webui: ensure that CEF works with local communication

Special handling of file responses required.
When file not exists, 404 reqply shoould be returned

gui/cefdisplay/src/simple_app.cxx

@@ -84,9 +84,10 @@ public:
 
    int fTransferOffset{0};
 
-   explicit TGuiResourceHandler()
+   explicit TGuiResourceHandler(bool dummy = false)
    {
-      fArg = std::make_shared<TCefHttpCallArg>();
+      if (!dummy)
+         fArg = std::make_shared<TCefHttpCallArg>();
    }
 
    virtual ~TGuiResourceHandler() {}
@@ -97,9 +98,12 @@ public:
    {
       CEF_REQUIRE_IO_THREAD();
 
-      fArg->AssignCallback(callback);
-
-      gHandlingServer->SubmitHttp(fArg);
+      if (fArg) {
+         fArg->AssignCallback(callback);
+         gHandlingServer->SubmitHttp(fArg);
+      } else {
+         callback->Continue();
+      }
 
       return true;
    }
@@ -108,7 +112,7 @@ public:
    {
       CEF_REQUIRE_IO_THREAD();
 
-      if (fArg->Is404()) {
+      if (!fArg || fArg->Is404()) {
          response->SetMimeType("text/html");
          response->SetStatus(404);
          response_length = 0;
@@ -117,16 +121,14 @@ public:
          response->SetStatus(200);
          response_length = fArg->GetContentLength();
 
-         printf("SET RESPONSE len %d type %s\n", (int) response_length, fArg->GetContentType());
-
          if (fArg->NumHeader() > 0) {
-            printf("******* Response with extra headers\n");
+            // printf("******* Response with extra headers\n");
             CefResponse::HeaderMap headers;
             for (Int_t n = 0; n < fArg->NumHeader(); ++n) {
                TString name = fArg->GetHeaderName(n);
                TString value = fArg->GetHeader(name.Data());
                headers.emplace(CefString(name.Data()), CefString(value.Data()));
-               printf("   header %s %s\n", name.Data(), value.Data());
+               // printf("   header %s %s\n", name.Data(), value.Data());
             }
             response->SetHeaderMap(headers);
          }
@@ -216,8 +218,6 @@ public:
    {
       std::string addr = request->GetURL().ToString();
 
-      printf("REQUEST %s\n", addr.c_str());
-
       TUrl url(addr.c_str());
 
       const char *inp_path = url.GetFile();
@@ -229,15 +229,11 @@ public:
       if (gHandlingServer->IsFileRequested(inp_path, fname)) {
          // process file - no need for special requests handling
 
-         const char *mime = THttpServer::GetMimeType(fname.Data());
-
-         // static std::string str_content = THttpServer::ReadFileContent(fname.Data());
-
-         printf("Sending file %s mime %s\n", fname.Data(), mime);
+         // when file not exists - return nullptr
+         if (gSystem->AccessPathName(fname.Data()))
+            return new TGuiResourceHandler(true);
 
-         // Create a stream reader for |html_content|.
-         //CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForData(
-         //   static_cast<void *>(const_cast<char *>(str_content.c_str())), str_content.size());
+         const char *mime = THttpServer::GetMimeType(fname.Data());
 
          CefRefPtr<CefStreamReader> stream = CefStreamReader::CreateForFile(fname.Data());
 
@@ -248,7 +244,7 @@ public:
 
       std::string inp_method = request->GetMethod().ToString();
 
-      printf("REQUEST METHOD %s\n", inp_method.c_str());
+      // printf("REQUEST METHOD %s\n", inp_method.c_str());
 
       TGuiResourceHandler *handler = new TGuiResourceHandler();
       handler->fArg->SetMethod(inp_method.c_str());
@@ -311,7 +307,7 @@ void SimpleApp::OnBeforeCommandLineProcessing(const CefString &process_type, Cef
 {
    std::string name = process_type.ToString();
    std::string prog = command_line->GetProgram().ToString();
-   printf("OnBeforeCommandLineProcessing %s %s\n", name.c_str(), prog.c_str());
+   // printf("OnBeforeCommandLineProcessing %s %s\n", name.c_str(), prog.c_str());
 //   if (fBatch) {
 //      command_line->AppendSwitch("disable-gpu");
 //      command_line->AppendSwitch("disable-gpu-compositing");
@@ -324,8 +320,7 @@ void SimpleApp::OnBeforeChildProcessLaunch(CefRefPtr<CefCommandLine> command_lin
    std::string newprog = fCefMain;
    command_line->SetProgram(newprog);
 
-   printf("OnBeforeChildProcessLaunch %s LastBatch %s\n", command_line->GetProgram().ToString().c_str(), fLastBatch ? "true" : "false");
-
+   // printf("OnBeforeChildProcessLaunch %s LastBatch %s\n", command_line->GetProgram().ToString().c_str(), fLastBatch ? "true" : "false");
 
    if (fLastBatch) {
       command_line->AppendSwitch("disable-webgl");
@@ -334,17 +329,15 @@ void SimpleApp::OnBeforeChildProcessLaunch(CefRefPtr<CefCommandLine> command_lin
 //      command_line->AppendSwitch("disable-gpu-sandbox");
    }
 
-   auto str = command_line->GetCommandLineString().ToString();
-   printf("RUNNING %s\n", str.c_str());
-
-
+   // auto str = command_line->GetCommandLineString().ToString();
+   // printf("RUN %s\n", str.c_str());
 }
 
 void SimpleApp::OnContextInitialized()
 {
    CEF_REQUIRE_UI_THREAD();
 
-   // CefRegisterSchemeHandlerFactory("http", "rootserver.local", new ROOTSchemeHandlerFactory());
+   CefRegisterSchemeHandlerFactory("http", "rootserver.local", new ROOTSchemeHandlerFactory());
 
    if (!fFirstUrl.empty())
       StartWindow(fFirstUrl, fFirstBatch, fFirstRect);
@@ -527,19 +520,19 @@ protected:
 
          // cef_string_ascii_to_utf16(path2.Data(), path2.Length(), &settings.locales_dir_path);
 
-         // settings.no_sandbox = 1;
+         settings.no_sandbox = 1;
          // if (gROOT->IsWebDisplayBatch()) settings.single_process = true;
 
          // if (batch_mode)
          // settings.windowless_rendering_enabled = true;
 
-         settings.external_message_pump = true;
-         settings.multi_threaded_message_loop = false;
+         // settings.external_message_pump = true;
+         // settings.multi_threaded_message_loop = false;
 
          std::string plog = "cef.log";
          cef_string_ascii_to_utf16(plog.c_str(), plog.length(), &settings.log_file);
 
-         settings.log_severity = LOGSEVERITY_VERBOSE; // LOGSEVERITY_INFO, LOGSEVERITY_WARNING, LOGSEVERITY_ERROR, LOGSEVERITY_DISABLE
+         settings.log_severity = LOGSEVERITY_VERBOSE; // LOGSEVERITY_VERBOSE, LOGSEVERITY_INFO, LOGSEVERITY_WARNING, LOGSEVERITY_ERROR, LOGSEVERITY_DISABLE
          // settings.uncaught_exception_stack_size = 100;
          // settings.ignore_certificate_errors = true;