widget/IconLoader.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_widget_IconLoader_h_
   7 #define mozilla_widget_IconLoader_h_
   8
   9 #include "imgINotificationObserver.h"
  10 #include "mozilla/RefPtr.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsISupports.h"
  13
  14 class nsIURI;
  15 class nsINode;
  16 class imgRequestProxy;
  17 class imgIContainer;
  18
  19 namespace mozilla::widget {
  20
  21 /**
  22  * IconLoader is a utility for loading icons from either the disk or over
  23  * the network, and then using them in native OS widgetry like the macOS
  24  * global menu bar or the Windows notification area.
  25  */
  26
  27 class IconLoader : public imgINotificationObserver {
  28  public:
  29   // This is the interface that our listeners need to implement so that they can
  30   // be notified when the icon is loaded.
  31   class Listener {
  32    public:
  33     virtual nsresult OnComplete(imgIContainer* aContainer) = 0;
  34   };
  35
  36   // Create the loader.
  37   // aListener will be notified when the load is complete.
  38   // The loader does not keep an owning reference to the listener. Call Destroy
  39   // before the listener goes away.
  40   explicit IconLoader(Listener* aListener);
  41
  42  public:
  43   NS_DECL_ISUPPORTS
  44   NS_DECL_IMGINOTIFICATIONOBSERVER
  45
  46   // LoadIcon will start a load request for the icon.
  47   // The request may not complete until after LoadIcon returns.
  48   // If aIsInternalIcon is true, the document and principal will not be
  49   // used when loading.
  50   nsresult LoadIcon(nsIURI* aIconURI, nsINode* aNode,
  51                     bool aIsInternalIcon = false);
  52
  53   void Destroy();
  54
  55  protected:
  56   virtual ~IconLoader();
  57
  58  private:
  59   RefPtr<imgRequestProxy> mIconRequest;
  60
  61   // The listener, which is notified when loading completes.
  62   // Can be null, after a call to Destroy.
  63   // This is a non-owning reference and needs to be cleared with a call to
  64   // Destroy before the listener goes away.
  65   Listener* mListener;
  66 };
  67
  68 }  // namespace mozilla::widget
  69 #endif  // mozilla_widget_IconLoader_h_