LanguageClient: cancel find link at requests on rerequest

This avoids triggering the callback if we already requested a find link
at for a different position. Additionally we also cancel the request if
the document changes or the cursor moves inbetween requesting the link
and receiving the response.

Change-Id: Iffc7b08012a649397e7ca7dfc99d314a1bbf19f7
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/client.cpp

@@ -328,6 +328,7 @@ public:
     ProjectExplorer::Project *m_project = nullptr;
     QSet<TextEditor::IAssistProcessor *> m_runningAssistProcessors;
     SymbolSupport m_symbolSupport;
+    MessageId m_runningFindLinkRequest;
     ProgressManager m_progressManager;
     bool m_activateDocAutomatically = false;
     SemanticTokenSupport m_tokenSupport;
@@ -1112,6 +1113,8 @@ void Client::documentContentsChanged(TextEditor::TextDocument *document,
 {
     if (!d->m_openedDocument.contains(document) || !reachable())
         return;
+    if (d->m_runningFindLinkRequest.isValid())
+        cancelRequest(d->m_runningFindLinkRequest);
     if (d->m_diagnosticManager)
         d->m_diagnosticManager->disableDiagnostics(document);
     const QString method(DidChangeTextDocumentNotification::methodName);
@@ -1252,6 +1255,8 @@ TextEditor::HighlightingResult createHighlightingResult(const SymbolInformation
 
 void Client::cursorPositionChanged(TextEditor::TextEditorWidget *widget)
 {
+    if (d->m_runningFindLinkRequest.isValid())
+        cancelRequest(d->m_runningFindLinkRequest);
     TextEditor::TextDocument *document = widget->textDocument();
     if (d->m_documentsToUpdate.find(document) != d->m_documentsToUpdate.end())
         return; // we are currently changing this document so postpone the DocumentHighlightsRequest
@@ -1274,6 +1279,23 @@ SymbolSupport &Client::symbolSupport()
     return d->m_symbolSupport;
 }
 
+void Client::findLinkAt(TextEditor::TextDocument *document,
+                        const QTextCursor &cursor,
+                        Utils::LinkHandler callback,
+                        const bool resolveTarget)
+{
+    if (d->m_runningFindLinkRequest.isValid())
+        cancelRequest(d->m_runningFindLinkRequest);
+    d->m_runningFindLinkRequest = symbolSupport().findLinkAt(
+        document,
+        cursor,
+        [this, callback](const Link &link) {
+            d->m_runningFindLinkRequest = {};
+            callback(link);
+        },
+        resolveTarget);
+}
+
 void Client::requestCodeActions(const LanguageServerProtocol::DocumentUri &uri,
                                 const LanguageServerProtocol::Diagnostic &diagnostic)
 {

src/plugins/languageclient/client.h

@@ -149,6 +149,13 @@ public:
     void addAssistProcessor(TextEditor::IAssistProcessor *processor);
     void removeAssistProcessor(TextEditor::IAssistProcessor *processor);
     SymbolSupport &symbolSupport();
+    // In contrast to the findLinkAt of symbol support this find link makes sure that there is only
+    // one request running at a time and cancels the running request if the document changes, cursor
+    // moves or another link is requested
+    void findLinkAt(TextEditor::TextDocument *document,
+                    const QTextCursor &cursor,
+                    Utils::LinkHandler callback,
+                    const bool resolveTarget);
     DocumentSymbolCache *documentSymbolCache();
     HoverHandler *hoverHandler();
     QList<LanguageServerProtocol::Diagnostic> diagnosticsAt(const Utils::FilePath &filePath,

src/plugins/languageclient/languageclientmanager.cpp

@@ -463,7 +463,7 @@ void LanguageClientManager::editorOpened(Core::IEditor *editor)
                     [document = textEditor->textDocument()]
                     (const QTextCursor &cursor, const Utils::LinkHandler &callback, bool resolveTarget) {
                         if (auto client = clientForDocument(document))
-                            client->symbolSupport().findLinkAt(document, cursor, callback, resolveTarget);
+                            client->findLinkAt(document, cursor, callback, resolveTarget);
                     });
             connect(widget, &TextEditorWidget::requestUsages, this,
                     [document = textEditor->textDocument()](const QTextCursor &cursor) {

src/plugins/languageclient/languageclientsymbolsupport.cpp

@@ -137,13 +137,13 @@ static TextDocumentPositionParams generateDocPosParams(TextEditor::TextDocument
     return TextDocumentPositionParams(documentId, pos);
 }
 
-void SymbolSupport::findLinkAt(TextEditor::TextDocument *document,
-                               const QTextCursor &cursor,
-                               Utils::LinkHandler callback,
-                               const bool resolveTarget)
+MessageId SymbolSupport::findLinkAt(TextEditor::TextDocument *document,
+                                    const QTextCursor &cursor,
+                                    Utils::LinkHandler callback,
+                                    const bool resolveTarget)
 {
     if (!m_client->reachable())
-        return;
+        return {};
     GotoDefinitionRequest request(generateDocPosParams(document, cursor, m_client));
     std::optional<Utils::Link> linkUnderCursor;
     if (!resolveTarget) {
@@ -165,6 +165,7 @@ void SymbolSupport::findLinkAt(TextEditor::TextDocument *document,
                                           request,
                                           m_client->dynamicCapabilities(),
                                           m_client->capabilities());
+    return request.id();
 }
 
 bool SymbolSupport::supportsFindUsages(TextEditor::TextDocument *document) const

src/plugins/languageclient/languageclientsymbolsupport.h

@@ -25,7 +25,7 @@ class LANGUAGECLIENT_EXPORT SymbolSupport : public QObject
 public:
     explicit SymbolSupport(Client *client);
 
-    void findLinkAt(TextEditor::TextDocument *document,
+    LanguageServerProtocol::MessageId findLinkAt(TextEditor::TextDocument *document,
                     const QTextCursor &cursor,
                     Utils::LinkHandler callback,
                     const bool resolveTarget);