Move internal structures and some functions into diffutils.h

Change-Id: Ia55e556fdb8de3a2aeebf768ad9db66d840766f2
Reviewed-by: Jarek Kobus <jaroslaw.kobus@digia.com>

6 files changed, 463 insertions, 367 deletions

diff --git a/src/plugins/diffeditor/diffeditor.pro b/src/plugins/diffeditor/diffeditor.pro
index 6967772f8d..d015f3d1b4 100644
--- a/src/plugins/diffeditor/diffeditor.pro
+++ b/src/plugins/diffeditor/diffeditor.pro
@@ -11,6 +11,7 @@ HEADERS += diffeditor_global.h \
         diffeditormanager.h \
         diffeditorplugin.h \
         differ.h \
+        diffutils.h \
         sidebysidediffeditorwidget.h
 
 SOURCES += diffeditor.cpp \
@@ -21,6 +22,7 @@ SOURCES += diffeditor.cpp \
         diffeditormanager.cpp \
         diffeditorplugin.cpp \
         differ.cpp \
+        diffutils.cpp \
         sidebysidediffeditorwidget.cpp
 
 RESOURCES +=
diff --git a/src/plugins/diffeditor/diffeditor.qbs b/src/plugins/diffeditor/diffeditor.qbs
index e77f80318e..3ea42e4b79 100644
--- a/src/plugins/diffeditor/diffeditor.qbs
+++ b/src/plugins/diffeditor/diffeditor.qbs
@@ -31,6 +31,8 @@ QtcPlugin {
         "diffeditorplugin.h",
         "differ.cpp",
         "differ.h",
+        "diffutils.cpp",
+        "diffutils.h",
         "sidebysidediffeditorwidget.cpp",
         "sidebysidediffeditorwidget.h",
     ]
diff --git a/src/plugins/diffeditor/diffutils.cpp b/src/plugins/diffeditor/diffutils.cpp
new file mode 100644
index 0000000000..550f2a48ae
--- /dev/null
+++ b/src/plugins/diffeditor/diffutils.cpp
@@ -0,0 +1,351 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "diffutils.h"
+#include "differ.h"
+#include <QStringList>
+
+namespace DiffEditor {
+namespace Internal {
+
+static QList<TextLineData> assemblyRows(const QStringList &lines,
+                                        const QMap<int, int> &lineSpans)
+{
+    QList<TextLineData> data;
+
+    const int lineCount = lines.count();
+    for (int i = 0; i <= lineCount; i++) {
+        for (int j = 0; j < lineSpans.value(i); j++)
+            data.append(TextLineData(TextLineData::Separator));
+        if (i < lineCount)
+            data.append(lines.at(i));
+    }
+    return data;
+}
+
+static bool lastLinesEqual(const QStringList &leftLines,
+                           const QStringList &rightLines)
+{
+    const bool leftLineEqual = leftLines.count()
+            ? leftLines.last().isEmpty()
+            : true;
+    const bool rightLineEqual = rightLines.count()
+            ? rightLines.last().isEmpty()
+            : true;
+    return leftLineEqual && rightLineEqual;
+}
+
+static void handleLine(const QStringList &newLines,
+                       int line,
+                       QStringList *lines,
+                       int *lineNumber,
+                       int *charNumber)
+{
+    if (line < newLines.count()) {
+        const QString text = newLines.at(line);
+        if (lines->isEmpty() || line > 0) {
+            if (line > 0)
+                ++*lineNumber;
+            lines->append(text);
+        } else {
+            lines->last() += text;
+        }
+        *charNumber += text.count();
+    }
+}
+
+static void handleDifference(const QString &text,
+                             QStringList *lines,
+                             QMap<int, int> *changedPositions,
+                             int *lineNumber,
+                             int *charNumber)
+{
+    const int oldPosition = *lineNumber + *charNumber;
+    const QStringList newLeftLines = text.split(QLatin1Char('\n'));
+    for (int line = 0; line < newLeftLines.count(); ++line)
+        handleLine(newLeftLines, line, lines, lineNumber, charNumber);
+    const int newPosition = *lineNumber + *charNumber;
+    changedPositions->insert(oldPosition, newPosition);
+}
+
+/*
+ * leftDiffList can contain only deletions and equalities,
+ * while rightDiffList can contain only insertions and equalities.
+ * The number of equalities on both lists must be the same.
+*/
+ChunkData calculateOriginalData(const QList<Diff> &leftDiffList,
+                                const QList<Diff> &rightDiffList)
+{
+    ChunkData chunkData;
+
+    int i = 0;
+    int j = 0;
+
+    QStringList leftLines;
+    QStringList rightLines;
+
