Python: make interpreter configurable

Add settings page to setup python interpreter and use a combo box in the
run configuration to switch between those configured interpreter.

Change-Id: I51014b785ea822ee138d39c788149f1d22901e55
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/python/pythonsettings.h

@@ -0,0 +1,62 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** 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.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <utils/fileutils.h>
+
+#include <QUuid>
+
+namespace Python {
+namespace Internal {
+
+class Interpreter
+{
+public:
+    QString id;
+    QString name;
+    Utils::FilePath command;
+};
+
+class PythonSettings : public QObject
+{
+    Q_OBJECT
+public:
+    static void init();
+
+    static QList<Interpreter> interpreters();
+    static Interpreter defaultInterpreter();
+    static void setInterpreter(const QList<Interpreter> &interpreters, const QString &defaultId);
+    static PythonSettings *instance();
+
+signals:
+    void interpretersChanged(const QList<Interpreter> &interpreters, const QString &defaultId);
+
+private:
+    PythonSettings();
+};
+
+} // namespace Internal
+} // namespace PythonEditor