pyqtgraph/flowchart/Flowchart.py

# -*- coding: utf-8 -*-
from pyqtgraph.Qt import QtCore, QtGui
#from PyQt4 import QtCore, QtGui
#from PySide import QtCore, QtGui
#import Node as NodeMod
from Node import *
#import functions
from collections import OrderedDict
from pyqtgraph.widgets.TreeWidget import *
#from .. DataTreeWidget import *
import FlowchartTemplate
import FlowchartCtrlTemplate
from Terminal import Terminal
from numpy import ndarray
import library
from pyqtgraph.debug import printExc
import pyqtgraph.configfile as configfile
import pyqtgraph.dockarea as dockarea
import pyqtgraph as pg
import FlowchartGraphicsView

def strDict(d):
    return dict([(str(k), v) for k, v in d.iteritems()])


def toposort(deps, nodes=None, seen=None, stack=None, depth=0):
    """Topological sort. Arguments are:
      deps    dictionary describing dependencies where a:[b,c] means "a depends on b and c"
      nodes   optional, specifies list of starting nodes (these should be the nodes 
              which are not depended on by any other nodes) 
    """
    
    if nodes is None:
        ## run through deps to find nodes that are not depended upon
        rem = set()
        for dep in deps.itervalues():
            rem |= set(dep)
        nodes = set(deps.keys()) - rem
    if seen is None:
        seen = set()
        stack = []
    sorted = []
    #print "  "*depth, "Starting from", nodes
    for n in nodes:
        if n in stack:
            raise Exception("Cyclic dependency detected", stack + [n])
        if n in seen:
            continue
        seen.add(n)
        #print "  "*depth, "  descending into", n, deps[n]
        sorted.extend( toposort(deps, deps[n], seen, stack+[n], depth=depth+1))
        #print "  "*depth, "  Added", n
        sorted.append(n)
        #print "  "*depth, "  ", sorted
    return sorted
        

class Flowchart(Node):
    
    sigFileLoaded = QtCore.Signal(object)
    sigFileSaved = QtCore.Signal(object)
    
    
    #sigOutputChanged = QtCore.Signal() ## inherited from Node
    sigChartLoaded = QtCore.Signal()
    sigStateChanged = QtCore.Signal()
    
    def __init__(self, terminals=None, name=None, filePath=None):
        if name is None:
            name = "Flowchart"
        if terminals is None:
            terminals = {}
        self.filePath = filePath
        Node.__init__(self, name)  ## create node without terminals; we'll add these later
        
        self.inputWasSet = False  ## flag allows detection of changes in the absence of input change.
        self._nodes = {}
        self.nextZVal = 10
        #self.connects = []
        #self._chartGraphicsItem = FlowchartGraphicsItem(self)
        self._widget = None
        self._scene = None
        self.processing = False ## flag that prevents recursive node updates
        
        self.widget()
        
        self.inputNode = Node('Input', allowRemove=False, allowAddOutput=True)
        self.outputNode = Node('Output', allowRemove=False, allowAddInput=True)
        self.addNode(self.inputNode, 'Input', [-150, 0])
        self.addNode(self.outputNode, 'Output', [300, 0])
        
        self.outputNode.sigOutputChanged.connect(self.outputChanged)
        self.outputNode.sigTerminalRenamed.connect(self.internalTerminalRenamed)
        self.inputNode.sigTerminalRenamed.connect(self.internalTerminalRenamed)
        self.outputNode.sigTerminalRemoved.connect(self.internalTerminalRemoved)
        self.inputNode.sigTerminalRemoved.connect(self.internalTerminalRemoved)
        self.outputNode.sigTerminalAdded.connect(self.internalTerminalAdded)
        self.inputNode.sigTerminalAdded.connect(self.internalTerminalAdded)
        
        self.viewBox.autoRange(padding = 0.04)
            
        for name, opts in terminals.iteritems():
            self.addTerminal(name, **opts)
      
    def setInput(self, **args):
        #print "setInput", args
        #Node.setInput(self, **args)
        #print "  ....."
        self.inputWasSet = True
        self.inputNode.setOutput(**args)
        
    def outputChanged(self):
        self.widget().outputChanged(self.outputNode.inputValues())
        self.sigOutputChanged.emit(self)
        