+    // <line number, span count>
+    QMap<int, int> leftSpans;
+    QMap<int, int> rightSpans;
+    // <left line number, right line number>
+    QMap<int, int> equalLines;
+
+    int leftLineNumber = 0;
+    int rightLineNumber = 0;
+    int leftCharNumber = 0;
+    int rightCharNumber = 0;
+    int leftLineAligned = -1;
+    int rightLineAligned = -1;
+    bool lastLineEqual = true;
+
+    while (i <= leftDiffList.count() && j <= rightDiffList.count()) {
+        const Diff leftDiff = i < leftDiffList.count()
+                ? leftDiffList.at(i)
+                : Diff(Diff::Equal);
+        const Diff rightDiff = j < rightDiffList.count()
+                ? rightDiffList.at(j)
+                : Diff(Diff::Equal);
+
+        if (leftDiff.command == Diff::Delete) {
+            // process delete
+            handleDifference(leftDiff.text, &leftLines, &chunkData.changedLeftPositions, &leftLineNumber, &leftCharNumber);
+            lastLineEqual = lastLinesEqual(leftLines, rightLines);
+            i++;
+        }
+        if (rightDiff.command == Diff::Insert) {
+            // process insert
+            handleDifference(rightDiff.text, &rightLines, &chunkData.changedRightPositions, &rightLineNumber, &rightCharNumber);
+            lastLineEqual = lastLinesEqual(leftLines, rightLines);
+            j++;
+        }
+        if (leftDiff.command == Diff::Equal && rightDiff.command == Diff::Equal) {
+            // process equal
+            const QStringList newLeftLines = leftDiff.text.split(QLatin1Char('\n'));
+            const QStringList newRightLines = rightDiff.text.split(QLatin1Char('\n'));
+
+            int line = 0;
+
+            while (line < qMax(newLeftLines.count(), newRightLines.count())) {
+                handleLine(newLeftLines, line, &leftLines, &leftLineNumber, &leftCharNumber);
+                handleLine(newRightLines, line, &rightLines, &rightLineNumber, &rightCharNumber);
+
+                const int commonLineCount = qMin(newLeftLines.count(), newRightLines.count());
+                if (line < commonLineCount) {
+                    // try to align
+                    const int leftDifference = leftLineNumber - leftLineAligned;
+                    const int rightDifference = rightLineNumber - rightLineAligned;
+
+                    if (leftDifference && rightDifference) {
+                        bool doAlign = true;
+                        if (line == 0 // omit alignment when first lines of equalities are empty
+                                && (newLeftLines.at(0).isEmpty() || newRightLines.at(0).isEmpty())) {
+                            doAlign = false;
+                        }
+
+                        if (line == commonLineCount - 1) {
+                            // omit alignment when last lines of equalities are empty
+                            if (leftLines.last().isEmpty() || rightLines.last().isEmpty())
+                                doAlign = false;
+
+                            // unless it's the last dummy line (don't omit in that case)
+                            if (i == leftDiffList.count() && j == rightDiffList.count())
+                                doAlign = true;
+                        }
+
+                        if (doAlign) {
+                            // align here
+                            leftLineAligned = leftLineNumber;
+                            rightLineAligned = rightLineNumber;
+
+                            // insert separators if needed
+                            if (rightDifference > leftDifference)
+                                leftSpans.insert(leftLineNumber, rightDifference - leftDifference);
+                            else if (leftDifference > rightDifference)
+                                rightSpans.insert(rightLineNumber, leftDifference - rightDifference);
+                        }
+                    }
+                }
+
+                // check if lines are equal
+                if ((line < commonLineCount - 1) // before the last common line in equality
+                        || (line == commonLineCount - 1 // or the last common line in equality
+                            && i == leftDiffList.count() // and it's the last iteration
