xref: /haiku/src/apps/cortex/DiagramView/DiagramWire.h (revision 19ae20e67e91fc09cc9fc5c0e60e21e24e7a53eb)
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
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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
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28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 
32 // DiagramWire.h (Cortex/DiagramView)
33 //
34 // * PURPOSE
35 //   DiagramItem subclass serving as a graphical connection
36 //   between two DiagramEndPoints
37 //
38 // * HISTORY
39 //   c.lenz		25sep99		Begun
40 //
41 
42 #ifndef __DiagramWire_H__
43 #define __DiagramWire_H__
44 
45 #include "DiagramItem.h"
46 
47 #include <Region.h>
48 #include <Window.h>
49 
50 #include "cortex_defs.h"
51 __BEGIN_CORTEX_NAMESPACE
52 
53 class DiagramView;
54 class DiagramEndPoint;
55 
56 class DiagramWire : public DiagramItem
57 {
58 	friend class DiagramView;
59 
60 public:					// *** ctor/dtor
61 
62 	// both endpoints are set connected by this constructor
63 	// so be careful to only pass in valid pointers
64 						DiagramWire(
65 							DiagramEndPoint *fromWhich,
66 							DiagramEndPoint *toWhich);
67 
68 	// special constructor used only in drag&drop sessions for
69 	// temporary visual indication of the connection process
70 	// the isStartPoint lets you specify if the given EndPoint
71 	// is supposed to be treated as start or end point
72 						DiagramWire(
73 							DiagramEndPoint *fromWhich,
74 							bool isStartPoint = true);
75 
76 	virtual				~DiagramWire();
77 
78 public:					// *** accessors
79 
isDragging()80 	bool				isDragging() const
81 						{ return m_temporary; }
82 
83 	// returns a pointer to the "start/source" endpoint
startPoint()84 	DiagramEndPoint	   *startPoint() const
85 						{ return m_fromEndPoint; }
86 
87 	// returns the point from the m_fromEndPoints connectionPoint() method
88 	BPoint				startConnectionPoint() const;
89 
90 	// returns a pointer the "end/target" endpoint
endPoint()91 	DiagramEndPoint	   *endPoint() const
92 						{ return m_toEndPoint; }
93 
94 	// returns the point from the m_toEndPoints connectionPoint() method
95 	BPoint				endConnectionPoint() const;
96 
97 public:					// *** hook functions
98 
99 	// is called from Draw() to do the actual drawing
100 	virtual void		drawWire() = 0;
101 
102 	// is called by the connected diagramEndPoints whenever one is moved
103 	// if the argument is NULL then both endpoints should be evaluated
104 	virtual void		endPointMoved(
105 							DiagramEndPoint *which = 0)
106 						{ /* does nothing */ }
107 
108 public:					//  *** derived from DiagramItem
109 
110 	// returns the area in which the wire displays
Frame()111 	virtual BRect		Frame() const
112 						{ return BRect(startConnectionPoint(), endConnectionPoint()); }
113 
114 	// returns how close a given point is to the wire; the current
115 	// implementation returns a wide array of values, those above
116 	// approx. 0.5 are quite close to the wire
117 	float				howCloseTo(
118 							BPoint point) const;
119 
120 	// prepares the drawing stack and clipping region, then
121 	// calls drawWire
122 	void				Draw(
123 							BRect updateRect);
124 
125 	// is called from the parent DiagramViews MouseDown() implementation
126 	// if the Wire was hit; this version initiates selection and dragging
127 	virtual void		MouseDown(
128 							BPoint point,
129 							uint32 buttons,
130 							uint32 clicks);
131 
132 	// is called from the DiagramViews MouseMoved() when no message is being
133 	// dragged, but the mouse has moved above the wire
MouseOver(BPoint point,uint32 transit)134 	virtual void		MouseOver(
135 							BPoint point,
136 							uint32 transit)
137 						{ /* does nothing */ }
138 
139 
140 	// is called from the DiagramViews MouseMoved() when a message is being
141 	// dragged over the DiagramWire
142 	virtual void		MessageDragged(
143 							BPoint point,
144 							uint32 transit,
145 							const BMessage *message);
146 
147 	// is called from the DiagramViews MessageReceived() function when a
148 	// message has been dropped on the DiagramWire
MessageDropped(BPoint point,BMessage * message)149 	virtual void		MessageDropped(
150 							BPoint point,
151 							BMessage *message)
152 						{ /* does nothing */ }
153 
154 private:				// *** data
155 
156 	// pointer to the "from" EndPoint as assigned in the ctor
157 	DiagramEndPoint	   *m_fromEndPoint;
158 
159 	// pointer to the "to" EndPoint as assigned in the ctor
160 	DiagramEndPoint	   *m_toEndPoint;
161 
162 	// indicates that this is a connection used in a drag&drop session
163 	// and will be deleted after that
164 	bool				m_temporary;
165 
166 	// contains a BPoint for "temporary connections"
167 	BPoint				m_dragEndPoint;
168 };
169 
170 __END_CORTEX_NAMESPACE
171 #endif // __DiagramWire_H__
172