    def output(self):
        return self.outputNode.inputValues()
        
    def nodes(self):
        return self._nodes
        
    def addTerminal(self, name, **opts):
        term = Node.addTerminal(self, name, **opts)
        name = term.name()
        if opts['io'] == 'in':  ## inputs to the flowchart become outputs on the input node
            opts['io'] = 'out'
            opts['multi'] = False
            self.inputNode.sigTerminalAdded.disconnect(self.internalTerminalAdded)
            try:
                term2 = self.inputNode.addTerminal(name, **opts)
            finally:
                self.inputNode.sigTerminalAdded.connect(self.internalTerminalAdded)
                
        else:
            opts['io'] = 'in'
            #opts['multi'] = False
            self.outputNode.sigTerminalAdded.disconnect(self.internalTerminalAdded)
            try:
                term2 = self.outputNode.addTerminal(name, **opts)
            finally:
                self.outputNode.sigTerminalAdded.connect(self.internalTerminalAdded)
        return term

    def removeTerminal(self, name):
        #print "remove:", name
        term = self[name]
        inTerm = self.internalTerminal(term)
        Node.removeTerminal(self, name)
        inTerm.node().removeTerminal(inTerm.name())
        
    def internalTerminalRenamed(self, term, oldName):
        self[oldName].rename(term.name())
        
    def internalTerminalAdded(self, node, term):
        if term._io == 'in':
            io = 'out'
        else:
            io = 'in'
        Node.addTerminal(self, term.name(), io=io, renamable=term.isRenamable(), removable=term.isRemovable(), multiable=term.isMultiable())
        
    def internalTerminalRemoved(self, node, term):
        Node.removeTerminal(self, term.name())
        
    def terminalRenamed(self, term, oldName):
        newName = term.name()
        #print "flowchart rename", newName, oldName
        #print self.terminals
        Node.terminalRenamed(self, self[oldName], oldName)
        #print self.terminals
        for n in [self.inputNode, self.outputNode]:
            if oldName in n.terminals:
                n[oldName].rename(newName)

    def createNode(self, nodeType, name=None, pos=None):
        if name is None:
            n = 0
            while True:
                name = "%s.%d" % (nodeType, n)
                if name not in self._nodes:
                    break
                n += 1
                
        node = library.getNodeType(nodeType)(name)
        self.addNode(node, name, pos)
        return node
        
    def addNode(self, node, name, pos=None):
        if pos is None:
            pos = [0, 0]
        if type(pos) in [QtCore.QPoint, QtCore.QPointF]:
            pos = [pos.x(), pos.y()]
        item = node.graphicsItem()
        item.setZValue(self.nextZVal*2)
        self.nextZVal += 1
        #item.setParentItem(self.chartGraphicsItem())
        self.viewBox.addItem(item)
        #item.setPos(pos2.x(), pos2.y())
        item.moveBy(*pos)
        self._nodes[name] = node
        self.widget().addNode(node) 
        #QtCore.QObject.connect(node, QtCore.SIGNAL('closed'), self.nodeClosed)
        node.sigClosed.connect(self.nodeClosed)
        #QtCore.QObject.connect(node, QtCore.SIGNAL('renamed'), self.nodeRenamed)
        node.sigRenamed.connect(self.nodeRenamed)
        #QtCore.QObject.connect(node, QtCore.SIGNAL('outputChanged'), self.nodeOutputChanged)
        node.sigOutputChanged.connect(self.nodeOutputChanged)
        
    def removeNode(self, node):
        node.close()
        
    def nodeClosed(self, node):
        del self._nodes[node.name()]
        self.widget().removeNode(node)
        #QtCore.QObject.disconnect(node, QtCore.SIGNAL('closed'), self.nodeClosed)
        try:
            node.sigClosed.disconnect(self.nodeClosed)
        except TypeError:
            pass
        #QtCore.QObject.disconnect(node, QtCore.SIGNAL('renamed'), self.nodeRenamed)
        try:
            node.sigRenamed.disconnect(self.nodeRenamed)
        except TypeError:
            pass
        #QtCore.QObject.disconnect(node, QtCore.SIGNAL('outputChanged'), self.nodeOutputChanged)
        try:
            node.sigOutputChanged.disconnect(self.nodeOutputChanged)
        except TypeError:
            pass
        
