Copyright ã1994 by NeXT Computer, Inc.  All Rights Reserved.

NSCStringText 

Inherits From:	NSText : NSView : NSResponder : NSObject 

Conforms To:	NSChangeSpelling, NSIgnoreMisspelledWords (NSText)
NSCoding (NSResponder)
NSObject (NSObject)

Declared In:	AppKit/NSCStringText.h 

Class Description

The NSCStringText class declares the programmatic interface to objects that manage text using eight-bit character encodings. The encoding is the same as the default C string encoding provided by defaultCStringEncoding in the NSString class. NSCStringText can be used in situations where backwards compatibility with the detailed interfaces of the NEXTSTEP Text object is important. Applications that can use the interface of NSText should do so.

The NSCStringText class is unlike most other classes in the Application Kit in its complexity and range of features. One of its design goals is to provide a comprehensive set of text-handling features so that you'll rarely need to create a subclass. An NSCStringText object can (among other things):

·	Control the color of its text and background.

·	Control the font and layout characteristics of its text.

·	Control whether text is editable.

·	Wrap text on a word or character basis.

·	Write text to, or read it from, a file, as either RTF or plain ASCII data.

·	Display graphic images within its text.

·	Communicate with other applications through the Services menu.

·	Let another object, the delegate, dynamically control its properties.

·	Let the user copy and paste text within and between applications.

·	Let the user copy and paste font and format information between NSCStringText objects.

·	Let the user check the spelling of words in its text.

·	Let the user control the format of paragraphs by manipulating a ruler.

NSCStringText can deal only with eight-bit characters. Therefore, it is not able to deal with Unicode character sets, and NSCStringText can't be fully internationalized.

Plain and Rich NSCStringText Objects

When you create an NSCStringText object directly, by default it allows only one font, line height, text color, and paragraph format for the entire text. You can set the default font used by new NSCStringText instances by sending the NSCStringText class object a setDefaultFont: message. Once an NSCStringText object is created, you can alter its global settings using methods such as setFont:, setLineHeight:, setTextGray:, and setAlignment:. For convenience, such an NSCStringText object will be called a plain NSCStringText object.

To allow multiple values for these attributes, you must send the NSCStringText object a setRichText:YES message. An NSCStringText object that allows multiple fonts also allows multiple paragraph formats, line heights, and so on. For convenience, such an NSCStringText object will be called a rich NSCStringText object.

A rich NSCStringText object can use RTF (Rich Text Format) as an interchange format. Not all RTF control words are supported: On input, an NSCStringText object ignores any control word it doesn't recognize; some of those it can read and interpret it doesn't write out. Refer to the class description of NSText for a list of the RTF control words that an NSCStringText object recognizes. 

Note: An NSCStringText object writes eight-bit characters in the default C string encoding, which differs somewhat from the ANSI character set.

In an NSCStringText object, each sequence of characters having the same attributes is called a run. A plain NSCStringText object has only one run for the entire text. A rich NSCStringText object can have multiple runs. Methods such as setSelFont: and setSelColor: let you programmatically modify the attributes of the selected sequence of characters in a rich NSCStringText object. As discussed below, the user can set these attributes using the Font panel and the ruler.

NSCStringText objects are designed to work closely with various objects and services. Some of theseÐsuch as the delegate or an embedded graphic objectÐrequire a degree of programming on your part. OthersÐsuch as the Font panel, spelling checker, ruler, and Services menuÐtake no effort other than deciding whether the service should be enabled or disabled. The following sections discuss these interrelationships.

Notifying the NSCStringText Object's Delegate

Many of an NSCStringText object's actions can be controlled through an associated object, the NSCStringText object's delegate. If it implements any of the following methods, the delegate receives the corresponding message at the appropriate time:

textWillResize:
textDidResize:oldBounds:
textWillSetSel:toFont:
textWillConvert:fromFont:toFont:
textWillStartReadingRichText:
textWillFinishReadingRichText:
textWillWrite:
textDidRead:paperSize:

So, for example, if the delegate implements the textWillConvert:fromFont:toFont: method, it will receive notification upon the user's first attempt to change the font of the text. Moreover, depending on the method's return value, the delegate can either allow or prohibit changes to the text. See ªMethods Implemented by the Delegateº. The delegate can be any object you choose, and one delegate can control multiple NSCStringText objects.

