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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* Copyright (C) 2012 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "core/css/StyleInvalidationAnalysis.h"
#include "core/css/CSSSelectorList.h"
#include "core/css/StyleRuleImport.h"
#include "core/css/StyleSheetContents.h"
#include "core/dom/ContainerNode.h"
#include "core/dom/Document.h"
#include "core/dom/ElementTraversal.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/html/HTMLStyleElement.h"
namespace WebCore {
StyleInvalidationAnalysis::StyleInvalidationAnalysis(const Vector<StyleSheetContents*>& sheets)
: m_dirtiesAllStyle(false)
{
for (unsigned i = 0; i < sheets.size() && !m_dirtiesAllStyle; ++i)
analyzeStyleSheet(sheets[i]);
}
static bool determineSelectorScopes(const CSSSelectorList& selectorList, HashSet<StringImpl*>& idScopes, HashSet<StringImpl*>& classScopes)
{
for (const CSSSelector* selector = selectorList.first(); selector; selector = CSSSelectorList::next(selector)) {
const CSSSelector* scopeSelector = 0;
// This picks the widest scope, not the narrowest, to minimize the number of found scopes.
for (const CSSSelector* current = selector; current; current = current->tagHistory()) {
// Prefer ids over classes.
if (current->m_match == CSSSelector::Id)
scopeSelector = current;
else if (current->m_match == CSSSelector::Class && (!scopeSelector || scopeSelector->m_match != CSSSelector::Id))
scopeSelector = current;
CSSSelector::Relation relation = current->relation();
if (relation != CSSSelector::Descendant && relation != CSSSelector::Child && relation != CSSSelector::SubSelector)
break;
}
if (!scopeSelector)
return false;
ASSERT(scopeSelector->m_match == CSSSelector::Class || scopeSelector->m_match == CSSSelector::Id);
if (scopeSelector->m_match == CSSSelector::Id)
idScopes.add(scopeSelector->value().impl());
else
classScopes.add(scopeSelector->value().impl());
}
return true;
}
static bool hasDistributedRule(StyleSheetContents* styleSheetContents)
{
const Vector<RefPtr<StyleRuleBase> >& rules = styleSheetContents->childRules();
for (unsigned i = 0; i < rules.size(); i++) {
const StyleRuleBase* rule = rules[i].get();
if (!rule->isStyleRule())
continue;
const StyleRule* styleRule = toStyleRule(rule);
const CSSSelectorList& selectorList = styleRule->selectorList();
for (size_t selectorIndex = 0; selectorIndex != kNotFound; selectorIndex = selectorList.indexOfNextSelectorAfter(selectorIndex)) {
if (selectorList.hasShadowDistributedAt(selectorIndex))
return true;
}
}
return false;
}
static Node* determineScopingNodeForStyleScoped(HTMLStyleElement* ownerElement, StyleSheetContents* styleSheetContents)
{
ASSERT(ownerElement && ownerElement->isRegisteredAsScoped());
if (ownerElement->isInShadowTree()) {
if (hasDistributedRule(styleSheetContents)) {
ContainerNode* scope = ownerElement;
do {
scope = scope->containingShadowRoot()->shadowHost();
} while (scope->isInShadowTree());
return scope;
}
if (ownerElement->isRegisteredAsScoped())
return ownerElement->containingShadowRoot()->shadowHost();
}
return ownerElement->isRegisteredInShadowRoot() ? ownerElement->containingShadowRoot()->shadowHost() : ownerElement->parentNode();
}
static bool ruleAdditionMightRequireDocumentStyleRecalc(StyleRuleBase* rule)
{
// This funciton is conservative. We only return false when we know that
// the added @rule can't require style recalcs.
switch (rule->type()) {
case StyleRule::Import: // Whatever we import should do its own analysis, we don't need to invalidate the document here!
case StyleRule::Keyframes: // Keyframes never cause style invalidations and are handled during sheet insertion.
case StyleRule::Page: // Page rules apply only during printing, we force a full-recalc before printing.
return false;
case StyleRule::Media: // If the media rule doesn't apply, we could avoid recalc.
case StyleRule::FontFace: // If the fonts aren't in use, we could avoid recalc.
case StyleRule::Supports: // If we evaluated the supports-clause we could avoid recalc.
case StyleRule::Viewport: // If the viewport doesn't match, we could avoid recalcing.
