomic, strong) NSString *hyperLinkGUIDDeclared In
DTTextAttachment.hhyperLinkURL
The hyperlink URL of the receiver.
@property (nonatomic, strong) NSURL *hyperLinkURLDeclared In
DTTextAttachment.hClass Methods
registerClass:forTagName:
Registers your own class for use when encountering a specific tag Name. If you register a class for a previously registered class (or one of the predefined ones (img, iframe, object, video) then this replaces this with the newer registration.
+ (void)registerClass:(Class)theClass forTagName:(NSString *)tagNameParameters
- theClass
The class to instantiate in textAttachmentWithElement:options: when encountering a tag with this name
- tagName
The tag name to use this class for
Discussion
These registrations are permanent during the run time of your app. Custom attachment classes must implement the initWithElement:options: initializer and can implement the DTTextAttachmentDrawing and/or DTTextAttachmentHTMLPersistence protocols.
Declared In
DTTextAttachment.hregisteredClassForTagName:
The class to use for a tag name
+ (Class)registeredClassForTagName:(NSString *)tagNameParameters
- tagName
The tag name
Return Value
The class to use for attachments with with tag name, or nil if this should not be an attachment
Declared In
DTTextAttachment.htextAttachmentWithElement:options:
Initialize and return a DTTextAttachment with the specified DTHTMLElement and options. Convenience initializer. The element must have a valid tagName. The size of the returned text attachment is determined by the element, constrained by the option’s key for DTMaxImageSize. Any valid image resource included in the element (denoted by the method attributeForKey: “src”) is loaded and determines the text attachment size if it was not known before. If a size is too large the image is downsampled with sizeThatFitsKeepingAspectRatio() which preserves the aspect ratio.
+ (DTTextAttachment *)textAttachmentWithElement:(DTHTMLElement *)element options:(NSDictionary *)optionsParameters
- element
A DTHTMLElement that must have a valid tag name and should have a size. Any element attributes are copied to the text attachment’s elements.
- options
An NSDictionary of options. Used to specify the max image size with the key DTMaxImageSize.
Return Value
Returns the appropriate subclass of the class cluster
Declared In
DTTextAttachment.hInstance Methods
adjustVerticalAlignmentForFont:
Inspects the given font and records the font’s ascent, descent and leading. These values are then used during layout to properly respond with ascentForLayout, descentForLayout for the receiver’s verticalAlignment.
- (void)adjustVerticalAlignmentForFont:(CTFontRef)fontParameters
- font
The font to inspect
Declared In
DTTextAttachment.hascentForLayout
The ascent to use during layout so that the receiver can be display at its verticalAlignment.
- (CGFloat)ascentForLayoutDeclared In
DTTextAttachment.hdescentForLayout
The descent to use during layout so that the receiver can be display at its verticalAlignment.
- (CGFloat)descentForLayoutDeclared In
DTTextAttachment.hinitWithElement:options:
The designated initializer for members of the DTTextAttachment class cluster. If you need additional setup for custom subclasses then you should override this initializer.
- (id)initWithElement:(DTHTMLElement *)element options:(NSDictionary *)optionsParameters
- element
A DTHTMLElement that must have a valid tag name and should have a size. Any element attributes are copied to the text attachment’s elements.
- options
An NSDictionary of options. Used to specify the max image size with the key DTMaxImageSize.
Return Value
Returns an initialized DTTextAttachment built using the element and options parameters.
Declared In
DTTextAttachment.hsetDisplaySize:withMaxDisplaySize:
Updates the display size optionally passing a maximum size that it should not exceed.
- (void)setDisplaySize:(CGSize)displaySize withMaxDisplaySize:(CGSize)maxDisplaySizeParameters
- displaySize
The new size to display the content with
- maxDisplaySize
the maximum size that the content should be scaled to fit
Discussion
This method in contrast to using the displaySize property will use the originalSize and max display size to calculate missing dimensions.
Declared In
DTTextAttachment.h