DiffEditor: refactor loops and const correctness

Change-Id: I21af8db55ff5a012de04b4934de1940babf75058
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

5 files changed, 98 insertions, 150 deletions

diff --git a/src/plugins/diffeditor/diffeditor.cpp b/src/plugins/diffeditor/diffeditor.cpp
index 3b68137616..381813a683 100644
--- a/src/plugins/diffeditor/diffeditor.cpp
+++ b/src/plugins/diffeditor/diffeditor.cpp
@@ -390,16 +390,15 @@ TextEditorWidget *DiffEditor::rightEditorWidget() const
 void DiffEditor::documentHasChanged()
 {
     Utils::GuardLocker guard(m_ignoreChanges);
-    const QList<FileData> diffFileList = m_document->diffFiles();
+    const QList<FileData> &diffFileList = m_document->diffFiles();
 
     updateDescription();
     currentView()->setDiff(diffFileList, m_document->baseDirectory());
 
     m_entriesComboBox->clear();
-    const int count = diffFileList.count();
-    for (int i = 0; i < count; i++) {
-        const DiffFileInfo leftEntry = diffFileList.at(i).leftFileInfo;
-        const DiffFileInfo rightEntry = diffFileList.at(i).rightFileInfo;
+    for (const FileData &diffFile : diffFileList) {
+        const DiffFileInfo &leftEntry = diffFile.leftFileInfo;
+        const DiffFileInfo &rightEntry = diffFile.rightFileInfo;
         const QString leftShortFileName = Utils::FileName::fromString(leftEntry.fileName).fileName();
         const QString rightShortFileName = Utils::FileName::fromString(rightEntry.fileName).fileName();
         QString itemText;
@@ -528,11 +527,12 @@ void DiffEditor::reloadHasFinished(bool success)
 
     int index = -1;
     const QString startupFile = m_document->startupFile();
-    const QList<FileData> diffFileList = m_document->diffFiles();
+    const QList<FileData> &diffFileList = m_document->diffFiles();
     const int count = diffFileList.count();
     for (int i = 0; i < count; i++) {
-        const DiffFileInfo leftEntry = diffFileList.at(i).leftFileInfo;
-        const DiffFileInfo rightEntry = diffFileList.at(i).rightFileInfo;
+        const FileData &diffFile = diffFileList.at(i);
+        const DiffFileInfo &leftEntry = diffFile.leftFileInfo;
+        const DiffFileInfo &rightEntry = diffFile.rightFileInfo;
         if ((m_currentFileChunk.first.isEmpty()
              && m_currentFileChunk.second.isEmpty()
              && startupFile.endsWith(rightEntry.fileName))
diff --git a/src/plugins/diffeditor/differ.cpp b/src/plugins/diffeditor/differ.cpp
index ca5d912992..63a0014d37 100644
--- a/src/plugins/diffeditor/differ.cpp
+++ b/src/plugins/diffeditor/differ.cpp
@@ -85,16 +85,14 @@ static int commonOverlap(const QString &text1, const QString &text2)
     return 0;
 }
 
