summaryrefslogtreecommitdiffstats
path: root/dom/svg/DOMSVGNumberList.h
blob: 67994fe85149fc0bdeeca07287b00c8ab97d3edd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/* -*- Mode: C++; tab-width: 8; 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_DOMSVGNUMBERLIST_H__
#define MOZILLA_DOMSVGNUMBERLIST_H__

#include "DOMSVGAnimatedNumberList.h"
#include "nsCycleCollectionParticipant.h"
#include "nsDebug.h"
#include "nsTArray.h"
#include "SVGNumberList.h"
#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"

class nsSVGElement;

namespace mozilla {

class DOMSVGNumber;

/**
 * Class DOMSVGNumberList
 *
 * This class is used to create the DOM tearoff objects that wrap internal
 * SVGNumberList objects.
 *
 * See the architecture comment in DOMSVGAnimatedNumberList.h.
 *
 * This class is strongly intertwined with DOMSVGAnimatedNumberList and
 * DOMSVGNumber. We are a friend of DOMSVGAnimatedNumberList, and are
 * responsible for nulling out our DOMSVGAnimatedNumberList's pointer to us
 * when we die, essentially making its pointer to us a weak pointer. Similarly,
 * our DOMSVGNumber items are friends of us and responsible for nulling out our
 * pointers to them.
 *
 * Our DOM items are created lazily on demand as and when script requests them.
 */
class DOMSVGNumberList final : public nsISupports,
                               public nsWrapperCache
{
  friend class AutoChangeNumberListNotifier;
  friend class DOMSVGNumber;

  ~DOMSVGNumberList() {
    // Our mAList's weak ref to us must be nulled out when we die. If GC has
    // unlinked us using the cycle collector code, then that has already
    // happened, and mAList is null.
    if (mAList) {
      ( IsAnimValList() ? mAList->mAnimVal : mAList->mBaseVal ) = nullptr;
    }
  }

public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMSVGNumberList)

  DOMSVGNumberList(DOMSVGAnimatedNumberList *aAList,
                   const SVGNumberList &aInternalList)
    : mAList(aAList)
  {
    // aInternalList must be passed in explicitly because we can't use
    // InternalList() here. (Because it depends on IsAnimValList, which depends
    // on this object having been assigned to aAList's mBaseVal or mAnimVal,
    // which hasn't happend yet.)

    InternalListLengthWillChange(aInternalList.Length()); // Sync mItems
  }

  virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) override;

  nsISupports* GetParentObject()
  {
    return static_cast<nsIContent*>(Element());
  }

  /**
   * This will normally be the same as InternalList().Length(), except if we've
   * hit OOM in which case our length will be zero.
   */
  uint32_t LengthNoFlush() const {
    MOZ_ASSERT(mItems.Length() == 0 ||
               mItems.Length() == InternalList().Length(),
               "DOM wrapper's list length is out of sync");
    return mItems.Length();
  }

  /// Called to notify us to syncronize our length and detach excess items.
  void InternalListLengthWillChange(uint32_t aNewLength);

  /**
   * Returns true if our attribute is animating (in which case our animVal is
   * not simply a mirror of our baseVal).
   */
  bool IsAnimating() const {
    return mAList->IsAnimating();
  }
  /**
   * Returns true if there is an animated list mirroring the base list.
   */
  bool AnimListMirrorsBaseList() const {
    return mAList->mAnimVal && !mAList->IsAnimating();
  }

  uint32_t NumberOfItems() const
  {
    if (IsAnimValList()) {
      Element()->FlushAnimations();
    }
    return LengthNoFlush();
  }
  void Clear(ErrorResult& error);
  already_AddRefed<DOMSVGNumber> Initialize(DOMSVGNumber& newItem,
                                            ErrorResult& error);
  already_AddRefed<DOMSVGNumber> GetItem(uint32_t index, ErrorResult& error);
  already_AddRefed<DOMSVGNumber> IndexedGetter(uint32_t index, bool& found,
                                               ErrorResult& error);
  already_AddRefed<DOMSVGNumber> InsertItemBefore(DOMSVGNumber& newItem,
                                                  uint32_t index, ErrorResult& error);
  already_AddRefed<DOMSVGNumber> ReplaceItem(DOMSVGNumber& newItem, uint32_t index,
                                             ErrorResult& error);
  already_AddRefed<DOMSVGNumber> RemoveItem(uint32_t index,
                                            ErrorResult& error);
  already_AddRefed<DOMSVGNumber> AppendItem(DOMSVGNumber& newItem,
                                            ErrorResult& error)
  {
    return InsertItemBefore(newItem, LengthNoFlush(), error);
  }
  uint32_t Length() const
  {
    return NumberOfItems();
  }

private:

  nsSVGElement* Element() const {
    return mAList->mElement;
  }

  uint8_t AttrEnum() const {
    return mAList->mAttrEnum;
  }

  /// Used to determine if this list is the baseVal or animVal list.
  bool IsAnimValList() const {
    MOZ_ASSERT(this == mAList->mBaseVal || this == mAList->mAnimVal,
               "Calling IsAnimValList() too early?!");
    return this == mAList->mAnimVal;
  }

  /**
   * Get a reference to this object's corresponding internal SVGNumberList.
   *
   * To simplify the code we just have this one method for obtaining both
   * baseVal and animVal internal lists. This means that animVal lists don't
   * get const protection, but our setter methods guard against changing
   * animVal lists.
   */
  SVGNumberList& InternalList() const;

  /// Returns the DOMSVGNumber at aIndex, creating it if necessary.
  already_AddRefed<DOMSVGNumber> GetItemAt(uint32_t aIndex);

  void MaybeInsertNullInAnimValListAt(uint32_t aIndex);
  void MaybeRemoveItemFromAnimValListAt(uint32_t aIndex);

  // Weak refs to our DOMSVGNumber items. The items are friends and take care
  // of clearing our pointer to them when they die.
  FallibleTArray<DOMSVGNumber*> mItems;

  RefPtr<DOMSVGAnimatedNumberList> mAList;
};

} // namespace mozilla

#endif // MOZILLA_DOMSVGNUMBERLIST_H__