LCOV - code coverage report
Current view: directory - content/svg/content/src - SVGLength.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 87 0 0.0 %
Date: 2012-06-02 Functions: 9 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                 : #include "mozilla/Util.h"
      38                 : 
      39                 : #include "SVGLength.h"
      40                 : #include "nsSVGElement.h"
      41                 : #include "nsSVGSVGElement.h"
      42                 : #include "nsString.h"
      43                 : #include "nsSVGUtils.h"
      44                 : #include "nsTextFormatter.h"
      45                 : #include "prdtoa.h"
      46                 : #include "nsMathUtils.h"
      47                 : #include <limits>
      48                 : 
      49                 : namespace mozilla {
      50                 : 
      51                 : // Declare some helpers defined below:
      52                 : static void GetUnitString(nsAString& unit, PRUint16 unitType);
      53                 : static PRUint16 GetUnitTypeForString(const char* unitStr);
      54                 : 
      55                 : void
      56               0 : SVGLength::GetValueAsString(nsAString &aValue) const
      57                 : {
      58                 :   PRUnichar buf[24];
      59                 :   nsTextFormatter::snprintf(buf, sizeof(buf)/sizeof(PRUnichar),
      60               0 :                             NS_LITERAL_STRING("%g").get(),
      61               0 :                             (double)mValue);
      62               0 :   aValue.Assign(buf);
      63                 : 
      64               0 :   nsAutoString unitString;
      65               0 :   GetUnitString(unitString, mUnit);
      66               0 :   aValue.Append(unitString);
      67               0 : }
      68                 : 
      69                 : bool
      70               0 : SVGLength::SetValueFromString(const nsAString &aValue)
      71                 : {
      72                 :   float tmpValue;
      73                 :   PRUint16 tmpUnit;
      74                 : 
      75               0 :   NS_ConvertUTF16toUTF8 value(aValue);
      76               0 :   const char *str = value.get();
      77                 : 
      78               0 :   while (*str != '\0' && IsSVGWhitespace(*str)) {
      79               0 :     ++str;
      80                 :   }
      81                 :   char *unit;
      82               0 :   tmpValue = float(PR_strtod(str, &unit));
      83               0 :   if (unit != str && NS_finite(tmpValue)) {
      84               0 :     char *theRest = unit;
      85               0 :     if (*unit != '\0' && !IsSVGWhitespace(*unit)) {
      86               0 :       while (*theRest != '\0' && !IsSVGWhitespace(*theRest)) {
      87               0 :         ++theRest;
      88                 :       }
      89               0 :       nsCAutoString unitStr(unit, theRest - unit);
      90               0 :       tmpUnit = GetUnitTypeForString(unitStr.get());
      91               0 :       if (tmpUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_UNKNOWN) {
      92                 :         // nsSVGUtils::ReportToConsole
      93               0 :         return false;
      94                 :       }
      95                 :     } else {
      96               0 :       tmpUnit = nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER;
      97                 :     }
      98               0 :     while (*theRest && IsSVGWhitespace(*theRest)) {
      99               0 :       ++theRest;
     100                 :     }
     101               0 :     if (!*theRest) {
     102               0 :       mValue = tmpValue;
     103               0 :       mUnit = tmpUnit;
     104               0 :       return true;
     105                 :     }
     106                 :   }
     107               0 :   return false;
     108                 : }
     109                 : 
     110                 : inline static bool
     111               0 : IsAbsoluteUnit(PRUint8 aUnit)
     112                 : {
     113                 :   return aUnit >= nsIDOMSVGLength::SVG_LENGTHTYPE_CM &&
     114               0 :          aUnit <= nsIDOMSVGLength::SVG_LENGTHTYPE_PC;
     115                 : }
     116                 : 
     117                 : /**
     118                 :  * Helper to convert between different CSS absolute units without the need for
     119                 :  * an element, which provides more flexibility at the DOM level (and without
     120                 :  * the need for an intermediary conversion to user units, which avoids
     121                 :  * unnecessary overhead and rounding error).
