The Tor Browser: comparison layout/style/Declaration.h

--1:000000000000
+:7ee3ee4691ee
+/* -*- Mode: C++; tab-width: 2; 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/. */
+/*
+* representation of a declaration block (or style attribute) in a CSS
+* stylesheet
+*/
+#ifndef mozilla_css_Declaration_h
+#define mozilla_css_Declaration_h
+// This header is in EXPORTS because it's used in several places in content/,
+// but it's not really a public interface.
+#ifndef MOZILLA_INTERNAL_API
+#error "This file should only be included within libxul"
+#endif
+#include "mozilla/Attributes.h"
+#include "mozilla/MemoryReporting.h"
+#include "CSSVariableDeclarations.h"
+#include "nsCSSDataBlock.h"
+#include "nsCSSProperty.h"
+#include "nsCSSProps.h"
+#include "nsStringFwd.h"
+#include "nsTArray.h"
+#include <stdio.h>
+namespace mozilla {
+namespace css {
+// Declaration objects have unusual lifetime rules.  Every declaration
+// begins life in an invalid state which ends when InitializeEmpty or
+// CompressFrom is called upon it.  After that, it can be attached to
+// exactly one style rule, and will be destroyed when that style rule
+// is destroyed.  A declaration becomes immutable when its style rule's
+// |RuleMatched| method is called; after that, it must be copied before
+// it can be modified, which is taken care of by |EnsureMutable|.
+class Declaration {
+public:
+/**
+* Construct an |Declaration| that is in an invalid state (null
+* |mData|) and cannot be used until its |CompressFrom| method or
+* |InitializeEmpty| method is called.
+*/
+Declaration();
+Declaration(const Declaration& aCopy);
+~Declaration();
+/**
+* |ValueAppended| must be called to maintain this declaration's
+* |mOrder| whenever a property is parsed into an expanded data block
+* for this declaration.  aProperty must not be a shorthand.
+*/
+void ValueAppended(nsCSSProperty aProperty);
+void RemoveProperty(nsCSSProperty aProperty);
+bool HasProperty(nsCSSProperty aProperty) const;
+void GetValue(nsCSSProperty aProperty, nsAString& aValue) const;
+void GetAuthoredValue(nsCSSProperty aProperty, nsAString& aValue) const;
+bool HasImportantData() const {
+return mImportantData || mImportantVariables;
+}
+bool GetValueIsImportant(nsCSSProperty aProperty) const;
+bool GetValueIsImportant(const nsAString& aProperty) const;
+/**
+* Adds a custom property declaration to this object.
+*
+* @param aName The variable name (i.e., without the "--" prefix).
+* @param aType The type of value the variable has.
+* @param aValue The value of the variable, if aType is
+*   CSSVariableDeclarations::eTokenStream.
+* @param aIsImportant Whether the declaration is !important.
+* @param aOverrideImportant When aIsImportant is false, whether an
+*   existing !important declaration will be overridden.
+*/
+void AddVariableDeclaration(const nsAString& aName,
+CSSVariableDeclarations::Type aType,
+const nsString& aValue,
+bool aIsImportant,
+bool aOverrideImportant);
+/**
+* Removes a custom property declaration from this object.
+*
+* @param aName The variable name (i.e., without the "--" prefix).
+*/
+void RemoveVariableDeclaration(const nsAString& aName);
+/**
+* Returns whether a custom property declaration for a variable with
+* a given name exists on this object.
+*
+* @param aName The variable name (i.e., without the "--" prefix).
+*/
+bool HasVariableDeclaration(const nsAString& aName) const;
+/**
+* Gets the string value for a custom property declaration of a variable
+* with a given name.
+*
+* @param aName The variable name (i.e., without the "--" prefix).
+* @param aValue Out parameter into which the variable's value will be
+*   stored.  If the value is 'initial' or 'inherit', that exact string
+*   will be stored in aValue.
+*/
+void GetVariableDeclaration(const nsAString& aName, nsAString& aValue) const;
+/**
+* Returns whether the custom property declaration for a variable with
+* the given name was !important.
