Source code for pyqtgraph.flowchart.Node

__all__ = ["Node", "NodeGraphicsItem"]

import sys
from collections import OrderedDict

from .. import functions as fn
from ..debug import printExc
from ..graphicsItems.GraphicsObject import GraphicsObject
from ..Qt import QtCore, QtGui, QtWidgets
from .Terminal import Terminal

translate = QtCore.QCoreApplication.translate

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

[docs] class Node(QtCore.QObject): """ Node represents the basic processing unit of a flowchart. A Node subclass implements at least: 1) A list of input / output terminals and their properties 2) a process() function which takes the names of input terminals as keyword arguments and returns a dict with the names of output terminals as keys. A flowchart thus consists of multiple instances of Node subclasses, each of which is connected to other by wires between their terminals. A flowchart is, itself, also a special subclass of Node. This allows Nodes within the flowchart to connect to the input/output nodes of the flowchart itself. Optionally, a node class can implement the ctrlWidget() method, which must return a QWidget (usually containing other widgets) that will be displayed in the flowchart control panel. Some nodes implement fairly complex control widgets, but most nodes follow a simple form-like pattern: a list of parameter names and a single value (represented as spin box, check box, etc..) for each parameter. To make this easier, the CtrlNode subclass allows you to instead define a simple data structure that CtrlNode will use to automatically generate the control widget. """ sigOutputChanged = QtCore.Signal(object) # self sigClosed = QtCore.Signal(object) sigRenamed = QtCore.Signal(object, object) sigTerminalRenamed = QtCore.Signal(object, object) # term, oldName sigTerminalAdded = QtCore.Signal(object, object) # self, term sigTerminalRemoved = QtCore.Signal(object, object) # self, term
[docs] def __init__(self, name, terminals=None, allowAddInput=False, allowAddOutput=False, allowRemove=True): """ ============== ============================================================ **Arguments:** name The name of this specific node instance. It can be any string, but must be unique within a flowchart. Usually, we simply let the flowchart decide on a name when calling Flowchart.addNode(...) terminals Dict-of-dicts specifying the terminals present on this Node. Terminal specifications look like:: 'inputTerminalName': {'io': 'in'} 'outputTerminalName': {'io': 'out'} There are a number of optional parameters for terminals: multi, pos, renamable, removable, multiable, bypass. See the Terminal class for more information. allowAddInput bool; whether the user is allowed to add inputs by the context menu. allowAddOutput bool; whether the user is allowed to add outputs by the context menu. allowRemove bool; whether the user is allowed to remove this node by the context menu. ============== ============================================================ """ QtCore.QObject.__init__(self) self._name = name self._bypass = False self.bypassButton = None ## this will be set by the flowchart ctrl widget.. self._graphicsItem = None self.terminals = OrderedDict() self._inputs = OrderedDict() self._outputs = OrderedDict() self._allowAddInput = allowAddInput ## flags to allow the user to add/remove terminals self._allowAddOutput = allowAddOutput self._allowRemove = allowRemove self.exception = None if terminals is None: return for name, opts in terminals.items(): self.addTerminal(name, **opts)
[docs] def nextTerminalName(self, name): """Return an unused terminal name""" name2 = name i = 1 while name2 in self.terminals: name2 = "%s.%d" % (name, i) i += 1 return name2
[docs] def addInput(self, name="Input", **args): """Add a new input terminal to this Node with the given name. Extra keyword arguments are passed to Terminal.__init__. This is a convenience function that just calls addTerminal(io='in', ...)""" #print "Node.addInput called." return self.addTerminal(name, io='in', **args)
[docs] def addOutput(self, name="Output", **args): """Add a new output terminal to this Node with the given name. Extra keyword arguments are passed to Terminal.__init__. This is a convenience function that just calls addTerminal(io='out', ...)""" return self.addTerminal(name, io='out', **args)
[docs] def removeTerminal(self, term): """Remove the specified terminal from this Node. May specify either the terminal's name or the terminal itself. Causes sigTerminalRemoved to be emitted.""" if isinstance(term, Terminal): name = else: name = term term = self.terminals[name] #print "remove", name #term.disconnectAll() term.close() del self.terminals[name] if name in self._inputs: del self._inputs[name] if name in self._outputs: del self._outputs[name] self.graphicsItem().updateTerminals() self.sigTerminalRemoved.emit(self, term)
