diff -r 000000000000 -r 4f2f89ce4247 WebCore/html/StepRange.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/StepRange.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef StepRange_h
+#define StepRange_h
+
+#include <wtf/Noncopyable.h>
+
+namespace WebCore {
+
+class HTMLInputElement;
+class String;
+
+class StepRange : public Noncopyable {
+public:
+    bool hasStep;
+    double step;
+    double minimum;
+    double maximum; // maximum must be >= minimum.
+
+    explicit StepRange(const HTMLInputElement*);
+    double clampValue(double value);
+    double clampValue(const String& stringValue);
+
+    // Clamp the middle value according to the step
+    double defaultValue()
+    {
+        return clampValue((minimum + maximum) / 2);
+    }
+
+    // Map value into 0-1 range
+    double proportionFromValue(double value)
+    {
+        if (minimum == maximum)
+            return 0;
+
+        return (value - minimum) / (maximum - minimum);
+    }
+
+    // Map from 0-1 range to value
+    double valueFromProportion(double proportion)
+    {
+        return minimum + proportion * (maximum - minimum);
+    }
+
+    double valueFromElement(HTMLInputElement*, bool* wasClamped = 0);
+};
+
+}
+
+#endif // StepRange_h