/* -*- 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/. */

/* Helper class to help with generating anonymous path elements for

   <animateMotion> elements to use. */

#ifndef MOZILLA_SVGMOTIONSMILPATHUTILS_H_

#define MOZILLA_SVGMOTIONSMILPATHUTILS_H_

#include "mozilla/Attributes.h"

#include "gfxPlatform.h"

#include "mozilla/gfx/2D.h"

#include "mozilla/RefPtr.h"

#include "nsDebug.h"

#include "nsSMILParserUtils.h"

#include "nsStringFwd.h"

#include "nsTArray.h"

class nsSVGElement;

namespace mozilla {

class SVGMotionSMILPathUtils

{

  typedef mozilla::gfx::DrawTarget DrawTarget;

  typedef mozilla::gfx::Path Path;

  typedef mozilla::gfx::PathBuilder PathBuilder;

public:

  // Class to assist in generating a Path, based on

  // coordinates in the <animateMotion> from/by/to/values attributes.

  class PathGenerator {

  public:

    explicit PathGenerator(const nsSVGElement* aSVGElement)

      : mSVGElement(aSVGElement),

        mHaveReceivedCommands(false)

    {

      RefPtr<DrawTarget> drawTarget =

        gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();

      NS_ASSERTION(gfxPlatform::GetPlatform()->

                     SupportsAzureContentForDrawTarget(drawTarget),

                   "Should support Moz2D content drawing");

      mPathBuilder = drawTarget->CreatePathBuilder();

    }

    // Methods for adding various path commands to output path.

    // Note: aCoordPairStr is expected to be a whitespace and/or

    // comma-separated x,y coordinate-pair -- see description of

    // "the specified values for from, by, to, and values" at

    //    http://www.w3.org/TR/SVG11/animate.html#AnimateMotionElement

    void   MoveToOrigin();

    bool MoveToAbsolute(const nsAString& aCoordPairStr);

    bool LineToAbsolute(const nsAString& aCoordPairStr,

                          double& aSegmentDistance);

    bool LineToRelative(const nsAString& aCoordPairStr,

                          double& aSegmentDistance);

    // Accessor to let clients check if we've received any commands yet.

    inline bool HaveReceivedCommands() { return mHaveReceivedCommands; }

    // Accessor to get the finalized path

    already_AddRefed<Path> GetResultingPath();

  protected:

    // Helper methods

    bool ParseCoordinatePair(const nsAString& aStr,

                               float& aXVal, float& aYVal);

    // Member data

    const nsSVGElement* mSVGElement; // context for converting to user units

    RefPtr<PathBuilder> mPathBuilder;

    bool          mHaveReceivedCommands;

  };

  // Class to assist in passing each subcomponent of a |values| attribute to

  // a PathGenerator, for generating a corresponding Path.

  class MOZ_STACK_CLASS MotionValueParser :

    public nsSMILParserUtils::GenericValueParser

  {

  public:

    MotionValueParser(PathGenerator* aPathGenerator,

                      FallibleTArray<double>* aPointDistances)

      : mPathGenerator(aPathGenerator),

        mPointDistances(aPointDistances),

        mDistanceSoFar(0.0)

    {

      MOZ_ASSERT(mPointDistances->IsEmpty(),

                 "expecting point distances array to start empty");

    }

    // nsSMILParserUtils::GenericValueParser interface

    virtual bool Parse(const nsAString& aValueStr) override;

  protected:

    PathGenerator*          mPathGenerator;

    FallibleTArray<double>* mPointDistances;

    double                  mDistanceSoFar;

  };

};

} // namespace mozilla

#endif // MOZILLA_SVGMOTIONSMILPATHUTILS_H_