+                            && j == rightDiffList.count())) {
+                    if (line > 0 || lastLineEqual)
+                        equalLines.insert(leftLineNumber, rightLineNumber);
+                }
+
+                if (line > 0)
+                    lastLineEqual = true;
+
+                line++;
+            }
+            i++;
+            j++;
+        }
+    }
+
+    QList<TextLineData> leftData = assemblyRows(leftLines,
+                                                leftSpans);
+    QList<TextLineData> rightData = assemblyRows(rightLines,
+                                                 rightSpans);
+
+    // fill ending separators
+    for (int i = leftData.count(); i < rightData.count(); i++)
+        leftData.append(TextLineData(TextLineData::Separator));
+    for (int i = rightData.count(); i < leftData.count(); i++)
+        rightData.append(TextLineData(TextLineData::Separator));
+
+    const int visualLineCount = leftData.count();
+    int leftLine = -1;
+    int rightLine = -1;
+    for (int i = 0; i < visualLineCount; i++) {
+        const TextLineData &leftTextLine = leftData.at(i);
+        const TextLineData &rightTextLine = rightData.at(i);
+        RowData row(leftTextLine, rightTextLine);
+
+        if (leftTextLine.textLineType == TextLineData::TextLine)
+            ++leftLine;
+        if (rightTextLine.textLineType == TextLineData::TextLine)
+            ++rightLine;
+        if (equalLines.value(leftLine, -1) == rightLine)
+            row.equal = true;
+
+        chunkData.rows.append(row);
+    }
+    return chunkData;
+}
+
+FileData calculateContextData(const ChunkData &originalData, int contextLinesNumber)
+{
+    if (contextLinesNumber < 0)
+        return FileData(originalData);
+
+    const int joinChunkThreshold = 1;
+
+    FileData fileData;
+    QMap<int, bool> hiddenRows;
+    int i = 0;
+    while (i < originalData.rows.count()) {
+        const RowData &row = originalData.rows[i];
+        if (row.equal) {
+            // count how many equal
+            int equalRowStart = i;
+            i++;
+            while (i < originalData.rows.count()) {
+                const RowData originalRow = originalData.rows.at(i);
+                if (!originalRow.equal)
+                    break;
+                i++;
+            }
+            const bool first = equalRowStart == 0; // includes first line?
+            const bool last = i == originalData.rows.count(); // includes last line?
+
+            const int firstLine = first ? 0 : equalRowStart + contextLinesNumber;
+            const int lastLine = last ? originalData.rows.count() : i - contextLinesNumber;
+
+            if (firstLine < lastLine - joinChunkThreshold) {
+                for (int j = firstLine; j < lastLine; j++) {
+                    hiddenRows.insert(j, true);
+                }
+            }
+        } else {
+            // iterate to the next row
+            i++;
+        }
+    }
+    i = 0;
+    int leftCharCounter = 0;
+    int rightCharCounter = 0;
+    QMap<int, int>::ConstIterator leftChangedIt = originalData.changedLeftPositions.constBegin();
+    QMap<int, int>::ConstIterator rightChangedIt = originalData.changedRightPositions.constBegin();
+    const QMap<int, int>::ConstIterator leftChangedItEnd = originalData.changedLeftPositions.constEnd();
+    const QMap<int, int>::ConstIterator rightChangedItEnd = originalData.changedRightPositions.constEnd();
+    while (i < originalData.rows.count()) {
+        if (!hiddenRows.contains(i)) {
+            ChunkData chunkData;
+            int leftOffset = leftCharCounter;
+            int rightOffset = rightCharCounter;
+            chunkData.contextChunk = false;
+            while (i < originalData.rows.count()) {
+                if (hiddenRows.contains(i))
+                    break;
+                RowData rowData = originalData.rows.at(i);
+                chunkData.rows.append(rowData);
+
+                if (rowData.leftLine.textLineType == TextLineData::TextLine)
+                    leftCharCounter += rowData.leftLine.text.count() + 1; // +1 for '\n'
+                if (rowData.rightLine.textLineType == TextLineData::TextLine)