Adding Graphics to the Text

A rich NSCStringText object allows graphics to be embedded in the text. Each graphic is treated as a single (possibly large) ªcharacterº: The text's line height and character placement are adjusted to accommodate the graphic ªcharacter.º Graphics are embedded in the text in either of two ways: programmatically or directly through user actions. The programmatic approach is discussed first.

In the programmatic approach, you add an objectÐgenerally a subclass of NSCellÐto the text. This object manages the graphic image by drawing it when appropriate. Although NSCell subclasses are commonly used, the only requirement is that the embedded object responds to these messagesÐsee ªMethods Implemented by an Embedded Graphic Objectº for more information:

highlight:withFrame:inView:
drawWithFrame:inView:
trackMouse:inRect:ofView:untilMouseUp:
cellSize:
readRichText:forView:
richTextforView:

You place the graphic object in the text by sending the NSCStringText object a replaceSelWithCell: message.

An NSCStringText object displays a graphic in its text by sending the managing object a drawWithFrame:inView: message. To record the graphic to a file or to the pasteboard, the NSCStringText object sends the managing object a richTextforView: message. The object must then write an RTF control word along with any data (such as the path of a TIFF file containing its image data) it might need to recreate its image. To reestablish the text containing the graphic image from RTF data, an NSCStringText object must know which class to associate with particular RTF control words. You associate a control word with a class object by sending the NSCStringText class object a registerDirective:forClass: message. Thereafter, whenever an NSCStringText object finds the registered control word in the RTF data being read from a file or the pasteboard, it will create a new instance of the class and send the object a readRichText:forView: message.

An alternate means of adding an image to the text is for the user to drag an EPS or TIFF file icon directly into an NSCStringText object. The NSCStringText object automatically creates a graphic object to manage the display of the image. This feature requires a rich NSCStringText object that has been configured to receive dragged imagesÐsee the setImportsGraphics: method of the NSText class. 

Images that have been imported in this way can be written as RTFD documents. Programmatic creation of RTFD documents is not supported in this version of OpenStep. RTFD documents use a file package, or directory, to store the components of the document (the ªDº stands for ªdirectoryº). The file package has the name of the document plus a ª.rtfdº extension. The file package always contains a file called TXT.rtf for the text of the document, and one or more TIFF or EPS files for the images. An NSCStringText object can transfer information in an RTFD document to a file and read it from a fileÐsee the writeRTFDToFile:atomically: and readRTFDFromFile: methods in the NSText methods.

Cooperating with Other Objects and Services

NSCStringText objects are designed to work with the Application Kit's font conversion system. By default, an NSCStringText object keeps the Font panel updated with the font of the current selection. It also changes the font of the selection (for a rich NSCStringText object) or of the entire text (for a default NSCStringText object) to reflect the user's choices in the Font panel or menu. To disconnect an NSCStringText object from this service, send it a setUsesFontPanel:NO message (this method is actually implemented by NSTextÐthe superclass).

If an NSCStringText object is a subview of an NSScrollView, it can cooperate with the NSScrollView to display and update a ruler that displays formatting information. The NSScrollView retiles its subviews to make room for the ruler, and the NSCStringText object updates the ruler with the format information of the paragraph containing the selection. The toggleRuler: method controls the display of this ruler. Users can modify paragraph formats by manipulating the components of the ruler.

By means of the Services menu, an NSCStringText object can make use of facilities outside the scope of its own application. By default, an NSCStringText object registers with the services system that it can send and receive RTF and plain ASCII data. If the application containing the NSCStringText object has a Services menu, a menu item is added for each service provider that can accept or return these formats. To prevent NSCStringText objects from registering for services, send the NSCStringText class object an excludeFromServicesMenu:YES message before any NSCStringText objects are created.

Coordinates and sizes mentioned in the method descriptions below are in PostScript unitsÐ1/72 of an inch.

Initializing a New NSCStringText Object 

- (id)initWithFrame:(NSRect)frameRect	Returns a new NSCStringText object at frameRect 
text:(NSString *)theText		initialized with the contents of theText and with mode 
alignment:(NSTextAlignment)mode	 	alignment.

