/* -*- 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/. */

#ifndef MOZILLA_SVGNUMBERLIST_H__

#define MOZILLA_SVGNUMBERLIST_H__

#include "nsCOMPtr.h"

#include "nsDebug.h"

#include "nsIContent.h"

#include "nsINode.h"

#include "nsIWeakReferenceUtils.h"

#include "nsSVGElement.h"

#include "nsTArray.h"

namespace mozilla {

/**

 * ATTENTION! WARNING! WATCH OUT!!

 *

 * Consumers that modify objects of this type absolutely MUST keep the DOM

 * wrappers for those lists (if any) in sync!! That's why this class is so

 * locked down.

 *

 * The DOM wrapper class for this class is DOMSVGNumberList.

 */

class SVGNumberList

{

  friend class SVGAnimatedNumberList;

  friend class DOMSVGNumberList;

  friend class DOMSVGNumber;

public:

  SVGNumberList(){}

  ~SVGNumberList(){}

  // Only methods that don't make/permit modification to this list are public.

  // Only our friend classes can access methods that may change us.

  /// This may return an incomplete string on OOM, but that's acceptable.

  void GetValueAsString(nsAString& aValue) const;

  bool IsEmpty() const {

    return mNumbers.IsEmpty();

  }

  uint32_t Length() const {

    return mNumbers.Length();

  }

  const float& operator[](uint32_t aIndex) const {

    return mNumbers[aIndex];

  }

  bool operator==(const SVGNumberList& rhs) const {

    return mNumbers == rhs.mNumbers;

  }

  bool SetCapacity(uint32_t size) {

    return mNumbers.SetCapacity(size, fallible);

  }

  void Compact() {

    mNumbers.Compact();

  }

  // Access to methods that can modify objects of this type is deliberately

  // limited. This is to reduce the chances of someone modifying objects of

  // this type without taking the necessary steps to keep DOM wrappers in sync.

  // If you need wider access to these methods, consider adding a method to

  // SVGAnimatedNumberList and having that class act as an intermediary so it

  // can take care of keeping DOM wrappers in sync.

protected:

  /**

   * This may fail on OOM if the internal capacity needs to be increased, in

   * which case the list will be left unmodified.

   */

  nsresult CopyFrom(const SVGNumberList& rhs);

  float& operator[](uint32_t aIndex) {

    return mNumbers[aIndex];

  }

  /**

   * This may fail (return false) on OOM if the internal capacity is being

   * increased, in which case the list will be left unmodified.

   */

  bool SetLength(uint32_t aNumberOfItems) {

    return mNumbers.SetLength(aNumberOfItems, fallible);

  }

private:

  // Marking the following private only serves to show which methods are only

  // used by our friend classes (as opposed to our subclasses) - it doesn't

  // really provide additional safety.

  nsresult SetValueFromString(const nsAString& aValue);

  void Clear() {

    mNumbers.Clear();

  }

  bool InsertItem(uint32_t aIndex, const float &aNumber) {

    if (aIndex >= mNumbers.Length()) {

      aIndex = mNumbers.Length();

    }

    return !!mNumbers.InsertElementAt(aIndex, aNumber, fallible);

  }

  void ReplaceItem(uint32_t aIndex, const float &aNumber) {

    MOZ_ASSERT(aIndex < mNumbers.Length(),

               "DOM wrapper caller should have raised INDEX_SIZE_ERR");

    mNumbers[aIndex] = aNumber;

  }

  void RemoveItem(uint32_t aIndex) {

    MOZ_ASSERT(aIndex < mNumbers.Length(),

               "DOM wrapper caller should have raised INDEX_SIZE_ERR");

    mNumbers.RemoveElementAt(aIndex);

  }

  bool AppendItem(float aNumber) {

    return !!mNumbers.AppendElement(aNumber, fallible);

  }

protected:

  /* See SVGLengthList for the rationale for using FallibleTArray<float> instead

   * of FallibleTArray<float, 1>.

   */

  FallibleTArray<float> mNumbers;

};

/**

 * This SVGNumberList subclass is used by the SMIL code when a number list

 * is to be stored in an nsISMILValue instance. Since nsISMILValue objects may

 * be cached, it is necessary for us to hold a strong reference to our element

 * so that it doesn't disappear out from under us if, say, the element is

 * removed from the DOM tree.

 */

class SVGNumberListAndInfo : public SVGNumberList

{

public:

  SVGNumberListAndInfo()

    : mElement(nullptr)

  {}

  explicit SVGNumberListAndInfo(nsSVGElement *aElement)

    : mElement(do_GetWeakReference(static_cast<nsINode*>(aElement)))

  {}

  void SetInfo(nsSVGElement *aElement) {

    mElement = do_GetWeakReference(static_cast<nsINode*>(aElement));

  }

  nsSVGElement* Element() const {

    nsCOMPtr<nsIContent> e = do_QueryReferent(mElement);

    return static_cast<nsSVGElement*>(e.get());

  }

  nsresult CopyFrom(const SVGNumberListAndInfo& rhs) {

    mElement = rhs.mElement;

    return SVGNumberList::CopyFrom(rhs);

  }

  // Instances of this special subclass do not have DOM wrappers that we need

  // to worry about keeping in sync, so it's safe to expose any hidden base

  // class methods required by the SMIL code, as we do below.

  /**

   * Exposed so that SVGNumberList baseVals can be copied to

   * SVGNumberListAndInfo objects. Note that callers should also call

   * SetInfo() when using this method!

   */

  nsresult CopyFrom(const SVGNumberList& rhs) {

    return SVGNumberList::CopyFrom(rhs);

  }

  const float& operator[](uint32_t aIndex) const {

    return SVGNumberList::operator[](aIndex);

  }

  float& operator[](uint32_t aIndex) {

    return SVGNumberList::operator[](aIndex);

  }

  bool SetLength(uint32_t aNumberOfItems) {

    return SVGNumberList::SetLength(aNumberOfItems);

  }

private:

  // We must keep a weak reference to our element because we may belong to a

  // cached baseVal nsSMILValue. See the comments starting at:

  // https://bugzilla.mozilla.org/show_bug.cgi?id=515116#c15

  // See also https://bugzilla.mozilla.org/show_bug.cgi?id=653497

  nsWeakPtr mElement;

};

} // namespace mozilla

#endif // MOZILLA_SVGNUMBERLIST_H__