-static QList<Diff> decode(const QList<Diff> &diffList,
-                                  const QStringList &lines)
+static QList<Diff> decode(const QList<Diff> &diffList, const QStringList &lines)
 {
     QList<Diff> newDiffList;
     newDiffList.reserve(diffList.count());
-    for (int i = 0; i < diffList.count(); i++) {
-        Diff diff = diffList.at(i);
+    for (Diff diff : diffList) {
         QString text;
-        for (int j = 0; j < diff.text.count(); j++) {
-            const int idx = static_cast<ushort>(diff.text.at(j).unicode());
+        for (QChar c : diff.text) {
+            const int idx = static_cast<ushort>(c.unicode());
             text += lines.value(idx);
         }
         diff.text = text;
@@ -170,7 +168,7 @@ static QList<Diff> cleanupOverlaps(const QList<Diff> &diffList)
                 if (delInsOverlap > thisDiff.text.count() / 2
                         || delInsOverlap > nextDiff.text.count() / 2) {
                     thisDiff.text = thisDiff.text.left(thisDiff.text.count() - delInsOverlap);
-                    Diff equality = Diff(Diff::Equal, nextDiff.text.left(delInsOverlap));
+                    const Diff equality(Diff::Equal, nextDiff.text.left(delInsOverlap));
                     nextDiff.text = nextDiff.text.mid(delInsOverlap);
                     newDiffList.append(thisDiff);
                     newDiffList.append(equality);
@@ -183,7 +181,7 @@ static QList<Diff> cleanupOverlaps(const QList<Diff> &diffList)
                 if (insDelOverlap > thisDiff.text.count() / 2
                         || insDelOverlap > nextDiff.text.count() / 2) {
                     nextDiff.text = nextDiff.text.left(nextDiff.text.count() - insDelOverlap);
-                    Diff equality = Diff(Diff::Equal, thisDiff.text.left(insDelOverlap));
+                    const Diff equality(Diff::Equal, thisDiff.text.left(insDelOverlap));
                     thisDiff.text = thisDiff.text.mid(insDelOverlap);
                     newDiffList.append(nextDiff);
                     newDiffList.append(equality);
@@ -265,9 +263,7 @@ void Differ::splitDiffList(const QList<Diff> &diffList,
     leftDiffList->clear();
     rightDiffList->clear();
 
-    for (int i = 0; i < diffList.count(); i++) {
-        const Diff diff = diffList.at(i);
-
+    for (const Diff &diff : diffList) {
         if (diff.command != Diff::Delete)
             rightDiffList->append(diff);
         if (diff.command != Diff::Insert)
@@ -400,10 +396,9 @@ static QList<Diff> decodeReducedWhitespace(const QList<Diff> &input,
     QList<Diff> output;
 
     int counter = 0;
-    QMap<int, QString>::const_iterator it = codeMap.constBegin();
-    const QMap<int, QString>::const_iterator itEnd = codeMap.constEnd();
-    for (int i = 0; i < input.count(); i++) {
-        Diff diff = input.at(i);
+    auto it = codeMap.constBegin();
+    const auto itEnd = codeMap.constEnd();
+    for (Diff diff : input) {
         const int diffCount = diff.text.count();
         while ((it != itEnd) && (it.key() < counter + diffCount)) {
             const int reversePosition = diffCount + counter - it.key();
@@ -439,8 +434,8 @@ void Differ::diffWithWhitespaceReduced(const QString &leftInput,
 
     QMap<int, QString> leftCodeMap;
     QMap<int, QString> rightCodeMap;
-    const QString leftString = encodeReducedWhitespace(leftInput, &leftCodeMap);
-    const QString rightString = encodeReducedWhitespace(rightInput, &rightCodeMap);
+    const QString &leftString = encodeReducedWhitespace(leftInput, &leftCodeMap);
+    const QString &rightString = encodeReducedWhitespace(rightInput, &rightCodeMap);
 
     Differ differ;
     QList<Diff> diffList = differ.diff(leftString, rightString);
@@ -475,11 +470,11 @@ void Differ::unifiedDiffWithWhitespaceReduced(const QString &leftInput,
 
     QMap<int, QString> leftCodeMap;
     QMap<int, QString> rightCodeMap;
-    const QString leftString = encodeReducedWhitespace(leftInput, &leftCodeMap);
-    const QString rightString = encodeReducedWhitespace(rightInput, &rightCodeMap);
+    const QString &leftString = encodeReducedWhitespace(leftInput, &leftCodeMap);
+    const QString &rightString = encodeReducedWhitespace(rightInput, &rightCodeMap);
 
     Differ differ;
-    QList<Diff> diffList = differ.unifiedDiff(leftString, rightString);
+    const QList<Diff> &diffList = differ.unifiedDiff(leftString, rightString);
 