+*/
+bool GetVariableValueIsImportant(const nsAString& aName) const;
+uint32_t Count() const {
+return mOrder.Length();
+}
+// Returns whether we actually had a property at aIndex
+bool GetNthProperty(uint32_t aIndex, nsAString& aReturn) const;
+void ToString(nsAString& aString) const;
+nsCSSCompressedDataBlock* GetNormalBlock() const { return mData; }
+nsCSSCompressedDataBlock* GetImportantBlock() const { return mImportantData; }
+/**
+* Initialize this declaration as holding no data.  Cannot fail.
+*/
+void InitializeEmpty();
+/**
+* Transfer all of the state from |aExpandedData| into this declaration.
+* After calling, |aExpandedData| should be in its initial state.
+* Callers must make sure mOrder is updated as necessary.
+*/
+void CompressFrom(nsCSSExpandedDataBlock *aExpandedData) {
+NS_ABORT_IF_FALSE(!mData, "oops");
+NS_ABORT_IF_FALSE(!mImportantData, "oops");
+aExpandedData->Compress(getter_Transfers(mData),
+getter_Transfers(mImportantData));
+aExpandedData->AssertInitialState();
+}
+/**
+* Transfer all of the state from this declaration into
+* |aExpandedData| and put this declaration temporarily into an
+* invalid state (ended by |CompressFrom| or |InitializeEmpty|) that
+* should last only during parsing.  During this time only
+* |ValueAppended| should be called.
+*/
+void ExpandTo(nsCSSExpandedDataBlock *aExpandedData) {
+AssertMutable();
+aExpandedData->AssertInitialState();
+NS_ABORT_IF_FALSE(mData, "oops");
+aExpandedData->Expand(mData.forget(), mImportantData.forget());
+}
+/**
+* Do what |nsIStyleRule::MapRuleInfoInto| needs to do for a style
+* rule using this declaration for storage.
+*/
+void MapNormalRuleInfoInto(nsRuleData *aRuleData) const {
+NS_ABORT_IF_FALSE(mData, "called while expanded");
+mData->MapRuleInfoInto(aRuleData);
+if (mVariables) {
+mVariables->MapRuleInfoInto(aRuleData);
+}
+}
+void MapImportantRuleInfoInto(nsRuleData *aRuleData) const {
+NS_ABORT_IF_FALSE(mData, "called while expanded");
+NS_ABORT_IF_FALSE(mImportantData || mImportantVariables,
+"must have important data or variables");
+if (mImportantData) {
+mImportantData->MapRuleInfoInto(aRuleData);
+}
+if (mImportantVariables) {
+mImportantVariables->MapRuleInfoInto(aRuleData);
+}
+}
+/**
+* Attempt to replace the value for |aProperty| stored in this
+* declaration with the matching value from |aFromBlock|.
+* This method may only be called on a mutable declaration.
+* It will fail (returning false) if |aProperty| is shorthand,
+* is not already in this declaration, or does not have the indicated
+* importance level.  If it returns true, it erases the value in
+* |aFromBlock|.  |aChanged| is set to true if the declaration
+* changed as a result of the call, and to false otherwise.
+*/
+bool TryReplaceValue(nsCSSProperty aProperty, bool aIsImportant,
+nsCSSExpandedDataBlock& aFromBlock,
+bool* aChanged)
+{
+AssertMutable();
+NS_ABORT_IF_FALSE(mData, "called while expanded");
+if (nsCSSProps::IsShorthand(aProperty)) {
+*aChanged = false;
+return false;
+}
+nsCSSCompressedDataBlock *block = aIsImportant ? mImportantData : mData;
+// mImportantData might be null
+if (!block) {
+*aChanged = false;
+return false;
+}
+#ifdef DEBUG
+{
+nsCSSCompressedDataBlock *other = aIsImportant ? mData : mImportantData;
+NS_ABORT_IF_FALSE(!other || !other->ValueFor(aProperty) ||
+!block->ValueFor(aProperty),
+"Property both important and not?");
+}
+#endif
+return block->TryReplaceValue(aProperty, aFromBlock, aChanged);
+}
+bool HasNonImportantValueFor(nsCSSProperty aProperty) const {
+NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty), "must be longhand");
+return !!mData->ValueFor(aProperty);
+}
+/**
+* Return whether |this| may be modified.
+*/
+bool IsMutable() const {
+return !mImmutable;
+}
+/**
+* Copy |this|, if necessary to ensure that it can be modified.
