/*
 * 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.
 */


// DiagramItem.h (Cortex/DiagramView)
//
// * PURPOSE
//   DiagramItem subclass providing a basic implementation
//   of 'connectable' points inside a DiagramBox
//
// * HISTORY
//   c.lenz             25sep99         Begun
//

#ifndef __DiagramEndPoint_H__
#define __DiagramEndPoint_H__

#include <Looper.h>
#include <Region.h>

#include "DiagramItem.h"

#include "cortex_defs.h"
__BEGIN_CORTEX_NAMESPACE

class DiagramWire;

class DiagramEndPoint : public DiagramItem
{

public:                                 // *** ctor/dtor

                                                DiagramEndPoint(
                                                        BRect frame);

        virtual                         ~DiagramEndPoint();

public:                                 // *** accessors

        DiagramWire                *wire() const
                                                { return m_wire; }

public:                                 // *** hook functions

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

        // should return the BPoint that a connected wire uses as
        // a drawing offset; this implementation returns the center 
        // point of the EndPoint
        virtual BPoint          connectionPoint() const;

        // is called from MessageDragged() and MessageDropped() to 
        // let you verify that a connection is okay
        virtual bool            connectionRequested(
                                                        DiagramEndPoint *fromWhich);
        
        // is called whenever a connection has been made or a
        // temporary wire drag has been accepted
        virtual void            connected()
                                                { /* does nothing */ }

        // is called whenever a connection has been broken or a
        // temporary wire drag has finished
        virtual void            disconnected()
                                                { /* does nothing */ }

public:                                 // *** derived from DiagramItem

        // returns the EndPoints frame rectangle
        BRect                           Frame() const
                                                { return m_frame; }

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

        // is called from the parent DiagramBox's MouseDown() 
        // implementation if the EndPoint was hit; this version
        // initiates selection and dragging (i.e. connecting)
        virtual void            MouseDown(
                                                        BPoint point,
                                                        uint32 buttons,
                                                        uint32 clicks);

        // is called from the parent DiagramBox's MouseOver()
        // implementation if the mouse is over the EndPoint
        virtual void            MouseOver(
                                                        BPoint point,
                                                        uint32 transit)
                                                { /* does nothing */ }

        // is called from the parent DiagramBox's MessageDragged()
        // implementation of a message is being dragged of the
        // EndPoint; this implementation handles only wire drags
        // (i.e. M_WIRE_DRAGGED messages)
        virtual void            MessageDragged(
                                                        BPoint point,
                                                        uint32 transit,
                                                        const BMessage *message);
                                                        
        // is called from the parent DiagramBox's MessageDropped()
        // implementation if the message was dropped on the EndPoint;
        // this version handles wire dropping (connecting)
        virtual void            MessageDropped(
                                                        BPoint point,
                                                        BMessage *message);
                                                                
        // moves the EndPoint by the specified amount and returns in
        // updateRegion the frames of connected wires if there are any
        // NOTE: no drawing/refreshing is done in this method, that's
        // up to the parent
        void                            MoveBy(
                                                        float x,
                                                        float y,
                                                        BRegion *updateRegion);
                
        // resize the EndPoints frame rectangle without redraw
        virtual void            ResizeBy(
                                                        float horizontal,
                                                        float vertical);

public:                                 // *** connection methods

        // connect/disconnect and set the wire pointer accordingly
        void                            connect(
                                                        DiagramWire *wire);
        void                            disconnect();

        // returns true if the EndPoint is currently connected
        bool                            isConnected() const
                                                { return m_connected; }

        // returns true if the EndPoint is currently in a connection
        // process (i.e. it is either being dragged somewhere, or a
        // M_WIRE_DRAGGED message is being dragged over it
        bool                            isConnecting() const
                                                { return m_connecting; }

private:                                // *** data

        // the endpoints' frame rectangle
        BRect                           m_frame;

        // pointer to the wire object this endpoint might be
        // connected to
        DiagramWire                *m_wire;

        // indicates if the endpoint is currently connected
        // to another endpoint
        bool                            m_connected;
        
        // indicates that a connection is currently being made
        // but has not been confirmed yet
        bool                            m_connecting;
};

__END_CORTEX_NAMESPACE
#endif // __DiagramEndPoint_H__