    def nodeRenamed(self, node, oldName):
        del self._nodes[oldName]
        self._nodes[node.name()] = node
        self.widget().nodeRenamed(node, oldName)
        
    def arrangeNodes(self):
        pass
        
    def internalTerminal(self, term):
        """If the terminal belongs to the external Node, return the corresponding internal terminal"""
        if term.node() is self:
            if term.isInput():
                return self.inputNode[term.name()]
            else:
                return self.outputNode[term.name()]
        else:
            return term
        
    def connectTerminals(self, term1, term2):
        """Connect two terminals together within this flowchart."""
        term1 = self.internalTerminal(term1)
        term2 = self.internalTerminal(term2)
        term1.connectTo(term2)
        
        
    def process(self, **args):
        """
        Process data through the flowchart, returning the output.
        Keyword arguments must be the names of input terminals
        
        """
        data = {}  ## Stores terminal:value pairs
        
        ## determine order of operations
        ## order should look like [('p', node1), ('p', node2), ('d', terminal1), ...] 
        ## Each tuple specifies either (p)rocess this node or (d)elete the result from this terminal
        order = self.processOrder()
        #print "ORDER:", order
        
        ## Record inputs given to process()
        for n, t in self.inputNode.outputs().iteritems():
            if n not in args:
                raise Exception("Parameter %s required to process this chart." % n)
            data[t] = args[n]
        
        ret = {}
            
        ## process all in order
        for c, arg in order:
            
            if c == 'p':     ## Process a single node
                #print "===> process:", arg
                node = arg
                if node is self.inputNode:
                    continue  ## input node has already been processed.
                
                            
                ## get input and output terminals for this node
                outs = node.outputs().values()
                ins = node.inputs().values()
                
                ## construct input value dictionary
                args = {}
                for inp in ins:
                    inputs = inp.inputTerminals()
                    if len(inputs) == 0:
                        continue
                    if inp.isMultiValue():  ## multi-input terminals require a dict of all inputs
                        args[inp.name()] = dict([(i, data[i]) for i in inputs])
                    else:                   ## single-inputs terminals only need the single input value available
                        args[inp.name()] = data[inputs[0]]  
                        
                if node is self.outputNode:
                    ret = args  ## we now have the return value, but must keep processing in case there are other endpoint nodes in the chart
                else:
                    try:
                        if node.isBypassed():
                            result = node.processBypassed(args)
                        else:
                            result = node.process(display=False, **args)
                    except:
                        print "Error processing node %s. Args are: %s" % (str(node), str(args))
                        raise
                    for out in outs:
                        #print "    Output:", out, out.name()
                        #print out.name()
                        try:
                            data[out] = result[out.name()]
                        except:
                            print out, out.name()
                            raise
            elif c == 'd':   ## delete a terminal result (no longer needed; may be holding a lot of memory)
                #print "===> delete", arg
                if arg in data:
                    del data[arg]

        return ret
        
    def processOrder(self):
        """Return the order of operations required to process this chart.
        The order returned should look like [('p', node1), ('p', node2), ('d', terminal1), ...] 
        where each tuple specifies either (p)rocess this node or (d)elete the result from this terminal
        """
        
        ## first collect list of nodes/terminals and their dependencies
        deps = {}
        tdeps = {}   ## {terminal: [nodes that depend on terminal]}
        for name, node in self._nodes.iteritems():
            deps[node] = node.dependentNodes()
            for t in node.outputs().itervalues():
                tdeps[t] = t.dependentNodes()
            
        #print "DEPS:", deps
        ## determine correct node-processing order
        #deps[self] = []
        order = toposort(deps)
        #print "ORDER1:", order
        