     QList<Diff> leftDiffList;
     QList<Diff> rightDiffList;
@@ -606,10 +601,9 @@ static QList<Diff> decodeExpandedWhitespace(const QList<Diff> &input,
     QList<Diff> output;
 
     int counter = 0;
-    QMap<int, QPair<int, QString> >::const_iterator it = codeMap.constBegin();
-    const QMap<int, QPair<int, QString> >::const_iterator itEnd = codeMap.constEnd();
-    for (int i = 0; i < input.count(); i++) {
-        Diff diff = input.at(i);
+    auto it = codeMap.constBegin();
+    const auto itEnd = codeMap.constEnd();
+    for (Diff diff : input) {
         const int diffCount = diff.text.count();
         while ((it != itEnd) && (it.key() < counter + diffCount)) {
             const int replacementSize = it.value().first;
@@ -667,15 +661,15 @@ static bool diffWithWhitespaceExpandedInEqualities(const QList<Diff> &leftInput,
     QMap<int, QPair<int, QString> > commonRightCodeMap;
 
     while (l <= leftCount && r <= rightCount) {
-        Diff leftDiff = l < leftCount ? leftInput.at(l) : Diff(Diff::Equal);
-        Diff rightDiff = r < rightCount ? rightInput.at(r) : Diff(Diff::Equal);
+        const Diff leftDiff = l < leftCount ? leftInput.at(l) : Diff(Diff::Equal);
+        const Diff rightDiff = r < rightCount ? rightInput.at(r) : Diff(Diff::Equal);
 
         if (leftDiff.command == Diff::Equal && rightDiff.command == Diff::Equal) {
             QMap<int, QPair<int, QString> > leftCodeMap;
             QMap<int, QPair<int, QString> > rightCodeMap;
 
             bool ok = false;
-            QString commonEquality = encodeExpandedWhitespace(leftDiff.text,
+            const QString &commonEquality = encodeExpandedWhitespace(leftDiff.text,
                                           rightDiff.text,
                                           &leftCodeMap,
                                           &rightCodeMap,
@@ -684,18 +678,11 @@ static bool diffWithWhitespaceExpandedInEqualities(const QList<Diff> &leftInput,
                 return false;
 
             // join code map positions with common maps
-            QMapIterator<int, QPair<int, QString> > itLeft(leftCodeMap);
-            while (itLeft.hasNext()) {
-                itLeft.next();
-                commonLeftCodeMap.insert(leftText.count() + itLeft.key(),
-                                         itLeft.value());
-            }
-            QMapIterator<int, QPair<int, QString> > itRight(rightCodeMap);
-            while (itRight.hasNext()) {
-                itRight.next();
-                commonRightCodeMap.insert(rightText.count() + itRight.key(),
-                                          itRight.value());
-            }
+            for (auto it = leftCodeMap.cbegin(), end = leftCodeMap.cend(); it != end; ++it)
+                commonLeftCodeMap.insert(leftText.count() + it.key(), it.value());
+
+            for (auto it = rightCodeMap.cbegin(), end = rightCodeMap.cend(); it != end; ++it)
+                commonRightCodeMap.insert(rightText.count() + it.key(), it.value());
 
             leftText.append(commonEquality);
             rightText.append(commonEquality);
@@ -715,7 +702,7 @@ static bool diffWithWhitespaceExpandedInEqualities(const QList<Diff> &leftInput,
     }
 
     Differ differ;
-    QList<Diff> diffList = differ.cleanupSemantics(
+    const QList<Diff> &diffList = differ.cleanupSemantics(
                 differ.diff(leftText, rightText));
 
     QList<Diff> leftDiffList;
@@ -790,16 +777,16 @@ void Differ::ignoreWhitespaceBetweenEqualities(const QList<Diff> &leftInput,
     int r = 0;
 
     while (l <= leftCount && r <= rightCount) {
-        Diff leftDiff = l < leftCount
+        const Diff leftDiff = l < leftCount
                 ? leftInput.at(l)
                 : Diff(Diff::Equal);
-        Diff rightDiff = r < rightCount
+        const Diff rightDiff = r < rightCount
                 ? rightInput.at(r)
                 : Diff(Diff::Equal);
 
         if (leftDiff.command == Diff::Equal && rightDiff.command == Diff::Equal) {
-            Diff previousLeftDiff = l > 0 ? leftInput.at(l - 1) : Diff(Diff::Equal);
-            Diff previousRightDiff = r > 0 ? rightInput.at(r - 1) : Diff(Diff::Equal);
+            const Diff previousLeftDiff = l > 0 ? leftInput.at(l - 1) : Diff(Diff::Equal);
+            const Diff previousRightDiff = r > 0 ? rightInput.at(r - 1) : Diff(Diff::Equal);
 