     122                 :  *
     123                 :  * Example usage: to find out how many centimeters there are per inch:
     124                 :  *
     125                 :  *   GetAbsUnitsPerAbsUnit(nsIDOMSVGLength::SVG_LENGTHTYPE_CM,
     126                 :  *                         nsIDOMSVGLength::SVG_LENGTHTYPE_IN)
     127                 :  */
     128               0 : inline static float GetAbsUnitsPerAbsUnit(PRUint8 aUnits, PRUint8 aPerUnit)
     129                 : {
     130               0 :   NS_ABORT_IF_FALSE(IsAbsoluteUnit(aUnits), "Not a CSS absolute unit");
     131               0 :   NS_ABORT_IF_FALSE(IsAbsoluteUnit(aPerUnit), "Not a CSS absolute unit");
     132                 : 
     133                 :   float CSSAbsoluteUnitConversionFactors[5][5] = { // columns: cm, mm, in, pt, pc
     134                 :     // cm per...:
     135                 :     { 1.0, 0.1, 2.54, 0.035277777777777778, 0.42333333333333333 },
     136                 :     // mm per...:
     137                 :     { 10.0, 1.0, 25.4, 0.35277777777777778, 4.2333333333333333 },
     138                 :     // in per...:
     139                 :     { 0.39370078740157481, 0.039370078740157481, 1.0, 0.013888888888888889, 0.16666666666666667 },
     140                 :     // pt per...:
     141                 :     { 28.346456692913386, 2.8346456692913386, 72.0, 1.0, 12.0 },
     142                 :     // pc per...:
     143                 :     { 2.3622047244094489, 0.23622047244094489, 6.0, 0.083333333333333333, 1.0 }
     144               0 :   };
     145                 : 
     146                 :   // First absolute unit is SVG_LENGTHTYPE_CM = 6
     147               0 :   return CSSAbsoluteUnitConversionFactors[aUnits - 6][aPerUnit - 6];
     148                 : }
     149                 : 
     150                 : float
     151               0 : SVGLength::GetValueInSpecifiedUnit(PRUint8 aUnit,
     152                 :                                    const nsSVGElement *aElement,
     153                 :                                    PRUint8 aAxis) const
     154                 : {
     155               0 :   if (aUnit == mUnit) {
     156               0 :     return mValue;
     157                 :   }
     158               0 :   if ((aUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER &&
     159                 :        mUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_PX) ||
     160                 :       (aUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_PX &&
     161                 :        mUnit == nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER)) {
     162               0 :     return mValue;
     163                 :   }
     164               0 :   if (IsAbsoluteUnit(aUnit) && IsAbsoluteUnit(mUnit)) {
     165               0 :     return mValue * GetAbsUnitsPerAbsUnit(aUnit, mUnit);
     166                 :   }
     167                 : 
     168                 :   // Otherwise we do a two step convertion via user units. This can only
     169                 :   // succeed if aElement is non-null (although that's not sufficent to
     170                 :   // guarantee success).
     171                 : 
     172               0 :   float userUnitsPerCurrentUnit = GetUserUnitsPerUnit(aElement, aAxis);
     173                 :   float userUnitsPerNewUnit =
     174               0 :     SVGLength(0.0f, aUnit).GetUserUnitsPerUnit(aElement, aAxis);
     175                 : 
     176               0 :   NS_ASSERTION(userUnitsPerCurrentUnit >= 0 ||
     177                 :                !NS_finite(userUnitsPerCurrentUnit),
     178                 :                "bad userUnitsPerCurrentUnit");
     179               0 :   NS_ASSERTION(userUnitsPerNewUnit >= 0 ||
     180                 :                !NS_finite(userUnitsPerNewUnit),
     181                 :                "bad userUnitsPerNewUnit");
     182                 : 
     183               0 :   float value = mValue * userUnitsPerCurrentUnit / userUnitsPerNewUnit;
     184                 : 
     185                 :   // userUnitsPerCurrentUnit could be infinity, or userUnitsPerNewUnit could
     186                 :   // be zero.
