layout/generic/nsImageMap.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* code for HTML client-side image maps */
   8
   9 #ifndef nsImageMap_h
  10 #define nsImageMap_h
  11
  12 #include "mozilla/gfx/2D.h"
  13 #include "nsCOMPtr.h"
  14 #include "nsCoord.h"
  15 #include "nsTArray.h"
  16 #include "nsStubMutationObserver.h"
  17 #include "nsIDOMEventListener.h"
  18 #include "Units.h"
  19
  20 class Area;
  21 class nsImageFrame;
  22 class nsIFrame;
  23 class nsIContent;
  24 struct nsRect;
  25
  26 namespace mozilla {
  27 namespace dom {
  28 class HTMLAreaElement;
  29 }
  30 }  // namespace mozilla
  31
  32 class nsImageMap final : public nsStubMutationObserver,
  33                          public nsIDOMEventListener {
  34   typedef mozilla::gfx::DrawTarget DrawTarget;
  35   typedef mozilla::gfx::ColorPattern ColorPattern;
  36   typedef mozilla::gfx::StrokeOptions StrokeOptions;
  37
  38  public:
  39   nsImageMap();
  40
  41   void Init(nsImageFrame* aImageFrame, nsIContent* aMap);
  42
  43   /**
  44    * Return the first area element (in content order) for the given point in
  45    * CSS pixel coordinate or nullptr if the coordinate is outside all areas.
  46    */
  47   mozilla::dom::HTMLAreaElement* GetArea(const mozilla::CSSIntPoint& aPt) const;
  48
  49   /**
  50    * Return area elements count associated with the image map.
  51    */
  52   uint32_t AreaCount() const { return mAreas.Length(); }
  53
  54   /**
  55    * Return area element at the given index.
  56    */
  57   mozilla::dom::HTMLAreaElement* GetAreaAt(uint32_t aIndex) const;
  58
  59   void Draw(nsIFrame* aFrame, DrawTarget& aDrawTarget,
  60             const ColorPattern& aColor,
  61             const StrokeOptions& aStrokeOptions = StrokeOptions());
  62
  63   /**
  64    * Called just before the nsImageFrame releases us.
  65    * Used to break the cycle caused by the DOM listener.
  66    */
  67   void Destroy();
  68
  69   // nsISupports
  70   NS_DECL_ISUPPORTS
  71
  72   // nsIMutationObserver
  73   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
  74   NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
  75   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
  76   NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
  77   NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED
  78
  79   // nsIDOMEventListener
  80   NS_DECL_NSIDOMEVENTLISTENER
  81
  82   nsresult GetBoundsForAreaContent(nsIContent* aContent, nsRect& aBounds);
  83
  84   using AreaList = AutoTArray<mozilla::UniquePtr<Area>, 8>;
  85
  86  protected:
  87   virtual ~nsImageMap();
  88
  89   void FreeAreas();
  90
  91   void UpdateAreas();
  92
  93   void SearchForAreas(nsIContent* aParent);
  94
  95   void AddArea(mozilla::dom::HTMLAreaElement* aArea);
  96   void AreaRemoved(mozilla::dom::HTMLAreaElement* aArea);
  97
  98   void MaybeUpdateAreas(nsIContent* aContent);
  99
 100   nsImageFrame* mImageFrame;  // the frame that owns us
 101   nsCOMPtr<nsIContent> mMap;
 102
 103   // almost always has some entries
 104   AreaList mAreas;
 105
 106   // This is set when we search for all area children and tells us whether we
 107   // should consider the whole subtree or just direct children when we get
 108   // content notifications about changes inside the map subtree.
 109   bool mConsiderWholeSubtree;
 110 };
 111
 112 #endif /* nsImageMap_h */