Modifying the Frame Rectangle 

- (void)resizeTextWithOldBounds:(NSRect)oldBounds 
maxRect:(NSRect)maxRect	Used by the NSCStringText object to resize and redisplay itself. 

Laying Out the Text 

- (int)calcLine	Calculates line breaks. 

- (BOOL)changeTabStopAt:(float)oldX	 Resets the position of the specified tab stop.
to:(float)newX 

- (BOOL)charWrap	Returns whether extra long words are wrapped. 

- (void *)defaultParagraphStyle	Returns the default paragraph style. 

- (float)descentLine	Returns distance from base line to bottom of line. 

- (void)getMarginLeft:(float *)leftMargin	 Gets by reference the dimensions of margins around the 
right:(float *)rightMargin	 	text.
top:(float *)topMargin	 
bottom:(float *)bottomMargin	 

- (void)getMinWidth:(float *)width	Given the widthMax and heightMax, calculates the
minHeight:(float *)height		minimum area needed to display the text and returns
maxWidth:(float)widthMax		width and height by reference.
maxHeight:(float)heightMax		 

- (float)lineHeight	Returns height of a line of text. 

- (void *)paragraphStyleForFont:(NSFont *)fontId	Recalculates the paragraph style based on new font fontId 
alignment:(int)alignment	 and alignment.

- (void)setCharWrap:(BOOL)flag	Sets whether extra long words are wrapped. 

- (void)setDescentLine:(float)value	Sets the distance from the base line to the bottom of line to value.

- (void)setLineHeight:(float)value	Sets the height of a line of text to value. 

- (void)setMarginLeft:(float)leftMargin	Adjusts the margins around the text. 
right:(float)rightMargin	 
top:(float)topMargin	 
bottom:(float)bottomMargin

- (void)setNoWrap	Disables word wrap. 

- (void)setParagraphStyle:(void *)paraStyle	Sets the default paragraph style for the entire text. 

- (BOOL)setSelProp:(NSParagraphProperty)property
to:(float)value	Sets a paragraph property for one or more selected
		paragraphs to value.

Reporting Line and Position 

- (int)lineFromPosition:(int)position	Converts character position to line number. 

- (int)positionFromLine:(int)line	Converts line number to character position. 

Reading and Writing Text 

- (void)finishReadingRichText	Sent after the NSCStringText object reads RTF data. 

- (NSTextBlock *)firstTextBlock	Returns a pointer to the first text block in the NSCStringText object. 

- (NSRect)paragraphRect:(int)paraNumber	Returns the location and size of a paragraph identified by
start:(int *)startPos	 	paraNumber; also returns the starting and ending 
end:(int *)endPos	 	character positions by reference.

- (void)startReadingRichText	Sent before the NSCStringText object begins reading RTF data.

Editing Text 

- (void)clear:(id)sender	Deletes the selected text. 

- (void)hideCaret	Removes the caret from the text display. 

- (void)showCaret	Displays the previously hidden caret in the text display. 

Managing the Selection 

- (void)getSelectionStart:(NSSelPt *)start	Gets information (by reference) relating to the starting and
end:(NSSelPt *)end	 	ending character positions of the selection.

- (void)replaceSel:(NSString *)aString	Replaces the selection with aString. 

- (void)replaceSel:(NSString *)aString	Replaces the selection with length bytes of aString.
length:(int)length	 

- (void)replaceSel:(NSString *)aString	Replaces the selection with length bytes of aString.
length:(int)length	 	insertRuns is a pointer to the current run in the run
runs:(NSRunArray *)insertRuns	 	array.

- (void)scrollSelToVisible	Brings the selection within the frame rectangle. 

- (void)selectError	Selects all the text. 

- (void)selectNull	Deselects the current selection. 

- (void)setSelectionStart:(int)start	Selects text from characters start through end. 
end:(int)end

- (void)selectText:(id)sender	Makes the receiver the first responder and selects all text. 

Setting the Font 

+ (NSFont *)defaultFont	Returns the default NSFont object for NSCStringText objects.

+ (void)setDefaultFont:(NSFont *)anObject	Makes anObject the default NSFont object for NSCStringText objects. 