        ## construct list of operations
        ops = [('p', n) for n in order]
        
        ## determine when it is safe to delete terminal values
        dels = []
        for t, nodes in tdeps.iteritems():
            lastInd = 0
            lastNode = None
            for n in nodes:  ## determine which node is the last to be processed according to order
                if n is self:
                    lastInd = None
                    break
                else:
                    try:
                        ind = order.index(n)
                    except ValueError:
                        continue
                if lastNode is None or ind > lastInd:
                    lastNode = n
                    lastInd = ind
            #tdeps[t] = lastNode
            if lastInd is not None:
                dels.append((lastInd+1, t))
        dels.sort(lambda a,b: cmp(b[0], a[0]))
        for i, t in dels:
            ops.insert(i, ('d', t))
            
        return ops
        
        
    def nodeOutputChanged(self, startNode):
        """Triggered when a node's output values have changed. (NOT called during process())
        Propagates new data forward through network."""
        ## first collect list of nodes/terminals and their dependencies
        
        if self.processing:
            return
        self.processing = True
        try:
            deps = {}
            for name, node in self._nodes.iteritems():
                deps[node] = []
                for t in node.outputs().itervalues():
                    deps[node].extend(t.dependentNodes())
            
            ## determine order of updates 
            order = toposort(deps, nodes=[startNode])
            order.reverse()
            
            ## keep track of terminals that have been updated
            terms = set(startNode.outputs().values())
            
            #print "======= Updating", startNode
            #print "Order:", order
            for node in order[1:]:
                #print "Processing node", node
                for term in node.inputs().values():
                    #print "  checking terminal", term
                    deps = term.connections().keys()
                    update = False
                    for d in deps:
                        if d in terms:
                            #print "    ..input", d, "changed"
                            update = True
                            term.inputChanged(d, process=False)
                    if update:
                        #print "  processing.."
                        node.update()
                        terms |= set(node.outputs().values())
                    
        finally:
            self.processing = False
            if self.inputWasSet:
                self.inputWasSet = False
            else:
                self.sigStateChanged.emit()
        
        

    def chartGraphicsItem(self):
        """Return the graphicsItem which displays the internals of this flowchart.
        (graphicsItem() still returns the external-view item)"""
        #return self._chartGraphicsItem
        return self.viewBox
        
    def widget(self):
        if self._widget is None:
            self._widget = FlowchartCtrlWidget(self)
            self.scene = self._widget.scene()
            self.viewBox = self._widget.viewBox()
            #self._scene = QtGui.QGraphicsScene()
            #self._widget.setScene(self._scene)
            #self.scene.addItem(self.chartGraphicsItem())
            
            #ci = self.chartGraphicsItem()
            #self.viewBox.addItem(ci)
            #self.viewBox.autoRange()
        return self._widget

    def listConnections(self):
        conn = set()
        for n in self._nodes.itervalues():
            terms = n.outputs()
            for n, t in terms.iteritems():
                for c in t.connections():
                    conn.add((t, c))
        return conn

    def saveState(self):
        state = Node.saveState(self)
        state['nodes'] = []
        state['connects'] = []
        state['terminals'] = self.saveTerminals()
        
        for name, node in self._nodes.iteritems():
            cls = type(node)
            if hasattr(cls, 'nodeName'):
                clsName = cls.nodeName
                pos = node.graphicsItem().pos()
                ns = {'class': clsName, 'name': name, 'pos': (pos.x(), pos.y()), 'state': node.saveState()}
                state['nodes'].append(ns)
            
        conn = self.listConnections()
        for a, b in conn:
            state['connects'].append((a.node().name(), a.name(), b.node().name(), b.name()))
            
        state['inputNode'] = self.inputNode.saveState()
        state['outputNode'] = self.outputNode.saveState()
        
        return state
        
    def restoreState(self, state, clear=False):
        self.blockSignals(True)
        try:
            if clear:
                self.clear()
            Node.restoreState(self, state)
            nodes = state['nodes']
            nodes.sort(lambda a, b: cmp(a['pos'][0], b['pos'][0]))
            for n in nodes:
                if n['name'] in self._nodes:
                    self._nodes[n['name']].moveBy(*n['pos'])
                    continue
                try:
                    node = self.createNode(n['class'], name=n['name'])
                    node.restoreState(n['state'])
                except:
                    printExc("Error creating node %s: (continuing anyway)" % n['name'])
                #node.graphicsItem().moveBy(*n['pos'])
                
            self.inputNode.restoreState(state.get('inputNode', {}))
            self.outputNode.restoreState(state.get('outputNode', {}))
                
            self.restoreTerminals(state['terminals'])
            for n1, t1, n2, t2 in state['connects']:
                try:
                    self.connectTerminals(self._nodes[n1][t1], self._nodes[n2][t2])
                except:
                    print self._nodes[n1].terminals
                    print self._nodes[n2].terminals
                    printExc("Error connecting terminals %s.%s - %s.%s:" % (n1, t1, n2, t2))
                    