+                    rightCharCounter += rowData.rightLine.text.count() + 1; // +1 for '\n'
+                i++;
+            }
+            while (leftChangedIt != leftChangedItEnd) {
+                if (leftChangedIt.key() < leftOffset
+                        || leftChangedIt.key() > leftCharCounter)
+                    break;
+
+                const int startPos = leftChangedIt.key();
+                const int endPos = leftChangedIt.value();
+                chunkData.changedLeftPositions.insert(startPos - leftOffset, endPos - leftOffset);
+                leftChangedIt++;
+            }
+            while (rightChangedIt != rightChangedItEnd) {
+                if (rightChangedIt.key() < rightOffset
+                        || rightChangedIt.key() > rightCharCounter)
+                    break;
+
+                const int startPos = rightChangedIt.key();
+                const int endPos = rightChangedIt.value();
+                chunkData.changedRightPositions.insert(startPos - rightOffset, endPos - rightOffset);
+                rightChangedIt++;
+            }
+            fileData.chunks.append(chunkData);
+        } else {
+            ChunkData chunkData;
+            chunkData.contextChunk = true;
+            while (i < originalData.rows.count()) {
+                if (!hiddenRows.contains(i))
+                    break;
+                RowData rowData = originalData.rows.at(i);
+                chunkData.rows.append(rowData);
+
+                if (rowData.leftLine.textLineType == TextLineData::TextLine)
+                    leftCharCounter += rowData.leftLine.text.count() + 1; // +1 for '\n'
+                if (rowData.rightLine.textLineType == TextLineData::TextLine)
+                    rightCharCounter += rowData.rightLine.text.count() + 1; // +1 for '\n'
+                i++;
+            }
+            fileData.chunks.append(chunkData);
+        }
+    }
+    return fileData;
+}
+
+} // namespace Internal
+} // namespace DiffEditor
diff --git a/src/plugins/diffeditor/diffutils.h b/src/plugins/diffeditor/diffutils.h
new file mode 100644
index 0000000000..5d252d7eb8
--- /dev/null
+++ b/src/plugins/diffeditor/diffutils.h
@@ -0,0 +1,96 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#ifndef DIFFUTILS_H
+#define DIFFUTILS_H
+
+#include <QString>
+#include <QMap>
+#include "diffeditorcontroller.h"
+
+namespace DiffEditor {
+
+class Diff;
+
+namespace Internal {
+
+class TextLineData {
+public:
+    enum TextLineType {
+        TextLine,
+        Separator,
+        Invalid
+    };
+    TextLineData() : textLineType(Invalid) {}
+    TextLineData(const QString &txt) : textLineType(TextLine), text(txt) {}
+    TextLineData(TextLineType t) : textLineType(t) {}
+    TextLineType textLineType;
+    QString text;
+};
+
+class RowData {
+public:
+    RowData() : equal(false) {}
+    RowData(const TextLineData &l)
+        : leftLine(l), rightLine(l), equal(true) {}
+    RowData(const TextLineData &l, const TextLineData &r)
+        : leftLine(l), rightLine(r), equal(false) {}
+    TextLineData leftLine;
+    TextLineData rightLine;
+    bool equal;
+};
+
+class ChunkData {
+public:
+    ChunkData() : contextChunk(false) {}
+    QList<RowData> rows;
+    bool contextChunk;
+    // start position, end position, TextLineData::Separator lines not taken into account
+    QMap<int, int> changedLeftPositions; // counting from the beginning of the chunk
+    QMap<int, int> changedRightPositions; // counting from the beginning of the chunk
+};
+
+class FileData {
+public:
+    FileData() {}
+    FileData(const ChunkData &chunkData) { chunks.append(chunkData); }
+    QList<ChunkData> chunks;
+    DiffEditorController::DiffFileInfo leftFileInfo;
+    DiffEditorController::DiffFileInfo rightFileInfo;
+};
+
+ChunkData calculateOriginalData(const QList<Diff> &leftDiffList,
+                                const QList<Diff> &rightDiffList);
+FileData calculateContextData(const ChunkData &originalData,
+                              int contextLinesNumber);
+
+} // namespace Internal
+} // namespace DiffEditor
+
+#endif // DIFFUTILS_H
diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
index e64fb83c59..b6d62df7e1 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
@@ -29,6 +29,7 @@
 
