blob: c5452476f6f6bac87b9878a8912aecfa0f199afd [file] [log] [blame]
// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/css_variable_data.h"
#include "third_party/blink/renderer/platform/wtf/forward.h"
#include "third_party/blink/renderer/platform/wtf/hash_map.h"
#include "third_party/blink/renderer/platform/wtf/ref_counted.h"
#include "third_party/blink/renderer/platform/wtf/text/atomic_string_hash.h"
namespace blink {
// UADefinedVariable contains all the user agent defined environment variables.
// When adding a new variable the string equivalent needs to be added to
// |GetVariableName|.
enum class UADefinedVariable {
// The safe area insets are four environment variables that define a
// rectangle by its top, right, bottom, and left insets from the edge of
// the viewport.
// StyleEnvironmentVariables stores user agent and user defined CSS environment
// variables. It has a static root instance that stores global values and
// each document has a child that stores document level values.
class CORE_EXPORT StyleEnvironmentVariables
: public RefCounted<StyleEnvironmentVariables> {
static StyleEnvironmentVariables& GetRootInstance();
// Gets the name of a |UADefinedVariable| as a string.
static const AtomicString GetVariableName(UADefinedVariable);
// Create a new instance bound to |parent|.
static scoped_refptr<StyleEnvironmentVariables> Create(
StyleEnvironmentVariables& parent);
virtual ~StyleEnvironmentVariables();
// Set the value of the variable |name| and invalidate any dependents.
void SetVariable(const AtomicString& name,
scoped_refptr<CSSVariableData> value);
// Tokenize |value| and set it.
void SetVariable(const AtomicString& name, const String& value);
void SetVariable(const UADefinedVariable name, const String& value);
// Remove the variable |name| and invalidate any dependents.
void RemoveVariable(const AtomicString& name);
// Resolve the variable |name| by traversing the tree of
// |StyleEnvironmentVariables|.
virtual CSSVariableData* ResolveVariable(const AtomicString& name);
// Detach |this| from |parent|.
void DetachFromParent();
friend class StyleEnvironmentVariablesTest;
void ClearForTesting();
// Bind this instance to a |parent|. This should only be called once.
void BindToParent(StyleEnvironmentVariables& parent);
// Called by the parent to tell the child that variable |name| has changed.
void ParentInvalidatedVariable(const AtomicString& name);
StyleEnvironmentVariables() : parent_(nullptr) {}
// Called when variable |name| is changed. This will notify any children that
// this variable has changed.
virtual void InvalidateVariable(const AtomicString& name);
class RootOwner;
Vector<scoped_refptr<StyleEnvironmentVariables>> children_;
HashMap<AtomicString, scoped_refptr<CSSVariableData>> data_;
scoped_refptr<StyleEnvironmentVariables> parent_;
} // namespace blink