/*

 * 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. 

 */

#ifndef Scrollbar_h

#define Scrollbar_h

#include "ScrollTypes.h"

#include "Timer.h"

#include "Widget.h"

#include <wtf/MathExtras.h>

#include <wtf/PassRefPtr.h>

namespace WebCore {

class GraphicsContext;

class IntRect;

class ScrollbarClient;

class ScrollbarTheme;

class PlatformMouseEvent;

class Scrollbar : public Widget {

public:

    virtual ~Scrollbar();

    // Must be implemented by platforms that can't simply use the Scrollbar base class.  Right now the only platform that is not using the base class is GTK.

    static PassRefPtr<Scrollbar> createNativeScrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize size);

    static int pixelsPerLineStep() { return 40; }

    static float minFractionToStepWhenPaging() { return 0.875f; }

    static int maxOverlapBetweenPages();

    void setClient(ScrollbarClient* client) { m_client = client; }

    ScrollbarClient* client() const { return m_client; }

    virtual bool isCustomScrollbar() const { return false; }

    ScrollbarOrientation orientation() const { return m_orientation; }

    int value() const { return lroundf(m_currentPos); }

    float currentPos() const { return m_currentPos; }

    int pressedPos() const { return m_pressedPos; }

    int visibleSize() const { return m_visibleSize; }

    int totalSize() const { return m_totalSize; }

    int maximum() const { return m_totalSize - m_visibleSize; }        

    ScrollbarControlSize controlSize() const { return m_controlSize; }

    int lineStep() const { return m_lineStep; }

    int pageStep() const { return m_pageStep; }

    float pixelStep() const { return m_pixelStep; }

    ScrollbarPart pressedPart() const { return m_pressedPart; }

    ScrollbarPart hoveredPart() const { return m_hoveredPart; }

    virtual void setHoveredPart(ScrollbarPart);

    virtual void setPressedPart(ScrollbarPart);

    void setSteps(int lineStep, int pageStep, int pixelsPerStep = 1);

    bool setValue(int);

    void setProportion(int visibleSize, int totalSize);

    void setPressedPos(int p) { m_pressedPos = p; }

    bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1.0f);

    virtual void paint(GraphicsContext*, const IntRect& damageRect);

    bool enabled() const { return m_enabled; }

    virtual void setEnabled(bool e);

    bool isWindowActive() const;

    // These methods are used for platform scrollbars to give :hover feedback.  They will not get called

    // when the mouse went down in a scrollbar, since it is assumed the scrollbar will start

    // grabbing all events in that case anyway.

    bool mouseMoved(const PlatformMouseEvent&);

    bool mouseExited();

    // Used by some platform scrollbars to know when they've been released from capture.

    bool mouseUp();

    bool mouseDown(const PlatformMouseEvent&);

#if PLATFORM(QT)

    // For platforms that wish to handle context menu events.

    // FIXME: This is misplaced.  Normal hit testing should be used to populate a correct

    // context menu.  There's no reason why the scrollbar should have to do it.

    bool contextMenu(const PlatformMouseEvent& event);

#endif

    ScrollbarTheme* theme() const { return m_theme; }

    virtual void setParent(ScrollView*);

    virtual void setFrameRect(const IntRect&);

    virtual void invalidateRect(const IntRect&);

    bool suppressInvalidation() const { return m_suppressInvalidation; }

    void setSuppressInvalidation(bool s) { m_suppressInvalidation = s; }

    virtual void styleChanged() { }

    virtual IntRect convertToContainingView(const IntRect&) const;

    virtual IntRect convertFromContainingView(const IntRect&) const;

    virtual IntPoint convertToContainingView(const IntPoint&) const;

    virtual IntPoint convertFromContainingView(const IntPoint&) const;

private:

    virtual bool isScrollbar() const { return true; }

protected:

    Scrollbar(ScrollbarClient*, ScrollbarOrientation, ScrollbarControlSize, ScrollbarTheme* = 0);

    void updateThumb();

    virtual void updateThumbPosition();

    virtual void updateThumbProportion();

    void autoscrollTimerFired(Timer<Scrollbar>*);

    void startTimerIfNeeded(double delay);

    void stopTimerIfNeeded();

    void autoscrollPressedPart(double delay);

    ScrollDirection pressedPartScrollDirection();

    ScrollGranularity pressedPartScrollGranularity();

    void moveThumb(int pos);

    bool setCurrentPos(float pos);

    ScrollbarClient* m_client;

    ScrollbarOrientation m_orientation;

    ScrollbarControlSize m_controlSize;

    ScrollbarTheme* m_theme;

    int m_visibleSize;

    int m_totalSize;

    float m_currentPos;

    float m_dragOrigin;

    int m_lineStep;

    int m_pageStep;

    float m_pixelStep;

    ScrollbarPart m_hoveredPart;

    ScrollbarPart m_pressedPart;

    int m_pressedPos;

    bool m_enabled;

    Timer<Scrollbar> m_scrollTimer;

    bool m_overlapsResizer;

    bool m_suppressInvalidation;

};

}

#endif