layout/style/nsDOMCSSAttrDeclaration.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* DOM object for element.style */
   7
   8 #include "nsDOMCSSAttrDeclaration.h"
   9
  10 #include "mozilla/css/Declaration.h"
  11 #include "mozilla/css/StyleRule.h"
  12 #include "mozilla/dom/Element.h"
  13 #include "nsIDocument.h"
  14 #include "nsIDOMMutationEvent.h"
  15 #include "nsIURI.h"
  16 #include "nsNodeUtils.h"
  17 #include "xpcpublic.h"
  18 #include "nsWrapperCacheInlines.h"
  19
  20 namespace css = mozilla::css;
  21 namespace dom = mozilla::dom;
  22
  23 nsDOMCSSAttributeDeclaration::nsDOMCSSAttributeDeclaration(dom::Element* aElement,
  24                                                            bool aIsSMILOverride)
  25   : mElement(aElement)
  26   , mIsSMILOverride(aIsSMILOverride)
  27 {
  28   MOZ_COUNT_CTOR(nsDOMCSSAttributeDeclaration);
  29
  30   NS_ASSERTION(aElement, "Inline style for a NULL element?");
  31 }
  32
  33 nsDOMCSSAttributeDeclaration::~nsDOMCSSAttributeDeclaration()
  34 {
  35   MOZ_COUNT_DTOR(nsDOMCSSAttributeDeclaration);
  36 }
  37
  38 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_1(nsDOMCSSAttributeDeclaration, mElement)
  39
  40 // mElement holds a strong ref to us, so if it's going to be
  41 // skipped, the attribute declaration can't be part of a garbage
  42 // cycle.
  43 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsDOMCSSAttributeDeclaration)
  44   if (tmp->mElement && Element::CanSkip(tmp->mElement, true)) {
  45     if (tmp->PreservingWrapper()) {
  46       // Not relying on GetWrapper to unmark us gray because the
  47       // side-effect thing is pretty weird.
  48       JSObject* o = tmp->GetWrapperPreserveColor();
  49       xpc_UnmarkGrayObject(o);
  50     }
  51     return true;
  52   }
  53   return tmp->IsBlack();
  54 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
  55
  56 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsDOMCSSAttributeDeclaration)
  57   return tmp->IsBlack() ||
  58     (tmp->mElement && Element::CanSkipInCC(tmp->mElement));
  59 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
  60
  61 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsDOMCSSAttributeDeclaration)
  62   return tmp->IsBlack() ||
  63     (tmp->mElement && Element::CanSkipThis(tmp->mElement));
  64 NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
  65
  66 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMCSSAttributeDeclaration)
  67   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  68 NS_IMPL_QUERY_TAIL_INHERITING(nsDOMCSSDeclaration)
  69
  70 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMCSSAttributeDeclaration)
  71 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMCSSAttributeDeclaration)
  72
  73 nsresult
  74 nsDOMCSSAttributeDeclaration::SetCSSDeclaration(css::Declaration* aDecl)
  75 {
  76   NS_ASSERTION(mElement, "Must have Element to set the declaration!");
  77   css::StyleRule* oldRule =
  78     mIsSMILOverride ? mElement->GetSMILOverrideStyleRule() :
  79     mElement->GetInlineStyleRule();
  80   NS_ASSERTION(oldRule, "Element must have rule");
  81
  82   nsRefPtr<css::StyleRule> newRule =
  83     oldRule->DeclarationChanged(aDecl, false);
  84   if (!newRule) {
  85     return NS_ERROR_OUT_OF_MEMORY;
  86   }
  87
  88   return
  89     mIsSMILOverride ? mElement->SetSMILOverrideStyleRule(newRule, true) :
  90     mElement->SetInlineStyleRule(newRule, nullptr, true);
  91 }
  92
  93 nsIDocument*
  94 nsDOMCSSAttributeDeclaration::DocToUpdate()
  95 {
  96   // XXXbz this is a bit of a hack, especially doing it before the
  97   // BeginUpdate(), but this is a good chokepoint where we know we
  98   // plan to modify the CSSDeclaration, so need to notify
  99   // AttributeWillChange if this is inline style.
 100   if (!mIsSMILOverride) {
 101     nsNodeUtils::AttributeWillChange(mElement, kNameSpaceID_None,
 102                                      nsGkAtoms::style,
 103                                      nsIDOMMutationEvent::MODIFICATION);
 104   }
 105
 106   // We need OwnerDoc() rather than GetCurrentDoc() because it might
 107   // be the BeginUpdate call that inserts mElement into the document.
 108   return mElement->OwnerDoc();
 109 }
 110
 111 css::Declaration*
 112 nsDOMCSSAttributeDeclaration::GetCSSDeclaration(bool aAllocate)
 113 {
 114   if (!mElement)
 115     return nullptr;
 116
 117   css::StyleRule* cssRule;
 118   if (mIsSMILOverride)
 119     cssRule = mElement->GetSMILOverrideStyleRule();
 120   else
 121     cssRule = mElement->GetInlineStyleRule();
 122
 123   if (cssRule) {
 124     return cssRule->GetDeclaration();
 125   }
 126   if (!aAllocate) {
 127     return nullptr;
 128   }
 129
 130   // cannot fail
 131   css::Declaration *decl = new css::Declaration();
 132   decl->InitializeEmpty();
 133   nsRefPtr<css::StyleRule> newRule = new css::StyleRule(nullptr, decl);
 134
 135   // this *can* fail (inside SetAttrAndNotify, at least).
 136   nsresult rv;
 137   if (mIsSMILOverride)
 138     rv = mElement->SetSMILOverrideStyleRule(newRule, false);
 139   else
 140     rv = mElement->SetInlineStyleRule(newRule, nullptr, false);
 141
 142   if (NS_FAILED(rv)) {
 143     return nullptr; // the decl will be destroyed along with the style rule
 144   }
 145
 146   return decl;
 147 }
 148
 149 void
 150 nsDOMCSSAttributeDeclaration::GetCSSParsingEnvironment(CSSParsingEnvironment& aCSSParseEnv)
 151 {
 152   NS_ASSERTION(mElement, "Something is severely broken -- there should be an Element here!");
 153
 154   nsIDocument* doc = mElement->OwnerDoc();
 155   aCSSParseEnv.mSheetURI = doc->GetDocumentURI();
 156   aCSSParseEnv.mBaseURI = mElement->GetBaseURI();
 157   aCSSParseEnv.mPrincipal = mElement->NodePrincipal();
 158   aCSSParseEnv.mCSSLoader = doc->CSSLoader();
 159 }
 160
 161 NS_IMETHODIMP
 162 nsDOMCSSAttributeDeclaration::GetParentRule(nsIDOMCSSRule **aParent)
 163 {
 164   NS_ENSURE_ARG_POINTER(aParent);
 165
 166   *aParent = nullptr;
 167   return NS_OK;
 168 }
 169
 170 /* virtual */ nsINode*
 171 nsDOMCSSAttributeDeclaration::GetParentObject()
 172 {
 173   return mElement;
 174 }