"
 COPYRIGHT (c) 1994 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.
"

TwoColumnTextView subclass:#DiffTextView
	instanceVariableNames:'useColors showSeparators addedColor addedBgColor removedColor
		removedBgColor changedColor changedBgColor changedSpacesOnlyColor
		changedSpacesOnlyBgColor diffLineNumbers'
	classVariableNames:''
	poolDictionaries:''
	category:'Views-Text'
!

!DiffTextView class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 1994 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 view showing diff output (see unix manual pages)
    in a user-friendly form.
    The view is created and opened with:

        d := DiffTextView openOn:text1 and:text2

    or:
        d := DiffTextView openOn:text1 label:l1
                             and:text2 label:l2

    and it will show the differences side-by-side.
    For a real world application, see the ChangesBrowsers
    `compare' function.

    [see also:]
        TextView EditTextView
"
! !

!DiffTextView class methodsFor:'defaults'!

diffCommand
    "return the diff-command (with arguments)"

    ^ 'diff -b'
! !

!DiffTextView methodsFor:'accessing'!

text1:t1 text2:t2
    "set the two texts which are to be diffed"

    |tmpFile1 tmpFile2 name1 tmpName2 stream line text1 text2 diffList pidString|

    text1 := t1 asStringCollection.
    text2 := t2 asStringCollection.

    "
     save them texts in two temporary files ...
    "
    tmpFile1 := Filename newTemporary.
    stream := tmpFile1 writeStream.
    text1 do:[:line |
        stream nextPutAll:line; cr
    ].
    stream close.

    tmpFile2 := Filename newTemporary.
    stream := tmpFile2 writeStream.
    text2 do:[:line |
        stream nextPutAll:line; cr
    ].
    stream close.

    "
     start diff on it ...
    "
    stream := PipeStream 
                readingFrom:self class diffCommand , ' ' , 
                            tmpFile1 asString, ' ' , tmpFile2 asString.
    stream isNil ifTrue:[
        self error:'cannot execute diff'.
        text1 := text2 := nil.
    ] ifFalse:[
        diffList := OrderedCollection new.
        [stream atEnd] whileFalse:[
            line := stream nextLine.
            line notNil ifTrue:[diffList add:line]
        ].
        stream close.
    ].

    tmpFile1 delete.
    tmpFile2 delete.

    self updateListsFrom:text1 and:text2 diffs:diffList

    "
     |v|

     v := HVScrollableView for:DiffTextView.
     v scrolledView text1:('../libview/Color.st' asFilename readStream contents)
                    text2:('../libview/Color.st.old' asFilename readStream contents).
     v open
    "

    "
     |v t1 t2|

     t1 := '
one
two
three
four
'.
     t2 := '
one
two-a
two-b
three
three-b
four
'.

     v := DiffTextView new.
     v text1:t1 text2:t2.
     v open
    "

    "Modified: 25.4.1996 / 13:33:52 / cg"
! !

!DiffTextView methodsFor:'initialization'!

initStyle
    super initStyle.

    showSeparators := false.

    useColors := ColoredListEntry notNil.
    useColors ifTrue:[
        device hasColors ifTrue:[
            addedColor := Color black.
            addedBgColor := Color green.

            removedColor := Color white.
            removedBgColor := Color red.

            changedColor := Color white.
            changedBgColor := Color blue.

            changedSpacesOnlyColor := Color white.
            changedSpacesOnlyBgColor := Color blue lightened.
        ] ifFalse:[
            addedBgColor := removedBgColor := changedBgColor := Color black.
            addedColor := removedColor := changedColor := Color white.
        ]
    ].

    "Created: 16.11.1995 / 16:59:48 / cg"
! !

!DiffTextView methodsFor:'private'!

updateListsFrom:text1 and:text2 diffs:diffList
    "given the two texts in text1 and text2, and the diff-output in diffList,
     update my views contents"

    |idx1 idx2 dIdx dEnd state s nr1 nr2 nr3 op entry c l1 l2 any delta
     textView1 textView2 s1 s2|

    diffLineNumbers := OrderedCollection new.

    textView1 := textViews at:1.
    textView2 := textViews at:2.

    l1 := OrderedCollection new.
    l2 := OrderedCollection new.

    idx1 := 1.
    idx2 := 1.

    dIdx := 1.
    dEnd := diffList size + 1.
    state := #initial.
    [dIdx <= dEnd] whileTrue:[
        dIdx == dEnd ifTrue:[
            "dummy cleanup entry"
            entry := nil.
            state := #initial.
        ] ifFalse:[
            entry := diffList at:dIdx.
        ].

        state == #initial ifTrue:[
            "entry is of the form <nr> <op> <offs> [<offs2>]"

            "
             fill up to size difference from previous change
            "
            delta := l1 size - l2 size.
            delta > 0 ifTrue:[
                delta timesRepeat:[l2 add:nil]
            ] ifFalse:[
                delta < 0 ifTrue:[
                    delta negated timesRepeat:[l1 add:nil]
                ]
            ].