                
        finally:
            self.blockSignals(False)
            
        self.sigChartLoaded.emit()
        self.outputChanged()
        #self.sigOutputChanged.emit()
            
    def loadFile(self, fileName=None, startDir=None):
        if fileName is None:
            if startDir is None:
                startDir = self.filePath
            if startDir is None:
                startDir = '.'
            self.fileDialog = pg.FileDialog(None, "Load Flowchart..", startDir, "Flowchart (*.fc)")
            #self.fileDialog.setFileMode(QtGui.QFileDialog.AnyFile)
            #self.fileDialog.setAcceptMode(QtGui.QFileDialog.AcceptSave) 
            self.fileDialog.show()
            self.fileDialog.fileSelected.connect(self.loadFile)
            return
            ## NOTE: was previously using a real widget for the file dialog's parent, but this caused weird mouse event bugs..
            #fileName = QtGui.QFileDialog.getOpenFileName(None, "Load Flowchart..", startDir, "Flowchart (*.fc)")
        fileName = str(fileName)
        state = configfile.readConfigFile(fileName)
        self.restoreState(state, clear=True)
        self.viewBox.autoRange()
        #self.emit(QtCore.SIGNAL('fileLoaded'), fileName)
        self.sigFileLoaded.emit(fileName)
        
    def saveFile(self, fileName=None, startDir=None, suggestedFileName='flowchart.fc'):
        if fileName is None:
            if startDir is None:
                startDir = self.filePath
            if startDir is None:
                startDir = '.'
            self.fileDialog = pg.FileDialog(None, "Save Flowchart..", startDir, "Flowchart (*.fc)")
            #self.fileDialog.setFileMode(QtGui.QFileDialog.AnyFile)
            self.fileDialog.setAcceptMode(QtGui.QFileDialog.AcceptSave) 
            #self.fileDialog.setDirectory(startDir)
            self.fileDialog.show()
            self.fileDialog.fileSelected.connect(self.saveFile)
            return
            #fileName = QtGui.QFileDialog.getSaveFileName(None, "Save Flowchart..", startDir, "Flowchart (*.fc)")
        configfile.writeConfigFile(self.saveState(), fileName)
        self.sigFileSaved.emit(fileName)

    def clear(self):
        for n in self._nodes.values():
            if n is self.inputNode or n is self.outputNode:
                continue
            n.close()  ## calls self.nodeClosed(n) by signal
        #self.clearTerminals()
        self.widget().clear()
        
    def clearTerminals(self):
        Node.clearTerminals(self)
        self.inputNode.clearTerminals()
        self.outputNode.clearTerminals()

#class FlowchartGraphicsItem(QtGui.QGraphicsItem):
class FlowchartGraphicsItem(GraphicsObject):
    
    def __init__(self, chart):
        #print "FlowchartGraphicsItem.__init__"
        #QtGui.QGraphicsItem.__init__(self)
        GraphicsObject.__init__(self)
        self.chart = chart ## chart is an instance of Flowchart()
        self.updateTerminals()
        
    def updateTerminals(self):
        #print "FlowchartGraphicsItem.updateTerminals"
        self.terminals = {}
        bounds = self.boundingRect()
        inp = self.chart.inputs()
        dy = bounds.height() / (len(inp)+1)
        y = dy
        for n, t in inp.iteritems():
            item = t.graphicsItem()
            self.terminals[n] = item
            item.setParentItem(self)
            item.setAnchor(bounds.width(), y)
            y += dy
        out = self.chart.outputs()
        dy = bounds.height() / (len(out)+1)
        y = dy
        for n, t in out.iteritems():
            item = t.graphicsItem()
            self.terminals[n] = item
            item.setParentItem(self)
            item.setAnchor(0, y)
            y += dy
        
    def boundingRect(self):
        #print "FlowchartGraphicsItem.boundingRect"
        return QtCore.QRectF()
        
    def paint(self, p, *args):
        #print "FlowchartGraphicsItem.paint"
        pass
        #p.drawRect(self.boundingRect())
    

class FlowchartCtrlWidget(QtGui.QWidget):
    """The widget that contains the list of all the nodes in a flowchart and their controls, as well as buttons for loading/saving flowcharts."""
    
