dom/svg/DOMSVGTransform.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 #ifndef DOM_SVG_DOMSVGTRANSFORM_H_
   8 #define DOM_SVG_DOMSVGTRANSFORM_H_
   9
  10 #include "DOMSVGTransformList.h"
  11 #include "gfxMatrix.h"
  12 #include "nsCycleCollectionParticipant.h"
  13 #include "nsDebug.h"
  14 #include "nsID.h"
  15 #include "SVGTransform.h"
  16 #include "nsWrapperCache.h"
  17 #include "mozilla/Attributes.h"
  18 #include "mozilla/UniquePtr.h"
  19
  20 #define MOZ_SVG_LIST_INDEX_BIT_COUNT 31  // supports > 2 billion list items
  21
  22 namespace mozilla::dom {
  23
  24 struct DOMMatrix2DInit;
  25 class SVGElement;
  26 class SVGMatrix;
  27
  28 /**
  29  * DOM wrapper for an SVG transform. See DOMSVGLength.h.
  30  */
  31 class DOMSVGTransform final : public nsWrapperCache {
  32   template <class T>
  33   friend class AutoChangeTransformListNotifier;
  34
  35  public:
  36   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DOMSVGTransform)
  37   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DOMSVGTransform)
  38
  39   /**
  40    * Generic ctor for DOMSVGTransform objects that are created for an attribute.
  41    */
  42   DOMSVGTransform(DOMSVGTransformList* aList, uint32_t aListIndex,
  43                   bool aIsAnimValItem);
  44
  45   /**
  46    * Ctors for creating the objects returned by:
  47    *   SVGSVGElement.createSVGTransform(),
  48    *   SVGSVGElement.createSVGTransformFromMatrix(in DOMMatrix2DInit  matrix),
  49    *   SVGTransformList.createSVGTransformFromMatrix(in DOMMatrix2DInit  matrix)
  50    * which do not initially belong to an attribute.
  51    */
  52   DOMSVGTransform();
  53   explicit DOMSVGTransform(const gfxMatrix& aMatrix);
  54   DOMSVGTransform(const DOMMatrix2DInit& aMatrix, ErrorResult& rv);
  55
  56   /**
  57    * Ctor for creating an unowned copy. Used with Clone().
  58    */
  59   explicit DOMSVGTransform(const SVGTransform& aTransform);
  60
  61   /**
  62    * Create an unowned copy of an owned transform. The caller is responsible for
  63    * the first AddRef().
  64    */
  65   DOMSVGTransform* Clone() {
  66     NS_ASSERTION(mList, "unexpected caller");
  67     return new DOMSVGTransform(InternalItem());
  68   }
  69
  70   bool IsInList() const { return !!mList; }
  71
  72   /**
  73    * Returns true if our attribute is animating (in which case our animVal is
  74    * not simply a mirror of our baseVal).
  75    */
  76   bool IsAnimating() const { return mList && mList->IsAnimating(); }
  77
  78   /**
  79    * In future, if this class is used for non-list transforms, this will be
  80    * different to IsInList().
  81    */
  82   bool HasOwner() const { return !!mList; }
  83
  84   /**
  85    * This method is called to notify this DOM object that it is being inserted
  86    * into a list, and give it the information it needs as a result.
  87    *
  88    * This object MUST NOT already belong to a list when this method is called.
  89    * That's not to say that script can't move these DOM objects between
  90    * lists - it can - it's just that the logic to handle that (and send out
  91    * the necessary notifications) is located elsewhere (in
  92    * DOMSVGTransformList).)
  93    */
  94   void InsertingIntoList(DOMSVGTransformList* aList, uint32_t aListIndex,
  95                          bool aIsAnimValItem);
  96
  97   static uint32_t MaxListIndex() {
  98     return (1U << MOZ_SVG_LIST_INDEX_BIT_COUNT) - 1;
  99   }
 100
 101   /// This method is called to notify this object that its list index changed.
 102   void UpdateListIndex(uint32_t aListIndex) { mListIndex = aListIndex; }
 103
 104   /**
 105    * This method is called to notify this DOM object that it is about to be
 106    * removed from its current DOM list so that it can first make a copy of its
 107    * internal counterpart's values. (If it didn't do this, then it would
 108    * "lose" its value on being removed.)
 109    */
 110   void RemovingFromList();
 111
 112   SVGTransform ToSVGTransform() const { return Transform(); }
 113
 114   // WebIDL
 115   DOMSVGTransformList* GetParentObject() const { return mList; }
 116   JSObject* WrapObject(JSContext* aCx,
 117                        JS::Handle<JSObject*> aGivenProto) override;
 118   uint16_t Type() const;
 119   dom::SVGMatrix* GetMatrix();
 120   float Angle() const;
 121   void SetMatrix(const DOMMatrix2DInit& matrix, ErrorResult& rv);
 122   void SetTranslate(float tx, float ty, ErrorResult& rv);
 123   void SetScale(float sx, float sy, ErrorResult& rv);
 124   void SetRotate(float angle, float cx, float cy, ErrorResult& rv);
 125   void SetSkewX(float angle, ErrorResult& rv);
 126   void SetSkewY(float angle, ErrorResult& rv);
 127
 128  protected:
 129   ~DOMSVGTransform();
 130
 131   // Interface for SVGMatrix's use
 132   friend class dom::SVGMatrix;
 133   bool IsAnimVal() const { return mIsAnimValItem; }
 134   const gfxMatrix& Matrixgfx() const { return Transform().GetMatrix(); }
 135   void SetMatrix(const gfxMatrix& aMatrix);
 136
 137  private:
 138   SVGElement* Element() { return mList->Element(); }
 139
 140   /**
 141    * Get a reference to the internal SVGTransform list item that this DOM
 142    * wrapper object currently wraps.
 143    */
 144   SVGTransform& InternalItem();
 145   const SVGTransform& InternalItem() const;
 146
 147 #ifdef DEBUG
 148   bool IndexIsValid();
 149 #endif
 150
 151   const SVGTransform& Transform() const {
 152     return HasOwner() ? InternalItem() : *mTransform;
 153   }
 154   SVGTransform& Transform() {
 155     return HasOwner() ? InternalItem() : *mTransform;
 156   }
 157
 158   RefPtr<DOMSVGTransformList> mList;
 159
 160   // Bounds for the following are checked in the ctor, so be sure to update
 161   // that if you change the capacity of any of the following.
 162
 163   uint32_t mListIndex : MOZ_SVG_LIST_INDEX_BIT_COUNT;
 164   uint32_t mIsAnimValItem : 1;
 165
 166   // Usually this class acts as a wrapper for an SVGTransform object which is
 167   // part of a list and is accessed by going via the owning Element.
 168   //
 169   // However, in some circumstances, objects of this class may not be associated
 170   // with any particular list and thus, no internal SVGTransform object. In
 171   // that case we allocate an SVGTransform object on the heap to store the
 172   // data.
 173   UniquePtr<SVGTransform> mTransform;
 174 };
 175
 176 }  // namespace mozilla::dom
 177
 178 #undef MOZ_SVG_LIST_INDEX_BIT_COUNT
 179
 180 #endif  // DOM_SVG_DOMSVGTRANSFORM_H_