pyqtgraph/pyqtgraph/flowchart/NodeLibrary.py

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from pyqtgraph.pgcollections import OrderedDict
2013-12-22 04:41:37 +00:00
from .Node import Node
def isNodeClass(cls):
try:
if not issubclass(cls, Node):
return False
except:
return False
return hasattr(cls, 'nodeName')
class NodeLibrary:
"""
A library of flowchart Node types. Custom libraries may be built to provide
each flowchart with a specific set of allowed Node types.
"""
def __init__(self):
self.nodeList = OrderedDict()
self.nodeTree = OrderedDict()
def addNodeType(self, nodeClass, paths, override=False):
"""
Register a new node type. If the type's name is already in use,
an exception will be raised (unless override=True).
Arguments:
nodeClass - a subclass of Node (must have typ.nodeName)
paths - list of tuples specifying the location(s) this
type will appear in the library tree.
override - if True, overwrite any class having the same name
"""
if not isNodeClass(nodeClass):
raise Exception("Object %s is not a Node subclass" % str(nodeClass))
name = nodeClass.nodeName
if not override and name in self.nodeList:
raise Exception("Node type name '%s' is already registered." % name)
self.nodeList[name] = nodeClass
for path in paths:
root = self.nodeTree
for n in path:
if n not in root:
root[n] = OrderedDict()
root = root[n]
root[name] = nodeClass
def getNodeType(self, name):
try:
return self.nodeList[name]
except KeyError:
raise Exception("No node type called '%s'" % name)
def getNodeTree(self):
return self.nodeTree
def copy(self):
"""
Return a copy of this library.
"""
lib = NodeLibrary()
lib.nodeList = self.nodeList.copy()
lib.nodeTree = self.treeCopy(self.nodeTree)
return lib
@staticmethod
def treeCopy(tree):
copy = OrderedDict()
for k,v in tree.items():
if isNodeClass(v):
copy[k] = v
else:
copy[k] = NodeLibrary.treeCopy(v)
return copy
def reload(self):
"""
Reload Node classes in this library.
"""
raise NotImplementedError()