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
27namespace WebCore {
28
29class HTMLInputElement;
30
31class StepRange {
32    WTF_MAKE_NONCOPYABLE(StepRange);
33public:
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