LanguageClient: have one active client per open document

open a document in all clients supporting the document, but have just
one client that provide functionality like highlights, completions, and
find usages.

Change-Id: I6bd72eb022005ed643fefd1da139d482f4dd5279
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

4 files changed, 117 insertions, 111 deletions

diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index ad5f8d8e56..c4fb4058b9 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -278,63 +278,47 @@ Client::State Client::state() const
     return m_state;
 }
 
-bool Client::openDocument(TextEditor::TextDocument *document)
+void Client::openDocument(TextEditor::TextDocument *document)
 {
     using namespace TextEditor;
     if (!isSupportedDocument(document))
-        return false;
+        return;
+
+    m_openedDocument[document] = document->plainText();
+    if (m_state != Initialized)
+        return;
+
     const FilePath &filePath = document->filePath();
     const QString method(DidOpenTextDocumentNotification::methodName);
     if (Utils::optional<bool> registered = m_dynamicCapabilities.isRegistered(method)) {
         if (!registered.value())
-            return false;
+            return;
         const TextDocumentRegistrationOptions option(
             m_dynamicCapabilities.option(method).toObject());
         if (option.isValid(nullptr)
             && !option.filterApplies(filePath, Utils::mimeTypeForName(document->mimeType()))) {
-            return false;
+            return;
         }
     } else if (Utils::optional<ServerCapabilities::TextDocumentSync> _sync
                = m_serverCapabilities.textDocumentSync()) {
         if (auto options = Utils::get_if<TextDocumentSyncOptions>(&_sync.value())) {
             if (!options->openClose().value_or(true))
-                return false;
+                return;
         }
     }
-    auto uri = DocumentUri::fromFilePath(filePath);
-    showDiagnostics(uri);
-
-    connect(document,
-            &TextDocument::contentsChangedWithPosition,
-            this,
+    connect(document, &TextDocument::contentsChangedWithPosition, this,
             [this, document](int position, int charsRemoved, int charsAdded) {
-                documentContentsChanged(document, position, charsRemoved, charsAdded);
-            });
-
-    auto *oldCompletionProvider = qobject_cast<DocumentContentCompletionProvider *>(
-        document->completionAssistProvider());
-    // only replace the completion assist provider if it is the default one or null
-    if (oldCompletionProvider || !document->completionAssistProvider())
-        document->setCompletionAssistProvider(m_clientProviders.completionAssistProvider);
-    m_resetAssistProvider[document] = {oldCompletionProvider,
-                                       document->functionHintAssistProvider(),
-                                       document->quickFixAssistProvider()};
-    document->setFunctionHintAssistProvider(m_clientProviders.functionHintProvider);
-    document->setQuickFixAssistProvider(m_clientProviders.quickFixAssistProvider);
-    connect(document, &QObject::destroyed, this, [this, document] {
-        m_resetAssistProvider.remove(document);
+        documentContentsChanged(document, position, charsRemoved, charsAdded);
     });
-    const QString &text = document->plainText();
-    m_openedDocument.insert(document, text);
-
     TextDocumentItem item;
     item.setLanguageId(TextDocumentItem::mimeTypeToLanguageId(document->mimeType()));
-    item.setUri(uri);
-    item.setText(text);
+    item.setUri(DocumentUri::fromFilePath(filePath));
+    item.setText(document->plainText());
     item.setVersion(document->document()->revision());
     sendContent(DidOpenTextDocumentNotification(DidOpenTextDocumentParams(item)));
 
-    return true;
+    if (LanguageClientManager::clientForDocument(document) == this)
+        activateDocument(document);
 }
 
