@available(iOS 7.0, *)
文本布局方向
public enum NSTextLayoutOrientation : Int {
case horizontal // Lines rendered horizontally, grow top to bottom
case vertical // Lines rendered vertically, grow right to left
}
@available(iOS 7.0, *)
public enum NSGlyphProperty : Int {
case null // null glyph ignored for layout and display
case controlCharacter // control character such as tab, attachment, etc that has special behavior associated with
case elastic // glyphs with elastic glyph width behavior such as white spaces
case nonBaseCharacter // glyphs with combining properties. typically characters in Unicode Mn class.
}
@available(iOS 7.0, *)
public enum NSControlCharacterAction : Int {
case zeroAdvancement // glyphs with this action are filtered out from layout (notShownAttribute == YES)
case whitespace // the width for glyphs with this action are determined by -layoutManager:boundingBoxForControlGlyphAtIndex:forTextContainer:proposedLineFragment:glyphPosition:characterIndex: if the method is implemented; otherwise, same as NSControlCharacterZeroAdvancementAction
case horizontalTab // Treated as tab character
case lineBreak // Causes line break
case paragraphBreak // Causes paragraph break; firstLineIndent will be used for the following glyph
case containerBreak // Causes container break
}
public protocol NSTextLayoutOrientationProvider {
// A property describing the receiver's layout orientation. This property defines the default value for the range of string laid out in the receiver in absence of explicit NSVerticalGlyphFormAttributeName attribute. For example, when NSTextLayoutOrientationVertical, the default value for NSVerticalGlyphFormAttributeName is 1. When rendering into the receiver, the Text System assumes the coordinate system is appropriately rotated.
@available(iOS 7.0, *)
public var layoutOrientation: NSTextLayoutOrientation { get }
}
@available(iOS 7.0, *)
open class NSLayoutManager : NSObject, NSCoding {
// Designated Initializer. Sets up this instance. The NSLayoutManager starts off without an NSTextStorage.
/**************************** Initialization ****************************/
public init()
public init?(coder: NSCoder)
// Accessor for the NSTextStorage object owning the receiver.
// Avoid assigning a text storage directly through this property. Adding a layout manager to a text storage through -[NSTextStorage addLayoutManager:] will use the property for assigning the new text storage.
/*************************** Text storage ***************************/
unowned(unsafe) open var textStorage: NSTextStorage?
// NSTextContainer objects owner by the receiver.
/**************************** Text containers ****************************/
open var textContainers: [NSTextContainer] { get }
// Add a container to the end of the array. Must invalidate layout of all glyphs after the previous last container (i.e., glyphs that were not previously laid out because they would not fit anywhere).
open func addTextContainer(_ container: NSTextContainer)
// Insert a container into the array before the container at index. Must invalidate layout of all glyphs in the containers from the one previously at index to the last container.
open func insertTextContainer(_ container: NSTextContainer, at index: Int)
// Removes the container at index from the array. Must invalidate layout of all glyphs in the container being removed and any containers which come after it.
open func removeTextContainer(at index: Int)
// Called by NSTextContainer whenever it changes size or shape. Invalidates layout of all glyphs in container and all subsequent containers.
open func textContainerChangedGeometry(_ container: NSTextContainer)
/**************************** Delegate ****************************/
unowned(unsafe) open var delegate: NSLayoutManagerDelegate?
// If YES, then whitespace and other "invisible" characters will be shown with special glyphs or other drawing. The default is NO.
/*********************** Global layout manager options ***********************/
open var showsInvisibleCharacters: Bool
// If YES, then control characters will be rendered visibly (usually like "^M"). The default is NO.
open var showsControlCharacters: Bool
// 0.0 - 1.0. Whenever (width of the real contents of the line) / (the line fragment width) is below this value, hyphenation will be attempted when laying out the line. By default, the value is 0.0, meaning hyphenation is off. A value of 1.0 causes hyphenation to be attempted always. Note that hyphenation will slow down text layout and increase memory usage, so it should be used sparingly. Maybe overridden on a per-paragraph basis by the NSParagraphStyle's hyphenationFactor.
open var hyphenationFactor: CGFloat
// By default, a layout manager will use leading as specified by the font. However, this is not appropriate for most UI text, for which a fixed leading is usually specified by UI layout guidelines. These methods allow the use of the font's leading to be turned off.
open var usesFontLeading: Bool
// If YES, then the layout manager may perform glyph generation and layout for a given portion of the text, without having glyphs or layout for preceding portions. The default is NO. Turning this setting on will significantly alter which portions of the text will have glyph generation or layout performed when a given generation-causing method is invoked. It also gives significant performance benefits, especially for large documents.
