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/fossilcommitwidget.cpp

@@ -0,0 +1,169 @@
+/****************************************************************************
+**
+** 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 "fossilcommitwidget.h"
+#include "branchinfo.h"
+
+#include <texteditor/texteditorsettings.h>
+#include <texteditor/fontsettings.h>
+#include <texteditor/texteditorconstants.h>
+
+#include <utils/completingtextedit.h>
+#include <utils/qtcassert.h>
+
+#include <QSyntaxHighlighter>
+#include <QTextEdit>
+
+#include <QRegularExpression>
+#include <QDir>
+
+namespace Fossil {
+namespace Internal {
+
+// Retrieve the comment char format from the text editor.
+static QTextCharFormat commentFormat()
+{
+    const TextEditor::FontSettings settings = TextEditor::TextEditorSettings::instance()->fontSettings();
+    return settings.toTextCharFormat(TextEditor::C_COMMENT);
+}
+
+// Highlighter for Fossil submit messages.
+// Marks up [ticket-id] fields in the message.
+class FossilSubmitHighlighter : QSyntaxHighlighter
+{
+public:
+    explicit FossilSubmitHighlighter(Utils::CompletingTextEdit *parent);
+    void highlightBlock(const QString &text) final;
+
+private:
+    const QTextCharFormat m_commentFormat;
+    const QRegularExpression m_keywordPattern;
+};
+
+FossilSubmitHighlighter::FossilSubmitHighlighter(Utils::CompletingTextEdit *parent) : QSyntaxHighlighter(parent),
+    m_commentFormat(commentFormat()),
+    m_keywordPattern("\\[([0-9a-f]{5,40})\\]")
+{
+    QTC_CHECK(m_keywordPattern.isValid());
+}
+
+void FossilSubmitHighlighter::highlightBlock(const QString &text)
+{
+    // Fossil commit message allows listing of [ticket-id],
+    // where ticket-id is a partial SHA1.
+    // Match the ticket-ids and highlight them for convenience.
+
+    // Format keywords
+    QRegularExpressionMatchIterator i = m_keywordPattern.globalMatch(text);
+    while (i.hasNext()) {
+        const QRegularExpressionMatch keywordMatch = i.next();
+        QTextCharFormat charFormat = format(0);
+        charFormat.setFontItalic(true);
+        setFormat(keywordMatch.capturedStart(0), keywordMatch.capturedLength(0), charFormat);
+    }
+}
+
+
+FossilCommitWidget::FossilCommitWidget() : m_commitPanel(new QWidget)
+{
+    m_commitPanelUi.setupUi(m_commitPanel);
+    insertTopWidget(m_commitPanel);
+    new FossilSubmitHighlighter(descriptionEdit());
+    m_branchValidator = new QRegularExpressionValidator(QRegularExpression("[^\\n]*"), this);
+
+    connect(m_commitPanelUi.branchLineEdit, &QLineEdit::textChanged,
+            this, &FossilCommitWidget::branchChanged);
+}
+
+void FossilCommitWidget::setFields(const QString &repoPath, const BranchInfo &branch,
+                                   const QStringList &tags, const QString &userName)
+{
+    m_commitPanelUi.localRootLineEdit->setText(QDir::toNativeSeparators(repoPath));
+    m_commitPanelUi.currentBranchLineEdit->setText(branch.name());
+    const QString tagsText = tags.join(", ");
+    m_commitPanelUi.currentTagsLineEdit->setText(tagsText);
+    m_commitPanelUi.authorLineEdit->setText(userName);
+
+    branchChanged();
+}
+
+QString FossilCommitWidget::newBranch() const
+{
+    const QString branchName = m_commitPanelUi.branchLineEdit->text().trimmed();
+    return branchName;
+}
+
+QStringList FossilCommitWidget::tags() const
+{
+    QString tagsText = m_commitPanelUi.tagsLineEdit->text().trimmed();
+    if (tagsText.isEmpty())
+        return QStringList();
+
+    tagsText.replace(',', ' ');
+    const QStringList tags = tagsText.split(' ', QString::SkipEmptyParts);
+    return tags;
+}
+
+QString FossilCommitWidget::committer() const
+{
+    const QString author = m_commitPanelUi.authorLineEdit->text();
+    if (author.isEmpty())
+        return QString();
+
+    const QString user = author;
+    return user;
+}
+
+bool FossilCommitWidget::isPrivateOptionEnabled() const
+{
+    return m_commitPanelUi.isPrivateCheckBox->isChecked();
+}
+
+bool FossilCommitWidget::canSubmit() const
+{
+    QString message = cleanupDescription(descriptionText()).trimmed();
+
+    if (m_commitPanelUi.invalidBranchLabel->isVisible() || message.isEmpty())
+        return false;
+
+    return VcsBase::SubmitEditorWidget::canSubmit();
+}
+
+void FossilCommitWidget::branchChanged()
+{
+    m_commitPanelUi.invalidBranchLabel->setVisible(!isValidBranch());
+
+    updateSubmitAction();
+}
+
+bool FossilCommitWidget::isValidBranch() const
+{
+    int pos = m_commitPanelUi.branchLineEdit->cursorPosition();
+    QString text = m_commitPanelUi.branchLineEdit->text();
+    return m_branchValidator->validate(text, pos) == QValidator::Acceptable;
+}
+
+} // namespace Internal
+} // namespace Fossil