List printers managed by extensions in print preview

extensions/browser/api/printer_provider/printer_provider_api.h

 // Copyright 2015 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.
 
 #ifndef EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_API_H_
 #define EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_API_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 31 matching lines @@
     PRINT_ERROR_INVALID_TICKET,
     PRINT_ERROR_INVALID_DATA
   };
 
   // Struct describing print job that should be forwarded to an extension via
   // chrome.printerProvider.onPrintRequested event.
   struct PrintJob {
     PrintJob();
     ~PrintJob();
 
-    // The id of the printer that should handle the print job. This identifies
-    // a printer within an extension and is provided by the extension via
-    // chrome.printerProvider.onGetPrintersRequested event callback.
+    // The id of the printer that should handle the print job. The id is
+    // formatted as <extension_id>:<printer_id>, where <extension_id> is the
+    // id of the extension that manages the printer, and <printer_id> is
+    // the the printer's id within the extension (as reported via
+    // chrome.printerProvider.onGetPrintersRequested event callback).
     std::string printer_id;
 
     // The print job ticket.
     std::string ticket_json;
 
     // Content type of the document that should be printed.
     std::string content_type;
 
     // The document data that should be printed.
     std::string document_bytes;
@@ skipping 11 matching lines @@
   explicit PrinterProviderAPI(content::BrowserContext* browser_context);
   ~PrinterProviderAPI() override;
 
   // Requests list of supported printers from extensions implementing
   // chrome.printerProvider API. It dispatches
   // chrome.printerProvider.onGetPrintersRequested event. The callback is
   // called once for every extension handling the event with a list of its
   // supported printers. The printer values reported by an extension are
   // added "extensionId" property that is set to the ID of the extension
   // returning the list.
+  // Note that the "id" property of printer values reported by an extension are
+  // rewriten as "<extension_id>:<id>" to ensure they are unique across
+  // different extensions.
   void DispatchGetPrintersRequested(const GetPrintersCallback& callback);
 
-  // Requests printer capability from the extension with id |extension_id| for
-  // the printer with id |printer_id|. |printer_id| should be one of the printer
-  // ids reported by |GetPrinters| callback.
+  // Requests printer capability for a printer with id |printer_id|.
+  // |printer_id| should be one of the printer ids reported by |GetPrinters|
+  // callback.
   // It dispatches chrome.printerProvider.onGetCapabilityRequested event
-  // to the extension.
+  // to the extension that manages the printer (which can be determined from
+  // |printer_id| value).
   // |callback| is passed a dictionary value containing printer capabilities as
   // reported by the extension.
-  void DispatchGetCapabilityRequested(const std::string& extension_id,
-                                      const std::string& printer_id,
+  void DispatchGetCapabilityRequested(const std::string& printer_id,
                                       const GetCapabilityCallback& callback);
 
-  // It dispatches chrome.printerProvider.onPrintRequested event to the
-  // extension with id |extension_id| with the provided print job.
+  // It dispatches chrome.printerProvider.onPrintRequested event with the
+  // provided print job. The event is dispatched only to the extension that
+  // manages printer with id |job.printer_id|.
   // |callback| is passed the print status returned by the extension, and it
   // must not be null.
-  void DispatchPrintRequested(const std::string& extension_id,
-                              const PrintJob& job,
+  void DispatchPrintRequested(const PrintJob& job,
                               const PrintCallback& callback);
 
  private:
   friend class BrowserContextKeyedAPIFactory<PrinterProviderAPI>;
 
   // Holds information about a pending onGetPrintersRequested request;
   // in particular, the list of extensions to which the event was dispatched but
   // which haven't yet responded, and the |GetPrinters| callback associated with
   // the event.
   class GetPrintersRequest {
@@ skipping 85 matching lines @@
 
    private:
     int last_request_id_;
     std::map<int, PrintCallback> pending_requests_;
   };
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() { return "PrinterProvider"; }
 
   // PrinterProviderInternalAPIObserver implementation:
-  void OnGetPrintersResult(const Extension* extension,
-                           int request_id,
-                           const base::ListValue& result) override;
+  void OnGetPrintersResult(
+      const Extension* extension,
+      int request_id,
+      const PrinterProviderInternalAPIObserver::PrinterInfoVector& result)
+      override;
   void OnGetCapabilityResult(const Extension* extension,
                              int request_id,
                              const base::DictionaryValue& result) override;
   void OnPrintResult(
       const Extension* extension,
       int request_id,
       core_api::printer_provider_internal::PrintError error) override;
 
   // Called before chrome.printerProvider.onGetPrintersRequested event is
   // dispatched to an extension. It returns whether the extension is interested
@@ skipping 20 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(PrinterProviderAPI);
 };
 
 template <>
 void BrowserContextKeyedAPIFactory<
     PrinterProviderAPI>::DeclareFactoryDependencies();
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_API_H_