 #include "sidebysidediffeditorwidget.h"
 #include "diffeditorguicontroller.h"
+#include "diffutils.h"
 
 #include <QPlainTextEdit>
 #include <QVBoxLayout>
@@ -66,260 +67,7 @@ using namespace TextEditor;
 
 namespace DiffEditor {
 
-class TextLineData {
-public:
-    enum TextLineType {
-        TextLine,
-        Separator,
-        Invalid
-    };
-    TextLineData() : textLineType(Invalid) {}
-    TextLineData(const QString &txt) : textLineType(TextLine), text(txt) {}
-    TextLineData(TextLineType t) : textLineType(t) {}
-    TextLineType textLineType;
-    QString text;
-};
-
-class RowData {
-public:
-    RowData() : equal(false) {}
-    RowData(const TextLineData &l)
-        : leftLine(l), rightLine(l), equal(true) {}
-    RowData(const TextLineData &l, const TextLineData &r)
-        : leftLine(l), rightLine(r), equal(false) {}
-    TextLineData leftLine;
-    TextLineData rightLine;
-    bool equal;
-};
-
-class ChunkData {
-public:
-    ChunkData() : contextChunk(false) {}
-    QList<RowData> rows;
-    bool contextChunk;
-    // start position, end position, TextLineData::Separator lines not taken into account
-    QMap<int, int> changedLeftPositions; // counting from the beginning of the chunk
-    QMap<int, int> changedRightPositions; // counting from the beginning of the chunk
-};
-
-class FileData {
-public:
-    FileData() {}
-    FileData(const ChunkData &chunkData) { chunks.append(chunkData); }
-    QList<ChunkData> chunks;
-    DiffEditorController::DiffFileInfo leftFileInfo;
-    DiffEditorController::DiffFileInfo rightFileInfo;
-};
-
-//////////////////////
-
-static QList<TextLineData> assemblyRows(const QStringList &lines,
-                                        const QMap<int, int> &lineSpans)
-{
-    QList<TextLineData> data;
-
-    const int lineCount = lines.count();
-    for (int i = 0; i <= lineCount; i++) {
-        for (int j = 0; j < lineSpans.value(i); j++)
-            data.append(TextLineData(TextLineData::Separator));
-        if (i < lineCount)
-            data.append(lines.at(i));
-    }
-    return data;
-}
-
-static void handleLine(const QStringList &newLines,
-                       int line,
-                       QStringList *lines,
-                       int *lineNumber,
-                       int *charNumber)
-{
-    if (line < newLines.count()) {
-        const QString text = newLines.at(line);
-        if (lines->isEmpty() || line > 0) {
-            if (line > 0)
-                ++*lineNumber;
-            lines->append(text);
-        } else {
-            lines->last() += text;
-        }
-        *charNumber += text.count();
-    }
-}
-
-static void handleDifference(const QString &text,
-                             QStringList *lines,
-                             QMap<int, int> *changedPositions,
-                             int *lineNumber,
-                             int *charNumber)
-{
-    const int oldPosition = *lineNumber + *charNumber;
-    const QStringList newLeftLines = text.split(QLatin1Char('\n'));
-    for (int line = 0; line < newLeftLines.count(); ++line)
-        handleLine(newLeftLines, line, lines, lineNumber, charNumber);
-    const int newPosition = *lineNumber + *charNumber;
-    changedPositions->insert(oldPosition, newPosition);
-}
-
-static bool lastLinesEqual(const QStringList &leftLines,
-                           const QStringList &rightLines)
-{
-    const bool leftLineEqual = leftLines.count()
-            ? leftLines.last().isEmpty()
-            : true;
-    const bool rightLineEqual = rightLines.count()
-            ? rightLines.last().isEmpty()
-            : true;
-    return leftLineEqual && rightLineEqual;
-}
-
-/*
- * leftDiffList can contain only deletions and equalities,
- * while rightDiffList can contain only insertions and equalities.
- * The number of equalities on both lists must be the same.
-*/
-static ChunkData calculateOriginalData(const QList<Diff> &leftDiffList,
-                                       const QList<Diff> &rightDiffList)
-{
-    ChunkData chunkData;
-
-    int i = 0;
-    int j = 0;
-
-    QStringList leftLines;
-    QStringList rightLines;
-
-    // <line number, span count>
-    QMap<int, int> leftSpans;
-    QMap<int, int> rightSpans;
-    // <left line number, right line number>
-    QMap<int, int> equalLines;
-
-    int leftLineNumber = 0;
-    int rightLineNumber = 0;
-    int leftCharNumber = 0;
-    int rightCharNumber = 0;
-    int leftLineAligned = -1;
-    int rightLineAligned = -1;
-    bool lastLineEqual = true;
-
-    while (i <= leftDiffList.count() && j <= rightDiffList.count()) {
-        const Diff leftDiff = i < leftDiffList.count()
-                ? leftDiffList.at(i)
-                : Diff(Diff::Equal);
-        const Diff rightDiff = j < rightDiffList.count()
-                ? rightDiffList.at(j)
-                : Diff(Diff::Equal);
-
-        if (leftDiff.command == Diff::Delete) {
-            // process delete