             if (previousLeftDiff.command == Diff::Delete
                     && previousRightDiff.command == Diff::Insert) {
@@ -887,22 +874,22 @@ void Differ::diffBetweenEqualities(const QList<Diff> &leftInput,
     int r = 0;
 
     while (l <= leftCount && r <= rightCount) {
-        Diff leftDiff = l < leftCount
+        const Diff leftDiff = l < leftCount
                 ? leftInput.at(l)
                 : Diff(Diff::Equal);
-        Diff rightDiff = r < rightCount
+        const Diff rightDiff = r < rightCount
                 ? rightInput.at(r)
                 : Diff(Diff::Equal);
 
         if (leftDiff.command == Diff::Equal && rightDiff.command == Diff::Equal) {
-            Diff previousLeftDiff = l > 0 ? leftInput.at(l - 1) : Diff(Diff::Equal);
-            Diff previousRightDiff = r > 0 ? rightInput.at(r - 1) : Diff(Diff::Equal);
+            const Diff previousLeftDiff = l > 0 ? leftInput.at(l - 1) : Diff(Diff::Equal);
+            const Diff previousRightDiff = r > 0 ? rightInput.at(r - 1) : Diff(Diff::Equal);
 
             if (previousLeftDiff.command == Diff::Delete
                     && previousRightDiff.command == Diff::Insert) {
                 Differ differ;
                 differ.setDiffMode(Differ::CharMode);
-                QList<Diff> commonOutput = differ.cleanupSemantics(
+                const QList<Diff> commonOutput = differ.cleanupSemantics(
                             differ.diff(previousLeftDiff.text, previousRightDiff.text));
 
                 QList<Diff> outputLeftDiffList;
@@ -1008,7 +995,7 @@ QList<Diff> Differ::unifiedDiff(const QString &text1, const QString &text2)
     QString encodedText2;
     QStringList subtexts = encode(text1, text2, &encodedText1, &encodedText2);
 
-    DiffMode diffMode = m_currentDiffMode;
+    const DiffMode diffMode = m_currentDiffMode;
     m_currentDiffMode = CharMode;
 
     // Each different subtext is a separate symbol
@@ -1223,8 +1210,8 @@ QList<Diff> Differ::diffMyersSplit(
     const QString text21 = text2.left(y);
     const QString text22 = text2.mid(y);
 
-    QList<Diff> diffList1 = preprocess1AndDiff(text11, text21);
-    QList<Diff> diffList2 = preprocess1AndDiff(text12, text22);
+    const QList<Diff> &diffList1 = preprocess1AndDiff(text11, text21);
+    const QList<Diff> &diffList2 = preprocess1AndDiff(text12, text22);
     return diffList1 + diffList2;
 }
 
@@ -1331,8 +1318,7 @@ QString Differ::encode(const QString &text,
         subtextStart = subtextEnd;
 
