/*
 * Copyright (c) 1999-2000, Eric Moon.
 * 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.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR 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.
 */


// DiagramWire.h (Cortex/DiagramView)
//
// * PURPOSE
//   DiagramItem subclass serving as a graphical connection
//   between two DiagramEndPoints
//
// * HISTORY
//   c.lenz             25sep99         Begun
//

#ifndef __DiagramWire_H__
#define __DiagramWire_H__

#include "DiagramItem.h"

#include <Region.h>
#include <Window.h>

#include "cortex_defs.h"
__BEGIN_CORTEX_NAMESPACE

class DiagramView;
class DiagramEndPoint;

class DiagramWire : public DiagramItem
{
        friend class DiagramView;

public:                                 // *** ctor/dtor

        // both endpoints are set connected by this constructor
        // so be careful to only pass in valid pointers
                                                DiagramWire(
                                                        DiagramEndPoint *fromWhich,
                                                        DiagramEndPoint *toWhich);

        // special constructor used only in drag&drop sessions for
        // temporary visual indication of the connection process
        // the isStartPoint lets you specify if the given EndPoint
        // is supposed to be treated as start or end point
                                                DiagramWire(
                                                        DiagramEndPoint *fromWhich,
                                                        bool isStartPoint = true);

        virtual                         ~DiagramWire();

public:                                 // *** accessors

        bool                            isDragging() const
                                                { return m_temporary; }

        // returns a pointer to the "start/source" endpoint
        DiagramEndPoint    *startPoint() const
                                                { return m_fromEndPoint; }

        // returns the point from the m_fromEndPoints connectionPoint() method
        BPoint                          startConnectionPoint() const;
        
        // returns a pointer the "end/target" endpoint
        DiagramEndPoint    *endPoint() const
                                                { return m_toEndPoint; }

        // returns the point from the m_toEndPoints connectionPoint() method
        BPoint                          endConnectionPoint() const;

public:                                 // *** hook functions

        // is called from Draw() to do the actual drawing
        virtual void            drawWire() = 0;

        // is called by the connected diagramEndPoints whenever one is moved
        // if the argument is NULL then both endpoints should be evaluated
        virtual void            endPointMoved(
                                                        DiagramEndPoint *which = 0)
                                                { /* does nothing */ }

public:                                 //  *** derived from DiagramItem

        // returns the area in which the wire displays
        virtual BRect           Frame() const
                                                { return BRect(startConnectionPoint(), endConnectionPoint()); }

        // returns how close a given point is to the wire; the current
        // implementation returns a wide array of values, those above
        // approx. 0.5 are quite close to the wire
        float                           howCloseTo(
                                                        BPoint point) const;

        // prepares the drawing stack and clipping region, then
        // calls drawWire
        void                            Draw(
                                                        BRect updateRect);

        // is called from the parent DiagramViews MouseDown() implementation 
        // if the Wire was hit; this version initiates selection and dragging
        virtual void            MouseDown(
                                                        BPoint point,
                                                        uint32 buttons,
                                                        uint32 clicks);

        // is called from the DiagramViews MouseMoved() when no message is being 
        // dragged, but the mouse has moved above the wire
        virtual void            MouseOver(
                                                        BPoint point,
                                                        uint32 transit)
                                                { /* does nothing */ }
                

        // is called from the DiagramViews MouseMoved() when a message is being 
        // dragged over the DiagramWire
        virtual void            MessageDragged(
                                                        BPoint point,
                                                        uint32 transit,
                                                        const BMessage *message);

        // is called from the DiagramViews MessageReceived() function when a 
        // message has been dropped on the DiagramWire
        virtual void            MessageDropped(
                                                        BPoint point,
                                                        BMessage *message)
                                                { /* does nothing */ }

private:                                // *** data

        // pointer to the "from" EndPoint as assigned in the ctor
        DiagramEndPoint    *m_fromEndPoint;

        // pointer to the "to" EndPoint as assigned in the ctor
        DiagramEndPoint    *m_toEndPoint;

        // indicates that this is a connection used in a drag&drop session
        // and will be deleted after that
        bool                            m_temporary;

        // contains a BPoint for "temporary connections"
        BPoint                          m_dragEndPoint;
};

__END_CORTEX_NAMESPACE
#endif // __DiagramWire_H__