Print Preview: Change getPrivetPrinters to cr.sendWithPromise

chrome/browser/ui/webui/print_preview/print_preview_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
 
 #include <ctype.h>
 #include <stddef.h>
 
 #include <map>
@@ skipping 181 matching lines @@
 const char kCloudPrintUrl[] = "cloudPrintUrl";
 // Name of a dictionary field holding the state of selection for document.
 const char kDocumentHasSelection[] = "documentHasSelection";
 // Dictionary field holding the default destination selection rules.
 const char kDefaultDestinationSelectionRules[] =
     "defaultDestinationSelectionRules";
 
 // Id of the predefined PDF printer.
 const char kLocalPdfPrinterId[] = "Save as PDF";
 
+// Timeout for searching for privet printers, in seconds.
+const int kPrivetTimeoutSec = 5;
+
 // Get the print job settings dictionary from |args|. The caller takes
 // ownership of the returned DictionaryValue. Returns NULL on failure.
 std::unique_ptr<base::DictionaryValue> GetSettingsDictionary(
     const base::ListValue* args) {
   std::string json_str;
   if (!args->GetString(0, &json_str)) {
     NOTREACHED() << "Could not read JSON argument";
     return NULL;
   }
   if (json_str.empty()) {
@@ skipping 396 matching lines @@
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("getInitialSettings",
       base::Bind(&PrintPreviewHandler::HandleGetInitialSettings,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("forceOpenNewTab",
       base::Bind(&PrintPreviewHandler::HandleForceOpenNewTab,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("getPrivetPrinters",
       base::Bind(&PrintPreviewHandler::HandleGetPrivetPrinters,
                  base::Unretained(this)));
-  web_ui()->RegisterMessageCallback("stopGetPrivetPrinters",
-      base::Bind(&PrintPreviewHandler::HandleStopGetPrivetPrinters,
-                 base::Unretained(this)));
   web_ui()->RegisterMessageCallback("getPrivetPrinterCapabilities",
       base::Bind(&PrintPreviewHandler::HandleGetPrivetPrinterCapabilities,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "getExtensionPrinters",
       base::Bind(&PrintPreviewHandler::HandleGetExtensionPrinters,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "getExtensionPrinterCapabilities",
       base::Bind(&PrintPreviewHandler::HandleGetExtensionPrinterCapabilities,
@@ skipping 37 matching lines @@
   CHECK(!callback_id.empty());
 
   AllowJavascript();
 
   printer_backend_proxy()->EnumeratePrinters(
       base::Bind(&PrintPreviewHandler::SetupPrinterList,
                  weak_factory_.GetWeakPtr(), callback_id));
 }
 
 void PrintPreviewHandler::HandleGetPrivetPrinters(const base::ListValue* args) {
-  if (!PrivetPrintingEnabled())
-    return web_ui()->CallJavascriptFunctionUnsafe("onPrivetPrinterSearchDone");
+  std::string callback_id;
+  CHECK(args->GetString(0, &callback_id));
+  CHECK(!callback_id.empty());
+
+  AllowJavascript();
+
+  if (!PrivetPrintingEnabled()) {
+    RejectJavascriptCallback(base::Value(callback_id), base::Value(false));
+  }
 #if BUILDFLAG(ENABLE_SERVICE_DISCOVERY)
   using local_discovery::ServiceDiscoverySharedClient;
   scoped_refptr<ServiceDiscoverySharedClient> service_discovery =
       ServiceDiscoverySharedClient::GetInstance();
+  privet_callback_id_ = callback_id;

[dpapad, 2017/06/06 21:16:33]

Should we assert that privet_callback_id_ is not already before assigning a new
value?

[rbpotter, 2017/06/07 02:37:46]

Done.

   StartPrivetLister(service_discovery);
 #endif
 }
 
-void PrintPreviewHandler::HandleStopGetPrivetPrinters(
-    const base::ListValue* args) {
+void PrintPreviewHandler::StopPrivetLister() {
 #if BUILDFLAG(ENABLE_SERVICE_DISCOVERY)
+  privet_lister_timer_.reset();
   if (PrivetPrintingEnabled() && printer_lister_) {
     printer_lister_->Stop();
   }
+  ResolveJavascriptCallback(base::Value(privet_callback_id_),
+                            base::Value(true));
 #endif
 }
 
 void PrintPreviewHandler::HandleGetPrivetPrinterCapabilities(
     const base::ListValue* args) {
 #if BUILDFLAG(ENABLE_SERVICE_DISCOVERY)
   std::string name;
   bool success = args->GetString(0, &name);
   DCHECK(success);
 
@@ skipping 816 matching lines @@
   DCHECK(tmp_data->front());
 
   *data = tmp_data;
   *title = print_preview_ui()->initiator_title();
   return true;
 }
 
 #if BUILDFLAG(ENABLE_SERVICE_DISCOVERY)
 void PrintPreviewHandler::StartPrivetLister(const scoped_refptr<
     local_discovery::ServiceDiscoverySharedClient>& client) {
-  if (!PrivetPrintingEnabled())
-    return web_ui()->CallJavascriptFunctionUnsafe("onPrivetPrinterSearchDone");
-
   Profile* profile = Profile::FromWebUI(web_ui());
   DCHECK(!service_discovery_client_.get() ||
          service_discovery_client_.get() == client.get());
   service_discovery_client_ = client;
   printer_lister_ = base::MakeUnique<cloud_print::PrivetLocalPrinterLister>(
       service_discovery_client_.get(), profile->GetRequestContext(), this);
+  privet_lister_timer_.reset(new base::OneShotTimer());
+  privet_lister_timer_->Start(FROM_HERE,
+                              base::TimeDelta::FromSeconds(kPrivetTimeoutSec),
+                              this, &PrintPreviewHandler::StopPrivetLister);
   printer_lister_->Start();
 }
 
 void PrintPreviewHandler::LocalPrinterChanged(
     const std::string& name,
     bool has_local_printing,
     const cloud_print::DeviceDescription& description) {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (has_local_printing ||
       command_line->HasSwitch(switches::kEnablePrintPreviewRegisterPromos)) {
     base::DictionaryValue info;
     FillPrinterDescription(name, description, has_local_printing, &info);
-    web_ui()->CallJavascriptFunctionUnsafe("onPrivetPrinterChanged", info);
+    FireWebUIListener("privet-printer-added", info);
   }
 }
 
 void PrintPreviewHandler::LocalPrinterRemoved(const std::string& name) {
 }
 
 void PrintPreviewHandler::LocalPrinterCacheFlushed() {
 }
 
 void PrintPreviewHandler::PrivetCapabilitiesUpdateClient(
@@ skipping 242 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }