WriteStream subclass:#TextCollectorStream

	instanceVariableNames:'access lineLimit partialLastLine'

	classVariableNames:''

	poolDictionaries:''

	category:'Streams-Misc'

!

!TextCollectorStream class methodsFor:'documentation'!

documentation

"

    a textCollectorStream is much like a regular writeStream.

    In addition to collecting characters, it does a delayed update

    of its collection, and may be used as a model for a TextView to

    work like a TextCollector.

    Currently ListViews are optimezed for StringCollections as model.

    So stream on a StringCollection for best performance.

    [author:]

        Stefan Vogel

    [see also:]

        WriteStream

        TextCollector StringCollection

"

!

examples

"

                                        [exBegin]

    |s|

    s := TextCollectorStream on:StringCollection new.

    s show:'Hello '.

    s showCR:'World'.

    s contents inspect

                                        [exEnd]

"

!

history

    "Created: 18.2.1997 / 13:18:17 / stefan"

! !

!TextCollectorStream class methodsFor:'defaults'!

defaultLineLimit

    "the number of lines remembered by default"

    ^ 600

    "Created: 18.2.1997 / 14:41:38 / stefan"

! !

!TextCollectorStream methodsFor:'accessing'!

access

    "return the value of the instance variable 'access' (automatically generated)"

    ^ access

    "Created: 19.2.1997 / 09:01:21 / stefan"

!

access:something

    "set the value of the instance variable 'access' (automatically generated)"

    access := something.

    "Created: 19.2.1997 / 09:01:21 / stefan"

!

lineLimit

    "return the value of the instance variable 'lineLimit' (automatically generated)"

    ^ lineLimit

    "Created: 19.2.1997 / 09:01:21 / stefan"

!

lineLimit:something

    "set the value of the instance variable 'lineLimit' (automatically generated)"

    lineLimit := something.

    "Created: 19.2.1997 / 09:01:21 / stefan"

! !

!TextCollectorStream methodsFor:'initialization'!

initialize

    super initialize.

"/    access := RecursionLock new.

    lineLimit := self class defaultLineLimit.

    "first line is empty"    

    partialLastLine := false.

    "Created: 18.2.1997 / 14:39:50 / stefan"

    "Modified: 19.2.1997 / 11:59:01 / stefan"

!

on:aCollection

    self initialize.

    ^ super on:aCollection.

    "Created: 19.2.1997 / 08:59:45 / stefan"

!

on:aCollection from:start to:end

    self initialize.

    ^ super on:aCollection from:start to:end.

    "Created: 19.2.1997 / 09:00:07 / stefan"

!

with:aCollection

    self initialize.

    ^ super with:aCollection.

    "Created: 19.2.1997 / 09:00:24 / stefan"

! !

!TextCollectorStream methodsFor:'writing'!

nextPut:anObject

    "an Object may be a Character (cr or nl), or anything 

     responding to #printString."

    |string newPartialLastLine size|

    (writeLimit notNil

     and:[position >= writeLimit]) ifTrue:[

        WriteErrorSignal raiseErrorString:'write beyond writeLimit'

    ].

    anObject isCharacter ifTrue:[       

        ((anObject == Character cr) or:[anObject == Character nl]) ifTrue:[

            partialLastLine ifFalse:[

                collection add:''.      "add empty line"

                position := position + 1.

            ].

            partialLastLine := false.

            ^ anObject.

        ].

    ].

    string := anObject printString.

    (string includes:Character cr) ifTrue:[

        newPartialLastLine := (string last ~= Character cr).

        string := string asStringCollection.

        partialLastLine ifTrue:[

            string at:1 put:(collection removeLast, (string at:1)).

        ].

        size := collection size + string size.

        size > lineLimit ifTrue:[

            collection removeFirst:(size - lineLimit min:(collection size)).

            position := lineLimit.

        ].

        collection addAll:string.

        position := position + string size.

        partialLastLine := newPartialLastLine.

    ] ifFalse:[

        partialLastLine ifTrue:[

            collection add:(collection removeLast, string).

        ] ifFalse:[

            collection add:string.

            position := position + 1.

        ].

        partialLastLine := true.

    ].

    ^ anObject

    "Created: 18.2.1997 / 14:29:51 / stefan"

    "Modified: 19.2.1997 / 11:47:37 / stefan"

!

show:anObject

    self nextPut:anObject

    "Created: 18.2.1997 / 17:20:53 / stefan"

!

showCR:anObject

    self nextPut:anObject; nextPut:Character cr

    "Created: 18.2.1997 / 17:21:12 / stefan"

! !

!TextCollectorStream class methodsFor:'documentation'!

version

    ^ '$Header: /cvs/stx/stx/libbasic/TextCollectorStream.st,v 1.1 1997-02-19 12:06:26 stefan Exp $'

! !