         if (lineToCode->contains(line)) {
-            int code = lineToCode->value(line);
-            codes += QChar(static_cast<ushort>(code));
+            codes += QChar(static_cast<ushort>(lineToCode->value(line)));
         } else {
             lines->append(line);
             lineToCode->insert(line, lines->count() - 1);
@@ -1429,7 +1415,7 @@ QList<Diff> Differ::cleanupSemantics(const QList<Diff> &diffList)
     // equality index, equality data
     QList<EqualityData> equalities;
     for (int i = 0; i <= diffList.count(); i++) {
-        Diff diff = i < diffList.count()
+        const Diff diff = i < diffList.count()
                   ? diffList.at(i)
                   : Diff(Diff::Equal); // dummy, ensure we process to the end
                                        // even when diffList doesn't end with equality
@@ -1461,7 +1447,7 @@ QList<Diff> Differ::cleanupSemantics(const QList<Diff> &diffList)
     QMap<int, bool> equalitiesToBeSplit;
     int i = 0;
     while (i < equalities.count()) {
-        const EqualityData data = equalities.at(i);
+        const EqualityData &data = equalities.at(i);
         if (data.textCount <= qMax(data.deletesBefore, data.insertsBefore)
                 && data.textCount <= qMax(data.deletesAfter, data.insertsAfter)) {
             if (i > 0) {
diff --git a/src/plugins/diffeditor/selectabletexteditorwidget.cpp b/src/plugins/diffeditor/selectabletexteditorwidget.cpp
index 0e8a8ccc6f..9ae9deace6 100644
--- a/src/plugins/diffeditor/selectabletexteditorwidget.cpp
+++ b/src/plugins/diffeditor/selectabletexteditorwidget.cpp
@@ -75,15 +75,10 @@ static QList<DiffSelection> subtractSelection(
 void SelectableTextEditorWidget::setSelections(const QMap<int, QList<DiffSelection> > &selections)
 {
     m_diffSelections.clear();
-    QMapIterator<int, QList<DiffSelection> > itBlock(selections);
-    while (itBlock.hasNext()) {
-        itBlock.next();
-
-        const QList<DiffSelection> diffSelections = itBlock.value();
+    for (auto it = selections.cbegin(), end = selections.cend(); it != end; ++it) {
+        const QList<DiffSelection> diffSelections = it.value();
         QList<DiffSelection> workingList;
-        for (int i = 0; i < diffSelections.count(); i++) {
-            const DiffSelection &diffSelection = diffSelections.at(i);
-
+        for (const DiffSelection &diffSelection : diffSelections) {
             if (diffSelection.start == -1 && diffSelection.end == 0)
                 continue;
 
@@ -100,7 +95,7 @@ void SelectableTextEditorWidget::setSelections(const QMap<int, QList<DiffSelecti
             }
             workingList.append(diffSelection);
         }
-        m_diffSelections.insert(itBlock.key(), workingList);
+        m_diffSelections.insert(it.key(), workingList);
     }
 }
 
@@ -114,8 +109,7 @@ void SelectableTextEditorWidget::paintBlock(QPainter *painter,
     QList<DiffSelection> diffs = m_diffSelections.value(blockNumber);
 
     QVector<QTextLayout::FormatRange> newSelections;
-    for (int i = 0; i < diffs.count(); i++) {
-        const DiffSelection &diffSelection = diffs.at(i);
+    for (const DiffSelection &diffSelection : diffs) {
         if (diffSelection.format) {
             QTextLayout::FormatRange formatRange;
             formatRange.start = qMax(0, diffSelection.start);
diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
index 93da9efad4..7852dc7df2 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.cpp
@@ -152,8 +152,8 @@ SideDiffEditorWidget::SideDiffEditorWidget(QWidget *parent)
     SelectableTextEditorWidget::setDisplaySettings(settings);
 
     connect(this, &TextEditorWidget::tooltipRequested, [this](const QPoint &point, int position) {
-        int block = document()->findBlock(position).blockNumber();
-        auto it = m_fileInfo.constFind(block);
+        const int block = document()->findBlock(position).blockNumber();
+        const auto it = m_fileInfo.constFind(block);
         if (it != m_fileInfo.constEnd())
             ToolTip::show(point, it.value().fileName, this);
         else
@@ -197,8 +197,9 @@ void SideDiffEditorWidget::applyFontSettings()
 
 QString SideDiffEditorWidget::lineNumber(int blockNumber) const
 {
-    if (m_lineNumbers.contains(blockNumber))
-        return QString::number(m_lineNumbers.value(blockNumber));
+    const auto it = m_lineNumbers.constFind(blockNumber);
+    if (it != m_lineNumbers.constEnd())
+        return QString::number(it.value());
     return QString();
 }
 
@@ -215,8 +216,7 @@ bool SideDiffEditorWidget::selectionVisible(int blockNumber) const
 bool SideDiffEditorWidget::replacementVisible(int blockNumber) const
 {
     return isChunkLine(blockNumber) || (isFileLine(blockNumber)
-           && TextDocumentLayout::isFolded(
-                                            document()->findBlockByNumber(blockNumber)));
+           && TextDocumentLayout::isFolded(document()->findBlockByNumber(blockNumber)));
 }
 
 QColor SideDiffEditorWidget::replacementPenColor(int blockNumber) const
@@ -232,8 +232,8 @@ QString SideDiffEditorWidget::plainTextFromSelection(const QTextCursor &cursor)
     if (startPosition == endPosition)
         return QString(); // no selection
 
