archive-freepcb-codeproject/ConnectionIterator.cpp at cpt · nkhorman/archive-freepcb-codeproject · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/* CConnectionIterator implementation

This class is sort of a "super-iterator" for moving through the
array of connections in a net
Unlike standard iterators, it can be used by processes which
add or remove connections without losing its place
For this to work, any function that adds or removes connections has to
notify the iterator

Rules, assuming m_net->nconnects > 0:
	if current_ic == -1, the current connection was removed or never selected,
		but the position of the iterator is still maintained by prev_ic and next_ic
	if prev_ic == -1, we are at the beginning of the connection array
	if next_ic == -1, we are at the end of the connection array
	if an external process removes a connection, it must call Removed(ic)
	if an external process adds a connection, it must call Added()

Example:
	// remove any connections with more than 5 segments
	CConnectionIterator cci( net );
	for( int ic=cci.First(); ic=cci.Next(); ic!=-1 )
	{
		cconnect * c = &net->connect[ic];
		if( c->nsegs > 5 )
		{
			net->connect.RemoveAt(ic);
			cci.Removed(ic);
		}
	}
*/

CConnectionIterator::CConnectionIterator( cnet * net )
{
	if( net->m_cci )
		ASSERT(0);	// iterator already exist, error
	// link this iterator with net
	m_net = net;
	net->m_cci = this;
	// initialize to point to start of array, before first connection
	// calling Next() will select the first connection
	prev_ic = -1;
	current_ic = -1;
	if( m_net->nconnects )
		next_ic = 0;
	else
		next_ic = -1;
}

CConnectionIterator::~CConnectionIterator()
{
	m_net->m_cci = NULL;	//notify net we are gone
}

int CConnectionIterator::First()
{
	prev_ic = -1;
	if( m_net->nconnects == 0 )
	{
		current_ic = -1;
		next_ic = -1;
	}
	else if( m_net->nconnects == 1 )
	{
		current_ic = 0;
		next_ic = -1;
	}
	else
	{
		current_ic = 0;
		next_ic = 1;
	}
	return current_ic;
}

int CConnectionIterator::Last()
{
	next_ic = -1;
	if( m_net->nconnects == 0 )
	{
		prev_ic = -1;
		current_ic = -1;
	}
	else if( m_net->nconnects == 1 )
	{
		current_ic = m_net->nconnects - 1;
		prev_ic = -1;
	}
	else
	{
		current_ic = m_net->nconnects - 1;
		prev_ic = current_ic - 1;
	}
	return current_ic;
}

int CConnectionIterator::Next()
{
	if( m_net->nconnects == 0 )
	{
		prev_ic = -1;
		current_ic = -1;
		next_ic = -1;
	}
	else
	{
		if( next_ic == -1 )
		{
			// we are already at end
			current_ic = -1;
			prev_ic = m_net->nconnects - 1;
		}
		else
		{
			// next_ic is valid, set current_ic = next_ic
			current_ic = next_ic;
			if( current_ic == m_net->nconnects-1 )
				next_ic = -1;
			else
				next_ic = current_ic + 1;
			if( current_ic == 0 )
				prev_ic = -1;
			else
				prev_ic = current_ic - 1;
		}
	}
	return current_ic;
}

int CConnectionIterator::Prev()
{
	if( m_net->nconnects == 0 )
	{
		prev_ic = -1;
		current_ic = -1;
		next_ic = -1;
	}
	else
	{
		if( prev_ic == -1 )
		{
			// we are already at start
			current_ic = -1;
			next_ic = 0;
		}
		else
		{
			// prev_ic is valid, set current_ic = prev_ic
			current_ic = prev_ic;
			if( current_ic == 0 )
				prev_ic = -1;
			else
				prev_ic = current_ic - 1;
			if( current_ic == m_net->nconnects-1 )
				next_ic = -1;
			else
				next_ic = current_ic + 1;
		}
	}
	return current_ic;
}

// should be called after removing a connection
void CConnectionIterator::Removed( int ic )
{
	if( m_net->nconnects == 0 )
	{
		prev_ic = current_ic = next_ic = -1;
	}
	else
	{
		if( ic == current_ic )
		{
			// mark current_ic removed
			// shift next_ic down, if possible
			current_ic = -1;
			if( next_ic > 0 )
				next_ic--;
			else
				next_ic = -1;
		}
		else if( ic == next_ic )
		{
			// shift next_ic up if possible
			if( next_ic < m_net->nconnects-1 )
				next_ic++;
			else
				next_ic = -1;
		}
		else if( ic <= prev_ic )
		{
			// shift all down if possible
			if( prev_ic > 0 )
				prev_ic--;
			else
				prev_ic = -1;
			if( current_ic > 0 )
				current_ic--;
			else
				current_ic = -1;
			if( next_ic > 0 )
				current_ic--;
			else
				next_ic = -1;
		}
	}
}