/*

 * Copyright (C) 2010 Google 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:

 *

 *     * Redistributions of source code must retain the above copyright

 * notice, this list of conditions and the following disclaimer.

 *     * 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.

 *     * Neither the name of Google Inc. nor the names of its

 * contributors may be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "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 THE COPYRIGHT

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 */

#ifndef WebScrollbar_h

#define WebScrollbar_h

#include "WebCanvas.h"

#include "WebCommon.h"

namespace WebKit {

class WebInputEvent;

class WebScrollbarClient;

struct WebRect;

class WebScrollbar {

public:

    enum Orientation {

        Horizontal,

        Vertical

    };

    enum ScrollDirection {

        ScrollBackward,

        ScrollForward

    };

    enum ScrollGranularity {

        ScrollByLine,

        ScrollByPage,

        ScrollByDocument,

        ScrollByPixel

    };

    // Creates a WebScrollbar.

    WEBKIT_API static WebScrollbar* create(WebScrollbarClient*, Orientation);

    virtual ~WebScrollbar() {}

    // Gets the thickness of the scrollbar in pixels.

    WEBKIT_API static int defaultThickness();

    // Sets the rectangle of the scrollbar.

    virtual void setLocation(const WebRect&) = 0;

    // Gets the current value (i.e. position inside the region).

    virtual int value() const = 0;

    // Sets the current value.

    virtual void setValue(int position) = 0;

    // Sets the size of the scrollable region in pixels.  i.e. if a document is

    // 800x10000 pixels and the viewport is 1000x1000 pixels, then setLocation

    // for the vertical scrollbar would have passed in a rectangle like:

    //            (800 - defaultThickness(), 0) (defaultThickness() x 10000)

    // and setDocumentSize(10000)

    virtual void setDocumentSize(int size) = 0;

    // Scroll back or forward with the given granularity.

    virtual void scroll(ScrollDirection, ScrollGranularity, float multiplier) = 0;

    // Paint the given rectangle.

    virtual void paint(WebCanvas*, const WebRect&) = 0;

    // Returns true iff the given event was used.

    virtual bool handleInputEvent(const WebInputEvent&) = 0;

};

} // namespace WebKit

#endif