-            handleDifference(leftDiff.text, &leftLines, &chunkData.changedLeftPositions, &leftLineNumber, &leftCharNumber);
-            lastLineEqual = lastLinesEqual(leftLines, rightLines);
-            i++;
-        }
-        if (rightDiff.command == Diff::Insert) {
-            // process insert
-            handleDifference(rightDiff.text, &rightLines, &chunkData.changedRightPositions, &rightLineNumber, &rightCharNumber);
-            lastLineEqual = lastLinesEqual(leftLines, rightLines);
-            j++;
-        }
-        if (leftDiff.command == Diff::Equal && rightDiff.command == Diff::Equal) {
-            // process equal
-            const QStringList newLeftLines = leftDiff.text.split(QLatin1Char('\n'));
-            const QStringList newRightLines = rightDiff.text.split(QLatin1Char('\n'));
-
-            int line = 0;
-
-            while (line < qMax(newLeftLines.count(), newRightLines.count())) {
-                handleLine(newLeftLines, line, &leftLines, &leftLineNumber, &leftCharNumber);
-                handleLine(newRightLines, line, &rightLines, &rightLineNumber, &rightCharNumber);
-
-                const int commonLineCount = qMin(newLeftLines.count(), newRightLines.count());
-                if (line < commonLineCount) {
-                    // try to align
-                    const int leftDifference = leftLineNumber - leftLineAligned;
-                    const int rightDifference = rightLineNumber - rightLineAligned;
-
-                    if (leftDifference && rightDifference) {
-                        bool doAlign = true;
-                        if (line == 0 // omit alignment when first lines of equalities are empty
-                                && (newLeftLines.at(0).isEmpty() || newRightLines.at(0).isEmpty())) {
-                            doAlign = false;
-                        }
-
-                        if (line == commonLineCount - 1) {
-                            // omit alignment when last lines of equalities are empty
-                            if (leftLines.last().isEmpty() || rightLines.last().isEmpty())
-                                doAlign = false;
-
-                            // unless it's the last dummy line (don't omit in that case)
-                            if (i == leftDiffList.count() && j == rightDiffList.count())
-                                doAlign = true;
-                        }
-
-                        if (doAlign) {
-                            // align here
-                            leftLineAligned = leftLineNumber;
-                            rightLineAligned = rightLineNumber;
-
-                            // insert separators if needed
-                            if (rightDifference > leftDifference)
-                                leftSpans.insert(leftLineNumber, rightDifference - leftDifference);
-                            else if (leftDifference > rightDifference)
-                                rightSpans.insert(rightLineNumber, leftDifference - rightDifference);
-                        }
-                    }
-                }
-
-                // check if lines are equal
-                if ((line < commonLineCount - 1) // before the last common line in equality
-                        || (line == commonLineCount - 1 // or the last common line in equality
-                            && i == leftDiffList.count() // and it's the last iteration
-                            && j == rightDiffList.count())) {
-                    if (line > 0 || lastLineEqual)
-                        equalLines.insert(leftLineNumber, rightLineNumber);
-                }
-
-                if (line > 0)
-                    lastLineEqual = true;
-
-                line++;
-            }
-            i++;
-            j++;
-        }
-    }
-
-    QList<TextLineData> leftData = assemblyRows(leftLines,
-                                                leftSpans);
-    QList<TextLineData> rightData = assemblyRows(rightLines,
-                                                 rightSpans);
-
-    // fill ending separators
-    for (int i = leftData.count(); i < rightData.count(); i++)
-        leftData.append(TextLineData(TextLineData::Separator));
-    for (int i = rightData.count(); i < leftData.count(); i++)
-        rightData.append(TextLineData(TextLineData::Separator));
-
-    const int visualLineCount = leftData.count();
-    int leftLine = -1;
-    int rightLine = -1;
-    for (int i = 0; i < visualLineCount; i++) {
-        const TextLineData &leftTextLine = leftData.at(i);
-        const TextLineData &rightTextLine = rightData.at(i);
-        RowData row(leftTextLine, rightTextLine);
-
-        if (leftTextLine.textLineType == TextLineData::TextLine)
-            ++leftLine;
-        if (rightTextLine.textLineType == TextLineData::TextLine)
-            ++rightLine;
-        if (equalLines.value(leftLine, -1) == rightLine)
-            row.equal = true;
-
-        chunkData.rows.append(row);
-    }
-    return chunkData;
-}
+using namespace Internal;
 