@available(iOS 7.0, *)
open var allowsNonContiguousLayout: Bool
// Even if non-contiguous layout is allowed, it may not always be used, and there may not always be layout holes. This method returns YES if there might currently be non-contiguous portions of the text laid out.
@available(iOS 7.0, *)
open var hasNonContiguousLayout: Bool { get }
// This removes all glyphs for the old character range, adjusts the character indices of all the subsequent glyphs by the change in length, and invalidates the new character range. If actualCharRange is non-NULL it will be set to the actual range invalidated after any necessary expansion.
/************************** Invalidation **************************/
open func invalidateGlyphs(forCharacterRange charRange: NSRange, changeInLength delta: Int, actualCharacterRange actualCharRange: NSRangePointer?)
// This method invalidates the layout information for the given range of characters. If actualCharRange is non-NULL it will be set to the actual range invalidated after any necessary expansion.
@available(iOS 7.0, *)
open func invalidateLayout(forCharacterRange charRange: NSRange, actualCharacterRange actualCharRange: NSRangePointer?)
// These methods invalidate display for the glyph or character range given. For the character range variant, unlaid parts of the range are remembered and will be redisplayed at some point later when the layout is available. For the glyph range variant any part of the range that does not yet have glyphs generated is ignored. Neither method actually causes layout.
open func invalidateDisplay(forCharacterRange charRange: NSRange)
open func invalidateDisplay(forGlyphRange glyphRange: NSRange)
// Sent from processEditing in NSTextStorage. The newCharRange is the range in the final string which was explicitly edited. The invalidatedRange includes portions that changed as a result of attribute fixing. invalidatedRange is either equal to newCharRange or larger. Layout managers should not change the contents of the text storage during the execution of this message.
@available(iOS 7.0, *)
open func processEditing(for textStorage: NSTextStorage, edited editMask: NSTextStorageEditActions, range newCharRange: NSRange, changeInLength delta: Int, invalidatedRange invalidatedCharRange: NSRange)
// These methods allow clients to specify exactly the portions of the document for which they wish to have glyphs or layout. This is particularly important if non-contiguous layout is enabled. The layout manager still reserves the right to perform glyph generation or layout for larger ranges. If non-contiguous layout is not enabled, then the range in question will always effectively be extended to start at the beginning of the text.
/************************ Causing glyph generation and layout ************************/
open func ensureGlyphs(forCharacterRange charRange: NSRange)
open func ensureGlyphs(forGlyphRange glyphRange: NSRange)
open func ensureLayout(forCharacterRange charRange: NSRange)
open func ensureLayout(forGlyphRange glyphRange: NSRange)
open func ensureLayout(for container: NSTextContainer)
open func ensureLayout(forBoundingRect bounds: CGRect, in container: NSTextContainer)
// Sets the initial glyphs and properties for a character range. This method is invoked mainly from the glyph generation process. Only place apps are allowed to directly call this method is from -layoutManager:shouldGenerateGlyphs:properties:characterIndexes:forGlyphRange:. Each array has glyphRange.length items. charIndexes must be contiguous (no skipped indexes). It allows multiple items to have a same character index (a character index generating multiple glyph IDs). Due to the font substitution, aFont passed into this method might not match the font in the attributes dictionary. Calling this method for a range with the layout information invalidates the layout and display.
/************************ Set glyphs and glyph properties ************************/
@available(iOS 7.0, *)
open func setGlyphs(_ glyphs: UnsafePointer<CGGlyph>, properties props: UnsafePointer<NSGlyphProperty>, characterIndexes charIndexes: UnsafePointer<Int>, font aFont: UIFont, forGlyphRange glyphRange: NSRange)
// Returns the total number of glyphs. If non-contiguous layout is not enabled, this will force generation of glyphs for all characters.