 void Client::sendContent(const IContent &content)
@@ -371,7 +355,38 @@ void Client::closeDocument(TextEditor::TextDocument *document)
     const DidCloseTextDocumentParams params(TextDocumentIdentifier{uri});
     m_highlights[uri].clear();
     sendContent(uri, DidCloseTextDocumentNotification(params));
+    deactivateDocument(document);
+}
+
+void Client::activateDocument(TextEditor::TextDocument *document)
+{
+    auto uri = DocumentUri::fromFilePath(document->filePath());
+    showDiagnostics(uri);
+    SemanticHighligtingSupport::applyHighlight(document, m_highlights.value(uri), capabilities());
+    // only replace the assist provider if the completion provider is the default one or null
+    if (!document->completionAssistProvider()
+        || qobject_cast<TextEditor::DocumentContentCompletionProvider *>(
+            document->completionAssistProvider())) {
+        m_resetAssistProvider[document] = {document->completionAssistProvider(),
+                                           document->functionHintAssistProvider(),
+                                           document->quickFixAssistProvider()};
+        document->setCompletionAssistProvider(m_clientProviders.completionAssistProvider);
+        document->setFunctionHintAssistProvider(m_clientProviders.functionHintProvider);
+        document->setQuickFixAssistProvider(m_clientProviders.quickFixAssistProvider);
+    }
+    for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document)) {
+        updateEditorToolBar(editor);
+        if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor))
+            textEditor->editorWidget()->addHoverHandler(hoverHandler());
+    }
+}
+
+void Client::deactivateDocument(TextEditor::TextDocument *document)
+{
+    hideDiagnostics(document);
     resetAssistProviders(document);
+    if (TextEditor::SyntaxHighlighter *highlighter = document->syntaxHighlighter())
+        highlighter->clearAllExtraFormats();
 }
 
 bool Client::documentOpen(TextEditor::TextDocument *document) const
@@ -835,6 +850,8 @@ void Client::showDiagnostics(Core::IDocument *doc)
 
 void Client::hideDiagnostics(TextEditor::TextDocument *doc)
 {
+    if (!doc)
+        return;
     DocumentUri uri = DocumentUri::fromFilePath(doc->filePath());
     for (TextMark *mark : m_diagnostics.value(uri))
         doc->removeMark(mark);
@@ -1038,9 +1055,12 @@ void Client::handleDiagnostics(const PublishDiagnosticsParams &params)
         Utils::transform(diagnostics, [fileName = uri.toFilePath()](const Diagnostic &diagnostic) {
             return new TextMark(fileName, diagnostic);
     });
-    showDiagnostics(uri);
-
-    requestCodeActions(uri, diagnostics);
+    // TextMarks are already added in the TextEditor::TextMark constructor
+    // so hide them if we are not the active client for this document
+    if (LanguageClientManager::clientForUri(uri) != this)
+        hideDiagnostics(TextEditor::TextDocument::textDocumentForFileName(uri.toFilePath()));
+    else
+        requestCodeActions(uri, diagnostics);
 }
 
 void Client::handleSemanticHighlight(const SemanticHighlightingParams &params)
@@ -1051,8 +1071,10 @@ void Client::handleSemanticHighlight(const SemanticHighlightingParams &params)
     TextEditor::TextDocument *doc = TextEditor::TextDocument::textDocumentForFileName(
         uri.toFilePath());
 
-    if (!doc || (!version.isNull() && doc->document()->revision() != version.value()))
+    if (!doc || LanguageClientManager::clientForDocument(doc) != this
+        || (!version.isNull() && doc->document()->revision() != version.value())) {
         return;
+    }
 
     const TextEditor::HighlightingResults results = SemanticHighligtingSupport::generateResults(
         params.lines());
@@ -1066,8 +1088,10 @@ void Client::rehighlight()
 {
     using namespace TextEditor;
     for (auto it = m_highlights.begin(), end = m_highlights.end(); it != end; ++it) {
-        if (TextDocument *doc = TextDocument::textDocumentForFileName(it.key().toFilePath()))
-            SemanticHighligtingSupport::applyHighlight(doc, it.value(), capabilities());
+        if (TextDocument *doc = TextDocument::textDocumentForFileName(it.key().toFilePath())) {
+            if (LanguageClientManager::clientForDocument(doc) == this)
+                SemanticHighligtingSupport::applyHighlight(doc, it.value(), capabilities());
+        }
     }
 }
 
