content/svg/content/src/SVGMotionSMILPathUtils.h
author Ehsan Akhgari <ehsan@mozilla.com>
Mon, 17 Oct 2011 10:59:28 -0400
changeset 79324 ec7577dec4fceef0ac2717416d9c48289402d935
parent 78238 e7854b4d29ba905ae3994f821b160c989bac4260
child 79326 f93960a93ad97a56d308bd9ce25d97cbc175d524
child 86301 e31b47c574bff4c89cff38855b40a56865092388
permissions -rw-r--r--
Bug 690892 - Replace PR_TRUE/PR_FALSE with true/false on mozilla-central; rs=dbaron Landing on a CLOSED TREE

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * 1.1 (the "License"); you may not use this file except in compliance with
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 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is the Mozilla SVG project.
 *
 * The Initial Developer of the Original Code is the Mozilla Foundation.
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 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *   Daniel Holbert <dholbert@mozilla.com>
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/* Helper class to help with generating anonymous path elements for
   <animateMotion> elements to use. */

#ifndef MOZILLA_SVGMOTIONSMILPATHUTILS_H_
#define MOZILLA_SVGMOTIONSMILPATHUTILS_H_

#include "nsSMILParserUtils.h"
#include "nsAutoPtr.h"
#include "nsTArray.h"
#include "nsDebug.h"
#include "gfxContext.h"
#include "nsSVGUtils.h"
#include "gfxPlatform.h"

class nsSVGElement;
class nsIContent;
class nsIDocument;
class nsAString;

namespace mozilla {

class SVGMotionSMILPathUtils {
public:
  // Class to assist in generating a gfxFlattenedPath, based on
  // coordinates in the <animateMotion> from/by/to/values attributes.
  class PathGenerator {
  public:
    PathGenerator(const nsSVGElement* aSVGElement)
      : mSVGElement(aSVGElement),
        mGfxContext(gfxPlatform::GetPlatform()->ScreenReferenceSurface()),
        mHaveReceivedCommands(false)
    {}

    // 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<gfxFlattenedPath> GetResultingPath();

  protected:
    // Helper methods
    bool ParseCoordinatePair(const nsAString& aStr,
                               float& aXVal, float& aYVal);

    // Member data
    const nsSVGElement* mSVGElement; // context for converting to user units
    gfxContext    mGfxContext;
    bool          mHaveReceivedCommands;
  };

  // Class to assist in passing each subcomponent of a |values| attribute to
  // a PathGenerator, for generating a corresponding gfxFlattenedPath.
  class MotionValueParser : public nsSMILParserUtils::GenericValueParser
  {
  public:
    MotionValueParser(PathGenerator* aPathGenerator,
                      nsTArray<double>* aPointDistances)
      : mPathGenerator(aPathGenerator),
        mPointDistances(aPointDistances),
        mDistanceSoFar(0.0)
    {
      NS_ABORT_IF_FALSE(mPointDistances->IsEmpty(),
                        "expecting point distances array to start empty");
    }

    // nsSMILParserUtils::GenericValueParser interface
    virtual nsresult Parse(const nsAString& aValueStr);

  protected:
    PathGenerator*    mPathGenerator;
    nsTArray<double>* mPointDistances;
    double            mDistanceSoFar;
  };

};

} // namespace mozilla

#endif // MOZILLA_SVGMOTIONSMILPATHUTILS_H_