-    QTextBlock startBlock = document()->findBlock(startPosition);
-    QTextBlock endBlock = document()->findBlock(endPosition);
+    const QTextBlock startBlock = document()->findBlock(startPosition);
+    const QTextBlock endBlock = document()->findBlock(endPosition);
     QTextBlock block = startBlock;
     QString text;
     bool textInserted = false;
@@ -283,26 +283,17 @@ int SideDiffEditorWidget::blockNumberForFileIndex(int fileIndex) const
     if (fileIndex < 0 || fileIndex >= m_fileInfo.count())
         return -1;
 
-    QMap<int, DiffFileInfo>::const_iterator it
-            = m_fileInfo.constBegin();
-    for (int i = 0; i < fileIndex; i++)
-        ++it;
-
-    return it.key();
+    return (m_fileInfo.constBegin() + fileIndex).key();
 }
 
 int SideDiffEditorWidget::fileIndexForBlockNumber(int blockNumber) const
 {
-    QMap<int, DiffFileInfo>::const_iterator it = m_fileInfo.constBegin();
-    QMap<int, DiffFileInfo>::const_iterator itEnd = m_fileInfo.constEnd();
-
     int i = -1;
-    while (it != itEnd) {
+    for (auto it = m_fileInfo.cbegin(), end = m_fileInfo.cend(); it != end; ++it, ++i) {
         if (it.key() > blockNumber)
             break;
-        ++it;
-        ++i;
     }
+
     return i;
 }
 
@@ -311,8 +302,7 @@ int SideDiffEditorWidget::chunkIndexForBlockNumber(int blockNumber) const
     if (m_chunkInfo.isEmpty())
         return -1;
 
-    QMap<int, QPair<int, int> >::const_iterator it
-            = m_chunkInfo.upperBound(blockNumber);
+    auto it = m_chunkInfo.upperBound(blockNumber);
     if (it == m_chunkInfo.constBegin())
         return -1;
 
@@ -537,8 +527,6 @@ SideBySideDiffEditorWidget::SideBySideDiffEditorWidget(QWidget *parent)
 
     connect(m_leftEditor, &QPlainTextEdit::cursorPositionChanged,
             this, &SideBySideDiffEditorWidget::leftCursorPositionChanged);
-//    connect(m_leftEditor->document()->documentLayout(), &QAbstractTextDocumentLayout::documentSizeChanged,
-//            this, &SideBySideDiffEditorWidget::leftDocumentSizeChanged);
 
     connect(m_rightEditor->verticalScrollBar(), &QAbstractSlider::valueChanged,
             this, &SideBySideDiffEditorWidget::rightVSliderChanged);
@@ -686,9 +674,8 @@ void SideBySideDiffEditorWidget::showDiff()
     QString leftTexts, rightTexts;
     int blockNumber = 0;
     QChar separator = QLatin1Char('\n');
-    for (int i = 0; i < m_controller.m_contextFileData.count(); i++) {
+    for (const FileData &contextFileData : m_controller.m_contextFileData) {
         QString leftText, rightText;
-        const FileData &contextFileData = m_controller.m_contextFileData.at(i);
 
         leftFormats[blockNumber].append(DiffSelection(&m_controller.m_fileLineFormat));
         rightFormats[blockNumber].append(DiffSelection(&m_controller.m_fileLineFormat));
@@ -710,7 +697,7 @@ void SideBySideDiffEditorWidget::showDiff()
             blockNumber++;
         } else {
             for (int j = 0; j < contextFileData.chunks.count(); j++) {
-                ChunkData chunkData = contextFileData.chunks.at(j);
+                const ChunkData &chunkData = contextFileData.chunks.at(j);
 
                 int leftLineNumber = chunkData.leftStartingLineNumber;
                 int rightLineNumber = chunkData.rightStartingLineNumber;
@@ -730,8 +717,7 @@ void SideBySideDiffEditorWidget::showDiff()
                     m_leftEditor->setChunkIndex(blockNumber, chunkData.rows.count(), j);
                     m_rightEditor->setChunkIndex(blockNumber, chunkData.rows.count(), j);
 
