LanguageClient: Introduce ClientRequestTask

This class is going to be used inside TaskTree.

Change-Id: Ia227a8f41e4557b45053cb018497a7eca8f8ac6a
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/languageclient/clientrequesttask.h

@@ -0,0 +1,78 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include "languageclient_global.h"
+
+#include "client.h"
+
+#include <languageserverprotocol/lsptypes.h>
+#include <languageserverprotocol/lsputils.h>
+#include <languageserverprotocol/workspace.h>
+#include <utils/tasktree.h>
+
+namespace LanguageClient {
+
+
+template <typename Request>
+class LANGUAGECLIENT_EXPORT ClientRequestTask
+{
+public:
+    virtual ~ClientRequestTask()
+    {
+        if (m_id)
+            m_client->cancelRequest(*m_id); // In order to not to invoke a response callback anymore
+    }
+
+    void setClient(Client *client) { m_client = client; }
+    Client *client() const { return m_client; }
+    void setParams(const typename Request::Parameters &params) { m_params = params; }
+
+    void start()
+    {
+        QTC_ASSERT(isRunning(), return);
+        QTC_ASSERT(preStartCheck(), m_callback({}); return);
+
+        Request request(m_params);
+        request.setResponseCallback([this](const typename Request::Response &response) {
+            m_response = response;
+            m_id = {};
+            m_callback(response);
+        });
+        m_id = request.id();
+        m_client->sendMessage(request);
+    }
+
+    bool isRunning() const { return m_id.has_value(); }
+    virtual bool preStartCheck() { return m_client && m_client->reachable() && m_params.isValid(); }
+
+    typename Request::Response response() const { return m_response; }
+    void setResponseCallback(typename Request::ResponseCallback callback) { m_callback = callback; }
+
+private:
+    Client *m_client = nullptr;
+    typename Request::Parameters m_params;
+    typename Request::ResponseCallback m_callback;
+    std::optional<LanguageServerProtocol::MessageId> m_id;
+    typename Request::Response m_response;
+};
+
+class LANGUAGECLIENT_EXPORT WorkspaceSymbolRequestTask
+    : public ClientRequestTask<LanguageServerProtocol::WorkspaceSymbolRequest>
+{
+public:
+    bool preStartCheck() override;
+};
+
+class LANGUAGECLIENT_EXPORT ClientRequestTaskAdapter
+    : public Utils::Tasking::TaskAdapter<WorkspaceSymbolRequestTask>
+{
+public:
+    ClientRequestTaskAdapter();
+    void start() final;
+};
+
+} // namespace LanguageClient
+
+QTC_DECLARE_CUSTOM_TASK(WorkspaceSymbolRequest, LanguageClient::WorkspaceSymbolRequestTask);