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      1 /*
      2  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
      3  *
      4  * This library is free software; you can redistribute it and/or
      5  * modify it under the terms of the GNU Library General Public
      6  * License as published by the Free Software Foundation; either
      7  * version 2 of the License, or (at your option) any later version.
      8  *
      9  * This library is distributed in the hope that it will be useful,
     10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     12  * Library General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU Library General Public License
     15  * along with this library; see the file COPYING.LIB.  If not, write to
     16  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     17  * Boston, MA 02110-1301, USA.
     18  *
     19  */
     20 
     21 #include "config.h"
     22 #include "StepRange.h"
     23 
     24 #include "HTMLInputElement.h"
     25 #include "HTMLNames.h"
     26 #include "HTMLParserIdioms.h"
     27 #include <wtf/MathExtras.h>
     28 #include <wtf/text/WTFString.h>
     29 
     30 using namespace std;
     31 
     32 namespace WebCore {
     33 
     34 using namespace HTMLNames;
     35 
     36 StepRange::StepRange(const HTMLInputElement* element)
     37 {
     38     if (element->hasAttribute(precisionAttr)) {
     39         step = 1.0;
     40         hasStep = !equalIgnoringCase(element->getAttribute(precisionAttr), "float");
     41     } else
     42         hasStep = element->getAllowedValueStep(&step);
     43 
     44     maximum = element->maximum();
     45     minimum = element->minimum();
     46 }
     47 
     48 double StepRange::clampValue(double value)
     49 {
     50     double clampedValue = max(minimum, min(value, maximum));
     51     if (!hasStep)
     52         return clampedValue;
     53     // Rounds clampedValue to minimum + N * step.
     54     clampedValue = minimum + round((clampedValue - minimum) / step) * step;
     55     if (clampedValue > maximum)
     56        clampedValue -= step;
     57     ASSERT(clampedValue >= minimum);
     58     ASSERT(clampedValue <= maximum);
     59     return clampedValue;
     60 }
     61 
     62 double StepRange::clampValue(const String& stringValue)
     63 {
     64     double value;
     65     bool parseSuccess = parseToDoubleForNumberType(stringValue, &value);
     66     if (!parseSuccess)
     67         value = (minimum + maximum) / 2;
     68     return clampValue(value);
     69 }
     70 
     71 double StepRange::valueFromElement(HTMLInputElement* element, bool* wasClamped)
     72 {
     73     double oldValue;
     74     bool parseSuccess = parseToDoubleForNumberType(element->value(), &oldValue);
     75     if (!parseSuccess)
     76         oldValue = (minimum + maximum) / 2;
     77     double newValue = clampValue(oldValue);
     78 
     79     if (wasClamped)
     80         *wasClamped = !parseSuccess || newValue != oldValue;
     81 
     82     return newValue;
     83 }
     84 
     85 }
     86