[docs] def terminalRenamed(self, term, oldName): """Called after a terminal has been renamed Causes sigTerminalRenamed to be emitted.""" newName = for d in [self.terminals, self._inputs, self._outputs]: if oldName not in d: continue d[newName] = d[oldName] del d[oldName] self.graphicsItem().updateTerminals() self.sigTerminalRenamed.emit(term, oldName)
[docs] def addTerminal(self, name, **opts): """Add a new terminal to this Node with the given name. Extra keyword arguments are passed to Terminal.__init__. Causes sigTerminalAdded to be emitted.""" name = self.nextTerminalName(name) term = Terminal(self, name, **opts) self.terminals[name] = term if term.isInput(): self._inputs[name] = term elif term.isOutput(): self._outputs[name] = term self.graphicsItem().updateTerminals() self.sigTerminalAdded.emit(self, term) return term
[docs] def inputs(self): """Return dict of all input terminals. Warning: do not modify.""" return self._inputs
[docs] def outputs(self): """Return dict of all output terminals. Warning: do not modify.""" return self._outputs
[docs] def process(self, **kargs): """Process data through this node. This method is called any time the flowchart wants the node to process data. It will be called with one keyword argument corresponding to each input terminal, and must return a dict mapping the name of each output terminal to its new value. This method is also called with a 'display' keyword argument, which indicates whether the node should update its display (if it implements any) while processing this data. This is primarily used to disable expensive display operations during batch processing. """ return {}
[docs] def graphicsItem(self): """Return the GraphicsItem for this node. Subclasses may re-implement this method to customize their appearance in the flowchart.""" if self._graphicsItem is None: self._graphicsItem = NodeGraphicsItem(self) return self._graphicsItem
def __getitem__(self, item): #return getattr(self, item) """Return the terminal with the given name""" if item not in self.terminals: raise KeyError(item) else: return self.terminals[item]
[docs] def name(self): """Return the name of this node.""" return self._name
[docs] def rename(self, name): """Rename this node. This will cause sigRenamed to be emitted.""" oldName = self._name self._name = name #self.emit(QtCore.SIGNAL('renamed'), self, oldName) self.sigRenamed.emit(self, oldName)
[docs] def dependentNodes(self): """Return the list of nodes which provide direct input to this node""" nodes = set() for t in self.inputs().values(): nodes |= set([i.node() for i in t.inputTerminals()]) return nodes
#return set([t.inputTerminals().node() for t in self.listInputs().values()]) def __repr__(self): return "<Node %s @%x>" % (, id(self))
[docs] def ctrlWidget(self): """Return this Node's control widget. By default, Nodes have no control widget. Subclasses may reimplement this method to provide a custom widget. This method is called by Flowcharts when they are constructing their Node list.""" return None
[docs] def bypass(self, byp): """Set whether this node should be bypassed. When bypassed, a Node's process() method is never called. In some cases, data is automatically copied directly from specific input nodes to output nodes instead (see the bypass argument to Terminal.__init__). This is usually called when the user disables a node from the flowchart control panel. """ self._bypass = byp if self.bypassButton is not None: self.bypassButton.setChecked(byp) self.update()
[docs] def isBypassed(self): """Return True if this Node is currently bypassed.""" return self._bypass
[docs] def setInput(self, **args): """Set the values on input terminals. For most nodes, this will happen automatically through Terminal.inputChanged. This is normally only used for nodes with no connected inputs.""" changed = False for k, v in args.items(): term = self._inputs[k] oldVal = term.value() if not fn.eq(oldVal, v): changed = True term.setValue(v, process=False) if changed and '_updatesHandled_' not in args: self.update()
[docs] def inputValues(self): """Return a dict of all input values currently assigned to this node.""" vals = {} for n, t in self.inputs().items(): vals[n] = t.value() return vals
[docs] def outputValues(self): """Return a dict of all output values currently generated by this node.""" vals = {} for n, t in self.outputs().items(): vals[n] = t.value() return vals
[docs] def connected(self, localTerm, remoteTerm): """Called whenever one of this node's terminals is connected elsewhere.""" pass
[docs] def disconnected(self, localTerm, remoteTerm): """Called whenever one of this node's terminals is disconnected from another.""" pass