@@ -1131,6 +1155,10 @@ void Client::intializeCallback(const InitializeRequest::Response &initResponse)
             .value_or(capabilities().documentSymbolProvider().value_or(false))) {
         TextEditor::IOutlineWidgetFactory::updateOutline();
     }
+
+    for (TextEditor::TextDocument *document : m_openedDocument.keys())
+        openDocument(document);
+
     emit initialized(m_serverCapabilities);
 }
 
diff --git a/src/plugins/languageclient/client.h b/src/plugins/languageclient/client.h
index eadcdfefd4..eca70444a6 100644
--- a/src/plugins/languageclient/client.h
+++ b/src/plugins/languageclient/client.h
@@ -95,8 +95,10 @@ public:
     bool reachable() const { return m_state == Initialized; }
 
     // document synchronization
-    bool openDocument(TextEditor::TextDocument *document);
+    void openDocument(TextEditor::TextDocument *document);
     void closeDocument(TextEditor::TextDocument *document);
+    void activateDocument(TextEditor::TextDocument *document);
+    void deactivateDocument(TextEditor::TextDocument *document);
     bool documentOpen(TextEditor::TextDocument *document) const;
     void documentContentsSaved(TextEditor::TextDocument *document);
     void documentWillSave(Core::IDocument *document);
diff --git a/src/plugins/languageclient/languageclientmanager.cpp b/src/plugins/languageclient/languageclientmanager.cpp
index e84d69768e..923b521bfd 100644
--- a/src/plugins/languageclient/languageclientmanager.cpp
+++ b/src/plugins/languageclient/languageclientmanager.cpp
@@ -117,9 +117,6 @@ void LanguageClientManager::startClient(Client *client)
             &Client::initialized,
             &managerInstance->m_currentDocumentLocatorFilter,
             &DocumentLocatorFilter::updateCurrentClient);
-    connect(client, &Client::initialized, managerInstance, [client]() {
-        managerInstance->clientInitialized(client);
-    });
 }
 
 Client *LanguageClientManager::startClient(BaseSettings *setting, ProjectExplorer::Project *project)
@@ -301,19 +298,23 @@ Client *LanguageClientManager::clientForDocument(TextEditor::TextDocument *docum
     return document == nullptr ? nullptr : managerInstance->m_clientForDocument[document].data();
 }
 
-bool LanguageClientManager::reOpenDocumentWithClient(TextEditor::TextDocument *document, Client *client)
+Client *LanguageClientManager::clientForFilePath(const Utils::FilePath &filePath)
 {
-    Utils::ExecuteOnDestruction outlineUpdater(&TextEditor::IOutlineWidgetFactory::updateOutline);
-    if (Client *currentClient = clientForDocument(document)) {
-        currentClient->closeDocument(document);
-        currentClient->hideDiagnostics(document);
-    }
-    managerInstance->m_clientForDocument.remove(document);
-    if (!managerInstance->openDocumentWithClient(document, client))
-        return false;
+    return clientForDocument(TextEditor::TextDocument::textDocumentForFileName(filePath));
+}
 
-    client->showDiagnostics(document);
-    return true;
+Client *LanguageClientManager::clientForUri(const DocumentUri &uri)
+{
+    return clientForFilePath(uri.toFilePath());
+}
+
+void LanguageClientManager::reOpenDocumentWithClient(TextEditor::TextDocument *document, Client *client)
+{
+    Utils::ExecuteOnDestruction outlineUpdater(&TextEditor::IOutlineWidgetFactory::updateOutline);
+    if (Client *currentClient = clientForDocument(document))
+        currentClient->deactivateDocument(document);
+    managerInstance->m_clientForDocument[document] = client;
+    client->activateDocument(document);
 }
 
 QVector<Client *> LanguageClientManager::reachableClients()
@@ -332,19 +333,6 @@ void LanguageClientManager::sendToAllReachableServers(const IContent &content)
     sendToInterfaces(content, reachableClients());
 }
 
