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 #ifndef StepRange_h 22 #define StepRange_h 23 24 #include <wtf/Forward.h> 25 #include <wtf/Noncopyable.h> 26 27 namespace WebCore { 28 29 class HTMLInputElement; 30 31 class StepRange { 32 WTF_MAKE_NONCOPYABLE(StepRange); 33 public: 34 bool hasStep; 35 double step; 36 double minimum; 37 double maximum; // maximum must be >= minimum. 38 39 explicit StepRange(const HTMLInputElement*); 40 double clampValue(double value); 41 double clampValue(const String& stringValue); 42 43 // Clamp the middle value according to the step 44 double defaultValue() 45 { 46 return clampValue((minimum + maximum) / 2); 47 } 48 49 // Map value into 0-1 range 50 double proportionFromValue(double value) 51 { 52 if (minimum == maximum) 53 return 0; 54 55 return (value - minimum) / (maximum - minimum); 56 } 57 58 // Map from 0-1 range to value 59 double valueFromProportion(double proportion) 60 { 61 return minimum + proportion * (maximum - minimum); 62 } 63 64 double valueFromElement(HTMLInputElement*, bool* wasClamped = 0); 65 }; 66 67 } 68 69 #endif // StepRange_h 70
