Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 212 insertions, 0 deletions

diff --git a/dom/svg/DOMSVGLength.h b/dom/svg/DOMSVGLength.h
new file mode 100644
index 0000000000..8aeee2d574
--- /dev/null
+++ b/dom/svg/DOMSVGLength.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 DOM_SVG_DOMSVGLENGTH_H_
+#define DOM_SVG_DOMSVGLENGTH_H_
+
+#include "DOMSVGLengthList.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsDebug.h"
+#include "nsTArray.h"
+#include "SVGLength.h"
+#include "mozilla/Attributes.h"
+#include "nsWrapperCache.h"
+
+#define MOZ_SVG_LIST_INDEX_BIT_COUNT 22  // supports > 4 million list items
+
+namespace mozilla {
+
+class ErrorResult;
+
+namespace dom {
+class SVGElement;
+
+/**
+ * Class DOMSVGLength
+ *
+ * This class creates the DOM objects that wrap internal SVGLength objects that
+ * are in an SVGLengthList. It is also used to create the objects returned by
+ * SVGSVGElement.createSVGLength().
+ *
+ * For the DOM wrapper classes for non-list SVGLength, see SVGAnimatedLength.h.
+ *
+ * See the architecture comment in DOMSVGAnimatedLengthList.h.
+ *
+ * This class is strongly intertwined with DOMSVGAnimatedLengthList and
+ * DOMSVGLengthList. We are a friend of DOMSVGLengthList, and are responsible
+ * for nulling out our DOMSVGLengthList's pointer to us when we die, making it
+ * a real weak pointer.
+ *
+ * When objects of this type are in a DOMSVGLengthList they belong to an
+ * attribute. While they belong to an attribute, the objects' values come from
+ * their corresponding internal SVGLength objects in the internal SVGLengthList
+ * objects for the attribute. Getting and setting values of a DOMSVGLength
+ * requires reading and writing to its internal SVGLength. However, if the
+ * DOMSVGLength is detached from its DOMSVGLengthList then it first makes a
+ * copy of its internal SVGLength's value and unit so that it doesn't appear to
+ * "lose" its value from script's perspective on being removed from the list.
+ * This means that these DOM tearoffs have space to store these values, even
+ * though they're not used in the common case.
+ *
+ * Objects of this type are also used to reflect the baseVal and animVal of
+ * a single, non-list SVGLength attribute. Getting and settings values of the
+ * DOMSVGLength in this case requires reading and writing to the corresponding
+ * SVGAnimatedLength object.
+ *
+ * This class also stores its current list index, attribute enum, and whether
+ * it belongs to a baseVal or animVal list. This is so that objects of this
+ * type can find their corresponding internal SVGLength.
+ *
+ * To use these classes for <length> attributes as well as <list-of-length>
+ * attributes, we would need to take a bit from mListIndex and use that to
+ * indicate whether the object belongs to a list or non-list attribute, then
+ * if-else as appropriate. The bug for doing that work is:
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=571734
+ */
+class DOMSVGLength final : public nsWrapperCache {
+  template <class T>
+  friend class AutoChangeLengthListNotifier;
+
+  /**
+   * Ctor for creating the object returned by
+   * SVGAnimatedLength::ToDOMBaseVal/ToDOMAnimVal
+   */
+  DOMSVGLength(SVGAnimatedLength* aVal, dom::SVGElement* aSVGElement,
+               bool aAnimVal);
+
+  ~DOMSVGLength() { CleanupWeakRefs(); }
+
+ public:
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(DOMSVGLength)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(DOMSVGLength)
+
+  /**
+   * Generic ctor for DOMSVGLength objects that are created for an attribute.
+   */
+  DOMSVGLength(DOMSVGLengthList* aList, uint8_t aAttrEnum, uint32_t aListIndex,
+               bool aIsAnimValItem);
+
+  /**
+   * Ctor for creating the objects returned by SVGSVGElement.createSVGLength(),
+   * which do not initially belong to an attribute.
+   */
+  DOMSVGLength();
+
+  static already_AddRefed<DOMSVGLength> GetTearOff(SVGAnimatedLength* aVal,
+                                                   dom::SVGElement* aSVGElement,
+                                                   bool aAnimVal);
+
+  /**
+   * Create an unowned copy of a length that is owned or is reflecting a single
+   * attribute. The caller is responsible for the first AddRef().
