gecko-dev/dom/media/TextTrackRegion.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 et tw=78: */
/* 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_dom_TextTrackRegion_h
#define mozilla_dom_TextTrackRegion_h

#include "nsCycleCollectionParticipant.h"
#include "nsString.h"
#include "nsWrapperCache.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/dom/TextTrack.h"
#include "mozilla/Preferences.h"

namespace mozilla {
namespace dom {

class GlobalObject;
class TextTrack;

class TextTrackRegion final : public nsISupports,
                              public nsWrapperCache
{
public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(TextTrackRegion)

  static bool RegionsEnabled(JSContext* cx, JSObject* obj)
  {
    return Preferences::GetBool("media.webvtt.enabled") &&
           Preferences::GetBool("media.webvtt.regions.enabled");
  }

  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;

  nsISupports* GetParentObject() const
  {
    return mParent;
  }

  explicit TextTrackRegion(nsISupports* aGlobal);

  /** WebIDL Methods. */

  static already_AddRefed<TextTrackRegion>
  Constructor(const GlobalObject& aGlobal, ErrorResult& aRv);

  double Lines() const
  {
    return mLines;
  }

  void SetLines(double aLines)
  {
    mLines = aLines;
  }

  double Width() const
  {
    return mWidth;
  }

  void SetWidth(double aWidth, ErrorResult& aRv)
  {
    if (!InvalidValue(aWidth, aRv)) {
      mWidth = aWidth;
    }
  }

  double RegionAnchorX() const
  {
    return mRegionAnchorX;
  }

  void SetRegionAnchorX(double aVal, ErrorResult& aRv)
  {
    if (!InvalidValue(aVal, aRv)) {
      mRegionAnchorX = aVal;
    }
  }

  double RegionAnchorY() const
  {
    return mRegionAnchorY;
  }

  void SetRegionAnchorY(double aVal, ErrorResult& aRv)
  {
    if (!InvalidValue(aVal, aRv)) {
      mRegionAnchorY = aVal;
    }
  }

  double ViewportAnchorX() const
  {
    return mViewportAnchorX;
  }

  void SetViewportAnchorX(double aVal, ErrorResult& aRv)
  {
    if (!InvalidValue(aVal, aRv)) {
      mViewportAnchorX = aVal;
    }
  }

  double ViewportAnchorY() const
  {
    return mViewportAnchorY;
  }

  void SetViewportAnchorY(double aVal, ErrorResult& aRv)
  {
    if (!InvalidValue(aVal, aRv)) {
      mViewportAnchorY = aVal;
    }
  }

  void GetScroll(nsAString& aScroll) const
  {
    aScroll = mScroll;
  }

  void SetScroll(const nsAString& aScroll, ErrorResult& aRv)
  {
    if (!aScroll.EqualsLiteral("") && !aScroll.EqualsLiteral("up")) {
      aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
      return;
    }

    mScroll = aScroll;
  }

  /** end WebIDL Methods. */


  // Helper to aid copying of a given TextTrackRegion's width, lines,
  // anchor, viewport and scroll values.
  void CopyValues(TextTrackRegion& aRegion);

  // -----helpers-------
  const nsAString& Scroll() const
  {
    return mScroll;
  }

private:
  ~TextTrackRegion() {}

  nsCOMPtr<nsISupports> mParent;
  double mWidth;
  long mLines;
  double mRegionAnchorX;
  double mRegionAnchorY;
  double mViewportAnchorX;
  double mViewportAnchorY;
  nsString mScroll;

  // Helper to ensure new value is in the range: 0.0% - 100.0%; throws
  // an IndexSizeError otherwise.
  inline bool InvalidValue(double aValue, ErrorResult& aRv)
  {
    if(aValue < 0.0  || aValue > 100.0) {
      aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
      return true;
    }

    return false;
  }

};

} //namespace dom
} //namespace mozilla

#endif //mozilla_dom_TextTrackRegion_h