Make PrinterProviderAPI a pure interface

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>
 
 #include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted_memory.h"
-#include "base/scoped_observer.h"
-#include "extensions/browser/api/printer_provider_internal/printer_provider_internal_api_observer.h"
-#include "extensions/browser/browser_context_keyed_api_factory.h"
-#include "extensions/browser/extension_registry_observer.h"
+#include "components/keyed_service/core/keyed_service.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
-class Extension;
-class ExtensionRegistry;
-class PrinterProviderInternalAPI;
+struct PrinterProviderPrintJob;
 }
 
 namespace extensions {
 
 // Implements chrome.printerProvider API events.
-class PrinterProviderAPI : public BrowserContextKeyedAPI,
-                           public PrinterProviderInternalAPIObserver,
-                           public ExtensionRegistryObserver {
+class PrinterProviderAPI : public KeyedService {
  public:
-  // 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. 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.
-    scoped_refptr<base::RefCountedMemory> document_bytes;
-  };
-
   using GetPrintersCallback =
       base::Callback<void(const base::ListValue& printers, bool done)>;
   using GetCapabilityCallback =
       base::Callback<void(const base::DictionaryValue& capability)>;
   using PrintCallback =
       base::Callback<void(bool success, const std::string& error)>;
 
-  static BrowserContextKeyedAPIFactory<PrinterProviderAPI>*
-  GetFactoryInstance();
+  static PrinterProviderAPI* Create(content::BrowserContext* context);
 
+  // Returns generic error string for print request.
   static std::string GetDefaultPrintError();
 
-  explicit PrinterProviderAPI(content::BrowserContext* browser_context);
-  ~PrinterProviderAPI() override;
+  // The API currently cannot handle very large files, so the document size that
+  // may be sent to an extension is restricted.
+  // TODO(tbarzic): Fix the API to support huge documents.
+  static const int kMaxDocumentSize = 50 * 1000 * 1000;
 
-  // 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);
+  ~PrinterProviderAPI() override {}
+
+  virtual void DispatchGetPrintersRequested(
+      const GetPrintersCallback& callback) = 0;
 
   // 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 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& printer_id,
-                                      const GetCapabilityCallback& callback);
+  virtual void DispatchGetCapabilityRequested(
+      const std::string& printer_id,
+      const GetCapabilityCallback& callback) = 0;
 