/************************ Get glyphs and glyph properties ************************/
open var numberOfGlyphs: Int { get }
// If non-contiguous layout is not enabled, these will cause generation of all glyphs up to and including glyphIndex. The first CGGlyphAtIndex variant returns kCGFontIndexInvalid if the requested index is out of the range (0, numberOfGlyphs), and optionally returns a flag indicating whether the requested index is in range. The second CGGlyphAtIndex variant raises a NSRangeError if the requested index is out of range.
@available(iOS 7.0, *)
open func cgGlyph(at glyphIndex: Int, isValidIndex: UnsafeMutablePointer<ObjCBool>?) -> CGGlyph
@available(iOS 7.0, *)
open func cgGlyph(at glyphIndex: Int) -> CGGlyph
@available(iOS 7.0, *)
open func isValidGlyphIndex(_ glyphIndex: Int) -> Bool
// If non-contiguous layout is not enabled, this will cause generation of all glyphs up to and including glyphIndex. It will return the glyph property associated with the glyph at the specified index.
@available(iOS 7.0, *)
open func propertyForGlyph(at glyphIndex: Int) -> NSGlyphProperty
// If non-contiguous layout is not enabled, this will cause generation of all glyphs up to and including glyphIndex. It will return the character index for the first character associated with the glyph at the specified index.
open func characterIndexForGlyph(at glyphIndex: Int) -> Int
// If non-contiguous layout is not enabled, this will cause generation of all glyphs up to and including those associated with the specified character. It will return the glyph index for the first glyph associated with the character at the specified index.
open func glyphIndexForCharacter(at charIndex: Int) -> Int
// Fills a passed-in buffer with a sequence of CGGlyphs. They will also optionally fill other passed-in buffers with the glyph properties, character indexes, and bidi levels corresponding to these glyphs. Each pointer passed in should either be NULL, or else point to sufficient memory to hold glyphRange.length elements. These methods return the number of glyphs filled in.
@available(iOS 7.0, *)
open func getGlyphs(in glyphRange: NSRange, glyphs glyphBuffer: UnsafeMutablePointer<CGGlyph>?, properties props: UnsafeMutablePointer<NSGlyphProperty>?, characterIndexes charIndexBuffer: UnsafeMutablePointer<Int>?, bidiLevels bidiLevelBuffer: UnsafeMutablePointer<UInt8>?) -> Int
/************************ Set layout information ************************/
// Associates the given container with the given range of glyphs. This method should be called by the typesetter first, before setting line fragment rect or any of the layout bits, for each range of glyphs it lays out. This method will reset several key layout attributes (like not shown and draws outside line fragment) to their default values. In the course of layout, all glyphs should end up being included in a range passed to this method. The range passed in is not expected to be the entire range of glyphs for that text container; usually, in fact, it will be the range for a given line fragment being laid out in that container.
open func setTextContainer(_ container: NSTextContainer, forGlyphRange glyphRange: NSRange)
// Associates the given line fragment bounds with the given range of glyphs. The typesetter should call this method second, after setting the line fragment rect and before setting the location or any of the layout bits. In the course of layout, all glyphs should end up being included in a range passed to this method, but only glyphs which start a new line fragment should be at the start of such ranges. Line fragment rects and line fragment used rects are always in container coordinates.
open func setLineFragmentRect(_ fragmentRect: CGRect, forGlyphRange glyphRange: NSRange, usedRect: CGRect)
// Sets the bounds and container for the extra line fragment. The extra line fragment is used when the text backing ends with a hard line break or when the text backing is totally empty, to define the extra line which needs to be displayed at the end of the text. Line fragment rects and line fragment used rects are always in container coordinates. This method should be invoked only when there is a non-empty extra line fragment.
open func setExtraLineFragmentRect(_ fragmentRect: CGRect, usedRect: CGRect, textContainer container: NSTextContainer)
// Sets the location for the first glyph of the given range. Setting the location for a glyph range implies that its first glyph is not nominally spaced with respect to the previous glyph. In the course of layout, all glyphs should end up being included in a range passed to this method, but only glyphs which start a new nominal range should be at the start of such ranges. The first glyph in a line fragment should always start a new nominal range. Glyph locations are given relative to their line fragment rect's origin.
