# Source code for pacman.model.graphs.abstract_vertex

```
# Copyright (c) 2017-2019 The University of Manchester
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from pacman.exceptions import PacmanConfigurationException
from pacman.model.graphs.common import ChipAndCore
class AbstractVertex(object):
""" A vertex in a graph.
"""
__slots__ = [
# Indicates if the Vertex has been added to a graph
"_added_to_graph",
# Label for the vertex. Changable until added to graph
"_label",
# the x, y (and p) this vertex MUST be placed on
"_fixed_location"
]
def __init__(self, label=None):
"""
:param str label: The optional name of the vertex
:param fixed_location:
The optional fixed location of the vertex.
Only if the Vertex is fixed before placement.
"""
self._label = label
self._added_to_graph = False
self._fixed_location = None
@property
def label(self):
""" The current label to the vertex.
This label could change when the vertex is added to the graph.
:rtype: str
"""
return self._label
[docs] def set_label(self, label):
""" Changes the label for a vertex *not yet added* to a graph.
:param str label: new value for the label
:raises PacmanConfigurationException:
If there is an attempt to change the label once the vertex has
been added to a graph
"""
if self._added_to_graph:
raise PacmanConfigurationException(
"As Labels are also IDs they can not be changed.")
self._label = label
[docs] def addedToGraph(self):
""" Records that the vertex has been added to a graph
:raises PacmanConfigurationException:
If there is an attempt to add the same vertex more than once
"""
self._added_to_graph = True
[docs] def get_fixed_location(self):
"""
The x, y and possibly p the vertex MUST be placed on.
Typically NONE! Does not have the value of a normal placememts.
Used instead of ChipAndCoreConstraint
:rtype: None or ChipAndCore
"""
return self._fixed_location
[docs] def set_fixed_location(self, x, y, p=None):
"""
:param ChipAndCore fixed_location:
"""
fixed_location = ChipAndCore(x, y, p)
if self._fixed_location is not None:
if fixed_location == self._fixed_location:
return
raise PacmanConfigurationException(
"Once set to a value fixed_location can not be changed")
self._fixed_location = fixed_location
```