    def __init__(self, chart):
        self.items = {}
        #self.loadDir = loadDir  ## where to look initially for chart files
        self.currentFileName = None
        QtGui.QWidget.__init__(self)
        self.chart = chart
        self.ui = FlowchartCtrlTemplate.Ui_Form()
        self.ui.setupUi(self)
        self.ui.ctrlList.setColumnCount(2)
        #self.ui.ctrlList.setColumnWidth(0, 200)
        self.ui.ctrlList.setColumnWidth(1, 20)
        self.ui.ctrlList.setVerticalScrollMode(self.ui.ctrlList.ScrollPerPixel)
        self.ui.ctrlList.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        
        self.chartWidget = FlowchartWidget(chart, self)
        #self.chartWidget.viewBox().autoRange()
        self.cwWin = QtGui.QMainWindow()
        self.cwWin.setWindowTitle('Flowchart')
        self.cwWin.setCentralWidget(self.chartWidget)
        self.cwWin.resize(1000,800)
        
        h = self.ui.ctrlList.header()
        h.setResizeMode(0, h.Stretch)
        
        self.ui.ctrlList.itemChanged.connect(self.itemChanged)
        self.ui.loadBtn.clicked.connect(self.loadClicked)
        self.ui.saveBtn.clicked.connect(self.saveClicked)
        self.ui.saveAsBtn.clicked.connect(self.saveAsClicked)
        self.ui.showChartBtn.toggled.connect(self.chartToggled)
        self.chart.sigFileLoaded.connect(self.setCurrentFile)
        self.ui.reloadBtn.clicked.connect(self.reloadClicked)
        self.chart.sigFileSaved.connect(self.fileSaved)
        
    
        
    #def resizeEvent(self, ev):
        #QtGui.QWidget.resizeEvent(self, ev)
        #self.ui.ctrlList.setColumnWidth(0, self.ui.ctrlList.viewport().width()-20)
        
    def chartToggled(self, b):
        if b:
            self.cwWin.show()
        else:
            self.cwWin.hide()

    def reloadClicked(self):
        try:
            self.chartWidget.reloadLibrary()
            self.ui.reloadBtn.success("Reloaded.")
        except:
            self.ui.reloadBtn.success("Error.")
            raise
            
            
    def loadClicked(self):
        newFile = self.chart.loadFile()
        #self.setCurrentFile(newFile)
        
    def fileSaved(self, fileName):
        self.setCurrentFile(fileName)
        self.ui.saveBtn.success("Saved.")
        
    def saveClicked(self):
        if self.currentFileName is None:
            self.saveAsClicked()
        else:
            try:
                self.chart.saveFile(self.currentFileName)
                #self.ui.saveBtn.success("Saved.")
            except:
                self.ui.saveBtn.failure("Error")
                raise
        
    def saveAsClicked(self):
        try:
            if self.currentFileName is None:
                newFile = self.chart.saveFile()
            else:
                newFile = self.chart.saveFile(suggestedFileName=self.currentFileName)
            #self.ui.saveAsBtn.success("Saved.")
            #print "Back to saveAsClicked."
        except:
            self.ui.saveBtn.failure("Error")
            raise
            