open func setLocation(_ location: CGPoint, forStartOfGlyphRange glyphRange: NSRange)
// Some glyphs are not shown. The typesetter decides which ones and sets this attribute in the layout manager to ensure that those glyphs will not be displayed.
open func setNotShownAttribute(_ flag: Bool, forGlyphAt glyphIndex: Int)
// Used to indicate that a particular glyph for some reason will draw outside of its line fragment rect. This can commonly happen if a fixed line height is used (consider a 12 point line height and a 24 point glyph). This information is important for determining whether additional lines need to be redrawn as a result of changes to any given line fragment.
open func setDrawsOutsideLineFragment(_ flag: Bool, forGlyphAt glyphIndex: Int)
// For a glyph corresponding to an attachment, this method should be called to set the size the attachment cell will occupy.
open func setAttachmentSize(_ attachmentSize: CGSize, forGlyphRange glyphRange: NSRange)
// Returns (by reference for the "get" method) the character index or glyph index or both of the first unlaid character/glyph in the layout manager at this time.
/************************ Get layout information ************************/
open func getFirstUnlaidCharacterIndex(_ charIndex: UnsafeMutablePointer<Int>?, glyphIndex: UnsafeMutablePointer<Int>?)
open var firstUnlaidCharacterIndex: Int { get }
open var firstUnlaidGlyphIndex: Int { get }
// Returns the container in which the given glyph is laid and (optionally) by reference the whole range of glyphs that are in that container. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment; if non-contiguous layout is not enabled and effectiveGlyphRange is non-NULL, this will additionally cause glyph generation and layout for the entire text container containing the specified glyph.
open func textContainer(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?) -> NSTextContainer?
@available(iOS 9.0, *)
open func textContainer(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?, withoutAdditionalLayout flag: Bool) -> NSTextContainer?
// Returns the container's currently used area. This determines the size that the view would need to be in order to display all the glyphs that are currently laid into the container. This causes neither glyph generation nor layout. Used rects are always in container coordinates.
open func usedRect(for container: NSTextContainer) -> CGRect
// Returns the rect for the line fragment in which the given glyph is laid and (optionally) by reference the whole range of glyphs that are in that fragment. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment. Line fragment rects are always in container coordinates.
open func lineFragmentRect(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?) -> CGRect
@available(iOS 9.0, *)
open func lineFragmentRect(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?, withoutAdditionalLayout flag: Bool) -> CGRect
// Returns the usage rect for the line fragment in which the given glyph is laid and (optionally) by reference the whole range of glyphs that are in that fragment. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment. Line fragment used rects are always in container coordinates.
open func lineFragmentUsedRect(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?) -> CGRect
@available(iOS 9.0, *)
open func lineFragmentUsedRect(forGlyphAt glyphIndex: Int, effectiveRange effectiveGlyphRange: NSRangePointer?, withoutAdditionalLayout flag: Bool) -> CGRect
// Return info about the extra line fragment. The extra line fragment is used for displaying the line at the end of document when the last character in the document causes a line or paragraph break. Since the extra line is not associated with any glyph inside the layout manager, the information is handed separately from other line fragment rects. Typically the extra line fragment is placed in the last document content text container along with other normal line fragment rects. Line fragment rects and line fragment used rects are always in container coordinates.
open var extraLineFragmentRect: CGRect { get }
open var extraLineFragmentUsedRect: CGRect { get }
open var extraLineFragmentTextContainer: NSTextContainer? { get }
// Returns the location for the given glyph within its line fragment. If this glyph does not have an explicit location set for it (i.e., it is part of (but not first in) a sequence of nominally spaced characters), the location is calculated by glyph advancements from the location of the most recent preceding glyph with a location set. Glyph locations are relative to their line fragment rect's origin. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment.
open func location(forGlyphAt glyphIndex: Int) -> CGPoint
// Some glyphs are not shown. This method returns whether the given glyph has been designated as not shown. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment.
open func notShownAttribute(forGlyphAt glyphIndex: Int) -> Bool
// Returns whether the glyph will draw outside of its line fragment rect. This will cause glyph generation and layout for the line fragment containing the specified glyph, or if non-contiguous layout is not enabled, up to and including that line fragment.
open func drawsOutsideLineFragment(forGlyphAt glyphIndex: Int) -> Bool
// For a glyph corresponding to an attachment, this method returns the size the attachment cell will occupy. Returns {-1,-1} if no attachment size has been set for the specified glyph.
open func attachmentSize(forGlyphAt glyphIndex: Int) -> CGSize
// Returns a range of truncated glyph range for a line fragment containing the specified index. When there is no truncation for the line fragment, it returns {NSNotFound, 0}.