   // 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 PrintJob& job,
-                              const PrintCallback& callback);
-
-  // The API currently cannot handle very large files, so the document size that
-  // may be sent to an extension is restricted.
-  // TODO(tbarzic): Fix the API to support huge documents.
-  static const int kMaxDocumentSize = 50 * 1000 * 1000;
-
- 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 {
-   public:
-    explicit GetPrintersRequest(const GetPrintersCallback& callback);
-    ~GetPrintersRequest();
-
-    // Adds an extension id to the list of the extensions that need to respond
-    // to the event.
-    void AddSource(const std::string& extension_id);
-
-    // Whether all extensions have responded to the event.
-    bool IsDone() const;
-
-    // Runs the callback for an extension and removes the extension from the
-    // list of extensions that still have to respond to the event.
-    void ReportForExtension(const std::string& extension_id,
-                            const base::ListValue& printers);
-
-   private:
-    // Callback reporting event result for an extension. Called once for each
-    // extension.
-    GetPrintersCallback callback_;
-
-    // The list of extensions that still have to respond to the event.
-    std::set<std::string> extensions_;
-  };
-
-  // Keeps track of pending chrome.printerProvider.onGetPrintersRequested
-  // requests.
-  class PendingGetPrintersRequests {
-   public:
-    PendingGetPrintersRequests();
-    ~PendingGetPrintersRequests();
-
-    // Adds a new request to the set of pending requests. Returns the id
-    // assigned to the request.
-    int Add(const GetPrintersCallback& callback);
-
-    // Completes a request for an extension. It runs the request callback with
-    // values reported by the extension.
-    bool CompleteForExtension(const std::string& extension_id,
-                              int request_id,
-                              const base::ListValue& result);
-
-    // Runs callbacks for the extension for all requests that are waiting for a
-    // response from the extension with the provided extension id. Callbacks are
-    // called as if the extension reported empty set of printers.
-    void FailAllForExtension(const std::string& extension_id);
-
-    // Adds an extension id to the list of the extensions that need to respond
-    // to the event.
-    bool AddSource(int request_id, const std::string& extension_id);
-
-   private:
-    int last_request_id_;
-    std::map<int, GetPrintersRequest> pending_requests_;
-
-    DISALLOW_COPY_AND_ASSIGN(PendingGetPrintersRequests);
-  };
-
-  // Keeps track of pending chrome.printerProvider.onGetCapabilityRequested
-  // requests for an extension.
-  class PendingGetCapabilityRequests {
-   public:
-    PendingGetCapabilityRequests();
-    ~PendingGetCapabilityRequests();
-
-    // Adds a new request to the set. Only information needed is the callback
-    // associated with the request. Returns the id assigned to the request.
-    int Add(const GetCapabilityCallback& callback);
-
-    // Completes the request with the provided request id. It runs the request
-    // callback and removes the request from the set.
-    bool Complete(int request_id, const base::DictionaryValue& result);
-
-    // Runs all pending callbacks with empty capability value and clears the
-    // set of pending requests.
-    void FailAll();
-
-   private:
-    int last_request_id_;
-    std::map<int, GetCapabilityCallback> pending_requests_;
-  };
-
-  // Keeps track of pending chrome.printerProvider.ontPrintRequested requests
-  // for an extension.
-  class PendingPrintRequests {
-   public:
-    PendingPrintRequests();
-    ~PendingPrintRequests();
-
-    // Adds a new request to the set. Only information needed is the callback
-    // associated with the request. Returns the id assigned to the request.
-    int Add(const PrintCallback& callback);
-
-    // Completes the request with the provided request id. It runs the request
-    // callback and removes the request from the set.
-    bool Complete(int request_id, bool success, const std::string& result);
-
-    // Runs all pending callbacks with ERROR_FAILED and clears the set of
-    // pending requests.
-    void FailAll();
-
-   private:
-    int last_request_id_;
-    std::map<int, PrintCallback> pending_requests_;
-  };
-
-  // BrowserContextKeyedAPI implementation.
-  static const bool kServiceRedirectedInIncognito = true;
-  static const char* service_name() { return "PrinterProvider"; }
-
-  // PrinterProviderInternalAPIObserver implementation:
-  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;
-
-  // ExtensionRegistryObserver implementation:
-  void OnExtensionUnloaded(content::BrowserContext* browser_context,
-                           const Extension* extension,
-                           UnloadedExtensionInfo::Reason reason) override;
-
-  // Called before chrome.printerProvider.onGetPrintersRequested event is
-  // dispatched to an extension. It returns whether the extension is interested
-  // in the event. If the extension listens to the event, it's added to the set
-  // of |request| sources. |request| is |GetPrintersRequest| object associated
-  // with the event.
-  bool WillRequestPrinters(int request_id,
-                           content::BrowserContext* browser_context,
-                           const Extension* extension,
-                           base::ListValue* args);
-
-  content::BrowserContext* browser_context_;
-
-  PendingGetPrintersRequests pending_get_printers_requests_;
-
-  std::map<std::string, PendingPrintRequests> pending_print_requests_;
-
-  std::map<std::string, PendingGetCapabilityRequests>
-      pending_capability_requests_;
-
-  ScopedObserver<PrinterProviderInternalAPI, PrinterProviderInternalAPIObserver>
-      internal_api_observer_;
-
-  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
-      extension_registry_observer_;
-
-  DISALLOW_COPY_AND_ASSIGN(PrinterProviderAPI);
+  virtual void DispatchPrintRequested(const PrinterProviderPrintJob& job,
+                                      const PrintCallback& callback) = 0;
 };
 
-template <>
-void BrowserContextKeyedAPIFactory<
-    PrinterProviderAPI>::DeclareFactoryDependencies();
-
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_PRINTER_PROVIDER_PRINTER_PROVIDER_API_H_