+*/
+Declaration* EnsureMutable();
+/**
+* Crash if |this| cannot be modified.
+*/
+void AssertMutable() const {
+NS_ABORT_IF_FALSE(IsMutable(), "someone forgot to call EnsureMutable");
+}
+/**
+* Mark this declaration as unmodifiable.  It's 'const' so it can
+* be called from ToString.
+*/
+void SetImmutable() const { mImmutable = true; }
+/**
+* Clear the data, in preparation for its replacement with entirely
+* new data by a call to |CompressFrom|.
+*/
+void ClearData() {
+AssertMutable();
+mData = nullptr;
+mImportantData = nullptr;
+mVariables = nullptr;
+mImportantVariables = nullptr;
+mOrder.Clear();
+mVariableOrder.Clear();
+}
+#ifdef DEBUG
+void List(FILE* out = stdout, int32_t aIndent = 0) const;
+#endif
+private:
+Declaration& operator=(const Declaration& aCopy) MOZ_DELETE;
+bool operator==(const Declaration& aCopy) const MOZ_DELETE;
+void GetValue(nsCSSProperty aProperty, nsAString& aValue,
+nsCSSValue::Serialization aValueSerialization) const;
+static void AppendImportanceToString(bool aIsImportant, nsAString& aString);
+// return whether there was a value in |aValue| (i.e., it had a non-null unit)
+bool AppendValueToString(nsCSSProperty aProperty, nsAString& aResult) const;
+bool AppendValueToString(nsCSSProperty aProperty, nsAString& aResult,
+nsCSSValue::Serialization aValueSerialization) const;
+// Helper for ToString with strange semantics regarding aValue.
+void AppendPropertyAndValueToString(nsCSSProperty aProperty,
+nsAutoString& aValue,
+nsAString& aResult) const;
+// helper for ToString that serializes a custom property declaration for
+// a variable with the specified name
+void AppendVariableAndValueToString(const nsAString& aName,
+nsAString& aResult) const;
+public:
+/**
+* Returns the property at the given index in the ordered list of
+* declarations.  For custom properties, eCSSPropertyExtra_variable
+* is returned.
+*/
+nsCSSProperty GetPropertyAt(uint32_t aIndex) const {
+uint32_t value = mOrder[aIndex];
+if (value >= eCSSProperty_COUNT) {
+return eCSSPropertyExtra_variable;
+}
+return nsCSSProperty(value);
+}
+/**
+* Gets the name of the custom property at the given index in the ordered
+* list of declarations.
+*/
+void GetCustomPropertyNameAt(uint32_t aIndex, nsAString& aResult) const {
+MOZ_ASSERT(mOrder[aIndex] >= eCSSProperty_COUNT);
+uint32_t variableIndex = mOrder[aIndex] - eCSSProperty_COUNT;
+aResult.Truncate();
+aResult.AppendLiteral("--");
+aResult.Append(mVariableOrder[variableIndex]);
+}
+size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+private:
+// The order of properties in this declaration.  Longhand properties are
+// represented by their nsCSSProperty value, and each custom property (--*)
+// is represented by a value that begins at eCSSProperty_COUNT.
+//
+// Subtracting eCSSProperty_COUNT from those values that represent custom
+// properties results in an index into mVariableOrder, which identifies the
+// specific variable the custom property declaration is for.
+nsAutoTArray<uint32_t, 8> mOrder;
+// variable names of custom properties found in mOrder
+nsTArray<nsString> mVariableOrder;
+// never null, except while expanded, or before the first call to
+// InitializeEmpty or CompressFrom.
+nsAutoPtr<nsCSSCompressedDataBlock> mData;
+// may be null
+nsAutoPtr<nsCSSCompressedDataBlock> mImportantData;
+// may be null
+nsAutoPtr<CSSVariableDeclarations> mVariables;
+// may be null
+nsAutoPtr<CSSVariableDeclarations> mImportantVariables;
+// set by style rules when |RuleMatched| is called;
+// also by ToString (hence the 'mutable').
+mutable bool mImmutable;
+};
+} // namespace css
+} // namespace mozilla
+#endif /* mozilla_css_Declaration_h */

The Tor Browser / file comparison

comparison: layout/style/Declaration.h

layout/style/Declaration.h