"

 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.

"

"{ Package: 'stx:libbasic2' }"

CharacterWriteStream 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 regular 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 ';

       nextPut:(Character codePoint:16r3C7).

     s contents inspect

                                                                [exEnd]

                                                                [exBegin]

     |s|

     s := TextStream on:''.

     s emphasis:#italic;

       nextPutAll:'hello';

       emphasis:nil;

       space;

       emphasis:#bold;

       nextPutAll:'world'.

     Transcript nextPutAll:(s contents)

                                                                [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"

    |stringContents|

    stringContents := super contents.

    (currentEmphasis isNil and:[runs isEmptyOrNil]) ifTrue:[

        "no emphasis information: answer a string"

        ^ stringContents

    ].

    self closeRun.

    ^ Text string:stringContents emphasisCollection:runs

    "

     Answer a Text containing unicode characters:

         (TextStream on:'')

            emphasis:#italic;

            nextPutAll:'hello';

            emphasis:nil;

            space;

            emphasis:#bold;

            nextPutAll:'world';

            space;

            nextPut:Character euro;

            contents.

     Answer a String:

         (TextStream on:'')

            nextPutAll:'hello';

            contents.

     Answer a Text:

         (TextStream on:Text new)

            nextPutAll:'hello';

            contents.

    "

    "Modified: / 28-01-2011 / 13:46:48 / cg"

!

emphasis

    "return the current emphasis"

    ^ currentEmphasis 

!

emphasis:newEmphasis

    "change the emphasis; all followup elements are appended with

     that emphasis in effect"

    position ~~ ZeroPosition ifTrue:[

        currentEmphasis ~= newEmphasis ifTrue:[

            self closeRun.

        ]

    ].

    currentEmphasis := newEmphasis

    "

     |s|

     s := TextStream on:String new.

     s emphasis:#italic;

       nextPutAll:'hello';

       emphasis:nil;

       space;

       emphasis:#bold;

       nextPutAll:'world'.

     s contents.

    "

!

stringContents

    "return the streams collected string contents"

    ^ super contents

! !

!TextStream methodsFor:'private'!

closeRun

    position ~~ ZeroPosition ifTrue:[

        runs isNil ifTrue:[

            runs := RunArray new:position-ZeroPosition withAll:currentEmphasis.

        ] ifFalse:[

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

        ]

    ]

! !

!TextStream methodsFor:'writing'!

nextPutAllText:aText

    "write some text to the stream and keep the emphasis"

    |string pos oldEmphasis|

    string := aText string.

    pos := 1.

    oldEmphasis := currentEmphasis.

    aText emphasis runsDo:[:len :emphasis |

        |nextPos|

        nextPos := pos + len.

        self emphasis:emphasis.

        self nextPutAll:string startingAt:pos to:nextPos - 1.

        pos := nextPos

    ].

    self emphasis:oldEmphasis

! !

!TextStream class methodsFor:'documentation'!

version

!

version_CVS

! !