Flowchart:

* Replaced dynamic imports with static
* Added NodeLibrary allowing multiple customized collections of Node types

examples/FlowchartCustomNode.py

@@ -83,9 +83,8 @@ class ImageViewNode(Node):
             else:
                 self.view.setImage(data)
 
-## register the class so it will appear in the menu of node types.
-## It will appear in the 'display' sub-menu.
-fclib.registerNodeType(ImageViewNode, [('Display',)])
+
+
         
 ## We will define an unsharp masking filter node as a subclass of CtrlNode.
 ## CtrlNode is just a convenience class that automatically creates its
@@ -113,12 +112,25 @@ class UnsharpMaskNode(CtrlNode):
         strength = self.ctrls['strength'].value()
         output = dataIn - (strength * scipy.ndimage.gaussian_filter(dataIn, (sigma,sigma)))
         return {'dataOut': output}
+
+
+## To make our custom node classes available in the flowchart context menu,
+## we can either register them with the default node library or make a
+## new library.
+
         
-## register the class so it will appear in the menu of node types.
-## It will appear in a new 'image' sub-menu.
-fclib.registerNodeType(UnsharpMaskNode, [('Image',)])
-    
-    
+## Method 1: Register to global default library:
+#fclib.registerNodeType(ImageViewNode, [('Display',)])
+#fclib.registerNodeType(UnsharpMaskNode, [('Image',)])
+
+## Method 2: If we want to make our custom node available only to this flowchart,
+## then instead of registering the node type globally, we can create a new 
+## NodeLibrary:
+library = fclib.LIBRARY.copy() # start with the default node set
+library.addNodeType(ImageViewNode, [('Display',)])
+library.addNodeType(UnsharpMaskNode, [('Image',)])
+fc.setLibrary(library)
+
 
 ## Now we will programmatically add nodes to define the function of the flowchart.
 ## Normally, the user will do this manually or by loading a pre-generated

pyqtgraph/flowchart/Flowchart.py

@@ -14,7 +14,7 @@ else:
     
 from .Terminal import Terminal
 from numpy import ndarray
-from . import library
+from .library import LIBRARY
 from pyqtgraph.debug import printExc
 import pyqtgraph.configfile as configfile
 import pyqtgraph.dockarea as dockarea
@@ -67,7 +67,8 @@ class Flowchart(Node):
     sigChartLoaded = QtCore.Signal()
     sigStateChanged = QtCore.Signal()
     
-    def __init__(self, terminals=None, name=None, filePath=None):
+    def __init__(self, terminals=None, name=None, filePath=None, library=None):
+        self.library = library or LIBRARY
         if name is None:
             name = "Flowchart"
         if terminals is None:
@@ -105,6 +106,10 @@ class Flowchart(Node):
         for name, opts in terminals.items():
             self.addTerminal(name, **opts)
       
+    def setLibrary(self, lib):
+        self.library = lib
+        self.widget().chartWidget.buildMenu()
+      
     def setInput(self, **args):
         """Set the input values of the flowchart. This will automatically propagate
         the new values throughout the flowchart, (possibly) causing the output to change.
@@ -194,7 +199,7 @@ class Flowchart(Node):
                     break
                 n += 1
                 
-        node = library.getNodeType(nodeType)(name)
+        node = self.library.getNodeType(nodeType)(name)
         self.addNode(node, name, pos)
         return node
         
@@ -846,13 +851,13 @@ class FlowchartWidget(dockarea.DockArea):
         self.nodeMenu.triggered.disconnect(self.nodeMenuTriggered)
         self.nodeMenu = None
         self.subMenus = []
-        library.loadLibrary(reloadLibs=True)
+        self.chart.library.reload()
         self.buildMenu()
         
     def buildMenu(self, pos=None):
         self.nodeMenu = QtGui.QMenu()
         self.subMenus = []
-        for section, nodes in library.getNodeTree().items():
+        for section, nodes in self.chart.library.getNodeTree().items():
             menu = QtGui.QMenu(section)
             self.nodeMenu.addMenu(menu)
             for name in nodes:

pyqtgraph/flowchart/NodeLibrary.py

@@ -0,0 +1,84 @@
+from pyqtgraph.pgcollections import OrderedDict
+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()

pyqtgraph/flowchart/library/__init__.py

@@ -1,103 +1,100 @@
 # -*- coding: utf-8 -*-
 from pyqtgraph.pgcollections import OrderedDict
-from pyqtgraph import importModules
+#from pyqtgraph import importModules
 import os, types
 from pyqtgraph.debug import printExc
-from ..Node import Node
+#from ..Node import Node
+from ..NodeLibrary import NodeLibrary, isNodeClass
 import pyqtgraph.reload as reload
 
 
-NODE_LIST = OrderedDict()  ## maps name:class for all registered Node subclasses
-NODE_TREE = OrderedDict()  ## categorized tree of Node subclasses
+# Build default library
+LIBRARY = NodeLibrary()
 
