/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */

/*
    Rosegarden
    A MIDI and audio sequencer and musical notation editor.
    Copyright 2000-2011 the Rosegarden development team.

    Other copyrights also apply to some parts of this work.  Please
    see the AUTHORS file and individual file headers for details.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef _RG_NOTATIONELEMENT_H_
#define _RG_NOTATIONELEMENT_H_

#include "base/Exception.h"
#include "base/ViewElement.h"
#include <vector>
#include "base/Event.h"


class QGraphicsItem;
class ItemList;


namespace Rosegarden
{

class Event;


/**
 * The Notation H and V layout is performed on a
 * NotationElementList. Once this is done, each NotationElement is
 * given a QGraphicsItem to take care of and place at its own proper
 * coordinates.
 *
 * @see NotationView#showElements()
 */

class NotationElement : public ViewElement
{
public:
    typedef Exception NoGraphicsItem;
    
    /**
     * Create a new NotationElement encapsulating the Event in
     * parameter.  NotationElement does not take ownership of the
     * event itself.
     */
    NotationElement(Event *event);

    /**
     * Only destroy the graphical representation of the Event, not the
     * Event itself
     */
    ~NotationElement();

    /**
     * Returns the time at which the Event is to be displayed in
     * notation (usually the result of notation quantization on the
     * raw event time)
     */
    virtual timeT getViewAbsoluteTime() const;

    /**
     * Returns the duration with which the Event is to be displayed in
     * notation (usually the result of notation quantization on the
     * raw event duration)
     */
    virtual timeT getViewDuration() const;

    /**
     * Return the position and horizontal size spanned by the item,
     * including adjoining space that "belongs" to the item.  This is
     * used when calculating which element is "under" the mouse
     * position.  The values are usually more extensive than the
     * position and size of the displayed element.  These are computed
     * by NotationHLayout and set to this class using
     * setLayoutAirspace
     */
    void getLayoutAirspace(double &x, double &width) {
        x = m_airX;
        width = m_airWidth;
    }

    void getSceneAirspace(double &x, double &width) {
        x = m_airX - getLayoutX() + getSceneX();
        width = m_airWidth;
    }

    /// returns the x pos of the associated scene item
    double getSceneX();

    /// returns the y pos of the associated scene item
    double getSceneY();

    /**
     * Sets the X coordinate and width of the space "underneath"
     * this element, i.e. the extents within which a mouse click
     * or some such might be considered to be interested in this
     * element as opposed to any other.  These are layout coords
     */
    void setLayoutAirspace(double x, double width) {
        m_airX = x; m_airWidth = width;
    }

    /// Returns true if the wrapped event is a rest
    bool isRest() const;

    /// Returns true if the wrapped event is a note
    bool isNote() const;

    /// Returns true if the wrapped event is a tuplet
    bool isTuplet() const;

    /// Returns true if the wrapped event is a grace note
    bool isGrace() const;

    /**
     * Sets the scene item representing this notation element on screen.
     *
     * NOTE: The object takes ownership of its scene item.
     */
    void setItem(QGraphicsItem *e, double sceneX, double sceneY);

    /**
     * Add an extra scene item associated with this element, for
     * example where an element has been split across two or more
     * staff rows.
     * 
     * The element will take ownership of these scene items and
     * delete them when it deletes the main scene item.
     */
    void addItem(QGraphicsItem *e, double sceneX, double sceneY);

    /**
     * Remove the main scene item and any additional ones.
     */
    void removeItem();

    /**
     * Reset the position of the scene item (which is assumed to
     * exist already).
     */
    void reposition(double sceneX, double sceneY);

    /**
     * Return true if setItem has been called more recently
     * than reposition.  If true, any code that positions this
     * element will probably not need to regenerate its item as
     * well, even if other indications suggest otherwise.
     */
    bool isRecentlyRegenerated() { return m_recentlyRegenerated; }

    bool isSelected();
    void setSelected(bool selected);

    /**
     * Return true if the element is a note which lies at exactly the
     * same place as another note.
     * Only valid after NotationVLayout::scanStaff() call.
     * Only a returned true is meaningful (when 2 notes are colliding, the
     * first element returns false and the second one returns true).
     */
    bool isColliding() { return m_isColliding; }

    void setIsColliding(bool value) { m_isColliding = value; }

    /// Returns the associated scene item
    QGraphicsItem *getItem() { return m_item; }

    static NotationElement *getNotationElement(QGraphicsItem *);

protected:
    double m_airX;
    double m_airWidth;
    bool m_recentlyRegenerated;
    bool m_isColliding;

    /**
     * The graphical representation of the event
     */
    QGraphicsItem *m_item;

    typedef std::vector<QGraphicsItem *> ItemList;
    ItemList *m_extraItems;
};

typedef ViewElementList NotationElementList;



}

#endif