Vcs: Add Fossil SCM integration plugin

* Qt Creator base-commit: f77af5e336
* Stand-alone plugin source tree for integration into qtc super-project
* Original release: https://github.com/nomadbyte/qtcreator-plugin-fossil
* Adapted from Bazaar plugin implementation

Configuring Fossil
------------------

1. Download the [Fossil SCM client](http://fossil-scm.org) and install `fossil`
   executable file in your `PATH`.

2. Create or designate a directory to store local Fossil repositories and
   remote clones. For example: `~/fossils/qt`.

3. Configure Version Control Options for the Fossil plugin to use
   the designated directory as `Local Repositories Default path`.

Now Fossil should become available as a VCS choice to create new local
repositories, as well as a choice in `New File or Project` to clone a
remote Fossil repository.

Change-Id: I630184c1b344184d9e08ae2fc24a5e4766f834b9
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

plugins/fossil/fossileditor.cpp

@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (c) 2016 Artur Shepilko
+** Contact: https://www.qt.io/licensing/
+**
+** 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "fossileditor.h"
+#include "annotationhighlighter.h"
+#include "constants.h"
+#include "fossilplugin.h"
+#include "fossilclient.h"
+
+#include <coreplugin/editormanager/editormanager.h>
+#include <utils/qtcassert.h>
+#include <utils/synchronousprocess.h>
+#include <vcsbase/diffandloghighlighter.h>
+
+#include <QRegExp>
+#include <QString>
+#include <QTextCursor>
+#include <QTextBlock>
+#include <QDir>
+#include <QFileInfo>
+
+namespace Fossil {
+namespace Internal {
+
+FossilEditorWidget::FossilEditorWidget() :
+    m_exactChangesetId(Constants::CHANGESET_ID_EXACT),
+    m_firstChangesetId(QString("\n") + Constants::CHANGESET_ID + " "),
+    m_nextChangesetId(m_firstChangesetId)
+{
+    QTC_ASSERT(m_exactChangesetId.isValid(), return);
+    QTC_ASSERT(m_firstChangesetId.isValid(), return);
+    QTC_ASSERT(m_nextChangesetId.isValid(), return);
+
+    setAnnotateRevisionTextFormat(tr("&Annotate %1"));
+    setAnnotatePreviousRevisionTextFormat(tr("Annotate &Parent Revision %1"));
+
+    const QRegExp exactDiffFileIdPattern(Constants::DIFFFILE_ID_EXACT);
+    QTC_ASSERT(exactDiffFileIdPattern.isValid(), return);
+    setDiffFilePattern(exactDiffFileIdPattern);
+
+    const QRegExp logChangePattern("^.*\\[([0-9a-f]{5,40})\\]");
+    QTC_ASSERT(logChangePattern.isValid(), return);
+    setLogEntryPattern(logChangePattern);
+}
+
+QSet<QString> FossilEditorWidget::annotationChanges() const
+{
+
+    const QString txt = toPlainText();
+    if (txt.isEmpty())
+        return QSet<QString>();
+
+    // extract changeset id at the beginning of each annotated line:
+    // <changeid> ...:
+
+    QSet<QString> changes;
+
+    QRegularExpressionMatch firstChangesetIdMatch = m_firstChangesetId.match(txt);
+    if (firstChangesetIdMatch.hasMatch()) {
+        QString changeId = firstChangesetIdMatch.captured(1);
+        changes.insert(changeId);
+
+        QRegularExpressionMatchIterator i = m_nextChangesetId.globalMatch(txt);
+        while (i.hasNext()) {
+            const QRegularExpressionMatch nextChangesetIdMatch = i.next();
+            changeId = nextChangesetIdMatch.captured(1);
+            changes.insert(changeId);
+        }
+    }
+    return changes;
+}
+
+QString FossilEditorWidget::changeUnderCursor(const QTextCursor &cursorIn) const
+{
+    QTextCursor cursor = cursorIn;
+    cursor.select(QTextCursor::WordUnderCursor);
+    if (cursor.hasSelection()) {
+        const QString change = cursor.selectedText();
+        QRegularExpressionMatch exactChangesetIdMatch = m_exactChangesetId.match(change);
+        if (exactChangesetIdMatch.hasMatch())
+            return change;
+    }
+    return QString();
+}
+
+
+VcsBase::BaseAnnotationHighlighter *FossilEditorWidget::createAnnotationHighlighter(const QSet<QString> &changes) const
+{
+    return new FossilAnnotationHighlighter(changes);
+}
+
+} // namespace Internal
+} // namespace Fossil