"

 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:'DiffCommandTemplate'

	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.

    The colors mean:

        red             - removed

        green           - added

        blue            - changed

        light-blue        changed, but not really (i.e. spaces only)

    For a real world application and use of this widget, 

    see the ChangesBrowsers `compare', 

    or the browsers 'compare with repository' functions.

    Notice:

        A diff command must be available on your system and found

        along the PATH (you will see a warning on stderr, if there is no diff).

        We use gnu-diff.

    [see also:]

        TextView EditTextView Diff3TextView

    [author:]

        Claus Gittinger

"

!

examples

"

                                                        [exBegin]

    |text1 text2|

    text1 := 'hello world

here is some difference

more text

this line has been removed

more text

more text

'.

    text2 := 'hello world

where is the difference ?

more text

more text

more text

this line has been added

'.

    DiffTextView openOn:text1 label:'text1'

                    and:text2 label:'text2'

                                                        [exEnd]

"

! !

!DiffTextView class methodsFor:'defaults'!

diffCommand

    "return the diff-command (with argument placeHolders)"

    DiffCommandTemplate isNil ifTrue:[

        OperatingSystem isMSDOSlike ifTrue:[

            (OperatingSystem canExecuteCommand:'diff') ifFalse:[

                'DiffTextView [warning]: no diff command found' errorPrintCR.

                ^ nil

            ].

            DiffCommandTemplate := 'diff %1 %2'

        ] ifFalse:[

            DiffCommandTemplate := 'diff -b %1 %2'

        ]

    ].

    ^ DiffCommandTemplate

    "Modified: / 30.1.1998 / 12:12:49 / cg"

!

diffCommandTemplate:aCommandTemplateString

    "set the diff-command template"

    OperatingSystem isMSDOSlike ifTrue:[

        ^ DiffCommandTemplate ? 'diff %1 %2'

    ].

    ^ DiffCommandTemplate ? 'diff -b %1 %2'

    "Modified: / 30.1.1998 / 12:10:34 / cg"

    "Created: / 30.1.1998 / 12:12:37 / cg"

! !

!DiffTextView methodsFor:'accessing'!

text1:t1 text2:t2

    "set the two texts which are to be diffed;

     execute DiffCommand and update the two textViews."

    |tmpFile1 tmpFile2 name1 tmpName2 stream line 

     text1 text2 diffList pidString diffTemplate diffCmd|

    text1 := t1 asStringCollection.

    text2 := t2 asStringCollection.

    diffTemplate := self class diffCommand.

    diffTemplate isNil ifTrue:[

        "/ self warn:'no diff command available'.

    ] ifFalse:[

        "

         save them texts in two temporary files ...

        "

        tmpFile1 := Filename newTemporary.

        stream := tmpFile1 writeStream.

        text1 do:[:line |

            line notNil ifTrue:[

                stream nextPutAll:line.

            ].

            stream cr

        ].

        stream close.

        tmpFile2 := Filename newTemporary.

        stream := tmpFile2 writeStream.

        text2 do:[:line |

            line notNil ifTrue:[

                stream nextPutAll:line.

            ].

            stream cr

        ].

        stream close.

        "

         start diff on it ...

        "

        diffCmd := diffTemplate

                    bindWith:tmpFile1 asString

                    with:tmpFile2 asString.

        stream := PipeStream readingFrom:diffCmd.

        stream isNil ifTrue:[

            stream := PipeStream readingFrom:('support' , Filename separator asString , diffCmd).

        ].

        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: / 5.5.1999 / 16:07:13 / cg"

! !

!DiffTextView methodsFor:'initialization'!

addNextPreviousButtons

    super addNextPreviousButtons.

    nextPrevButtonPanel beVisible.

!

initStyle

    super initStyle.

    showSeparators := false.

    (useColors := device hasColors) ifTrue:[

        addedColor := Color white.

        addedBgColor := Color red.

        removedColor := Color black.

        removedBgColor := Color green.

        changedColor := Color white.

        changedBgColor := Color blue.

        changedSpacesOnlyColor := Color white.

        changedSpacesOnlyBgColor := Color blue lightened.

    ] ifFalse:[

        showSeparators := true.

        (useColors := device hasGreyscales) ifTrue:[

            addedBgColor := removedBgColor := changedBgColor := Color grey:80.

            addedColor := removedColor := changedColor := Color black.

        ] ifFalse:[

            addedBgColor := removedBgColor := changedBgColor := Color black.

            addedColor := removedColor := changedColor := Color white.

        ].

        changedSpacesOnlyColor := Color white.

        changedSpacesOnlyBgColor := Color black.

    ].

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

    "Modified: 14.6.1996 / 16:14:39 / 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 line1 line2|

    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:[

                line1 := line2 := nil.

                (entry at:1) == $< ifTrue:[

                    useColors ifTrue:[

                        (l2 size >= idx1

                        and:[(s2 := line2 := l2 at:idx1) notNil

                        and:[(s2 asString withoutSeparators = (text1 at:idx1) withoutSeparators)

                              "/ or:[(s2 asString withoutSeparators withTabsExpanded = (text1 at:idx1) withoutSeparators withTabsExpanded)]  

                        ]]) ifTrue:[

                            line1 := Text string:(text1 at:idx1) 

                                         foregroundColor:changedSpacesOnlyColor

                                         backgroundColor:changedSpacesOnlyBgColor.

                            line2 := Text string:line2 asString 

                                         foregroundColor:changedSpacesOnlyColor 

                                         backgroundColor:changedSpacesOnlyBgColor.

                            line1 string withoutTrailingSeparators = line2 string withoutTrailingSeparators ifTrue:[

                                line1 := line1 string.

                                line2 := line2 string.

                            ].

                            l1 add:line1.

                            l2 at:idx1 put:line2.

                        ] ifFalse:[

                            line1 := Text string:(text1 at:idx1) 

                                         foregroundColor:changedColor 

                                         backgroundColor:changedBgColor.

                            l1 add:line1.

                        ]

                    ] ifFalse:[

                        l1 add:(text1 at:idx1).

                    ].

                    idx1 := idx1 + 1

                ] ifFalse:[

                    (entry at:1) == $> ifTrue:[

                        useColors ifTrue:[

                            (l1 size >= idx2

                            and:[(s1 := line1 := l1 at:idx2) notNil

                            and:[(s1 asString withoutSeparators = (text2 at:idx2) withoutSeparators)

                                  "/ or:[(s1 asString withoutSeparators withTabsExpanded = (text2 at:idx2) withoutSeparators withTabsExpanded)]  

                            ]]) ifTrue:[

                                line2 := Text string:(text2 at:idx2) 

                                            foregroundColor:changedSpacesOnlyColor 

                                            backgroundColor:changedSpacesOnlyBgColor.

                                line1 := Text string:line1 asString 

                                            foregroundColor:changedSpacesOnlyColor 

                                            backgroundColor:changedSpacesOnlyBgColor.

                                line1 string withoutTrailingSeparators = line2 string withoutTrailingSeparators ifTrue:[

                                    line1 := line1 string.

                                    line2 := line2 string.

                                ].

                                l2 add:line2.

                                l1 at:idx2 put:line1.

                            ] ifFalse:[

                                line2 := Text string:(text2 at:idx2) foregroundColor:changedColor backgroundColor:changedBgColor.

                                l2 add:line2

                            ]

                        ] 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:[