Experimental integration of DiffEditor

After enabling the plugin go to Tools|Diff...

Change-Id: I793b6faedb93f58039df0a62e82fe04a017978ee
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/diffeditor/diffeditorwidget.h

@@ -0,0 +1,159 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 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 DIFFEDITORWIDGET_H
+#define DIFFEDITORWIDGET_H
+
+#include "diffeditor_global.h"
+#include "differ.h"
+
+#include <QTextEdit>
+
+namespace TextEditor {
+class BaseTextEditorWidget;
+class SnippetEditorWidget;
+}
+
+QT_BEGIN_NAMESPACE
+class QPlainTextEdit;
+class QSplitter;
+class QSyntaxHighlighter;
+class QTextCharFormat;
+QT_END_NAMESPACE
+
+
+
+namespace DIFFEditor {
+
+class DiffViewEditorWidget;
+
+struct TextLineData {
+    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;
+};
+
+struct RowData {
+    RowData() : equal(true) {}
+    RowData(const TextLineData &l)
+        : leftLine(l), rightLine(l), equal(true) {}
+    RowData(const TextLineData &l, const TextLineData &r, bool e = false)
+        : leftLine(l), rightLine(r), equal(e) {}
+    RowData(const QString &txt)
+        : text(txt), equal(true) {}
+    TextLineData leftLine;
+    TextLineData rightLine;
+    QString text; // file of context description
+    bool equal; // true if left and right lines are equal, taking whitespaces into account (or both invalid)
+};
+
+struct ChunkData {
+    ChunkData() : skippedLinesBefore(0), leftOffset(0), rightOffset(0) {}
+    QList<RowData> rows;
+    int skippedLinesBefore; // info for text
+    int leftOffset;
+    int rightOffset;
+    // <absolute position in the file, absolute position in the file>
+    QMap<int, int> changedLeftPositions; // counting from the beginning of the chunk
+    QMap<int, int> changedRightPositions; // counting from the beginning of the chunk
+    QString text;
+};
+
+struct FileData {
+    FileData() {}
+    FileData(const ChunkData &chunkData) { chunks.append(chunkData); }
+    QList<ChunkData> chunks;
+    QList<int> chunkOffset;
+    QString text;
+};
+
+struct DiffData {
+    QList<FileData> files;
+    QString text;
+};
+
+class DIFFEDITOR_EXPORT DiffEditorWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    DiffEditorWidget(QWidget *parent = 0);
+    ~DiffEditorWidget();
+
+    void setDiff(const QString &leftText, const QString &rightText);
+    void setDiff(const QList<Diff> &diffList);
+    QTextCodec *codec() const;
+
+public slots:
+    void setContextLinesNumber(int lines);
+    void setIgnoreWhitespaces(bool ignore);
+
+protected:
+    TextEditor::SnippetEditorWidget *leftEditor() const;
+    TextEditor::SnippetEditorWidget *rightEditor() const;
+
+private slots:
+    void leftSliderChanged();
+    void rightSliderChanged();
+
+private:
+    bool isWhitespace(const QChar &c) const;
+    bool isWhitespace(const Diff &diff) const;
+    bool isEqual(const QList<Diff> &diffList, int diffNumber) const;
+    QList<QTextEdit::ExtraSelection> colorPositions(const QTextCharFormat &format,
+            QTextCursor &cursor,
+            const QMap<int, int> &positions) const;
+    void colorDiff(const FileData &fileData);
+    ChunkData calculateOriginalData(const QList<Diff> &diffList) const;
+    FileData calculateContextData(const ChunkData &originalData) const;
+    void showDiff();
+
+    DiffViewEditorWidget *m_leftEditor;
+    DiffViewEditorWidget *m_rightEditor;
+    QSplitter *m_splitter;
+
+    QList<Diff> m_diffList;
+    int m_contextLinesNumber;
+    bool m_ignoreWhitespaces;
+
+    ChunkData m_originalChunkData;
+    FileData m_contextFileData;
+    int m_leftSafePosHack;
+    int m_rightSafePosHack;
+};
+
+} // namespace DIFFEditor
+
+#endif // DIFFEDITORWIDGET_H