        #self.setCurrentFile(newFile)
            
    def setCurrentFile(self, fileName):
        self.currentFileName = fileName
        if fileName is None:
            self.ui.fileNameLabel.setText("<b>[ new ]</b>")
        else:
            self.ui.fileNameLabel.setText("<b>%s</b>" % os.path.split(self.currentFileName)[1])
        self.resizeEvent(None)

    def itemChanged(self, *args):
        pass
    
    def scene(self):
        return self.chartWidget.scene() ## returns the GraphicsScene object
    
    def viewBox(self):
        return self.chartWidget.viewBox()

    def nodeRenamed(self, node, oldName):
        self.items[node].setText(0, node.name())

    def addNode(self, node):
        ctrl = node.ctrlWidget()
        #if ctrl is None:
            #return
        item = QtGui.QTreeWidgetItem([node.name(), '', ''])
        self.ui.ctrlList.addTopLevelItem(item)
        byp = QtGui.QPushButton('X')
        byp.setCheckable(True)
        byp.setFixedWidth(20)
        item.bypassBtn = byp
        self.ui.ctrlList.setItemWidget(item, 1, byp)
        byp.node = node
        node.bypassButton = byp
        byp.setChecked(node.isBypassed())
        byp.clicked.connect(self.bypassClicked)
        
        if ctrl is not None:
            item2 = QtGui.QTreeWidgetItem()
            item.addChild(item2)
            self.ui.ctrlList.setItemWidget(item2, 0, ctrl)
            
        self.items[node] = item
        
    def removeNode(self, node):
        if node in self.items:
            item = self.items[node]
            #self.disconnect(item.bypassBtn, QtCore.SIGNAL('clicked()'), self.bypassClicked)
            try:
                item.bypassBtn.clicked.disconnect(self.bypassClicked)
            except TypeError:
                pass
            self.ui.ctrlList.removeTopLevelItem(item)
            
    def bypassClicked(self):
        btn = QtCore.QObject.sender(self)
        btn.node.bypass(btn.isChecked())
            
    def chartWidget(self):
        return self.chartWidget

    def outputChanged(self, data):
        pass
        #self.ui.outputTree.setData(data, hideRoot=True)

    def clear(self):
        self.chartWidget.clear()
        
    def select(self, node):
        item = self.items[node]
        self.ui.ctrlList.setCurrentItem(item)

class FlowchartWidget(dockarea.DockArea):
    """Includes the actual graphical flowchart and debugging interface"""
    def __init__(self, chart, ctrl):
        #QtGui.QWidget.__init__(self)
        dockarea.DockArea.__init__(self)
        self.chart = chart
        self.ctrl = ctrl
        self.hoverItem = None
        #self.setMinimumWidth(250)
        #self.setSizePolicy(QtGui.QSizePolicy(QtGui.QSizePolicy.Preferred, QtGui.QSizePolicy.Expanding))
        
        #self.ui = FlowchartTemplate.Ui_Form()
        #self.ui.setupUi(self)
        
        ## build user interface (it was easier to do it here than via developer)
        self.view = FlowchartGraphicsView.FlowchartGraphicsView(self)
        self.viewDock = dockarea.Dock('view', size=(1000,600))
        self.viewDock.addWidget(self.view)
        self.viewDock.hideTitleBar()
        self.addDock(self.viewDock)
    

        self.hoverText = QtGui.QTextEdit()
        self.hoverText.setReadOnly(True)
        self.hoverDock = dockarea.Dock('Hover Info', size=(1000,20))
        self.hoverDock.addWidget(self.hoverText)
        self.addDock(self.hoverDock, 'bottom')

        self.selInfo = QtGui.QWidget()
        self.selInfoLayout = QtGui.QGridLayout()
        self.selInfo.setLayout(self.selInfoLayout)
        self.selDescLabel = QtGui.QLabel()
        self.selNameLabel = QtGui.QLabel()
        self.selDescLabel.setWordWrap(True)
        self.selectedTree = pg.DataTreeWidget()
        #self.selectedTree.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAsNeeded)
        #self.selInfoLayout.addWidget(self.selNameLabel)
        self.selInfoLayout.addWidget(self.selDescLabel)
        self.selInfoLayout.addWidget(self.selectedTree)
        self.selDock = dockarea.Dock('Selected Node', size=(1000,200))
        self.selDock.addWidget(self.selInfo)
        self.addDock(self.selDock, 'bottom')
        
        self._scene = self.view.scene()
        self._viewBox = self.view.viewBox()
        #self._scene = QtGui.QGraphicsScene()
        #self._scene = FlowchartGraphicsView.FlowchartGraphicsScene()
        #self.view.setScene(self._scene)
        
        self.buildMenu()
        #self.ui.addNodeBtn.mouseReleaseEvent = self.addNodeBtnReleased
            
