cppeditor: add resource preview hover handler class

This adds a hover handler which will preview images
from within project resource.

Change-Id: I88bcb56a977e41ed4dc5bfe165e2c80d4396a21f
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cppeditor/resourcepreviewhoverhandler.h

@@ -0,0 +1,50 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Marc Reilly <marc.reilly+qtc@gmail.com>
+** 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 <texteditor/basehoverhandler.h>
+
+#include <QString>
+
+namespace CppEditor {
+namespace Internal {
+
+class ResourcePreviewHoverHandler : public TextEditor::BaseHoverHandler
+{
+public:
+
+private:
+    void identifyMatch(TextEditor::TextEditorWidget *editorWidget, int pos) override;
+    void operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point) override;
+
+private:
+    QString makeTooltip() const;
+
+    QString m_resPath;
+};
+
+} // namespace Internal
+} // namespace CppEditor