- (void)setFont:(NSFont *)fontObj	Sets the NSFont object and paragraph style for all text.
paragraphStyle:(void *)paragraphStyle	 

- (void)setSelFont:(NSFont *)fontObj	Sets the NSFont object for the selection.

- (void)setSelFont:(NSFont *)fontObj	Sets the NSFont object and paragraph style for the
paragraphStyle:(void *)paragraphStyle	 	selection. 

- (void)setSelFontFamily:(NSString *)fontName	Sets the font family for the selection. 

- (void)setSelFontSize:(float)size	Sets the font size for the selection. 

- (void)setSelFontStyle:(NSFontTraitMask)traits	Sets the font style for the selection. 

Finding Text 

- (BOOL)findText:(NSString *)textPattern	Searches for textPattern in the text, starting at the insertion
ignoreCase:(BOOL)ignoreCase		point. ignoreCase instructs the search to disregard case;
backwards:(BOOL)backwards		 backwards means search backwards; wrap means that
wrap:(BOOL)wrap		 when the search reaches the beginning or end of the text (depending on the direction), it should continue by wrapping to the end or beginning of the text.

Modifying Graphic Attributes 

- (NSColor *)runColor:(NSRun *)run	Returns the color of the specified text run. 

- (NSColor *)selColor	Returns the color of the selected text. 

- (void)setSelColor:(NSColor *)color	Sets the color of the selected text. 

Reusing an NSCStringText Object 

- (void)renewFont:(NSFont *)newFontObj	Resets the NSCStringText object to draw different text 
text:(NSString *)newText		newText in font newFontId within frame newFrame. 
frame:(NSRect)newFrame
tag:(int)newTag	 

- (void)renewFont:(NSString *)newFontName	Resets the NSCStringText object to draw different text 
size:(float)newFontSize		newText in the font identified by newFontName, 
style:(int)newFontStyle		newFontSize, and newFontStyle. Drawing occurs within 
text:(NSString *)newText		frame newFrame.
frame:(NSRect)newFrame
tag:(int)newTag	 

- (void)renewRuns:(NSRunArray *)newRuns	Resets the NSCStringText object to draw different text 
text:(NSString *)newText		newText in newFrame.
frame:(NSRect)newFrame
tag:(int)newTag	 

Setting Window Attributes 

- (BOOL)isRetainedWhileDrawing	Returns whether a retained window is used for drawing. 

- (void)setRetainedWhileDrawing:(BOOL)flag	Allows use of a retained window when drawing. 

Assigning a Tag 

- (void)setTag:(int)anInt	Makes anInt the NSCStringText object's tag. 

- (int)tag	Returns the NSCStringText object's tag. 

Handling Event Messages 

- (void)becomeKeyWindow	Activates the caret if selection has width of 0. 

- (void)moveCaret:(unsigned short)theKey	Moves the caret in response to arrow keys. 

- (void)resignKeyWindow	Deactivates the caret. 

Displaying Graphics within the Text 

+ registerDirective:(NSString *)directive	Associates an RTF control word (directive) with class
forClass:class		(usually NSCell and subclasses); objects of this class are encoded through RTF control words in NSCStringText objects. 

- (NSPoint)locationOfCell:(NSCell *)cell	Returns the location of cell. 

- (void)replaceSelWithCell:(NSCell *)cell	Replaces the selection with cell object cell. 

- (void)setLocation:(NSPoint)origin	Sets the origin point of cell. 
ofCell:(NSCell *)cell

Using the Services Menu and the Pasteboard

+ excludeFromServicesMenu:(BOOL)flag	Controls whether NSCStringText objects can register for services. 

- (BOOL)readSelectionFromPasteboard:(NSPasteboard *)pboard
	Replaces the selection with data from pasteboard pboard. 

- (id)validRequestorForSendType:(NSString *)sendType 
returnType:(NSString *)returnType	Determines which Service menu items are enabled. 

- (BOOL)writeSelectionToPasteboard:(NSPasteboard *)pboard 
types:(NSArray *)types	Copies the selection to pasteboard pboard.

Setting Tables and Functions 

- (const NSFSM *)breakTable	Returns the table defining word boundaries. 

- (const unsigned char *)charCategoryTable	Returns the table defining character categories. 

- (NSCharFilterFunc)charFilter	Returns the current character filter function. 