-                    for (int k = 0; k < chunkData.rows.count(); k++) {
-                        RowData rowData = chunkData.rows.at(k);
+                    for (const RowData &rowData : chunkData.rows) {
                         TextLineData leftLineData = rowData.leftLine;
                         TextLineData rightLineData = rowData.rightLine;
                         if (leftLineData.textLineType == TextLineData::TextLine) {
@@ -762,19 +748,17 @@ void SideBySideDiffEditorWidget::showDiff()
                                 rightFormats[blockNumber].append(DiffSelection(&m_spanLineFormat));
                         }
 
-                        QMapIterator<int, int> itLeft(leftLineData.changedPositions);
-                        while (itLeft.hasNext()) {
-                            itLeft.next();
+                        for (auto it = leftLineData.changedPositions.cbegin(),
+                                  end = leftLineData.changedPositions.cend(); it != end; ++it) {
                             leftFormats[blockNumber].append(
-                                        DiffSelection(itLeft.key(), itLeft.value(),
+                                        DiffSelection(it.key(), it.value(),
                                                       &m_controller.m_leftCharFormat));
                         }
 
-                        QMapIterator<int, int> itRight(rightLineData.changedPositions);
-                        while (itRight.hasNext()) {
-                            itRight.next();
+                        for (auto it = rightLineData.changedPositions.cbegin(),
+                                  end = rightLineData.changedPositions.cend(); it != end; ++it) {
                             rightFormats[blockNumber].append(
-                                        DiffSelection(itRight.key(), itRight.value(),
+                                        DiffSelection(it.key(), it.value(),
                                                       &m_controller.m_rightCharFormat));
                         }
 
@@ -851,8 +835,7 @@ void SideBySideDiffEditorWidget::slotLeftJumpToOriginalFileRequested(
         // The same file (e.g. in git diff), jump to the line number taken from the right editor.
         // Warning: git show SHA^ vs SHA or git diff HEAD vs Index
         // (when Working tree has changed in meantime) will not work properly.
-        for (int i = 0; i < fileData.chunks.count(); i++) {
-            const ChunkData chunkData = fileData.chunks.at(i);
+        for (const ChunkData &chunkData : fileData.chunks) {
 
             int leftLineNumber = chunkData.leftStartingLineNumber;
             int rightLineNumber = chunkData.rightStartingLineNumber;
diff --git a/src/plugins/diffeditor/unifieddiffeditorwidget.cpp b/src/plugins/diffeditor/unifieddiffeditorwidget.cpp
index 544adb5fbf..418c85f821 100644
--- a/src/plugins/diffeditor/unifieddiffeditorwidget.cpp
+++ b/src/plugins/diffeditor/unifieddiffeditorwidget.cpp
@@ -325,13 +325,13 @@ QString UnifiedDiffEditorWidget::showChunk(const ChunkData &chunkData,
                                                      // could have been added
                     for (int k = 0; k < blockDelta; k++)
                         (*selections)[*blockNumber + blockCount + 1 + k].append(&m_controller.m_leftLineFormat);
-                    QMapIterator<int, int> itPos(lineData.changedPositions);
-                    while (itPos.hasNext()) {
-                        itPos.next();
-                        const int startPos = itPos.key() < 0
-                                ? 1 : itPos.key() + 1;
-                        const int endPos = itPos.value() < 0
-                                ? itPos.value() : itPos.value() + 1;
+
+                    for (auto it = lineData.changedPositions.cbegin(),
+                              end = lineData.changedPositions.cend(); it != end; ++it) {
+                        const int startPos = it.key() < 0
+                                ? 1 : it.key() + 1;
+                        const int endPos = it.value() < 0
+                                ? it.value() : it.value() + 1;
                         (*selections)[*blockNumber + blockCount + 1].append(
                                     DiffSelection(startPos, endPos, &m_controller.m_leftCharFormat));
                     }
@@ -365,13 +365,13 @@ QString UnifiedDiffEditorWidget::showChunk(const ChunkData &chunkData,
 
