Implement clangd textDocument/switchSourceHeader

It will only be visible / enabled when clangd is running. For all other
servers there will be no change.
Signed-off-by: Waqar Ahmed <waqar.17a@gmail.com>

addons/lspclient/lspclientpluginview.cpp

@@ -329,6 +329,7 @@ class LSPClientActionView : public QObject
     QPointer<QAction> m_closeDynamic;
     QPointer<QAction> m_restartServer;
     QPointer<QAction> m_restartAll;
+    QPointer<QAction> m_switchSourceHeader;
 
     // toolview
     QScopedPointer<QWidget> m_toolView;
@@ -441,6 +442,8 @@ public:
         m_triggerFormat->setText(i18n("Format"));
         m_triggerRename = actionCollection()->addAction(QStringLiteral("lspclient_rename"), this, &self_type::rename);
         m_triggerRename->setText(i18n("Rename"));
+        m_switchSourceHeader = actionCollection()->addAction(QStringLiteral("lspclient_clangd_switchheader"), this, &self_type::clangdSwitchSourceHeader);
+        m_switchSourceHeader->setText(i18n("Switch Source Header"));
 
         // general options
         m_complDocOn = actionCollection()->addAction(QStringLiteral("lspclient_completion_doc"), this, &self_type::displayOptionChanged);
@@ -505,6 +508,7 @@ public:
         menu->addAction(m_findDecl);
         menu->addAction(m_findRef);
         menu->addAction(m_findImpl);
+        menu->addAction(m_switchSourceHeader);
         menu->addAction(m_triggerHighlight);
         menu->addAction(m_triggerSymbolInfo);
         menu->addAction(m_triggerFormat);
@@ -1766,6 +1770,21 @@ public:
         delayCancelRequest(std::move(handle));
     }
 
+    void clangdSwitchSourceHeader()
+    {
+        KTextEditor::View *activeView = m_mainWindow->activeView();
+        KTextEditor::Document *document = activeView->document();
+        auto server = m_serverManager->findServer(activeView);
+        if (!server || !document) {
+            return;
+        }
+
+        auto h = [this](const QString &reply) {
+            m_mainWindow->openUrl(QUrl(reply));
+        };
+        server->clangdSwitchSourceHeader(document->url(), this, h);
+    }
+
     static QStandardItem *getItem(const QStandardItemModel &model, const QUrl &url)
     {
         auto l = model.findItems(url.toLocalFile());
@@ -2256,6 +2275,7 @@ public:
         bool hoverEnabled = false, highlightEnabled = false;
         bool formatEnabled = false;
         bool renameEnabled = false;
+        bool isClangd = false;
 
         if (server) {
             const auto &caps = server->capabilities();
@@ -2287,6 +2307,8 @@ public:
                 connect(doc, &KTextEditor::Document::textChanged, this, &self_type::onTextChanged, Qt::UniqueConnection);
                 connect(doc, &KTextEditor::Document::documentUrlChanged, this, &self_type::onDocumentUrlChanged, Qt::UniqueConnection);
             }
+
+            isClangd = server->cmdline().front() == QStringLiteral("clangd");
         }
 
         if (m_findDef) {
@@ -2319,6 +2341,8 @@ public:
         if (m_restartServer) {
             m_restartServer->setEnabled(server);
         }
+        m_switchSourceHeader->setEnabled(isClangd);
+        m_switchSourceHeader->setVisible(isClangd);
 
         // update completion with relevant server
         m_completion->setServer(server);

addons/lspclient/lspclientserver.cpp

@@ -616,6 +616,11 @@ static LSPSignatureHelp parseSignatureHelp(const QJsonValue &result)
     return ret;
 }
 
+static QString parseClangdSwitchSourceHeader(const QJsonValue &result)
+{
+    return result.toString();
+}
+
 static QList<LSPTextEdit> parseTextEdit(const QJsonValue &result)
 {
     QList<LSPTextEdit> ret;
@@ -1180,6 +1185,12 @@ public:
         return send(init_request(QStringLiteral("textDocument/signatureHelp"), params), h);
     }
 
+    RequestHandle clangdSwitchSourceHeader(const QUrl &document, const GenericReplyHandler &h)
+    {
+        auto params = QJsonObject{{MEMBER_URI, document.toString()}};
+        return send(init_request(QStringLiteral("textDocument/switchSourceHeader"), params), h);
+    }
+
     RequestHandle documentFormatting(const QUrl &document, const LSPFormattingOptions &options, const GenericReplyHandler &h)
     {
         auto params = documentRangeFormattingParams(document, nullptr, options);
@@ -1441,6 +1452,11 @@ LSPClientServer::signatureHelp(const QUrl &document, const LSPPosition &pos, con
     return d->signatureHelp(document, pos, make_handler(h, context, parseSignatureHelp));
 }
 
+LSPClientServer::RequestHandle LSPClientServer::clangdSwitchSourceHeader(const QUrl &document, const QObject *context, const SwitchSourceHeaderHandler &h)
+{
+    return d->clangdSwitchSourceHeader(document, make_handler(h, context, parseClangdSwitchSourceHeader));
+}
+
 LSPClientServer::RequestHandle
 LSPClientServer::documentFormatting(const QUrl &document, const LSPFormattingOptions &options, const QObject *context, const FormattingReplyHandler &h)
 {

addons/lspclient/lspclientserver.h

@@ -59,6 +59,7 @@ using FormattingReplyHandler = ReplyHandler<QList<LSPTextEdit>>;
 using CodeActionReplyHandler = ReplyHandler<QList<LSPCodeAction>>;
 using WorkspaceEditReplyHandler = ReplyHandler<LSPWorkspaceEdit>;
 using ApplyEditReplyHandler = ReplyHandler<LSPApplyWorkspaceEditResponse>;
+using SwitchSourceHeaderHandler = ReplyHandler<QString>;
 
 class LSPClientPlugin;
 
@@ -117,6 +118,9 @@ public:
     RequestHandle documentCompletion(const QUrl &document, const LSPPosition &pos, const QObject *context, const DocumentCompletionReplyHandler &h);
     RequestHandle signatureHelp(const QUrl &document, const LSPPosition &pos, const QObject *context, const SignatureHelpReplyHandler &h);
 
+    // clangd specific
+    RequestHandle clangdSwitchSourceHeader(const QUrl &document, const QObject *context, const SwitchSourceHeaderHandler &h);
+
     RequestHandle documentFormatting(const QUrl &document, const LSPFormattingOptions &options, const QObject *context, const FormattingReplyHandler &h);
     RequestHandle documentRangeFormatting(const QUrl &document,
                                           const LSPRange &range,