gecko-dev/editor/libeditor/ChangeStyleTransaction.h

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/* -*- 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/. */
#ifndef mozilla_ChangeStyleTransaction_h
#define mozilla_ChangeStyleTransaction_h
#include "mozilla/EditTransactionBase.h" // base class
#include "nsCOMPtr.h" // nsCOMPtr members
#include "nsCycleCollectionParticipant.h" // various macros
#include "nsString.h" // nsString members
class nsAtom;
namespace mozilla {
namespace dom {
class Element;
} // namespace dom
/**
* A transaction that changes the value of a CSS inline style of a content
* node. This transaction covers add, remove, and change a property's value.
*/
class ChangeStyleTransaction final : public EditTransactionBase
{
protected:
ChangeStyleTransaction(dom::Element& aElement,
nsAtom& aProperty,
const nsAString& aValue,
bool aRemove);
public:
/**
* Creates a change style transaction. This never returns nullptr.
*
* @param aNode The node whose style attribute will be changed.
* @param aProperty The name of the property to change.
* @param aValue New value for aProperty.
*/
static already_AddRefed<ChangeStyleTransaction>
Create(dom::Element& aElement,
nsAtom& aProperty,
const nsAString& aValue);
/**
* Creates a change style transaction. This never returns nullptr.
*
* @param aNode The node whose style attribute will be changed.
* @param aProperty The name of the property to change.
* @param aValue The value to remove from aProperty.
*/
static already_AddRefed<ChangeStyleTransaction>
CreateToRemove(dom::Element& aElement,
nsAtom& aProperty,
const nsAString& aValue);
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeStyleTransaction,
EditTransactionBase)
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_EDITTRANSACTIONBASE
NS_IMETHOD RedoTransaction() override;
/**
* Returns true if the list of white-space separated values contains aValue
*
* @param aValueList [IN] a list of white-space separated values
* @param aValue [IN] the value to look for in the list
* @return true if the value is in the list of values
*/
static bool ValueIncludes(const nsAString& aValueList,
const nsAString& aValue);
private:
virtual ~ChangeStyleTransaction();
/*
* Adds the value aNewValue to list of white-space separated values aValues.
*
* @param aValues [IN/OUT] a list of wite-space separated values
* @param aNewValue [IN] a value this code adds to aValues if it is not
* already in
*/
void AddValueToMultivalueProperty(nsAString& aValues,
const nsAString& aNewValue);
/**
* Returns true if the property accepts more than one value.
*
* @param aCSSProperty [IN] the CSS property
* @return true if the property accepts more than one value
*/
bool AcceptsMoreThanOneValue(nsAtom& aCSSProperty);
/**
* Remove a value from a list of white-space separated values.
* @param aValues [IN] a list of white-space separated values
* @param aRemoveValue [IN] the value to remove from the list
*/
void RemoveValueFromListOfValues(nsAString& aValues,
const nsAString& aRemoveValue);
/**
* If the boolean is true and if the value is not the empty string,
* set the property in the transaction to that value; if the value
* is empty, remove the property from element's styles. If the boolean
* is false, just remove the style attribute.
*/
nsresult SetStyle(bool aAttributeWasSet, nsAString& aValue);
// The element to operate upon.
nsCOMPtr<dom::Element> mElement;
// The CSS property to change.
RefPtr<nsAtom> mProperty;
// The value to set the property to (ignored if mRemoveProperty==true).
nsString mValue;
// true if the operation is to remove mProperty from mElement.
bool mRemoveProperty;
// The value to set the property to for undo.
nsString mUndoValue;
// The value to set the property to for redo.
nsString mRedoValue;
// True if the style attribute was present and not empty before DoTransaction.
bool mUndoAttributeWasSet;
// True if the style attribute is present and not empty after DoTransaction.
bool mRedoAttributeWasSet;
};
} // namespace mozilla
#endif // #ifndef mozilla_ChangeStyleTransaction_h