                     for (int k = 0; k < blockDelta; k++)
                         (*selections)[*blockNumber + blockCount + 1 + k].append(&m_controller.m_rightLineFormat);
-                    QMapIterator<int, int> itPos(lineData.changedPositions);
-                    while (itPos.hasNext()) {
-                        itPos.next();
-                        const int startPos = itPos.key() < 0
-                                ? 1 : itPos.key() + 1;
-                        const int endPos = itPos.value() < 0
-                                ? itPos.value() : itPos.value() + 1;
+
+                    for (auto it = lineData.changedPositions.cbegin(),
+                              end = lineData.changedPositions.cend(); it != end; ++it) {
+                        const int startPos = it.key() < 0
+                                ? 1 : it.key() + 1;
+                        const int endPos = it.value() < 0
+                                ? it.value() : it.value() + 1;
                         (*selections)[*blockNumber + blockCount + 1].append
                                 (DiffSelection(startPos, endPos, &m_controller.m_rightCharFormat));
                     }
@@ -448,8 +448,7 @@ void UnifiedDiffEditorWidget::showDiff()
 
     QMap<int, QList<DiffSelection> > selections;
 
-    for (int i = 0; i < m_controller.m_contextFileData.count(); i++) {
-        const FileData &fileData = m_controller.m_contextFileData.at(i);
+    for (const FileData &fileData : m_controller.m_contextFileData) {
         const QString leftFileInfo = QLatin1String("--- ")
                 + fileData.leftFileInfo.fileName + QLatin1Char('\n');
         const QString rightFileInfo = QLatin1String("+++ ")
@@ -509,28 +508,17 @@ int UnifiedDiffEditorWidget::blockNumberForFileIndex(int fileIndex) const
     if (fileIndex < 0 || fileIndex >= m_fileInfo.count())
         return -1;
 
-    QMap<int, QPair<DiffFileInfo, DiffFileInfo> >::const_iterator it
-            = m_fileInfo.constBegin();
-    for (int i = 0; i < fileIndex; i++)
-        ++it;
-
-    return it.key();
+    return (m_fileInfo.constBegin() + fileIndex).key();
 }
 
 int UnifiedDiffEditorWidget::fileIndexForBlockNumber(int blockNumber) const
 {
-    QMap<int, QPair<DiffFileInfo, DiffFileInfo> >::const_iterator it
-            = m_fileInfo.constBegin();
-    QMap<int, QPair<DiffFileInfo, DiffFileInfo> >::const_iterator itEnd
-            = m_fileInfo.constEnd();
-
     int i = -1;
-    while (it != itEnd) {
+    for (auto it = m_fileInfo.cbegin(), end = m_fileInfo.cend(); it != end; ++it, ++i) {
         if (it.key() > blockNumber)
             break;
-        ++it;
-        ++i;
     }
+
     return i;
 }
 
@@ -539,8 +527,7 @@ int UnifiedDiffEditorWidget::chunkIndexForBlockNumber(int blockNumber) const
     if (m_chunkInfo.isEmpty())
         return -1;
 
-    QMap<int, QPair<int, int> >::const_iterator it
-            = m_chunkInfo.upperBound(blockNumber);
+    auto it = m_chunkInfo.upperBound(blockNumber);
     if (it == m_chunkInfo.constBegin())
         return -1;
 
@@ -577,14 +564,12 @@ void UnifiedDiffEditorWidget::jumpToOriginalFile(const QTextCursor &cursor)
     const int leftLineNumber = m_leftLineNumbers.value(blockNumber, -1);
     if (leftLineNumber >= 0) {
         if (leftFileName == rightFileName) {
-            for (int i = 0; i < fileData.chunks.count(); i++) {
-                const ChunkData chunkData = fileData.chunks.at(i);
+            for (const ChunkData &chunkData : fileData.chunks) {
 
                 int newLeftLineNumber = chunkData.leftStartingLineNumber;
                 int newRightLineNumber = chunkData.rightStartingLineNumber;
 
-                for (int j = 0; j < chunkData.rows.count(); j++) {
-                    const RowData rowData = chunkData.rows.at(j);
+                for (const RowData &rowData : chunkData.rows) {
                     if (rowData.leftLine.textLineType == TextLineData::TextLine)
                         newLeftLineNumber++;
                     if (rowData.rightLine.textLineType == TextLineData::TextLine)