src/apps/cortex/DiagramView/DiagramEndPoint.h

   1 /*
   2  * Copyright (c) 1999-2000, Eric Moon.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions, and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions, and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  27  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31
  32 // DiagramItem.h (Cortex/DiagramView)
  33 //
  34 // * PURPOSE
  35 //   DiagramItem subclass providing a basic implementation
  36 //   of 'connectable' points inside a DiagramBox
  37 //
  38 // * HISTORY
  39 //   c.lenz             25sep99         Begun
  40 //
  41
  42 #ifndef __DiagramEndPoint_H__
  43 #define __DiagramEndPoint_H__
  44
  45 #include <Looper.h>
  46 #include <Region.h>
  47
  48 #include "DiagramItem.h"
  49
  50 #include "cortex_defs.h"
  51 __BEGIN_CORTEX_NAMESPACE
  52
  53 class DiagramWire;
  54
  55 class DiagramEndPoint : public DiagramItem
  56 {
  57
  58 public:                                 // *** ctor/dtor
  59
  60                                                 DiagramEndPoint(
  61                                                         BRect frame);
  62
  63         virtual                         ~DiagramEndPoint();
  64
  65 public:                                 // *** accessors
  66
  67         DiagramWire                *wire() const
  68                                                 { return m_wire; }
  69
  70 public:                                 // *** hook functions
  71
  72         // is called from Draw() to do the actual drawing
  73         virtual void            drawEndPoint() = 0;
  74
  75         // should return the BPoint that a connected wire uses as
  76         // a drawing offset; this implementation returns the center
  77         // point of the EndPoint
  78         virtual BPoint          connectionPoint() const;
  79
  80         // is called from MessageDragged() and MessageDropped() to
  81         // let you verify that a connection is okay
  82         virtual bool            connectionRequested(
  83                                                         DiagramEndPoint *fromWhich);
  84
  85         // is called whenever a connection has been made or a
  86         // temporary wire drag has been accepted
  87         virtual void            connected()
  88                                                 { /* does nothing */ }
  89
  90         // is called whenever a connection has been broken or a
  91         // temporary wire drag has finished
  92         virtual void            disconnected()
  93                                                 { /* does nothing */ }
  94
  95 public:                                 // *** derived from DiagramItem
  96
  97         // returns the EndPoints frame rectangle
  98         BRect                           Frame() const
  99                                                 { return m_frame; }
 100
 101         // prepares the drawing stack and clipping region, then
 102         // calls drawEndPoint
 103         void                            Draw(
 104                                                         BRect updateRect);
 105
 106         // is called from the parent DiagramBox's MouseDown()
 107         // implementation if the EndPoint was hit; this version
 108         // initiates selection and dragging (i.e. connecting)
 109         virtual void            MouseDown(
 110                                                         BPoint point,
 111                                                         uint32 buttons,
 112                                                         uint32 clicks);
 113
 114         // is called from the parent DiagramBox's MouseOver()
 115         // implementation if the mouse is over the EndPoint
 116         virtual void            MouseOver(
 117                                                         BPoint point,
 118                                                         uint32 transit)
 119                                                 { /* does nothing */ }
 120
 121         // is called from the parent DiagramBox's MessageDragged()
 122         // implementation of a message is being dragged of the
 123         // EndPoint; this implementation handles only wire drags
 124         // (i.e. M_WIRE_DRAGGED messages)
 125         virtual void            MessageDragged(
 126                                                         BPoint point,
 127                                                         uint32 transit,
 128                                                         const BMessage *message);
 129
 130         // is called from the parent DiagramBox's MessageDropped()
 131         // implementation if the message was dropped on the EndPoint;
 132         // this version handles wire dropping (connecting)
 133         virtual void            MessageDropped(
 134                                                         BPoint point,
 135                                                         BMessage *message);
 136
 137         // moves the EndPoint by the specified amount and returns in
 138         // updateRegion the frames of connected wires if there are any
 139         // NOTE: no drawing/refreshing is done in this method, that's
 140         // up to the parent
 141         void                            MoveBy(
 142                                                         float x,
 143                                                         float y,
 144                                                         BRegion *updateRegion);
 145
 146         // resize the EndPoints frame rectangle without redraw
 147         virtual void            ResizeBy(
 148                                                         float horizontal,
 149                                                         float vertical);
 150
 151 public:                                 // *** connection methods
 152
 153         // connect/disconnect and set the wire pointer accordingly
 154         void                            connect(
 155                                                         DiagramWire *wire);
 156         void                            disconnect();
 157
 158         // returns true if the EndPoint is currently connected
 159         bool                            isConnected() const
 160                                                 { return m_connected; }
 161
 162         // returns true if the EndPoint is currently in a connection
 163         // process (i.e. it is either being dragged somewhere, or a
 164         // M_WIRE_DRAGGED message is being dragged over it
 165         bool                            isConnecting() const
 166                                                 { return m_connecting; }
 167
 168 private:                                // *** data
 169
 170         // the endpoints' frame rectangle
 171         BRect                           m_frame;
 172
 173         // pointer to the wire object this endpoint might be
 174         // connected to
 175         DiagramWire                *m_wire;
 176
 177         // indicates if the endpoint is currently connected
 178         // to another endpoint
 179         bool                            m_connected;
 180
 181         // indicates that a connection is currently being made
 182         // but has not been confirmed yet
 183         bool                            m_connecting;
 184 };
 185
 186 __END_CORTEX_NAMESPACE
 187 #endif // __DiagramEndPoint_H__