-void LanguageClientManager::clientInitialized(Client *client)
-{
-    for (auto document : m_clientForDocument.keys(client)) {
-        if (client->openDocument(document)) {
-            for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document)) {
-                updateEditorToolBar(editor);
-                if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor))
-                    textEditor->editorWidget()->addHoverHandler(client->hoverHandler());
-            }
-        }
-    }
-}
-
 void LanguageClientManager::clientFinished(Client *client)
 {
     constexpr int restartTimeoutS = 5;
@@ -372,27 +360,23 @@ void LanguageClientManager::editorOpened(Core::IEditor *editor)
     if (auto *textEditor = qobject_cast<BaseTextEditor *>(editor)) {
         if (TextEditorWidget *widget = textEditor->editorWidget()) {
             connect(widget, &TextEditorWidget::requestLinkAt, this,
-                    [this, filePath = editor->document()->filePath()]
+                    [this, document = textEditor->textDocument()]
                     (const QTextCursor &cursor, Utils::ProcessLinkCallback &callback) {
-                        findLinkAt(filePath, cursor, callback);
+                        findLinkAt(document, cursor, callback);
                     });
             connect(widget, &TextEditorWidget::requestUsages, this,
-                    [this, filePath = editor->document()->filePath()]
-                    (const QTextCursor &cursor){
-                        findUsages(filePath, cursor);
-                    });
-            connect(widget, &TextEditorWidget::cursorPositionChanged, this, [this, widget](){
-                        // TODO This would better be a compressing timer
-                        QTimer::singleShot(50, this,
-                                           [this, widget = QPointer<TextEditorWidget>(widget)]() {
-                            if (widget) {
-                                for (Client *client : this->reachableClients()) {
-                                    if (client->isSupportedDocument(widget->textDocument()))
-                                        client->cursorPositionChanged(widget);
-                                }
-                            }
-                        });
+                    [this, document = textEditor->textDocument()](const QTextCursor &cursor) {
+                        findUsages(document, cursor);
                     });
+            connect(widget, &TextEditorWidget::cursorPositionChanged, this, [this, widget]() {
+                // TODO This would better be a compressing timer
+                QTimer::singleShot(50, this, [widget = QPointer<TextEditorWidget>(widget)]() {
+                    if (!widget)
+                        return;
+                    if (Client *client = clientForDocument(widget->textDocument()))
+                        client->cursorPositionChanged(widget);
+                });
+            });
             updateEditorToolBar(editor);
             if (TextEditor::TextDocument *document = textEditor->textDocument()) {
                 if (Client *client = m_clientForDocument[document])
@@ -409,7 +393,6 @@ void LanguageClientManager::documentOpened(Core::IDocument *document)
         return;
 
     // check whether we have to start servers for this document
-    bool opened = false;
     for (BaseSettings *setting : LanguageClientSettings::currentPageSettings()) {
         QVector<Client *> clients = clientForSetting(setting);
         if (setting->isValid() && setting->m_enabled
@@ -434,28 +417,20 @@ void LanguageClientManager::documentOpened(Core::IDocument *document)
             } else if (setting->m_startBehavior == BaseSettings::RequiresFile && clients.isEmpty()) {
                 clients << startClient(setting);
             }
-            if (opened || clients.isEmpty())
-                continue;
-
             for (auto client : clients) {
-                if (openDocumentWithClient(textDocument, client)) {
-                    opened = true;
-                    continue;
-                }
+                openDocumentWithClient(textDocument, client);
+                if (m_clientForDocument.value(textDocument).isNull())
+                    m_clientForDocument[textDocument] = client;
             }
         }
     }
 }
 
-bool LanguageClientManager::openDocumentWithClient(TextEditor::TextDocument *document,
+void LanguageClientManager::openDocumentWithClient(TextEditor::TextDocument *document,
                                                    Client *client)
 {
-    if (!client || client->state() == Client::Error)
-        return false;
-    m_clientForDocument[document] = client;
-    if (client->state() == Client::Initialized)
-        return client->openDocument(document);
-    return true;
+    if (client && client->state() != Client::Error)
+        client->openDocument(document);
 }
 
 void LanguageClientManager::documentClosed(Core::IDocument *document)
@@ -483,14 +458,14 @@ void LanguageClientManager::documentWillSave(Core::IDocument *document)
     }
 }
 
