LanguageClient: add hover handler

Change-Id: Iddf30828ef26a157ab935d0abe708087ab123dd6
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/languageclienthoverhandler.h

@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** 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 <languageserverprotocol/languagefeatures.h>
+#include <texteditor/basehoverhandler.h>
+
+namespace LanguageClient {
+
+class Client;
+
+class HoverHandler : public TextEditor::BaseHoverHandler
+{
+    Q_DECLARE_TR_FUNCTIONS(HoverHandler)
+public:
+    explicit HoverHandler(Client *client);
+    ~HoverHandler() override;
+
+    void abort() override;
+
+protected:
+    void identifyMatch(TextEditor::TextEditorWidget *editorWidget,
+                       int pos,
+                       ReportPriority report) override;
+    void operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point) override;
+
+private:
+    void handleResponse(const LanguageServerProtocol::HoverRequest::Response &response);
+    void setContent(const LanguageServerProtocol::HoverContent &content);
+
+    QPointer<Client> m_client;
+    Utils::optional<LanguageServerProtocol::MessageId> m_currentRequest;
+    TextEditor::BaseHoverHandler::ReportPriority m_report;
+};
+
+} // namespace LanguageClient