- (const NSFSM *)clickTable	Returns the table defining double-click selection. 

- (NSTextFunc)drawFunc	Returns the current draw function. 

- (const unsigned char *)postSelSmartTable	Returns cut and paste table for right word boundary. 

- (const unsigned char *)preSelSmartTable	Returns cut and paste table for left word boundary. 

- (NSTextFunc)scanFunc	Returns the current scan function. 

- (void)setBreakTable:(const NSFSM *)aTable	Sets the table defining word boundaries. 

- (void)setCharCategoryTable:(const unsigned char *)aTable
	Sets the table defining character categories used in the word wrap or click tables.

- (void)setCharFilter:(NSCharFilterFunc)aFunction
	Makes aFunction the character filter function. 

- (void)setClickTable:(const NSFSM *)aTable	Sets the table defining double-click selection. 

- (void)setDrawFunc:(NSTextFunc)aFunction	Makes aFunction the function that draws the text. 

- (void)setPostSelSmartTable:(const unsigned char *)aTable
	Sets the cut and paste table for right word boundary. 

- (void)setPreSelSmartTable:(const unsigned char *)aTable
	Sets the cut and paste table for left word boundary. 

- (void)setScanFunc:(NSTextFunc)aFunction	Makes aFunction the scan function. 

- (void)setTextFilter:(NSTextFilterFunc)aFunction	Makes aFunction the text filter function. 

- (NSTextFilterFunc)textFilter	Returns the current text filter function. 

Printing 

- (void)adjustPageHeightNew:(float *)newBottom	Assists with automatic pagination of text. 
top:(float)oldTop	 
bottom:(float)oldBottom	 
limit:(float)bottomLimit

Implemented by an Embedded Graphic Object 

- (NSSize)cellSize	Embedded cell returns its size.

- (void)drawWithFrame:(NSRect)cellFrame	Embedded object draws itself, including frame, within
inView:(NSView *)controlView	 	cellFrame in controlView. 

- (void)highlight:(BOOL)flag	Embedded object highlights or unhighlights itself with
withFrame:(NSRect)cellFrame	 cellFrame of controlView, depending on the value of
inView:(NSView *)controlView	 flag.

- (void)readRichText:(NSString *)stringObject	 Embedded object reads its RTF representation from
forView:(NSView *)view	 	stringObject and initializes itself.

- (NSString *)richTextForView:(NSView *)view	Embedded object stores its RTF representation within view as a string object and returns it.

- (BOOL)trackMouse:(NSEvent *)theEvent	 Embedded object implements this method to track mouse
inRect:(NSRect)cellFrame	 	movement within tracking rectangle (cellFrame) and to
ofView:(NSView *)controlView	 	detect mouse-up event (untilMouseUp).
untilMouseUp:(BOOL)untilMouseUp	 

Implemented by the Delegate 

- (void)textDidRead:(NSCStringText *)textObject	Lets the delegate review paper size.
paperSize:(NSSize)paperSize	 

- (NSRect)textDidResize:(NSCStringText *)textObject
oldBounds:(NSRect)oldBounds	 Reports size change to delegate.

- (NSFont *)textWillConvert:(NSCStringText *)textObject
fromFont:(NSFont *)font	 Lets delegate intercede in selection's font change. 
toFont:(NSFont *)font

- (void)textWillFinishReadingRichText:(NSCStringText *)textObject
	Informs delegate that the NSCStringText object finished reading RTF data. 

- (void)textWillResize:(NSCStringText *)textObject
	Informs delegate of impending size change. 

- (void)textWillSetSel:(NSCStringText *)textObject
toFont:(NSFont *)font	Lets delegate intercede in the updating of the Font panel. 

- (void)textWillStartReadingRichText:(NSCStringText *)textObject
	Informs delegate that NSCStringText object will read RTF data. 

- (NSSize)textWillWrite:(NSCStringText *)textObject
	Lets the delegate specify paper size. 

Compatibility Methods

- (NSCStringTextInternalState *)cStringTextInternalState
	Returns a structure that represents the instance variables of the NSCStringText object. The structure is defined in appkit/NSCStringText.h, and in the ªTypes and Constantsº section of the Application Kit documentation. Note that this method is provided for applications that really must depend on changing the values of an NSCStringText object's instance variables.