LSP: react on file list changed signal from project

Fixes opening projects that lazy load their file lists. For example
CMake projects open without a file list. This list will be generated
after a successful configuration of the project.

When a session is loaded that contains an open document from a project
the document and project open signal is triggered when there is still no
connection between these two. So recheck the project for documents after
the file list got updated.

Also add documents that are already opened before they are assigned to a
project.

Change-Id: I6f2bde0edf88a505116b05efe5564318f2cfb892
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/client.cpp

@@ -842,7 +842,12 @@ const ProjectExplorer::Project *Client::project() const
 
 void Client::setCurrentProject(ProjectExplorer::Project *project)
 {
+    using namespace ProjectExplorer;
+    if (m_project)
+        disconnect(m_project, &Project::fileListChanged, this, &Client::projectFileListChanged);
     m_project = project;
+    if (m_project)
+        connect(m_project, &Project::fileListChanged, this, &Client::projectFileListChanged);
 }
 
 void Client::projectOpened(ProjectExplorer::Project *project)
@@ -878,6 +883,19 @@ void Client::projectClosed(ProjectExplorer::Project *project)
     sendContent(change);
 }
 
+void Client::projectFileListChanged()
+{
+    for (Core::IDocument *doc : Core::DocumentModel::openedDocuments()) {
+        if (m_project->isKnownFile(doc->filePath())) {
+            if (auto textDocument = qobject_cast<TextEditor::TextDocument *>(doc)) {
+                openDocument(textDocument);
+                if (!LanguageClientManager::clientForDocument(textDocument))
+                    LanguageClientManager::reOpenDocumentWithClient(textDocument, this);
+            }
+        }
+    }
+}
+
 void Client::setSupportedLanguage(const LanguageFilter &filter)
 {
     m_languagFilter = filter;

src/plugins/languageclient/client.h

@@ -130,6 +130,7 @@ public:
     const ProjectExplorer::Project *project() const;
     void projectOpened(ProjectExplorer::Project *project);
     void projectClosed(ProjectExplorer::Project *project);
+    void projectFileListChanged();
 
     void sendContent(const LanguageServerProtocol::IContent &content);
     void sendContent(const LanguageServerProtocol::DocumentUri &uri,

src/plugins/languageclient/languageclientmanager.cpp

@@ -35,6 +35,7 @@
 #include <languageserverprotocol/messages.h>
 #include <projectexplorer/session.h>
 #include <projectexplorer/project.h>
+#include <projectexplorer/projectexplorer.h>
 #include <texteditor/texteditor.h>
 #include <texteditor/textmark.h>
 #include <texteditor/textdocument.h>
@@ -75,7 +76,7 @@ LanguageClientManager::LanguageClientManager(QObject *parent)
     connect(EditorManager::instance(), &EditorManager::aboutToSave,
             this, &LanguageClientManager::documentWillSave);
     connect(SessionManager::instance(), &SessionManager::projectAdded,
-            this, &LanguageClientManager::projectAdded);
+            this, &LanguageClientManager::updateProject);
     connect(SessionManager::instance(), &SessionManager::projectRemoved,
             this, &LanguageClientManager::projectRemoved);
 }
@@ -608,7 +609,7 @@ void LanguageClientManager::findUsages(TextEditor::TextDocument *document, const
     }
 }
 
-void LanguageClientManager::projectAdded(ProjectExplorer::Project *project)
+void LanguageClientManager::updateProject(ProjectExplorer::Project *project)
 {
     for (BaseSettings *setting : m_currentSettings) {
         if (setting->isValid()
@@ -618,22 +619,36 @@ void LanguageClientManager::projectAdded(ProjectExplorer::Project *project)
                                      [project](QPointer<Client> client) {
                                          return client->project() == project;
                                      })
-                    == nullptr) {
+                == nullptr) {
+                Client *newClient = nullptr;
                 for (Core::IDocument *doc : Core::DocumentModel::openedDocuments()) {
-                    if (setting->m_languageFilter.isSupported(doc)) {
-                        if (project->isKnownFile(doc->filePath()))
-                            startClient(setting, project);
+                    if (setting->m_languageFilter.isSupported(doc)
+                        && project->isKnownFile(doc->filePath())) {
+                        if (auto textDoc = qobject_cast<TextEditor::TextDocument *>(doc)) {
+                            if (!newClient)
+                                newClient = startClient(setting, project);
+                            if (!newClient)
+                                break;
+                            openDocumentWithClient(textDoc, newClient);
+                            if (m_clientForDocument.value(textDoc) == nullptr)
+                                m_clientForDocument[textDoc] = newClient;
+                        }
                     }
                 }
             }
         }
     }
+    connect(project, &ProjectExplorer::Project::fileListChanged, this, [this, project]() {
+        updateProject(project);
+    });
+
     for (Client *interface : reachableClients())
         interface->projectOpened(project);
 }
 
 void LanguageClientManager::projectRemoved(ProjectExplorer::Project *project)
 {
+    project->disconnect(this);
     for (Client *interface : m_clients)
         interface->projectClosed(project);
 }

src/plugins/languageclient/languageclientmanager.h

@@ -106,7 +106,7 @@ private:
                     Utils::ProcessLinkCallback callback, const bool resolveTarget);
     void findUsages(TextEditor::TextDocument *document, const QTextCursor &cursor);
 
-    void projectAdded(ProjectExplorer::Project *project);
+    void updateProject(ProjectExplorer::Project *project);
     void projectRemoved(ProjectExplorer::Project *project);
 
     QVector<Client *> reachableClients();