TextDifferencer Class Reference

#include <Tools/Widgets/textdifferencer.h>

Public Member Functions
	TextDifferencer ()
void	cleanupEfficiency (QList< TextDifference > &diffs)
void	cleanupMerge (QList< TextDifference > &diffs)
void	cleanupSemantic (QList< TextDifference > &diffs)
void	cleanupSemanticLossless (QList< TextDifference > &diffs)
int	findCommonPrefix (const QString &text1, const QString &text2)
int	findCommonSuffix (const QString &text1, const QString &text2)
QList< TextDifference >	findDifferences (const QString &text1, const QString &text2)
QList< TextDifference >	findDifferences (const QString &text1, const QString &text2, bool checklines)

Static Public Member Functions
static QMap< int, StringHighlights >	compareLines (int keyA, int keyB, const QString &stringA, const QString &stringB)

Public Attributes
short	diffEditCost_
float	diffTimeout_

Protected Member Functions
QList< TextDifference >	bisect (const QString &text1, const QString &text2, clock_t deadline)
int	findCommonOverlap (const QString &text1, const QString &text2)
QStringList	halfMatch (const QString &text1, const QString &text2)
QList< QVariant >	linesToChars (const QString &text1, const QString &text2)

Constructor & Destructor Documentation

TextDifferencer()

TextDifferencer

(

)

Member Function Documentation

bisect()

QList< TextDifference > bisect ( const QString &  text1, const QString &  text2, clock_t  deadline  )

protected

Find the 'middle snake' of a diff, split the problem in two and return the recursively constructed diff. See Myers 1986 paper: An O(ND) Difference Algorithm and Its Variations.

Parameters

text1	Old string to be diffed.
text2	New string to be diffed.
deadline	Operation returns if this time is reached (comparison with clock()>deadline)

Returns

List of TextDifference objects.

cleanupEfficiency()

void cleanupEfficiency

(

QList< TextDifference > &

diffs

)

Reduce the number of edits by eliminating operationally trivial equalities.

Parameters

diffs

LinkedList of Diff objects.

cleanupMerge()

void cleanupMerge

(

QList< TextDifference > &

diffs

)

Reorder and merge like edit sections. Merge equalities. Any edit section can move as long as it doesn't cross an equality.

Parameters

diffs

LinkedList of Diff objects.

cleanupSemantic()

void cleanupSemantic

(

QList< TextDifference > &

diffs

)

Reduce the number of edits by eliminating semantically trivial equalities.

Parameters

diffs

List of TextDifference objects.

cleanupSemanticLossless()

void cleanupSemanticLossless

(

QList< TextDifference > &

diffs

)

compareLines()

QMap< int, StringHighlights > compareLines ( int  keyA, int  keyB, const QString &  stringA, const QString &  stringB  )

static

findCommonOverlap()

int findCommonOverlap ( const QString &  text1, const QString &  text2  )

protected

Determine if the suffix of one string is the prefix of another.

Parameters

text1	First string.
text2	Second string.

Returns

The number of characters common to the end of the first string and the start of the second string.

findCommonPrefix()

int findCommonPrefix	(	const QString &	text1,
		const QString &	text2
	)

Determine the common prefix of two strings.

Parameters

text1	First string.
text2	Second string.

Returns

The number of characters common to the start of each string.

findCommonSuffix()

int findCommonSuffix	(	const QString &	text1,
		const QString &	text2
	)

Determine the common suffix of two strings.

Parameters

text1	First string.
text2	Second string.

Returns

The number of characters common to the end of each string.

findDifferences() [1/2]

QList< TextDifference > findDifferences	(	const QString &	text1,
		const QString &	text2
	)

Find the differences between two texts. Run a faster slightly less optimal diff. This method allows the 'checklines' of diff_main() to be optional. Most of the time checklines is wanted, so default to true.

Parameters

text1	Old string to be diffed.
text2	New string to be diffed.

Returns

List of TextDifference objects.

findDifferences() [2/2]

QList< TextDifference > findDifferences	(	const QString &	text1,
		const QString &	text2,
		bool	checklines
	)

Find the differences between two texts.

Parameters

text1	Old string to be diffed.
text2	New string to be diffed.
checklines	Speedup flag. If false, then don't run a line -level diff first to identify the changed areas. If true, then run a faster slightly less optimal diff.

Returns

List of TextDifference objects.

halfMatch()

QStringList halfMatch ( const QString &  text1, const QString &  text2  )

protected

Do the two texts share a substring which is at least half the length of the longer text? This speedup can produce non-minimal diffs.

Parameters

text1	First string.
text2	Second string.

Returns

Five element String array, containing the prefix of text1, the suffix of text1, the prefix of text2, the suffix of text2 and the common middle. Or null if there was no match.

linesToChars()

QList< QVariant > linesToChars ( const QString &  text1, const QString &  text2  )

protected

Split two texts into a list of strings. Reduce the texts to a string of hashes where each Unicode character represents one line.

Parameters

text1	First string.
text2	Second string.

Returns

Three element Object array, containing the encoded text1, the encoded text2 and the List of unique strings. The zeroth element of the List of unique strings is intentionally blank.

Member Data Documentation

diffEditCost_

short diffEditCost_

diffTimeout_

float diffTimeout_