        self._scene.selectionChanged.connect(self.selectionChanged)
        self._scene.sigMouseHover.connect(self.hoverOver)
        #self.view.sigClicked.connect(self.showViewMenu)
        #self._scene.sigSceneContextMenu.connect(self.showViewMenu)
        #self._viewBox.sigActionPositionChanged.connect(self.menuPosChanged)
        
        
    def reloadLibrary(self):
        #QtCore.QObject.disconnect(self.nodeMenu, QtCore.SIGNAL('triggered(QAction*)'), self.nodeMenuTriggered)
        self.nodeMenu.triggered.disconnect(self.nodeMenuTriggered)
        self.nodeMenu = None
        self.subMenus = []
        library.loadLibrary(reloadLibs=True)
        self.buildMenu()
        
    def buildMenu(self, pos=None):
        self.nodeMenu = QtGui.QMenu()
        self.subMenus = []
        for section, nodes in library.getNodeTree().iteritems():
            menu = QtGui.QMenu(section)
            self.nodeMenu.addMenu(menu)
            for name in nodes:
                act = menu.addAction(name)
                act.nodeType = name
                act.pos = pos
            self.subMenus.append(menu)
        self.nodeMenu.triggered.connect(self.nodeMenuTriggered)
        return self.nodeMenu
    
    def menuPosChanged(self, pos):
        self.menuPos = pos
    
    def showViewMenu(self, ev):
        #QtGui.QPushButton.mouseReleaseEvent(self.ui.addNodeBtn, ev)
        #if ev.button() == QtCore.Qt.RightButton:
            #self.menuPos = self.view.mapToScene(ev.pos())
            #self.nodeMenu.popup(ev.globalPos())
        #print "Flowchart.showViewMenu called"

        #self.menuPos = ev.scenePos()
        self.buildMenu(ev.scenePos())
        self.nodeMenu.popup(ev.screenPos())
        
    def scene(self):
        return self._scene ## the GraphicsScene item

    def viewBox(self):
        return self._viewBox ## the viewBox that items should be added to

    def nodeMenuTriggered(self, action):
        nodeType = action.nodeType
        if action.pos is not None:
            pos = action.pos
        else:
            pos = self.menuPos
        pos = self.viewBox().mapSceneToView(pos)

        self.chart.createNode(nodeType, pos=pos)


    def selectionChanged(self):
        #print "FlowchartWidget.selectionChanged called."
        items = self._scene.selectedItems()
        #print "     scene.selectedItems: ", items
        if len(items) == 0:
            data = None
        else:
            item = items[0]
            if hasattr(item, 'node') and isinstance(item.node, Node):
                n = item.node
                self.ctrl.select(n)
                data = {'outputs': n.outputValues(), 'inputs': n.inputValues()}
                self.selNameLabel.setText(n.name())
                if hasattr(n, 'nodeName'):
                    self.selDescLabel.setText("<b>%s</b>: %s" % (n.nodeName, n.__class__.__doc__))
                else:
                    self.selDescLabel.setText("")
                if n.exception is not None:
                    data['exception'] = n.exception
            else:
                data = None
        self.selectedTree.setData(data, hideRoot=True)

    def hoverOver(self, items):
        #print "FlowchartWidget.hoverOver called."
        term = None
        for item in items:
            if item is self.hoverItem:
                return
            self.hoverItem = item
            if hasattr(item, 'term') and isinstance(item.term, Terminal):
                term = item.term
                break
        if term is None:
            self.hoverText.setPlainText("")
        else:
            val = term.value()
            if isinstance(val, ndarray):
                val = "%s %s %s" % (type(val).__name__, str(val.shape), str(val.dtype))
            else:
                val = str(val)
                if len(val) > 400:
                    val = val[:400] + "..."
            self.hoverText.setPlainText("%s.%s = %s" % (term.node().name(), term.name(), val))
            #self.hoverLabel.setCursorPosition(0)

    

    def clear(self):
        #self.outputTree.setData(None)
        self.selectedTree.setData(None)
        self.hoverText.setPlainText('')
        self.selNameLabel.setText('')
        self.selDescLabel.setText('')
        
        
class FlowchartNode(Node):
    pass