-def getNodeType(name):
-    try:
-        return NODE_LIST[name]
-    except KeyError:
-        raise Exception("No node type called '%s'" % name)
+# For backward compatibility, expose the default library's properties here:
+NODE_LIST = LIBRARY.nodeList
+NODE_TREE = LIBRARY.nodeTree
+registerNodeType = LIBRARY.addNodeType
+getNodeTree = LIBRARY.getNodeTree
+getNodeType = LIBRARY.getNodeType
 
-def getNodeTree():
-    return NODE_TREE
-
-def registerNodeType(cls, 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).
+# Add all nodes to the default library
+for modName in ['Data', 'Display', 'Filters', 'Operators']:
+    mod = __import__(modName, globals(), locals(), [], -1)
+    nodes = [getattr(mod, name) for name in dir(mod) if isNodeClass(getattr(mod, name))]
+    for node in nodes:
+        LIBRARY.addNodeType(node, [(modName,)])
     
-    Arguments:
-        cls - 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(cls):
-        raise Exception("Object %s is not a Node subclass" % str(cls))
+#NODE_LIST = OrderedDict()  ## maps name:class for all registered Node subclasses
+#NODE_TREE = OrderedDict()  ## categorized tree of Node subclasses
+
+#def getNodeType(name):
+    #try:
+        #return NODE_LIST[name]
+    #except KeyError:
+        #raise Exception("No node type called '%s'" % name)
+
+#def getNodeTree():
+    #return NODE_TREE
+
+#def registerNodeType(cls, 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).
     
-    name = cls.nodeName
-    if not override and name in NODE_LIST:
-        raise Exception("Node type name '%s' is already registered." % name)
+    #Arguments:
+        #cls - 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(cls):
+        #raise Exception("Object %s is not a Node subclass" % str(cls))
     
-    NODE_LIST[name] = cls
-    for path in paths:
-        root = NODE_TREE
-        for n in path:
-            if n not in root:
-                root[n] = OrderedDict()
-            root = root[n]
-        root[name] = cls
-
-
-
-def isNodeClass(cls):
-    try:
-        if not issubclass(cls, Node):
-            return False
-    except:
-        return False
-    return hasattr(cls, 'nodeName')
-
-def loadLibrary(reloadLibs=False, libPath=None):
-    """Import all Node subclasses found within files in the library module."""
-
-    global NODE_LIST, NODE_TREE
-    #if libPath is None:
-        #libPath = os.path.dirname(os.path.abspath(__file__))
+    #name = cls.nodeName
+    #if not override and name in NODE_LIST:
+        #raise Exception("Node type name '%s' is already registered." % name)
     
-    if reloadLibs:
-        reload.reloadAll(libPath)
+    #NODE_LIST[name] = cls
+    #for path in paths:
+        #root = NODE_TREE
+        #for n in path:
+            #if n not in root:
+                #root[n] = OrderedDict()
+            #root = root[n]
+        #root[name] = cls
+
+
+
+#def isNodeClass(cls):
+    #try:
+        #if not issubclass(cls, Node):
+            #return False
+    #except:
+        #return False
+    #return hasattr(cls, 'nodeName')
+
+#def loadLibrary(reloadLibs=False, libPath=None):
+    #"""Import all Node subclasses found within files in the library module."""
+
+    #global NODE_LIST, NODE_TREE
+    
+    #if reloadLibs:
+        #reload.reloadAll(libPath)
         
-    mods = importModules('', globals(), locals())
-    #for f in frozenSupport.listdir(libPath):
-        #pathName, ext = os.path.splitext(f)
-        #if ext not in ('.py', '.pyc') or '__init__' in pathName or '__pycache__' in pathName:
-            #continue
-        #try:
-            ##print "importing from", f
-            #mod = __import__(pathName, globals(), locals())
-        #except:
-            #printExc("Error loading flowchart library %s:" % pathName)
-            #continue
+    #mods = importModules('', globals(), locals())
         
-    for name, mod in mods.items():
-        nodes = []
-        for n in dir(mod):
-            o = getattr(mod, n)
-            if isNodeClass(o):
-                #print "  ", str(o)
-                registerNodeType(o, [(name,)], override=reloadLibs)
-                #nodes.append((o.nodeName, o))
-        #if len(nodes) > 0:
-            #NODE_TREE[name] = OrderedDict(nodes)
-            #NODE_LIST.extend(nodes)
-    #NODE_LIST = OrderedDict(NODE_LIST)
+    #for name, mod in mods.items():
+        #nodes = []
+        #for n in dir(mod):
+            #o = getattr(mod, n)
+            #if isNodeClass(o):
+                #registerNodeType(o, [(name,)], override=reloadLibs)
     
-def reloadLibrary():
-    loadLibrary(reloadLibs=True)
+#def reloadLibrary():
+    #loadLibrary(reloadLibs=True)
     
-loadLibrary()
-#NODE_LIST = []
-#for o in locals().values():
-    #if type(o) is type(AddNode) and issubclass(o, Node) and o is not Node and hasattr(o, 'nodeName'):
-            #NODE_LIST.append((o.nodeName, o))
-#NODE_LIST.sort(lambda a,b: cmp(a[0], b[0]))
-#NODE_LIST = OrderedDict(NODE_LIST)
+#loadLibrary()
+
+
+