-void LanguageClientManager::findLinkAt(const Utils::FilePath &filePath,
+void LanguageClientManager::findLinkAt(TextEditor::TextDocument *document,
                                        const QTextCursor &cursor,
                                        Utils::ProcessLinkCallback callback)
 {
-    const DocumentUri uri = DocumentUri::fromFilePath(filePath);
-    const TextDocumentIdentifier document(uri);
+    const DocumentUri uri = DocumentUri::fromFilePath(document->filePath());
+    const TextDocumentIdentifier documentId(uri);
     const Position pos(cursor);
-    TextDocumentPositionParams params(document, pos);
+    TextDocumentPositionParams params(documentId, pos);
     GotoDefinitionRequest request(params);
     request.setResponseCallback([callback](const GotoDefinitionRequest::Response &response){
         if (Utils::optional<GotoResult> _result = response.result()) {
@@ -547,14 +522,14 @@ QList<Core::SearchResultItem> generateSearchResultItems(const LanguageClientArra
     return result;
 }
 
-void LanguageClientManager::findUsages(const Utils::FilePath &filePath, const QTextCursor &cursor)
+void LanguageClientManager::findUsages(TextEditor::TextDocument *document, const QTextCursor &cursor)
 {
-    const DocumentUri uri = DocumentUri::fromFilePath(filePath);
-    const TextDocumentIdentifier document(uri);
+    const DocumentUri uri = DocumentUri::fromFilePath(document->filePath());
+    const TextDocumentIdentifier documentId(uri);
     const Position pos(cursor);
     QTextCursor termCursor(cursor);
     termCursor.select(QTextCursor::WordUnderCursor);
-    ReferenceParams params(TextDocumentPositionParams(document, pos));
+    ReferenceParams params(TextDocumentPositionParams(documentId, pos));
     params.setContext(ReferenceParams::ReferenceContext(true));
     FindReferencesRequest request(params);
     auto callback = [this, wordUnderCursor = termCursor.selectedText()]
diff --git a/src/plugins/languageclient/languageclientmanager.h b/src/plugins/languageclient/languageclientmanager.h
index f12e2f9d48..8c03eaa26b 100644
--- a/src/plugins/languageclient/languageclientmanager.h
+++ b/src/plugins/languageclient/languageclientmanager.h
@@ -77,7 +77,9 @@ public:
     static QVector<Client *> clientForSetting(const BaseSettings *setting);
     static const BaseSettings *settingForClient(Client *setting);
     static Client *clientForDocument(TextEditor::TextDocument *document);
-    static bool reOpenDocumentWithClient(TextEditor::TextDocument *document, Client *client);
+    static Client *clientForFilePath(const Utils::FilePath &filePath);
+    static Client *clientForUri(const LanguageServerProtocol::DocumentUri &uri);
+    static void reOpenDocumentWithClient(TextEditor::TextDocument *document, Client *client);
 
 signals:
     void shutdownFinished();
@@ -87,13 +89,13 @@ private:
 
     void editorOpened(Core::IEditor *editor);
     void documentOpened(Core::IDocument *document);
-    bool openDocumentWithClient(TextEditor::TextDocument *document, Client *client);
+    void openDocumentWithClient(TextEditor::TextDocument *document, Client *client);
     void documentClosed(Core::IDocument *document);
     void documentContentsSaved(Core::IDocument *document);
     void documentWillSave(Core::IDocument *document);
-    void findLinkAt(const Utils::FilePath &filePath, const QTextCursor &cursor,
+    void findLinkAt(TextEditor::TextDocument *document, const QTextCursor &cursor,
                     Utils::ProcessLinkCallback callback);
-    void findUsages(const Utils::FilePath &filePath, const QTextCursor &cursor);
+    void findUsages(TextEditor::TextDocument *document, const QTextCursor &cursor);
 
     void projectAdded(ProjectExplorer::Project *project);
     void projectRemoved(ProjectExplorer::Project *project);
@@ -101,7 +103,6 @@ private:
     QVector<Client *> reachableClients();
     void sendToAllReachableServers(const LanguageServerProtocol::IContent &content);
 
-    void clientInitialized(Client *client);
     void clientFinished(Client *client);
 
     bool m_shuttingDown = false;