/*
 * Copyright 2006, Haiku.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Ingo Weinhold <bonefish@cs.tu-berlin.de>
 */
#ifndef SCROLLER_H
#define SCROLLER_H

#include <Rect.h>

class Scrollable;

class Scroller {
 public:
                                                                Scroller();
        virtual                                         ~Scroller();

                        void                            SetScrollTarget(Scrollable* target);
                        Scrollable*                     ScrollTarget() const;

                        void                            SetDataRect(BRect dataRect);
                        BRect                           DataRect() const;

                        void                            SetScrollOffset(BPoint offset);
                        BPoint                          ScrollOffset() const;

                        void                            SetVisibleSize(float width, float height);
                        BRect                           VisibleBounds() const;
                        BRect                           VisibleRect() const;

        virtual void                            SetScrollingEnabled(bool enabled);
                        bool                            IsScrollingEnabled() const
                                                                        { return fScrollingEnabled; }

        virtual bool                            IsScrolling() const;

protected:
        virtual void                            DataRectChanged(BRect oldDataRect,
                                                                                                BRect newDataRect);
        virtual void                            ScrollOffsetChanged(BPoint oldOffset,
                                                                                                        BPoint newOffset);
        virtual void                            VisibleSizeChanged(float oldWidth,
                                                                                                   float oldHeight,
                                                                                                   float newWidth,
                                                                                                   float newHeight);
        virtual void                            ScrollTargetChanged(Scrollable* oldTarget,
                                                                                                        Scrollable* newTarget);

 protected:
                        Scrollable*                     fScrollTarget;
                        bool                            fScrollingEnabled;

        friend class Scrollable;
};


#endif  // SCROLLER_H