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 "nsIContentPolicy.h"
  13 #include "nsISupports.h"
  14
  15 class nsIURI;
  16 class nsINode;
  17 class imgRequestProxy;
  18 class imgIContainer;
  19
  20 namespace mozilla::widget {
  21
  22 /**
  23  * IconLoader is a utility for loading icons from either the disk or over
  24  * the network, and then using them in native OS widgetry like the macOS
  25  * global menu bar or the Windows notification area.
  26  */
  27
  28 class IconLoader : public imgINotificationObserver {
  29  public:
  30   /**
  31    * IconLoader itself is cross-platform, but each platform needs to supply
  32    * it with a Helper that does the platform-specific conversion work. The
  33    * Helper needs to implement the OnComplete method in order to handle the
  34    * imgIContainer of the loaded icon.
  35    */
  36   class Helper : public nsISupports {
  37    public:
  38     // Helper needs to implement nsISupports in order for its subclasses to
  39     // participate in cycle collection
  40     virtual nsresult OnComplete(imgIContainer* aContainer,
  41                                 const nsIntRect& aRect) = 0;
  42
  43    protected:
  44     virtual ~Helper() = default;
  45   };
  46
  47   IconLoader(Helper* aHelper, nsINode* aContent,
  48              const nsIntRect& aImageRegionRect);
  49
  50  public:
  51   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  52   NS_DECL_IMGINOTIFICATIONOBSERVER
  53   NS_DECL_CYCLE_COLLECTION_CLASS(IconLoader)
  54
  55   // LoadIcon will start a load request for the icon.
  56   // The request may not complete until after LoadIcon returns.
  57   // If aIsInternalIcon is true, the document and principal will not be
  58   // used when loading.
  59   nsresult LoadIcon(nsIURI* aIconURI, bool aIsInternalIcon = false);
  60
  61   void ReleaseJSObjects() { mContent = nullptr; }
  62
  63   void Destroy();
  64
  65  protected:
  66   virtual ~IconLoader();
  67
  68  private:
  69   nsresult OnFrameComplete(imgIRequest* aRequest);
  70
  71   nsCOMPtr<nsINode> mContent;
  72   nsContentPolicyType mContentType;
  73   RefPtr<imgRequestProxy> mIconRequest;
  74   nsIntRect mImageRegionRect;
  75   bool mLoadedIcon;
  76   RefPtr<Helper> mHelper;
  77 };
  78
  79 }  // namespace mozilla::widget
  80 #endif  // mozilla_widget_IconLoader_h_