            "
             except for the first chunk, add a separating line
            "
            l1 size ~~ 0 ifTrue:[
                showSeparators ifTrue:[
                    l1 add:'--------'.
                    l2 add:'--------'.
                ]
            ].
            "
             in cleanup ?
            "
            entry isNil ifTrue:[
                nr1 := text1 size + 1.
                nr2 := text2 size + 1.
                state := #finish.
            ] ifFalse:[
                diffLineNumbers add:l1 size.

                s := ReadStream on:entry.
                nr1 := Integer readFrom:s.
                s peek == $, ifTrue:[
                    s next.
                    Integer readFrom:s
                ].
                op := s next.
                nr2 := Integer readFrom:s.
                s peek == $, ifTrue:[
                    s next.
                    nr3 := Integer readFrom:s
                ] ifFalse:[
                    nr3 := nil
                ].

                op == $c ifTrue:[
                    state := #changed.
                ] ifFalse:[
                    op == $a ifTrue:[
                        state := #added.
                    ] ifFalse:[
                        op == $d ifTrue:[
                            state := #deleted
                        ] ifFalse:[
                            self halt:'unexpected diff entry'.
                        ]
                    ]
                ].

            ].

"/ nr1 print. ' ' print. op print. ' ' print. nr2 print. ' , ' print. nr3 printNL.

            "
             copy over unchanged lines
            "
            any := false.
            [idx1 < nr1] whileTrue:[
"/ '< add:' print. idx1 printNL.
                l1 add:(text1 at:idx1).
                idx1 := idx1 + 1.
                any := true.
            ].
            [idx2 < nr2] whileTrue:[
"/ '> add:' print. idx2 printNL.
                l2 add:(text2 at:idx2).
                idx2 := idx2 + 1.
                any := true.
            ].

            state == #added ifTrue:[
                l1 add:(text1 at:idx1).
                idx1 := idx1 + 1.
            ].
            state == #deleted ifTrue:[
                l2 add:(text2 at:idx2).
                idx2 := idx2 + 1.
            ].


            "
             add a separating line, except at end
            "
            any ifTrue:[
                state ~~ #finish ifTrue:[
                    showSeparators ifTrue:[
                        l1 add:'--------'.
                        l2 add:'--------'.
                    ]
                ]
            ].

        ] ifFalse:[
            state == #changed ifTrue:[
                (entry at:1) == $< ifTrue:[
                    useColors ifTrue:[
                        (l2 size >= idx1
                        and:[(s2 := l2 at:idx1) notNil
                             and:[s2 asString withoutSeparators = (text1 at:idx1) withoutSeparators]]) ifTrue:[
                            l1 add:(ColoredListEntry string:(text1 at:idx1) foregroundColor:changedSpacesOnlyColor backgroundColor:changedSpacesOnlyBgColor).
                            l2 at:idx1 put:(ColoredListEntry string:(l2 at:idx1) asString foregroundColor:changedSpacesOnlyColor backgroundColor:changedSpacesOnlyBgColor).
                        ] ifFalse:[
                            l1 add:(ColoredListEntry string:(text1 at:idx1) foregroundColor:changedColor backgroundColor:changedBgColor).
                        ]
                    ] ifFalse:[
                        l1 add:(text1 at:idx1).
                    ].
                    idx1 := idx1 + 1
                ] ifFalse:[
                    (entry at:1) == $> ifTrue:[
                        useColors ifTrue:[
                            (l1 size >= idx2
                            and:[(s1 := l1 at:idx2) notNil
                                and:[s1 asString withoutSeparators = (text2 at:idx2) withoutSeparators]]) ifTrue:[
                                l2 add:(ColoredListEntry string:(text2 at:idx2) foregroundColor:changedSpacesOnlyColor backgroundColor:changedSpacesOnlyBgColor).
                                l1 at:idx2 put:(ColoredListEntry string:(l1 at:idx2) asString foregroundColor:changedSpacesOnlyColor backgroundColor:changedSpacesOnlyBgColor).
                            ] ifFalse:[
                                l2 add:(ColoredListEntry string:(text2 at:idx2) foregroundColor:changedColor backgroundColor:changedBgColor)
                            ]
                        ] ifFalse:[
                            l2 add:(text2 at:idx2).
                        ].
                        idx2 := idx2 + 1
                    ] ifFalse:[
                        (entry at:1) == $- ifTrue:[
                        ] ifFalse:[
                            state := #initial.
                            dIdx := dIdx - 1
                        ]
                    ]
                ]
            ] ifFalse:[
                state == #added ifTrue:[
                    (entry at:1) == $> ifTrue:[
                        useColors ifTrue:[
                            l2 add:(ColoredListEntry string:(text2 at:idx2) foregroundColor:addedColor backgroundColor:addedBgColor )
                        ] ifFalse:[
                            l2 add:(text2 at:idx2).
                        ].
                        idx2 := idx2 + 1.
                        l1 add:nil
                    ] ifFalse:[
                        state := #initial.
                        dIdx := dIdx - 1
                    ]
                ] ifFalse:[
                    state == #deleted ifTrue:[
                        (entry at:1) == $< ifTrue:[
                            useColors ifTrue:[
                                l1 add:(ColoredListEntry string:(text1 at:idx1) foregroundColor:removedColor backgroundColor:removedBgColor ).
                            ] ifFalse:[
                                l1 add:(text1 at:idx1).
                            ].
                            idx1 := idx1 + 1.
                            l2 add:nil
                        ] ifFalse:[
                            state := #initial.
                            dIdx := dIdx - 1
                        ]
                    ] 
                    "must be in finish otherwise"
                ]
            ]
        ].
        dIdx := dIdx + 1
    ].
    [l1 size < l2 size] whileTrue:[
        l1 add:''.
    ].
    [l2 size < l1 size] whileTrue:[
        l2 add:''.
    ].
    textView1 list:l1.
    textView2 list:l2

    "Modified: 25.4.1996 / 13:29:53 / cg"
! !

!DiffTextView class methodsFor:'documentation'!

version
^ '$Header: /cvs/stx/stx/libtool/DiffTextView.st,v 1.16 1996-04-25 11:34:57 cg Exp $'! !