LCOV - app.info - content/svg/content/src/SVGLength.h

LCOV - code coverage report
| Current view: | directory - content/svg/content/src - SVGLength.h (source / functions) |  | Found | Hit | Coverage |
| Test: | app.info | Lines: | 54 | 0 | 0.0 %
| Date: | 2012-04-21 | Functions: | 16 | 0 | 0.0 %

           1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
           2                 : /* ***** BEGIN LICENSE BLOCK *****
           3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
           4                 :  *
           5                 :  * The contents of this file are subject to the Mozilla Public License Version
           6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
           7                 :  * the License. You may obtain a copy of the License at
           8                 :  * http://www.mozilla.org/MPL/
           9                 :  *
          10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
          11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
          12                 :  * for the specific language governing rights and limitations under the
          13                 :  * License.
          14                 :  *
          15                 :  * The Original Code is Mozilla SVG Project code.
          16                 :  *
          17                 :  * The Initial Developer of the Original Code is the Mozilla Foundation.
          18                 :  * Portions created by the Initial Developer are Copyright (C) 2010
          19                 :  * the Initial Developer. All Rights Reserved.
          20                 :  *
          21                 :  * Contributor(s):
          22                 :  *
          23                 :  * Alternatively, the contents of this file may be used under the terms of
          24                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
          25                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
          26                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
          27                 :  * of those above. If you wish to allow use of your version of this file only
          28                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
          29                 :  * use your version of this file under the terms of the MPL, indicate your
          30                 :  * decision by deleting the provisions above and replace them with the notice
          31                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
          32                 :  * the provisions above, a recipient may use your version of this file under
          33                 :  * the terms of any one of the MPL, the GPL or the LGPL.
          34                 :  *
          35                 :  * ***** END LICENSE BLOCK ***** */
          36                 :
          37                 : #ifndef MOZILLA_SVGLENGTH_H__
          38                 : #define MOZILLA_SVGLENGTH_H__
          39                 :
          40                 : #include "nsDebug.h"
          41                 : #include "nsIDOMSVGLength.h"
          42                 : #include "nsMathUtils.h"
          43                 :
          44                 : class nsSVGElement;
          45                 :
          46                 : namespace mozilla {
          47                 :
          48                 : /**
          49                 :  * This SVGLength class is currently used for SVGLength *list* attributes only.
          50                 :  * The class that is currently used for <length> attributes is nsSVGLength2.
          51                 :  *
          52                 :  * The member mUnit should always be valid, but the member mValue may be
          53                 :  * numeric_limits<float>::quiet_NaN() under one circumstances (see the comment
          54                 :  * in SetValueAndUnit below). Even if mValue is valid, some methods may return
          55                 :  * numeric_limits<float>::quiet_NaN() if they involve a unit conversion that
          56                 :  * fails - see comments below.
          57                 :  *
          58                 :  * The DOM wrapper class for this class is DOMSVGLength.
          59                 :  */
          60                 : class SVGLength
          61               0 : {
          62                 : public:
          63                 :
          64               0 :   SVGLength()
          65                 : #ifdef DEBUG
          66                 :     : mValue(0.0f)
          67               0 :     , mUnit(nsIDOMSVGLength::SVG_LENGTHTYPE_UNKNOWN) // caught by IsValid()
          68                 : #endif
          69               0 :   {}
          70                 :
          71               0 :   SVGLength(float aValue, PRUint8 aUnit)
          72                 :     : mValue(aValue)
          73               0 :     , mUnit(aUnit)
          74                 :   {
          75               0 :     NS_ASSERTION(IsValid(), "Constructed an invalid length");
          76               0 :   }
          77                 :
          78               0 :   SVGLength(const SVGLength &aOther)
          79                 :     : mValue(aOther.mValue)
          80               0 :     , mUnit(aOther.mUnit)
          81               0 :   {}
          82                 :
          83               0 :   SVGLength& operator=(const SVGLength &rhs) {
          84               0 :     mValue = rhs.mValue;
          85               0 :     mUnit = rhs.mUnit;
          86               0 :     return *this;
          87                 :   }
          88                 :
          89               0 :   bool operator==(const SVGLength &rhs) const {
          90               0 :     return mValue == rhs.mValue && mUnit == rhs.mUnit;
          91                 :   }
          92                 :
          93                 :   void GetValueAsString(nsAString& aValue) const;
          94                 :
          95                 :   /**
          96                 :    * This method returns true, unless there was a parse failure, in which
          97                 :    * case it returns false (and the length is left unchanged).
          98                 :    */
          99                 :   bool SetValueFromString(const nsAString& aValue);
         100                 :
         101                 :   /**
         102                 :    * This will usually return a valid, finite number. There is one exception
         103                 :    * though - see the comment in SetValueAndUnit().
         104                 :    */
         105               0 :   float GetValueInCurrentUnits() const {
         106               0 :     return mValue;
         107                 :   }
         108                 :
         109               0 :   PRUint8 GetUnit() const {
         110               0 :     return mUnit;
         111                 :   }
         112                 :
         113               0 :   void SetValueInCurrentUnits(float aValue) {
         114               0 :     mValue = aValue;
         115               0 :     NS_ASSERTION(IsValid(), "Set invalid SVGLength");
         116               0 :   }
         117                 :
         118               0 :   void SetValueAndUnit(float aValue, PRUint8 aUnit) {
         119               0 :     mValue = aValue;
         120               0 :     mUnit = aUnit;
         121                 :
         122                 :     // IsValid() should always be true, with one exception: if
         123                 :     // SVGLengthListSMILType has to convert between unit types and the unit