// FIXME: Unclear if any of the rest need to cause style recalc:
case StyleRule::Region:
case StyleRule::Filter:
return true;
// These should all be impossible to reach:
case StyleRule::Unknown:
case StyleRule::Charset:
case StyleRule::Keyframe:
case StyleRule::Style:
break;
}
ASSERT_NOT_REACHED();
return true;
}
void StyleInvalidationAnalysis::analyzeStyleSheet(StyleSheetContents* styleSheetContents)
{
ASSERT(!styleSheetContents->isLoading());
// See if all rules on the sheet are scoped to some specific ids or classes.
// Then test if we actually have any of those in the tree at the moment.
const Vector<RefPtr<StyleRuleImport> >& importRules = styleSheetContents->importRules();
for (unsigned i = 0; i < importRules.size(); ++i) {
if (!importRules[i]->styleSheet())
continue;
analyzeStyleSheet(importRules[i]->styleSheet());
if (m_dirtiesAllStyle)
return;
}
if (styleSheetContents->hasSingleOwnerNode()) {
Node* ownerNode = styleSheetContents->singleOwnerNode();
if (ownerNode && ownerNode->hasTagName(HTMLNames::styleTag) && toHTMLStyleElement(ownerNode)->isRegisteredAsScoped()) {
m_scopingNodes.append(determineScopingNodeForStyleScoped(toHTMLStyleElement(ownerNode), styleSheetContents));
return;
}
}
const Vector<RefPtr<StyleRuleBase> >& rules = styleSheetContents->childRules();
for (unsigned i = 0; i < rules.size(); i++) {
StyleRuleBase* rule = rules[i].get();
if (!rule->isStyleRule()) {
if (ruleAdditionMightRequireDocumentStyleRecalc(rule)) {
m_dirtiesAllStyle = true;
return;
}
continue;
}
StyleRule* styleRule = toStyleRule(rule);
if (!determineSelectorScopes(styleRule->selectorList(), m_idScopes, m_classScopes)) {
m_dirtiesAllStyle = true;
return;
}
}
}
static bool elementMatchesSelectorScopes(const Element* element, const HashSet<StringImpl*>& idScopes, const HashSet<StringImpl*>& classScopes)
{
if (!idScopes.isEmpty() && element->hasID() && idScopes.contains(element->idForStyleResolution().impl()))
return true;
if (classScopes.isEmpty() || !element->hasClass())
return false;
const SpaceSplitString& classNames = element->classNames();
for (unsigned i = 0; i < classNames.size(); ++i) {
if (classScopes.contains(classNames[i].impl()))
return true;
}
return false;
}
void StyleInvalidationAnalysis::invalidateStyle(Document& document)
{
ASSERT(!m_dirtiesAllStyle);
if (!m_scopingNodes.isEmpty()) {
for (unsigned i = 0; i < m_scopingNodes.size(); ++i)
m_scopingNodes.at(i)->setNeedsStyleRecalc();
}
if (m_idScopes.isEmpty() && m_classScopes.isEmpty())
return;
Element* element = ElementTraversal::firstWithin(document);
while (element) {
if (elementMatchesSelectorScopes(element, m_idScopes, m_classScopes)) {
element->setNeedsStyleRecalc();
// The whole subtree is now invalidated, we can skip to the next sibling.
element = ElementTraversal::nextSkippingChildren(*element);
continue;
}
element = ElementTraversal::next(*element);
}
}
}
|
