"

 COPYRIGHT (c) 1996 by Claus Gittinger

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

WriteStream subclass:#TextStream

	instanceVariableNames:'runs currentEmphasis'

	classVariableNames:''

	poolDictionaries:''

	category:'Streams'

!

!TextStream class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1996 by Claus Gittinger

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    a textStream is much like a regulat writeStream;

    however, in addition to collecting characters, it keeps

    track of any change of the emphasis, and returns a Text instance

    as its contents (in contrast to a String instance).

    Can be used to collect up attributed text.

    [author:]

        Claus Gittinger

    [see also:]

        WriteStream

        Text String

"

!

examples

"

                                                                [exBegin]

     |s|

     s := TextStream on:''.

     s emphasis:#italic;

       nextPutAll:'hello';

       emphasis:nil;

       space;

       emphasis:#bold;

       nextPutAll:'world'.

     s contents inspect

                                                                [exEnd]

                                                                [exBegin]

     |s|

     s := TextStream on:''.

     s emphasis:#italic;

       nextPutAll:'hello';

       emphasis:nil;

       space;

       emphasis:#bold;

       nextPutAll:'world'.

     Dialog

        warn:(s contents)

                                                                [exEnd]

                                                                [exBegin]

     |s1 s2 flipFlop|

     s1 := PipeStream readingFrom:'ls -l'.

     s2 := TextStream on:''.

     flipFlop := true.

     [s1 atEnd] whileFalse:[

        flipFlop ifTrue:[

            s2 emphasis:(#color->Color red)

        ] ifFalse:[

            s2 emphasis:nil

        ].

        flipFlop := flipFlop not.

        s2 nextPutAll:(s1 nextLine).

        s2 cr.

     ].

     s1 close.

     (EditTextView new contents:s2 contents) open

                                                                [exEnd]

"

! !

!TextStream methodsFor:'accessing'!

contents

    "return the streams collected contents"

    self closeRun.

    ^ Text string:super contents emphasisCollection:runs

    "

     |s|

     s := TextStream on:String new.

     s emphasis:#italic.

     s nextPutAll:'hello'.

     s emphasis:nil.

     s space.

     s emphasis:#bold.

     s nextPutAll:'world'.

     s contents

    "

!

emphasis:aSymbol

    position ~~ 1 ifTrue:[

        self closeRun.

    ].

    currentEmphasis := aSymbol

    "

     |s|

     s := TextStream on:String new.

     s emphasis:#italic.

     s nextPutAll:'hello'.

     s emphasis:nil.

     s space.

     s emphasis:#bold.

     s nextPutAll:'world'.

     s contents

    "

! !

!TextStream methodsFor:'private'!

closeRun

    position ~~ 1 ifTrue:[

        runs isNil ifTrue:[

            runs := RunArray new:position-1 withAll:currentEmphasis

        ] ifFalse:[

            runs add:currentEmphasis withOccurrences:(position - runs size - 1)

        ]

    ]

! !

!TextStream class methodsFor:'documentation'!

version

    ^ '$Header: /cvs/stx/stx/libbasic2/TextStream.st,v 1.1 1996-05-14 16:48:26 cg Exp $'

! !