@available(iOS 7.0, *)
open func truncatedGlyphRange(inLineFragmentForGlyphAt glyphIndex: Int) -> NSRange
// Returns the range of glyphs that are generated from the characters in the given charRange. If actualCharRange is not NULL, it will return by reference the actual range of characters that fully define the glyph range returned. This range may be identical to or slightly larger than the requested character range. For example, if the text storage contains the characters "o" and (umlaut) and the glyph store contains the single precomposed glyph (o-umlaut), and if the character range given encloses only the first or second character, then actualCharRange will be set to enclose both characters. If the length of charRange is zero, the resulting glyph range will be a zero-length range just after the glyph(s) corresponding to the preceding character, and actualCharRange will also be zero-length. If non-contiguous layout is not enabled, this will force the generation of glyphs for all characters up to and including the end of the specified range.
/************************ More sophisticated queries ************************/
open func glyphRange(forCharacterRange charRange: NSRange, actualCharacterRange actualCharRange: NSRangePointer?) -> NSRange
// Returns the range of characters that generated the glyphs in the given glyphRange. If actualGlyphRange is not NULL, it will return by reference the full range of glyphs generated by the character range returned. This range may be identical or slightly larger than the requested glyph range. For example, if the text storage contains the character (o-umlaut) and the glyph store contains the two atomic glyphs "o" and (umlaut), and if the glyph range given encloses only the first or second glyph, then actualGlyphRange will be set to enclose both glyphs. If the length of glyphRange is zero, the resulting character range will be a zero-length range just after the character(s) corresponding to the preceding glyph, and actualGlyphRange will also be zero-length. If non-contiguous layout is not enabled, this will force the generation of glyphs for all characters up to and including the end of the returned range.
open func characterRange(forGlyphRange glyphRange: NSRange, actualGlyphRange: NSRangePointer?) -> NSRange
// Returns the range of characters which have been laid into the given container. This is a less efficient method than the similar -textContainerForGlyphAtIndex:effectiveRange:.
open func glyphRange(for container: NSTextContainer) -> NSRange
// Returns the range including the first glyph from glyphIndex on back that has a location set and up to, but not including the next glyph that has a location set.
open func range(ofNominallySpacedGlyphsContaining glyphIndex: Int) -> NSRange
// Returns the smallest bounding rect which completely encloses the glyphs in the given glyphRange that are in the given container. The range is intersected with the container's range before computing the bounding rect. This method can be used to translate glyph ranges into display rectangles for invalidation. Bounding rects are always in container coordinates.
open func boundingRect(forGlyphRange glyphRange: NSRange, in container: NSTextContainer) -> CGRect
// Returns a contiguous glyph range containing all glyphs that would need to be displayed in order to draw all glyphs that fall (even partially) within the bounding rect given. This range might include glyphs which do not fall into the rect at all. At most this will return the glyph range for the whole container. The WithoutAdditionalLayout variant will not generate glyphs or perform layout in attempting to answer, and thus may not be entirely correct. Bounding rects are always in container coordinates.
open func glyphRange(forBoundingRect bounds: CGRect, in container: NSTextContainer) -> NSRange
open func glyphRange(forBoundingRectWithoutAdditionalLayout bounds: CGRect, in container: NSTextContainer) -> NSRange
// Returns the index of the glyph falling under the given point, expressed in the given container's coordinate system. If no glyph is under the point, the nearest glyph is returned, where nearest is defined according to the requirements of selection by touch or mouse. Clients who wish to determine whether the the point actually lies within the bounds of the glyph returned should follow this with a call to boundingRectForGlyphRange:inTextContainer: and test whether the point falls in the rect returned by that method. If partialFraction is non-NULL, it will return by reference the fraction of the distance between the location of the glyph returned and the location of the next glyph.
