/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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/. */

/*

 * A base class which implements nsIStyleSheetLinkingElement and can

 * be subclassed by various content nodes that want to load

 * stylesheets (<style>, <link>, processing instructions, etc).

 */

#ifndef nsStyleLinkElement_h___

#define nsStyleLinkElement_h___

#include "mozilla/Attributes.h"

#include "mozilla/CORSMode.h"

#include "mozilla/StyleSheetInlines.h"

#include "mozilla/Unused.h"

#include "mozilla/net/ReferrerPolicy.h"

#include "nsCOMPtr.h"

#include "nsIStyleSheetLinkingElement.h"

#include "nsTArray.h"

class nsIDocument;

class nsIURI;

namespace mozilla {

class CSSStyleSheet;

namespace dom {

class ShadowRoot;

} // namespace dom

} // namespace mozilla

class nsStyleLinkElement : public nsIStyleSheetLinkingElement

{

public:

  nsStyleLinkElement();

  virtual ~nsStyleLinkElement();

  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override = 0;

  mozilla::StyleSheet* GetSheet() const { return mStyleSheet; }

  // nsIStyleSheetLinkingElement

  void SetStyleSheet(mozilla::StyleSheet* aStyleSheet) override;

  mozilla::StyleSheet* GetStyleSheet() override;

  void InitStyleLinkElement(bool aDontLoadStyle) override;

  mozilla::Result<Update, nsresult>

    UpdateStyleSheet(nsICSSLoaderObserver*) override;

  void SetEnableUpdates(bool aEnableUpdates) override;

  void GetCharset(nsAString& aCharset) override;

  void OverrideBaseURI(nsIURI* aNewBaseURI) override;

  void SetLineNumber(uint32_t aLineNumber) override;

  uint32_t GetLineNumber() override;

  void SetColumnNumber(uint32_t aColumnNumber) override;

  uint32_t GetColumnNumber() override;

  enum RelValue {

    ePREFETCH =     0x00000001,

    eDNS_PREFETCH = 0x00000002,

    eSTYLESHEET =   0x00000004,

    eNEXT =         0x00000008,

    eALTERNATE =    0x00000010,

    ePRECONNECT =   0x00000020,

    // NOTE: 0x40 is unused

    ePRELOAD =      0x00000080

  };

  // The return value is a bitwise or of 0 or more RelValues.

  static uint32_t ParseLinkTypes(const nsAString& aTypes);

  void UpdateStyleSheetInternal()

  {

    mozilla::Unused << UpdateStyleSheetInternal(nullptr, nullptr);

  }

protected:

  /**

   * @param aOldDocument   should be non-null only if we're updating because we

   *                       removed the node from the document.

   * @param aOldShadowRoot should be non-null only if we're updating because we

   *                       removed the node from a shadow tree.

   * @param aForceUpdate true will force the update even if the URI has not

   *                     changed.  This should be used in cases when something

   *                     about the content that affects the resulting sheet

   *                     changed but the URI may not have changed.

   *

   * TODO(emilio): Should probably pass a single DocumentOrShadowRoot.

   */

  mozilla::Result<Update, nsresult> UpdateStyleSheetInternal(

      nsIDocument* aOldDocument,

      mozilla::dom::ShadowRoot* aOldShadowRoot,

      ForceUpdate = ForceUpdate::No);

  // Gets a suitable title and media for SheetInfo out of an element, which

  // needs to be `this`.

  //

  // NOTE(emilio): Needs nsString instead of nsAString because of

  // CompressWhitespace.

  static void GetTitleAndMediaForElement(const mozilla::dom::Element&,

                                         nsString& aTitle,

                                         nsString& aMedia);

  // Returns whether the type attribute specifies the text/css mime type.

  static bool IsCSSMimeTypeAttribute(const mozilla::dom::Element&);

  virtual mozilla::Maybe<SheetInfo> GetStyleSheetInfo() = 0;

  // CC methods

  void Unlink();

  void Traverse(nsCycleCollectionTraversalCallback &cb);

private:

  /**

   * @param aOldDocument should be non-null only if we're updating because we

   *                     removed the node from the document.

   * @param aOldShadowRoot The ShadowRoot that used to contain the style.

   *                     Passed as a parameter because on an update, the node

   *                     is removed from the tree before the sheet is removed

   *                     from the ShadowRoot.

   * @param aForceUpdate true will force the update even if the URI has not

   *                     changed.  This should be used in cases when something

   *                     about the content that affects the resulting sheet

   *                     changed but the URI may not have changed.

   */

  mozilla::Result<Update, nsresult>

    DoUpdateStyleSheet(nsIDocument* aOldDocument,

                       mozilla::dom::ShadowRoot* aOldShadowRoot,

                       nsICSSLoaderObserver* aObserver,

                       ForceUpdate);

  RefPtr<mozilla::StyleSheet> mStyleSheet;

protected:

  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;

  bool mDontLoadStyle;

  bool mUpdatesEnabled;

  uint32_t mLineNumber;

  uint32_t mColumnNumber;

};

#endif /* nsStyleLinkElement_h___ */