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       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #ifndef SVGTRANSFORMLISTSMILTYPE_H_
       8             : #define SVGTRANSFORMLISTSMILTYPE_H_
       9             : 
      10             : #include "mozilla/Attributes.h"
      11             : #include "nsISMILType.h"
      12             : #include "nsTArray.h"
      13             : 
      14             : class nsSMILValue;
      15             : 
      16             : namespace mozilla {
      17             : 
      18             : class nsSVGTransform;
      19             : class SVGTransformList;
      20             : class SVGTransformSMILData;
      21             : 
      22             : ////////////////////////////////////////////////////////////////////////
      23             : // SVGTransformListSMILType
      24             : //
      25             : // Operations for animating an nsSVGTransformList.
      26             : //
      27             : // This class is confused somewhat by the fact that:
      28             : // (i)  An <animateTransform> element animates an SVGTransformList
      29             : // (ii) BUT <animateTransform> only allows the user to specify animation values
      30             : //      for an nsSVGTransform
      31             : //
      32             : // This may be rectified in a future edition of SVG but for now it means that
      33             : // the underlying value of an animation may be something of the form:
      34             : //
      35             : //   rotate(90) scale(2) skewX(50)
      36             : //
      37             : // BUT the animation values can only ever be SINGLE transform operations such as
      38             : //
      39             : //   rotate(90)
      40             : //
      41             : //   (actually the syntax here is:
      42             : //      <animateTransform type="rotate" from="0" to="90"...
      43             : //      OR maybe
      44             : //      <animateTransform type="rotate" values="0; 90; 30; 50"...
      45             : //      OR even (with a rotation centre)
      46             : //      <animateTransform type="rotate" values="0 50 20; 30 50 20; 70 0 0"...)
      47             : //
      48             : // This has many implications for the number of elements we expect in the
      49             : // transform array supplied for each operation.
      50             : //
      51             : // For example, Add() only ever operates on the values specified on an
      52             : // <animateTransform> element and so these values can only ever contain 0 or
      53             : // 1 TRANSFORM elements as the syntax doesn't allow more. (A "value" here is
      54             : // a single element in the values array such as "0 50 20" above.)
      55             : //
      56             : // Likewise ComputeDistance() only ever operates within the values specified on
      57             : // an <animateTransform> element so similar conditions hold.
      58             : //
      59             : // However, SandwichAdd() combines with a base value which may contain 0..n
      60             : // transforms either because the base value of the attribute specifies a series
      61             : // of transforms, e.g.
      62             : //
      63             : //   <circle transform="translate(30) rotate(50)"... >
      64             : //     <animateTransform.../>
      65             : //   </circle>
      66             : //
      67             : // or because several animations target the same attribute and are additive and
      68             : // so are simply appended on to the transformation array, e.g.
      69             : //
      70             : //   <circle transform="translate(30)"... >
      71             : //     <animateTransform type="rotate" additive="sum".../>
      72             : //     <animateTransform type="scale" additive="sum".../>
      73             : //     <animateTransform type="skewX" additive="sum".../>
      74             : //   </circle>
      75             : //
      76             : // Similar conditions hold for Interpolate() which in cases such as to-animation
      77             : // may have use a start-value the base value of the target attribute (which as
      78             : // we have seen above can contain 0..n elements) whilst the end-value comes from
      79             : // the <animateTransform> and so can only hold 1 transform.
      80             : //
      81             : class SVGTransformListSMILType : public nsISMILType
      82             : {
      83             : public:
      84             :   // Singleton for nsSMILValue objects to hold onto.
      85             :   static SVGTransformListSMILType*
      86           0 :   Singleton()
      87             :   {
      88           0 :     static SVGTransformListSMILType sSingleton;
      89           0 :     return &sSingleton;
      90             :   }
      91             : 
      92             : protected:
      93             :   // nsISMILType Methods
      94             :   // -------------------
      95             :   virtual void     Init(nsSMILValue& aValue) const override;
      96             :   virtual void     Destroy(nsSMILValue& aValue) const override;
      97             :   virtual nsresult Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const override;
      98             :   virtual bool     IsEqual(const nsSMILValue& aLeft,
      99             :                            const nsSMILValue& aRight) const override;
     100             :   virtual nsresult Add(nsSMILValue& aDest,
     101             :                        const nsSMILValue& aValueToAdd,
     102             :                        uint32_t aCount) const override;
     103             :   virtual nsresult SandwichAdd(nsSMILValue& aDest,
     104             :                                const nsSMILValue& aValueToAdd) const override;
     105             :   virtual nsresult ComputeDistance(const nsSMILValue& aFrom,
     106             :                                    const nsSMILValue& aTo,
     107             :                                    double& aDistance) const override;
     108             :   virtual nsresult Interpolate(const nsSMILValue& aStartVal,
     109             :                                const nsSMILValue& aEndVal,
     110             :                                double aUnitDistance,
     111             :                                nsSMILValue& aResult) const override;
     112             : 
     113             : public:
     114             :   // Transform array accessors
     115             :   // -------------------------
     116             :   static nsresult AppendTransform(const SVGTransformSMILData& aTransform,
     117             :                                   nsSMILValue& aValue);
     118             :   static bool AppendTransforms(const SVGTransformList& aList,
     119             :                                  nsSMILValue& aValue);
     120             :   static bool GetTransforms(const nsSMILValue& aValue,
     121             :                               FallibleTArray<nsSVGTransform>& aTransforms);
     122             : 
     123             : 
     124             : private:
     125             :   // Private constructor: prevent instances beyond my singleton.
     126           0 :   constexpr SVGTransformListSMILType() {}
     127             : };
     128             : 
     129             : } // end namespace mozilla
     130             : 
     131             : #endif // SVGLISTTRANSFORMSMILTYPE_H_