open func glyphIndex(for point: CGPoint, in container: NSTextContainer, fractionOfDistanceThroughGlyph partialFraction: UnsafeMutablePointer<CGFloat>?) -> Int
open func glyphIndex(for point: CGPoint, in container: NSTextContainer) -> Int
open func fractionOfDistanceThroughGlyph(for point: CGPoint, in container: NSTextContainer) -> CGFloat
// Returns the index of the character falling under the given point, expressed in the given container's coordinate system. If no character is under the point, the nearest character is returned, where nearest is defined according to the requirements of selection by touch or mouse. This is not simply equivalent to taking the result of the corresponding glyph index method and converting it to a character index, because in some cases a single glyph represents more than one selectable character, for example an fi ligature glyph. In that case, there will be an insertion point within the glyph, and this method will return one character or the other, depending on whether the specified point lies to the left or the right of that insertion point. In general, this method will return only character indexes for which there is an insertion point (see next method). The partial fraction is a fraction of the distance from the insertion point logically before the given character to the next one, which may be either to the right or to the left depending on directionality.
open func characterIndex(for point: CGPoint, in container: NSTextContainer, fractionOfDistanceBetweenInsertionPoints partialFraction: UnsafeMutablePointer<CGFloat>?) -> Int
// Allows clients to obtain all insertion points for a line fragment in one call. The caller specifies the line fragment by supplying one character index within it, and can choose whether to obtain primary or alternate insertion points, and whether they should be in logical or in display order. The return value is the number of insertion points returned. Each pointer passed in should either be NULL, or else point to sufficient memory to hold as many elements as there are insertion points in the line fragment (which cannot be more than the number of characters + 1). The positions buffer passed in will be filled in with the positions of the insertion points, in the order specified, and the charIndexes buffer passed in will be filled in with the corresponding character indexes. Positions indicate a transverse offset relative to the line fragment rect's origin. Internal caching is used to ensure that repeated calls to this method for the same line fragment (possibly with differing values for other arguments) will not be significantly more expensive than a single call.
open func getLineFragmentInsertionPoints(forCharacterAt charIndex: Int, alternatePositions aFlag: Bool, inDisplayOrder dFlag: Bool, positions: UnsafeMutablePointer<CGFloat>?, characterIndexes charIndexes: UnsafeMutablePointer<Int>?) -> Int
// Enumerates line fragments intersecting with glyphRange.
@available(iOS 7.0, *)
open func enumerateLineFragments(forGlyphRange glyphRange: NSRange, using block: @escaping (CGRect, CGRect, NSTextContainer, NSRange, UnsafeMutablePointer<ObjCBool>) -> Swift.Void)
// Enumerates enclosing rects for glyphRange in textContainer. If a selected range is given in the second argument, the rectangles returned will be correct for drawing the selection. Selection rectangles are generally more complicated than enclosing rectangles and supplying a selected range is the clue these methods use to determine whether to go to the trouble of doing this special work. If the caller is interested in this more from an enclosing point of view rather than a selection point of view, pass {NSNotFound, 0} as the selected range. This method will do the minimum amount of work required to answer the question.
@available(iOS 7.0, *)
open func enumerateEnclosingRects(forGlyphRange glyphRange: NSRange, withinSelectedGlyphRange selectedRange: NSRange, in textContainer: NSTextContainer, using block: @escaping (CGRect, UnsafeMutablePointer<ObjCBool>) -> Swift.Void)
// These methods are primitives for drawing. You can override these to perform additional drawing, or to replace text drawing entirely, but not to change layout. You can call them if you want, but focus must already be locked on the destination view or image. -drawBackgroundForGlyphRange:atPoint: draws the background color and selection and marked range aspects of the text display, along with block decoration such as table backgrounds and borders. -drawGlyphsForGlyphRange:atPoint: draws the actual glyphs, including attachments, as well as any underlines or strikethroughs. In either case all of the specified glyphs must lie in a single container.
