--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/osswebengine/WebCore/platform/ScrollBar.cpp	Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2004, 2006 Apple Computer, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "ScrollBar.h"
+
+#include <algorithm>
+
+using std::max;
+using std::min;
+
+namespace WebCore {
+
+Scrollbar::Scrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize controlSize)
+    : m_client(client)
+    , m_orientation(orientation)
+    , m_controlSize(controlSize)
+    , m_visibleSize(0)
+    , m_totalSize(0)
+    , m_currentPos(0)
+    , m_lineStep(0)
+    , m_pageStep(0)
+    , m_pixelStep(1)
+{
+}
+
+bool Scrollbar::setValue(int v)
+{
+    v = max(min(v, m_totalSize - m_visibleSize), 0);
+    if (value() == v)
+        return false; // Our value stayed the same.
+    m_currentPos = v;
+
+    updateThumbPosition();
+
+    if (client())
+        client()->valueChanged(this);
+    
+    return true;
+}
+
+void Scrollbar::setProportion(int visibleSize, int totalSize)
+{
+    if (visibleSize == m_visibleSize && totalSize == m_totalSize)
+        return;
+
+    m_visibleSize = visibleSize;
+    m_totalSize = totalSize;
+
+    updateThumbProportion();
+}
+
+void Scrollbar::setSteps(int lineStep, int pageStep, int pixelsPerStep)
+{
+    m_lineStep = lineStep;
+    m_pageStep = pageStep;
+    m_pixelStep = 1.0f / pixelsPerStep;
+}
+
+bool Scrollbar::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)
+{
+    float step = 0;
+    if ((direction == ScrollUp && m_orientation == VerticalScrollbar) || (direction == ScrollLeft && m_orientation == HorizontalScrollbar))
+        step = -1;
+    else if ((direction == ScrollDown && m_orientation == VerticalScrollbar) || (direction == ScrollRight && m_orientation == HorizontalScrollbar)) 
+        step = 1;
+    
+    if (granularity == ScrollByLine)
+        step *= m_lineStep;
+    else if (granularity == ScrollByPage)
+        step *= m_pageStep;
+    else if (granularity == ScrollByDocument)
+        step *= m_totalSize;
+    else if (granularity == ScrollByPixel)
+        step *= m_pixelStep;
+        
+    float newPos = m_currentPos + step * multiplier;
+    float maxPos = m_totalSize - m_visibleSize;
+    newPos = max(min(newPos, maxPos), 0.0f);
+
+    if (newPos == m_currentPos)
+        return false;
+    
+    int oldValue = value();
+    m_currentPos = newPos;
+    updateThumbPosition();
+    
+    if (value() != oldValue && client())
+        client()->valueChanged(this);
+    
+    // return true even if the integer value did not change so that scroll event gets eaten
+    return true;
+}
+}