Introduce a basic client for the language server protocol

The language server protocol is used to transport language specific
information needed to efficiently edit source files. For example
completion, go to operations and symbol information. These information
are transferred via JSON-RPC. The complete definition can be found under
https://microsoft.github.io/language-server-protocol/specification.

This language server protocol support consists of two major parts, the
C++ representation of the language server protocol, and the client part
for the communication with an external language server.

The TypeScript definitions of the protocol interfaces are transferred to
C++ classes. Those classes have getter and setter for every interface
value. Optional values from the protocol are represented by
Utils::optional<ValueType>. The JSON objects that are used to transfer
the data between client and server are hidden by a specialized
JsonObject class derived from QJsonObject. Additionally this JsonObject
provides a validity check that is capable of creating a detailed error
message for malformed, or at least unexpected JSON representation of the
protocol.

The client is the interface between Qt Creator and language server
functionality, like completion, diagnostics, document and workspace
synchronization. The base client converts the data that is sent from/to
the server between the raw byte array and the corresponding C++ objects.
The transportat layer is defined in a specialized base client (this
initial change will only support stdio language server). The running
clients are handled inside the language client manager, which is also
used to connect global and exclusive Qt Creator functionality to the
clients.

Task-number: QTCREATORBUG-20284
Change-Id: I8e123e20c3f14ff7055c505319696d5096fe1704
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

2 files changed, 7 insertions, 2 deletions

diff --git a/src/plugins/coreplugin/editormanager/editormanager.cpp b/src/plugins/coreplugin/editormanager/editormanager.cpp
index f33143bc40..5c8f39747d 100644
--- a/src/plugins/coreplugin/editormanager/editormanager.cpp
+++ b/src/plugins/coreplugin/editormanager/editormanager.cpp
@@ -2166,8 +2166,10 @@ bool EditorManagerPrivate::saveDocument(IDocument *document)
         success = DocumentManager::saveDocument(document);
     }
 
-    if (success)
+    if (success) {
         addDocumentToRecentFiles(document);
+        emit m_instance->saved(document);
+    }
 
     return success;
 }
@@ -2200,8 +2202,10 @@ bool EditorManagerPrivate::saveDocumentAs(IDocument *document)
     // a good way out either (also the undo stack would be lost). Perhaps the best is to
     // re-think part of the editors design.
 
-    if (success)
+    if (success) {
         addDocumentToRecentFiles(document);
+        emit m_instance->saved(document);
+    }
 
     updateActions();
     return success;
diff --git a/src/plugins/coreplugin/editormanager/editormanager.h b/src/plugins/coreplugin/editormanager/editormanager.h
index 30023e2bc7..6cd9dd88a1 100644
--- a/src/plugins/coreplugin/editormanager/editormanager.h
+++ b/src/plugins/coreplugin/editormanager/editormanager.h
@@ -179,6 +179,7 @@ signals:
     void findOnFileSystemRequest(const QString &path);
     void openFileProperties(const Utils::FileName &path);
     void aboutToSave(IDocument *document);
+    void saved(IDocument *document);
     void autoSaved();
     void currentEditorAboutToChange(Core::IEditor *editor);