+   */
+  DOMSVGLength* Copy();
+
+  /**
+   * Returns true if our attribute is animating.
+   */
+  bool IsAnimating() const;
+
+  /**
+   * In future, if this class is used for non-list lengths, this will be
+   * different to IsInList().
+   */
+  bool HasOwner() const { return !!mOwner; }
+
+  /**
+   * This method is called to notify this DOM object that it is being inserted
+   * into a list, and give it the information it needs as a result.
+   *
+   * This object MUST NOT already belong to a list when this method is called.
+   * That's not to say that script can't move these DOM objects between
+   * lists - it can - it's just that the logic to handle that (and send out
+   * the necessary notifications) is located elsewhere (in DOMSVGLengthList).)
+   */
+  void InsertingIntoList(DOMSVGLengthList* aList, uint8_t aAttrEnum,
+                         uint32_t aListIndex, bool aIsAnimValItem);
+
+  static uint32_t MaxListIndex() {
+    return (1U << MOZ_SVG_LIST_INDEX_BIT_COUNT) - 1;
+  }
+
+  /// This method is called to notify this object that its list index changed.
+  void UpdateListIndex(uint32_t aListIndex) { mListIndex = aListIndex; }
+
+  /**
+   * This method is called to notify this DOM object that it is about to be
+   * removed from its current DOM list so that it can first make a copy of its
+   * internal counterpart's values. (If it didn't do this, then it would
+   * "lose" its value on being removed.)
+   */
+  void RemovingFromList();
+
+  SVGLength ToSVGLength();
+
+  // WebIDL
+  uint16_t UnitType();
+  float GetValue(ErrorResult& aRv);
+  void SetValue(float aUserUnitValue, ErrorResult& aRv);
+  float ValueInSpecifiedUnits();
+  void SetValueInSpecifiedUnits(float aValue, ErrorResult& aRv);
+  void GetValueAsString(nsAString& aValue);
+  void SetValueAsString(const nsAString& aValue, ErrorResult& aRv);
+  void NewValueSpecifiedUnits(uint16_t aUnit, float aValue, ErrorResult& aRv);
+  void ConvertToSpecifiedUnits(uint16_t aUnit, ErrorResult& aRv);
+
+  nsISupports* GetParentObject() { return mOwner; }
+
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+ private:
+  dom::SVGElement* Element();
+
+  uint8_t AttrEnum() const { return mAttrEnum; }
+
+  /**
+   * Get a reference to the internal SVGLength list item that this DOM wrapper
+   * object currently wraps.
+   *
+   * To simplify the code we just have this one method for obtaining both
+   * baseVal and animVal internal items. This means that animVal items don't
+   * get const protection, but then our setter methods guard against changing
+   * animVal items.
+   */
+  SVGLength& InternalItem();
+
+#ifdef DEBUG
+  bool IndexIsValid();
+#endif
+
+  /**
+   * Clears soon-to-be-invalid weak references in external objects that were
+   * set up during the creation of this object. This should be called during
+   * destruction and during cycle collection.
+   */
+  void CleanupWeakRefs();
+
+  RefPtr<nsISupports> mOwner;  // Either a DOMSVGLengthList if we're in a list,
+                               // an SVGElement if we're an attribute or null
+
+  // Bounds for the following are checked in the ctor, so be sure to update
+  // that if you change the capacity of any of the following.
+
+  uint32_t mListIndex : MOZ_SVG_LIST_INDEX_BIT_COUNT;
+  uint32_t mAttrEnum : 4;  // supports up to 16 attributes
+  uint32_t mIsAnimValItem : 1;
+
+  // The following members are only used when we're not in a list:
+  uint32_t mUnit : 5;  // can handle 31 units (the 10 SVG 1.1 units + rem, vw,
+                       // vh, wm, calc + future additions)
+  float mValue = 0.0f;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#undef MOZ_SVG_LIST_INDEX_BIT_COUNT
+
+#endif  // DOM_SVG_DOMSVGLENGTH_H_