Import QML preview plugin into Qt Creator

... and relicense it as GPL or Commercial.

Fixes: QTCREATORBUG-21838
Change-Id: I28d58ee963e1c63aa4a8bbe4525faade7201c353
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/qmlpreview/qmlpreviewconnectionmanager.h

@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** 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 "qmlpreviewplugin.h"
+#include "qmlpreviewclient.h"
+#include "qmlpreviewfileontargetfinder.h"
+
+#include <qmldebug/qmldebugconnectionmanager.h>
+#include <utils/fileinprojectfinder.h>
+#include <utils/filesystemwatcher.h>
+
+namespace ProjectExplorer {
+class Target;
+}
+
+namespace QmlPreview {
+namespace Internal {
+
+class QmlPreviewConnectionManager : public QmlDebug::QmlDebugConnectionManager
+{
+    Q_OBJECT
+public:
+    virtual ~QmlPreviewConnectionManager();
+
+    explicit QmlPreviewConnectionManager(QObject *parent = nullptr);
+    void setTarget(ProjectExplorer::Target *target);
+    void setFileLoader(QmlPreviewFileLoader fileLoader);
+    void setFileClassifier(QmlPreviewFileClassifier fileClassifier);
+    void setFpsHandler(QmlPreviewFpsHandler fpsHandler);
+
+signals:
+    void loadFile(const QString &filename, const QString &changedFile, const QByteArray &contents);
+    void zoom(float zoomFactor);
+    void language(const QString &locale);
+    void rerun();
+    void restart();
+
+protected:
+    void createClients() override;
+    void destroyClients() override;
+
+private:
+    Utils::FileInProjectFinder m_projectFileFinder;
+    QmlPreviewFileOnTargetFinder m_targetFileFinder;
+    QPointer<QmlPreviewClient> m_clientPlugin;
+    Utils::FileSystemWatcher m_fileSystemWatcher;
+    QUrl m_lastLoadedUrl;
+    QmlPreviewFileLoader m_fileLoader = nullptr;
+    QmlPreviewFileClassifier m_fileClassifier = nullptr;
+    QmlPreviewFpsHandler m_fpsHandler = nullptr;
+};
+
+} // namespace Internal
+} // namespace QmlPreview