         124                 :     // conversion is undefined, it will end up passing in and setting
         125                 :     // numeric_limits<float>::quiet_NaN(). Because of that we only check the
         126                 :     // unit here, and allow mValue to be invalid. The painting code has to be
         127                 :     // able to handle NaN anyway, since conversion to user units may fail in
         128                 :     // general.
         129                 :
         130               0 :     NS_ASSERTION(IsValidUnitType(mUnit), "Set invalid SVGLength");
         131               0 :   }
         132                 :
         133                 :   /**
         134                 :    * If it's not possible to convert this length's value to user units, then
         135                 :    * this method will return numeric_limits<float>::quiet_NaN().
         136                 :    */
         137               0 :   float GetValueInUserUnits(const nsSVGElement *aElement, PRUint8 aAxis) const {
         138               0 :     return mValue * GetUserUnitsPerUnit(aElement, aAxis);
         139                 :   }
         140                 :
         141                 :   /**
         142                 :    * Sets this length's value, converting the supplied user unit value to this
         143                 :    * lengths *current* unit (i.e. leaving the length's unit unchanged).
         144                 :    *
         145                 :    * This method returns true, unless the user unit value couldn't be
         146                 :    * converted to this length's current unit, in which case it returns false
         147                 :    * (and the length is left unchanged).
         148                 :    */
         149               0 :   bool SetFromUserUnitValue(float aUserUnitValue,
         150                 :                               nsSVGElement *aElement,
         151                 :                               PRUint8 aAxis) {
         152               0 :     float uuPerUnit = GetUserUnitsPerUnit(aElement, aAxis);
         153               0 :     float value = aUserUnitValue / uuPerUnit;
         154               0 :     if (uuPerUnit > 0 && NS_finite(value)) {
         155               0 :       mValue = value;
         156               0 :       NS_ASSERTION(IsValid(), "Set invalid SVGLength");
         157               0 :       return true;
         158                 :     }
         159               0 :     return false;
         160                 :   }
         161                 :
         162                 :   /**
         163                 :    * Get this length's value in the units specified.
         164                 :    *
         165                 :    * This method returns numeric_limits<float>::quiet_NaN() if it is not
         166                 :    * possible to convert the value to the specified unit.
         167                 :    */
         168                 :   float GetValueInSpecifiedUnit(PRUint8 aUnit,
         169                 :                                 const nsSVGElement *aElement,
         170                 :                                 PRUint8 aAxis) const;
         171                 :
         172                 :   /**
         173                 :    * Convert this length's value to the unit specified.
         174                 :    *
         175                 :    * This method returns true, unless it isn't possible to convert the
         176                 :    * length to the specified unit. In that case the length is left unchanged
         177                 :    * and this method returns false.
         178                 :    */
         179               0 :   bool ConvertToUnit(PRUint32 aUnit, nsSVGElement *aElement, PRUint8 aAxis) {
         180               0 :     float val = GetValueInSpecifiedUnit(aUnit, aElement, aAxis);
         181               0 :     if (NS_finite(val)) {
         182               0 :       mValue = val;
         183               0 :       mUnit = aUnit;
         184               0 :       NS_ASSERTION(IsValid(), "Set invalid SVGLength");
         185               0 :       return true;
         186                 :     }
         187               0 :     return false;
         188                 :   }
         189                 :
         190                 :   bool IsPercentage() const {
         191                 :     return mUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_PERCENTAGE;
         192                 :   }
         193                 :
         194               0 :   static bool IsValidUnitType(PRUint16 unit) {
         195                 :     return unit > nsIDOMSVGLength::SVG_LENGTHTYPE_UNKNOWN &&
         196               0 :            unit <= nsIDOMSVGLength::SVG_LENGTHTYPE_PC;
         197                 :   }
         198                 :
         199                 : private:
         200                 :
         201                 : #ifdef DEBUG
         202               0 :   bool IsValid() const {
         203               0 :     return NS_finite(mValue) && IsValidUnitType(mUnit);
         204                 :   }
         205                 : #endif
         206                 :
         207                 :   /**
         208                 :    * Returns the number of user units per current unit.
         209                 :    *
         210                 :    * This method returns numeric_limits<float>::quiet_NaN() if the conversion
         211                 :    * factor between the length's current unit and user units is undefined (see
         212                 :    * the comments for GetUserUnitsPerInch and GetUserUnitsPerPercent).
         213                 :    */
         214                 :   float GetUserUnitsPerUnit(const nsSVGElement *aElement, PRUint8 aAxis) const;
         215                 :
         216                 :   /**
         217                 :    * The conversion factor between user units (CSS px) and CSS inches is
         218                 :    * constant: 96 px per inch.
         219                 :    */
         220               0 :   static float GetUserUnitsPerInch()
         221                 :   {
         222               0 :     return 96.0;
         223                 :   }
         224                 :
         225                 :   /**
         226                 :    * The conversion factor between user units and percentage units depends on
         227                 :    * aElement being non-null, and on aElement having a viewport element
         228                 :    * ancestor with only appropriate SVG elements between aElement and that
         229                 :    * ancestor. If that's not the case, then the conversion factor is undefined.
         230                 :    *
         231                 :    * This function returns a non-negative value if the conversion factor is
         232                 :    * defined, otherwise it returns numeric_limits<float>::quiet_NaN().
         233                 :    */
         234                 :   static float GetUserUnitsPerPercent(const nsSVGElement *aElement, PRUint8 aAxis);
         235                 :
         236                 :   float mValue;
         237                 :   PRUint8 mUnit;
         238                 : };
         239                 :
         240                 : } // namespace mozilla
         241                 :
         242                 : #endif // MOZILLA_SVGLENGTH_H__

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