"
 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'
	 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.
"
!

version
    ^ '$Header: /cvs/stx/stx/libtool/DiffTextView.st,v 1.10 1995-11-16 16:27:16 cg Exp $'
!

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

       d := DiffTextView openOn:text1 and:text2.

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

!DiffTextView class methodsFor:'defaults'!

diffCommand
    ^ 'diff -b'
! !


!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.
	] 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|

    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:[
		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.

"/            state == #added ifTrue:[
"/                l1 add:(text1 at:idx1).
"/                idx1 := idx1 + 1.
"/            ].

	    "
	     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:[
			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:[
			    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: 16.11.1995 / 17:09:35 / cg"
! !

!DiffTextView methodsFor:'accessing'!

text1:t1 text2:t2
    |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
    "
! !