Add printer status backend for Chrome OS Print Preview

- Accepts a printer id, kicks off a printer status request, then
  once complete broadcasts the status to "printer-status-update".

Bug: 1059607
Change-Id: I91b30632a6682a4705616d714038a7826483753c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2128236
Commit-Queue: Gavin Williams <gavinwill@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760330}

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

@@ -30,6 +30,7 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/debug_daemon/debug_daemon_client.h"
 #include "chromeos/printing/printer_configuration.h"
+#include "chromeos/printing/printer_translator.h"
 #include "components/prefs/pref_service.h"
 #include "components/printing/browser/printer_capabilities.h"
 #include "content/public/browser/browser_task_traits.h"
@@ -238,6 +239,22 @@ void LocalPrinterHandlerChromeos::StartGetEulaUrl(
                      weak_factory_.GetWeakPtr(), std::move(cb)));
 }
 
+void LocalPrinterHandlerChromeos::StartPrinterStatusRequest(
+    const std::string& printer_id,
+    PrinterStatusRequestCallback callback) {
+  printers_manager_->FetchPrinterStatus(
+      printer_id,
+      base::BindOnce(&LocalPrinterHandlerChromeos::OnPrinterStatusUpdated,
+                     weak_factory_.GetWeakPtr(), std::move(callback)));
+}
+
+void LocalPrinterHandlerChromeos::OnPrinterStatusUpdated(
+    PrinterStatusRequestCallback callback,
+    const chromeos::CupsPrinterStatus& cups_printers_status) {
+  std::move(callback).Run(
+      CreateCupsPrinterStatusDictionary(cups_printers_status));
+}
+
 void LocalPrinterHandlerChromeos::OnPrinterInstalled(
     const chromeos::Printer& printer,
     GetCapabilityCallback cb,

chrome/browser/ui/webui/print_preview/local_printer_handler_chromeos.h

@@ -54,6 +54,9 @@ class LocalPrinterHandlerChromeos : public PrinterHandler {
                   PrintCallback callback) override;
   void StartGetEulaUrl(const std::string& destination_id,
                        GetEulaUrlCallback cb) override;
+  void StartPrinterStatusRequest(
+      const std::string& printer_id,
+      PrinterStatusRequestCallback callback) override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(LocalPrinterHandlerChromeosTest,
@@ -83,6 +86,10 @@ class LocalPrinterHandlerChromeos : public PrinterHandler {
                           bool record_usb_setup_source,
                           chromeos::PrinterSetupResult result);
 
+  void OnPrinterStatusUpdated(
+      PrinterStatusRequestCallback callback,
+      const chromeos::CupsPrinterStatus& cups_printers_status);
+
   Profile* const profile_;
   content::WebContents* const preview_web_contents_;
   chromeos::CupsPrintersManager* printers_manager_;

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

@@ -649,6 +649,11 @@ void PrintPreviewHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       "getEulaUrl", base::BindRepeating(&PrintPreviewHandler::HandleGetEulaUrl,
                                         base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      "requestPrinterStatus",
+      base::BindRepeating(
+          &PrintPreviewHandler::HandleRequestPrinterStatusUpdate,
+          base::Unretained(this)));
 #endif
 }
 
@@ -1586,4 +1591,23 @@ void PrintPreviewHandler::SendManipulateSettingsForTest(
   FireWebUIListener("manipulate-settings-for-test", settings);
 }
 
+#if defined(OS_CHROMEOS)
+void PrintPreviewHandler::HandleRequestPrinterStatusUpdate(
+    const base::ListValue* args) {
+  CHECK_EQ(1U, args->GetList().size());
+  PrinterHandler* handler = GetPrinterHandler(PrinterType::kLocal);
+  handler->StartPrinterStatusRequest(
+      args->GetList()[0].GetString(),
+      base::BindOnce(&PrintPreviewHandler::OnPrinterStatusUpdated,
+                     weak_factory_.GetWeakPtr()));
+}
+
+void PrintPreviewHandler::OnPrinterStatusUpdated(
+    const base::Value& cups_printer_status) {
+  // "printer-status-update" will also trigger non-PrintPreview UI for
+  // consuming fresh printer statuses.
+  FireWebUIListener("printer-status-update", cups_printer_status);
+}
+#endif
+
 }  // namespace printing

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

@@ -310,6 +310,14 @@ class PrintPreviewHandler : public content::WebUIMessageHandler,
   void OnPrintResult(const std::string& callback_id,
                      const base::Value& error);
 
+#if defined(OS_CHROMEOS)
+  // Called to initiate a status request for a printer.
+  void HandleRequestPrinterStatusUpdate(const base::ListValue* args);
+
+  // Invokes Web UI Listener "printer-status-update" with new printer status.
+  void OnPrinterStatusUpdated(const base::Value& cups_printer_status);
+#endif
+
   // A count of how many requests received to regenerate preview data.
   // Initialized to 0 then incremented and emitted to a histogram.
   int regenerate_preview_request_count_ = 0;

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

@@ -70,6 +70,12 @@ void PrinterHandler::StartGetEulaUrl(const std::string& destination_id,
                                      GetEulaUrlCallback callback) {
   NOTREACHED();
 }
+
+void PrinterHandler::StartPrinterStatusRequest(
+    const std::string& printer_id,
+    PrinterStatusRequestCallback callback) {
+  NOTREACHED();
+}
 #endif
 
 }  // namespace printing

chrome/browser/ui/webui/print_preview/printer_handler.h

@@ -52,6 +52,8 @@ class PrinterHandler {
 #if defined(OS_CHROMEOS)
   using GetEulaUrlCallback =
       base::OnceCallback<void(const std::string& license)>;
+  using PrinterStatusRequestCallback =
+      base::OnceCallback<void(const base::Value& cups_printer_status)>;
 #endif
 
   // Creates an instance of a PrinterHandler for extension printers.
@@ -121,6 +123,12 @@ class PrinterHandler {
   // |callback| should be called in response to the request.
   virtual void StartGetEulaUrl(const std::string& destination_id,
                                GetEulaUrlCallback callback);
+
+  // Initiates a status request for specified printer.
+  // |printer_id|: Printer id.
+  // |callback|: should be called in response to the request.
+  virtual void StartPrinterStatusRequest(const std::string& printer_id,
+                                         PrinterStatusRequestCallback callback);
 #endif
 };