 //////////////////////
 
@@ -1076,6 +824,7 @@ void SideBySideDiffEditorWidget::setDiff(const QList<DiffList> &diffList)
     m_diffList = diffList;
     m_originalChunkData.clear();
     m_contextFileData.clear();
+    const int contextLinesNumber = m_guiController ? m_guiController->contextLinesNumber() : 3;
 
     for (int i = 0; i < m_diffList.count(); i++) {
         const DiffList &dl = m_diffList.at(i);
@@ -1084,7 +833,7 @@ void SideBySideDiffEditorWidget::setDiff(const QList<DiffList> &diffList)
         handleWhitespaces(dl.diffList, &leftDiffs, &rightDiffs);
         ChunkData chunkData = calculateOriginalData(leftDiffs, rightDiffs);
         m_originalChunkData.append(chunkData);
-        FileData fileData = calculateContextData(chunkData);
+        FileData fileData = calculateContextData(chunkData, contextLinesNumber);
         fileData.leftFileInfo = dl.leftFileInfo;
         fileData.rightFileInfo = dl.rightFileInfo;
         m_contextFileData.append(fileData);
@@ -1110,10 +859,11 @@ void SideBySideDiffEditorWidget::handleWhitespaces(const QList<Diff> &input,
 void SideBySideDiffEditorWidget::setContextLinesNumber(int lines)
 {
     Q_UNUSED(lines)
+    const int contextLinesNumber = m_guiController ? m_guiController->contextLinesNumber() : 3;
 
     for (int i = 0; i < m_contextFileData.count(); i++) {
         const FileData oldFileData = m_contextFileData.at(i);
-        FileData newFileData = calculateContextData(m_originalChunkData.at(i));
+        FileData newFileData = calculateContextData(m_originalChunkData.at(i), contextLinesNumber);
         newFileData.leftFileInfo = oldFileData.leftFileInfo;
         newFileData.rightFileInfo = oldFileData.rightFileInfo;
         m_contextFileData[i] = newFileData;
@@ -1147,112 +897,6 @@ void SideBySideDiffEditorWidget::setCurrentDiffFileIndex(int diffFileIndex)
     m_rightEditor->centerCursor();
 }
 
-FileData SideBySideDiffEditorWidget::calculateContextData(const ChunkData &originalData) const
-{
-    const int contextLinesNumber = m_guiController ? m_guiController->contextLinesNumber() : 3;
-    if (contextLinesNumber < 0)
-        return FileData(originalData);
-
-    const int joinChunkThreshold = 1;
-
-    FileData fileData;
-    QMap<int, bool> hiddenRows;
-    int i = 0;
-    while (i < originalData.rows.count()) {
-        const RowData &row = originalData.rows[i];
-        if (row.equal) {
-            // count how many equal
-            int equalRowStart = i;
-            i++;
-            while (i < originalData.rows.count()) {
-                const RowData originalRow = originalData.rows.at(i);
-                if (!originalRow.equal)
-                    break;
-                i++;
-            }
-            const bool first = equalRowStart == 0; // includes first line?
-            const bool last = i == originalData.rows.count(); // includes last line?
-
-            const int firstLine = first ? 0 : equalRowStart + contextLinesNumber;
-            const int lastLine = last ? originalData.rows.count() : i - contextLinesNumber;
-
-            if (firstLine < lastLine - joinChunkThreshold) {
-                for (int j = firstLine; j < lastLine; j++) {
-                    hiddenRows.insert(j, true);
-                }
-            }
-        } else {
-            // iterate to the next row
-            i++;
-        }
-    }
-    i = 0;
-    int leftCharCounter = 0;
-    int rightCharCounter = 0;
-    QMap<int, int>::ConstIterator leftChangedIt = originalData.changedLeftPositions.constBegin();
-    QMap<int, int>::ConstIterator rightChangedIt = originalData.changedRightPositions.constBegin();
-    const QMap<int, int>::ConstIterator leftChangedItEnd = originalData.changedLeftPositions.constEnd();
-    const QMap<int, int>::ConstIterator rightChangedItEnd = originalData.changedRightPositions.constEnd();
-    while (i < originalData.rows.count()) {
-        if (!hiddenRows.contains(i)) {
-            ChunkData chunkData;
-            int leftOffset = leftCharCounter;
-            int rightOffset = rightCharCounter;
-            chunkData.contextChunk = false;
-            while (i < originalData.rows.count()) {
-                if (hiddenRows.contains(i))
-                    break;
-                RowData rowData = originalData.rows.at(i);
-                chunkData.rows.append(rowData);
-
-                if (rowData.leftLine.textLineType == TextLineData::TextLine)
-                    leftCharCounter += rowData.leftLine.text.count() + 1; // +1 for '\n'
-                if (rowData.rightLine.textLineType == TextLineData::TextLine)
-                    rightCharCounter += rowData.rightLine.text.count() + 1; // +1 for '\n'
-                i++;
-            }
-            while (leftChangedIt != leftChangedItEnd) {
-                if (leftChangedIt.key() < leftOffset
-                        || leftChangedIt.key() > leftCharCounter)
-                    break;
-
-                const int startPos = leftChangedIt.key();
-                const int endPos = leftChangedIt.value();
-                chunkData.changedLeftPositions.insert(startPos - leftOffset, endPos - leftOffset);
-                leftChangedIt++;
-            }
-            while (rightChangedIt != rightChangedItEnd) {
-                if (rightChangedIt.key() < rightOffset
-                        || rightChangedIt.key() > rightCharCounter)
-                    break;
-
-                const int startPos = rightChangedIt.key();
-                const int endPos = rightChangedIt.value();
-                chunkData.changedRightPositions.insert(startPos - rightOffset, endPos - rightOffset);
-                rightChangedIt++;
-            }
-            fileData.chunks.append(chunkData);
-        } else {
-            ChunkData chunkData;
-            chunkData.contextChunk = true;
-            while (i < originalData.rows.count()) {
-                if (!hiddenRows.contains(i))
-                    break;
-                RowData rowData = originalData.rows.at(i);
-                chunkData.rows.append(rowData);
-
-                if (rowData.leftLine.textLineType == TextLineData::TextLine)
-                    leftCharCounter += rowData.leftLine.text.count() + 1; // +1 for '\n'
-                if (rowData.rightLine.textLineType == TextLineData::TextLine)
-                    rightCharCounter += rowData.rightLine.text.count() + 1; // +1 for '\n'
-                i++;
-            }
-            fileData.chunks.append(chunkData);
-        }
-    }
-    return fileData;
-}
-
 void SideBySideDiffEditorWidget::showDiff()
 {
     // TODO: remember the line number of the line in the middle
diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.h b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
index cf7cbbd884..ae05759957 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.h
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
@@ -46,11 +46,13 @@ QT_END_NAMESPACE
 
 
 namespace DiffEditor {
-
 class DiffEditorGuiController;
 class SideDiffEditorWidget;
+
+namespace Internal {
 class ChunkData;
 class FileData;
+}
 
 class DIFFEDITOR_EXPORT SideBySideDiffEditorWidget : public QWidget
 {
@@ -101,8 +103,7 @@ private:
     QList<QTextEdit::ExtraSelection> colorPositions(const QTextCharFormat &format,
             QTextCursor &cursor,
             const QMap<int, int> &positions) const;
-    void colorDiff(const QList<FileData> &fileDataList);
-    FileData calculateContextData(const ChunkData &originalData) const;
+    void colorDiff(const QList<Internal::FileData> &fileDataList);
     void showDiff();
     void synchronizeFoldings(SideDiffEditorWidget *source, SideDiffEditorWidget *destination);
     void jumpToOriginalFile(const QString &fileName, int lineNumber, int columnNumber);
@@ -114,8 +115,8 @@ private:
     QSplitter *m_splitter;
 
     QList<DiffList> m_diffList; // list of original outputs from differ
-    QList<ChunkData> m_originalChunkData; // one big chunk for every file, ignoreWhitespace taken into account
-    QList<FileData> m_contextFileData; // ultimate data to be shown, contextLinesNumber taken into account
+    QList<Internal::ChunkData> m_originalChunkData; // one big chunk for every file, ignoreWhitespace taken into account
+    QList<Internal::FileData> m_contextFileData; // ultimate data to be shown, contextLinesNumber taken into account
 
     bool m_foldingBlocker;
     QString m_source;