1 files changed, 81 insertions, 0 deletions
diff --git a/widget/IconLoader.h b/widget/IconLoader.h
new file mode 100644
index 0000000000..9d21478b2b
--- /dev/null
+++ b/widget/IconLoader.h
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_widget_IconLoader_h_
+#define mozilla_widget_IconLoader_h_
+
+#include "imgINotificationObserver.h"
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsIContentPolicy.h"
+#include "nsISupports.h"
+
+class nsIURI;
+class nsINode;
+class imgRequestProxy;
+class imgIContainer;
+
+namespace mozilla::widget {
+
+/**
+ * IconLoader is a utility for loading icons from either the disk or over
+ * the network, and then using them in native OS widgetry like the macOS
+ * global menu bar or the Windows notification area.
+ */
+
+class IconLoader : public imgINotificationObserver {
+ public:
+  /**
+   * IconLoader itself is cross-platform, but each platform needs to supply
+   * it with a Helper that does the platform-specific conversion work. The
+   * Helper needs to implement the OnComplete method in order to handle the
+   * imgIContainer of the loaded icon.
+   */
+  class Helper : public nsISupports {
+   public:
+    // Helper needs to implement nsISupports in order for its subclasses to
+    // participate in cycle collection
+    virtual nsresult OnComplete(imgIContainer* aContainer,
+                                const nsIntRect& aRect) = 0;
+
+   protected:
+    virtual ~Helper() = default;
+  };
+
+  IconLoader(Helper* aHelper, nsINode* aContent,
+             const nsIntRect& aImageRegionRect);
+
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_IMGINOTIFICATIONOBSERVER
+  NS_DECL_CYCLE_COLLECTION_CLASS(IconLoader)
+
+  // LoadIcon will start a load request for the icon.
+  // The request may not complete until after LoadIcon returns.
+  // If aIsInternalIcon is true, the document and principal will not be
+  // used when loading.
+  nsresult LoadIcon(nsIURI* aIconURI, bool aIsInternalIcon = false);
+
+  void ReleaseJSObjects() { mContent = nullptr; }
+
+  void Destroy();
+
+ protected:
+  virtual ~IconLoader();
+
+ private:
+  nsresult OnFrameComplete(imgIRequest* aRequest);
+
+  nsCOMPtr<nsINode> mContent;
+  nsContentPolicyType mContentType;
+  RefPtr<imgRequestProxy> mIconRequest;
+  nsIntRect mImageRegionRect;
+  bool mLoadedIcon;
+  RefPtr<Helper> mHelper;
+};
+
+}  // namespace mozilla::widget
+#endif  // mozilla_widget_IconLoader_h_