/************************ Drawing support ************************/
open func drawBackground(forGlyphRange glyphsToShow: NSRange, at origin: CGPoint)
open func drawGlyphs(forGlyphRange glyphsToShow: NSRange, at origin: CGPoint)
// This is the glyph rendering primitive method. Renders glyphs at positions into the graphicsContext. The positions are in the user space coordinate system. graphicsContext that passed in is already configured according to the text attributes arguments: font, textMatrix, and attributes. The font argument represents the font applied to the graphics state. The value can be different from the NSFontAttributeName value in the attributes argument because of various font substitutions that the system automatically executes. The textMatrix is the affine transform mapping the text space coordinate system to the user space coordinate system. The tx and ty components of textMatrix are ignored since Quartz overrides them with the glyph positions.
@available(iOS 7.0, *)
open func showCGGlyphs(_ glyphs: UnsafePointer<CGGlyph>, positions: UnsafePointer<CGPoint>, count glyphCount: Int, font: UIFont, matrix textMatrix: CGAffineTransform, attributes: [String : Any] = [:], in graphicsContext: CGContext)
// This is the primitive used by -drawBackgroundForGlyphRange:atPoint: for actually filling rects with a particular background color, whether due to a background color attribute, a selected or marked range highlight, a block decoration, or any other rect fill needed by that method. As with -showCGGlyphs:..., the character range and color are merely for informational purposes; the color will already be set in the graphics state. If for any reason you modify it, you must restore it before returning from this method. You should never call this method, but you might override it. The default implementation will simply fill the specified rect array.
@available(iOS 7.0, *)
open func fillBackgroundRectArray(_ rectArray: UnsafePointer<CGRect>, count rectCount: Int, forCharacterRange charRange: NSRange, color: UIColor)
// The first of these methods actually draws an appropriate underline for the glyph range given. The second method potentially breaks the range it is given up into subranges and calls drawUnderline... for ranges that should actually have the underline drawn. As examples of why there are two methods, consider two situations. First, in all cases you don't want to underline the leading and trailing whitespace on a line. The -underlineGlyphRange... method is passed glyph ranges that have underlining turned on, but it will then look for this leading and trailing white space and only pass the ranges that should actually be underlined to -drawUnderline... Second, if the underlineType: indicates that only words, (i.e., no whitespace), should be underlined, then -underlineGlyphRange... will carve the range it is passed up into words and only pass word ranges to -drawUnderline.
open func drawUnderline(forGlyphRange glyphRange: NSRange, underlineType underlineVal: NSUnderlineStyle, baselineOffset: CGFloat, lineFragmentRect lineRect: CGRect, lineFragmentGlyphRange lineGlyphRange: NSRange, containerOrigin: CGPoint)
open func underlineGlyphRange(_ glyphRange: NSRange, underlineType underlineVal: NSUnderlineStyle, lineFragmentRect lineRect: CGRect, lineFragmentGlyphRange lineGlyphRange: NSRange, containerOrigin: CGPoint)
// These two methods parallel the two corresponding underline methods, but draw strikethroughs instead of underlines.
open func drawStrikethrough(forGlyphRange glyphRange: NSRange, strikethroughType strikethroughVal: NSUnderlineStyle, baselineOffset: CGFloat, lineFragmentRect lineRect: CGRect, lineFragmentGlyphRange lineGlyphRange: NSRange, containerOrigin: CGPoint)
open func strikethroughGlyphRange(_ glyphRange: NSRange, strikethroughType strikethroughVal: NSUnderlineStyle, lineFragmentRect lineRect: CGRect, lineFragmentGlyphRange lineGlyphRange: NSRange, containerOrigin: CGPoint)
}
public protocol NSLayoutManagerDelegate : NSObjectProtocol {
// This is sent whenever layoutManager is about to store the initial glyph information via -setGlyphs:properties:characterIndexes:forGlyphRange:. This method allows customizing the initial glyph generation process. It can invoke -setGlyphs:properties:characterIndexes:forGlyphRange: with modified glyph information. The return value specifies the actual glyph range stored in this method. By returning 0, it can indicate layoutManager to do the default processing. Note that querying glyph information surrounding glyphRange could lead to recursion since the data might not be available, yet.
/************************ Glyph generation ************************/
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, shouldGenerateGlyphs glyphs: UnsafePointer<CGGlyph>, properties props: UnsafePointer<NSGlyphProperty>, characterIndexes charIndexes: UnsafePointer<Int>, font aFont: UIFont, forGlyphRange glyphRange: NSRange) -> Int
// These methods are invoked while each line is laid out. They allow NSLayoutManager delegate to customize the shape of line.