     187               0 :   if (NS_finite(value)) {
     188               0 :     return value;
     189                 :   }
     190               0 :   return std::numeric_limits<float>::quiet_NaN();
     191                 : }
     192                 : 
     193                 : #define INCHES_PER_MM_FLOAT float(0.0393700787)
     194                 : #define INCHES_PER_CM_FLOAT float(0.393700787)
     195                 : 
     196                 : float
     197               0 : SVGLength::GetUserUnitsPerUnit(const nsSVGElement *aElement, PRUint8 aAxis) const
     198                 : {
     199               0 :   switch (mUnit) {
     200                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER:
     201                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_PX:
     202               0 :       return 1.0f;
     203                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_MM:
     204               0 :       return INCHES_PER_MM_FLOAT * GetUserUnitsPerInch();
     205                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_CM:
     206               0 :       return INCHES_PER_CM_FLOAT * GetUserUnitsPerInch();
     207                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_IN:
     208               0 :       return GetUserUnitsPerInch();
     209                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_PT:
     210               0 :       return (1.0f/POINTS_PER_INCH_FLOAT) * GetUserUnitsPerInch();
     211                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_PC:
     212               0 :       return (12.0f/POINTS_PER_INCH_FLOAT) * GetUserUnitsPerInch();
     213                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_PERCENTAGE:
     214               0 :       return GetUserUnitsPerPercent(aElement, aAxis);
     215                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_EMS:
     216               0 :       return nsSVGUtils::GetFontSize(const_cast<nsSVGElement*>(aElement));
     217                 :     case nsIDOMSVGLength::SVG_LENGTHTYPE_EXS:
     218               0 :       return nsSVGUtils::GetFontXHeight(const_cast<nsSVGElement*>(aElement));
     219                 :     default:
     220               0 :       NS_NOTREACHED("Unknown unit type");
     221               0 :       return std::numeric_limits<float>::quiet_NaN();
     222                 :   }
     223                 : }
     224                 : 
     225                 : /* static */ float
     226               0 : SVGLength::GetUserUnitsPerPercent(const nsSVGElement *aElement, PRUint8 aAxis)
     227                 : {
     228               0 :   if (aElement) {
     229               0 :     nsSVGSVGElement *viewportElement = const_cast<nsSVGElement*>(aElement)->GetCtx();
     230               0 :     if (viewportElement) {
     231               0 :       return NS_MAX(viewportElement->GetLength(aAxis) / 100.0f, 0.0f);
     232                 :     }
     233                 :   }
     234               0 :   return std::numeric_limits<float>::quiet_NaN();
     235                 : }
     236                 : 
     237                 : // Helpers:
     238                 : 
     239                 : // These items must be at the same index as the nsIDOMSVGLength constants!
     240                 : static nsIAtom** const unitMap[] =
     241                 : {
     242                 :   nsnull, /* SVG_LENGTHTYPE_UNKNOWN */
     243                 :   nsnull, /* SVG_LENGTHTYPE_NUMBER */
     244                 :   &nsGkAtoms::percentage,
     245                 :   &nsGkAtoms::em,
     246                 :   &nsGkAtoms::ex,
     247                 :   &nsGkAtoms::px,
     248                 :   &nsGkAtoms::cm,
     249                 :   &nsGkAtoms::mm,
     250                 :   &nsGkAtoms::in,
     251                 :   &nsGkAtoms::pt,
     252                 :   &nsGkAtoms::pc
     253                 : };
     254                 : 
     255                 : static void
     256               0 : GetUnitString(nsAString& unit, PRUint16 unitType)
     257                 : {
     258               0 :   if (SVGLength::IsValidUnitType(unitType)) {
     259               0 :     if (unitMap[unitType]) {
     260               0 :       (*unitMap[unitType])->ToString(unit);
     261                 :     }
     262               0 :     return;
     263                 :   }
     264               0 :   NS_NOTREACHED("Unknown unit type"); // Someone's using an SVGLength with an invalid unit?
     265               0 :   return;
     266                 : }
     267                 : 
     268                 : static PRUint16
     269               0 : GetUnitTypeForString(const char* unitStr)
     270                 : {
     271               0 :   if (!unitStr || *unitStr == '\0')
     272               0 :     return nsIDOMSVGLength::SVG_LENGTHTYPE_NUMBER;
     273                 : 
     274               0 :   nsCOMPtr<nsIAtom> unitAtom = do_GetAtom(unitStr);
     275                 : 
     276               0 :   for (PRUint32 i = 1 ; i < ArrayLength(unitMap) ; i++) {
     277               0 :     if (unitMap[i] && *unitMap[i] == unitAtom) {
     278               0 :       return i;
     279                 :     }
     280                 :   }
     281               0 :   return nsIDOMSVGLength::SVG_LENGTHTYPE_UNKNOWN;
     282                 : }
     283                 : 
     284                 : } // namespace mozilla

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