// Returns the spacing after the line ending with glyphIndex.
/************************ Line layout ************************/
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, lineSpacingAfterGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat
// Returns the paragraph spacing before the line starting with glyphIndex.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, paragraphSpacingBeforeGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat
// Returns the paragraph spacing after the line ending with glyphIndex.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, paragraphSpacingAfterGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat
// Returns the control character action for the control character at charIndex.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, shouldUse action: NSControlCharacterAction, forControlCharacterAt charIndex: Int) -> NSControlCharacterAction
// Invoked while determining the soft line break point. When NO, NSLayoutManager tries to find the next line break opportunity before charIndex
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, shouldBreakLineByWordBeforeCharacterAt charIndex: Int) -> Bool
// Invoked while determining the hyphenation point. When NO, NSLayoutManager tries to find the next hyphenation opportunity before charIndex
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, shouldBreakLineByHyphenatingBeforeCharacterAt charIndex: Int) -> Bool
// Invoked for resolving the glyph metrics for NSControlCharacterWhitespaceAction control character.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, boundingBoxForControlGlyphAt glyphIndex: Int, for textContainer: NSTextContainer, proposedLineFragment proposedRect: CGRect, glyphPosition: CGPoint, characterIndex charIndex: Int) -> CGRect
// Allows NSLayoutManagerDelegate to customize the line fragment geometry before committing to the layout cache. The implementation of this method should make sure that the modified fragments are still valid inside the text container coordinate. When it returns YES, the layout manager uses the modified rects. Otherwise, it ignores the rects returned from this method.
@available(iOS 9.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, shouldSetLineFragmentRect lineFragmentRect: UnsafeMutablePointer<CGRect>, lineFragmentUsedRect: UnsafeMutablePointer<CGRect>, baselineOffset: UnsafeMutablePointer<CGFloat>, in textContainer: NSTextContainer, forGlyphRange glyphRange: NSRange) -> Bool
// This is sent whenever layout or glyphs become invalidated in a layout manager which previously had all layout complete.
/************************ Layout processing ************************/
@available(iOS 7.0, *)
optional public func layoutManagerDidInvalidateLayout(_ sender: NSLayoutManager)
// This is sent whenever a container has been filled. This method can be useful for paginating. The textContainer might be nil if we have completed all layout and not all of it fit into the existing containers. The atEnd flag indicates whether all layout is complete.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, didCompleteLayoutFor textContainer: NSTextContainer?, atEnd layoutFinishedFlag: Bool)
// This is sent right before layoutManager invalidates the layout due to textContainer changing geometry. The receiver of this method can react to the geometry change and perform adjustments such as recreating the exclusion path.
@available(iOS 7.0, *)
optional public func layoutManager(_ layoutManager: NSLayoutManager, textContainer: NSTextContainer, didChangeGeometryFrom oldSize: CGSize)
}
/************************ Deprecated 废弃，不赞成使用 ************************/
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionZeroAdvancement instead")
public var NSControlCharacterZeroAdvancementAction: Int { get }
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionWhitespace instead")
public var NSControlCharacterWhitespaceAction: Int { get }
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionHorizontalTab instead")
public var NSControlCharacterHorizontalTabAction: Int { get }
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionLineBreak instead")
public var NSControlCharacterLineBreakAction: Int { get }
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionParagraphBreak instead")
public var NSControlCharacterParagraphBreakAction: Int { get }
@available(iOS, introduced: 7.0, deprecated: 9.0, message: "Use NSControlCharacterActionContainerBreak instead")
public var NSControlCharacterContainerBreakAction: Int { get }
extension NSLayoutManager {
// These two methods are soft deprecated starting with iOS 9. It will be officially deprecated in a future release
open func glyph(at glyphIndex: Int, isValidIndex: UnsafeMutablePointer<ObjCBool>?) -> CGGlyph // Use -CGGlyphAtIndex:isValidIndex: instead
open func glyph(at glyphIndex: Int) -> CGGlyph // Use -CGGlyphAtIndex: instead
}
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