[docs] def update(self, signal=True): """Collect all input values, attempt to process new output values, and propagate downstream. Subclasses should call update() whenever thir internal state has changed (such as when the user interacts with the Node's control widget). Update is automatically called when the inputs to the node are changed. """ vals = self.inputValues() #print " inputs:", vals try: if self.isBypassed(): out = self.processBypassed(vals) else: out = self.process(**strDict(vals)) #print " output:", out if out is not None: if signal: self.setOutput(**out) else: self.setOutputNoSignal(**out) for n,t in self.inputs().items(): t.setValueAcceptable(True) self.clearException() except: #printExc( "Exception while processing %s:" % for n,t in self.outputs().items(): t.setValue(None) self.setException(sys.exc_info()) if signal: #self.emit(QtCore.SIGNAL('outputChanged'), self) ## triggers flowchart to propagate new data self.sigOutputChanged.emit(self) ## triggers flowchart to propagate new data
[docs] def processBypassed(self, args): """Called when the flowchart would normally call Node.process, but this node is currently bypassed. The default implementation looks for output terminals with a bypass connection and returns the corresponding values. Most Node subclasses will _not_ need to reimplement this method.""" result = {} for term in list(self.outputs().values()): byp = term.bypassValue() if byp is None: result[] = None else: result[] = args.get(byp, None) return result
def setOutput(self, **vals): self.setOutputNoSignal(**vals) #self.emit(QtCore.SIGNAL('outputChanged'), self) ## triggers flowchart to propagate new data self.sigOutputChanged.emit(self) ## triggers flowchart to propagate new data def setOutputNoSignal(self, **vals): for k, v in vals.items(): term = self.outputs()[k] term.setValue(v) #targets = term.connections() #for t in targets: ## propagate downstream #if t is term: #continue #t.inputChanged(term) term.setValueAcceptable(True) def setException(self, exc): self.exception = exc self.recolor() def clearException(self): self.setException(None) def recolor(self): if self.exception is None: self.graphicsItem().setPen(QtGui.QPen(QtGui.QColor(0, 0, 0))) else: self.graphicsItem().setPen(QtGui.QPen(QtGui.QColor(150, 0, 0), 3))
[docs] def saveState(self): """Return a dictionary representing the current state of this node (excluding input / output values). This is used for saving/reloading flowcharts. The default implementation returns this Node's position, bypass state, and information about each of its terminals. Subclasses may want to extend this method, adding extra keys to the returned dict.""" pos = self.graphicsItem().pos() state = {'pos': (pos.x(), pos.y()), 'bypass': self.isBypassed()} termsEditable = self._allowAddInput | self._allowAddOutput for term in list(self._inputs.values()) + list(self._outputs.values()): termsEditable |= term._renamable | term._removable | term._multiable if termsEditable: state['terminals'] = self.saveTerminals() return state
[docs] def restoreState(self, state): """Restore the state of this node from a structure previously generated by saveState(). """ pos = state.get('pos', (0,0)) self.graphicsItem().setPos(*pos) self.bypass(state.get('bypass', False)) if 'terminals' in state: self.restoreTerminals(state['terminals'])
def saveTerminals(self): terms = OrderedDict() for n, t in self.terminals.items(): terms[n] = (t.saveState()) return terms def restoreTerminals(self, state): for name in list(self.terminals.keys()): if name not in state: self.removeTerminal(name) for name, opts in state.items(): if name in self.terminals: term = self[name] term.setOpts(**opts) continue try: opts = strDict(opts) self.addTerminal(name, **opts) except: printExc("Error restoring terminal %s (%s):" % (str(name), str(opts))) def clearTerminals(self): for t in self.terminals.values(): t.close() self.terminals = OrderedDict() self._inputs = OrderedDict() self._outputs = OrderedDict()
[docs] def close(self): """Cleans up after the node--removes terminals, graphicsItem, widget""" self.disconnectAll() self.clearTerminals() item = self.graphicsItem() if item.scene() is not None: item.scene().removeItem(item) self._graphicsItem = None w = self.ctrlWidget() if w is not None: w.setParent(None) #self.emit(QtCore.SIGNAL('closed'), self) self.sigClosed.emit(self)
def disconnectAll(self): for t in self.terminals.values(): t.disconnectAll()
class TextItem(QtWidgets.QGraphicsTextItem): def __init__(self, text, parent, on_update): super().__init__(text, parent) self.on_update = on_update def focusOutEvent(self, ev): super().focusOutEvent(ev) if self.on_update is not None: self.on_update() def keyPressEvent(self, ev): if ev.key() == QtCore.Qt.Key.Key_Enter or ev.key() == QtCore.Qt.Key.Key_Return: if self.on_update is not None: self.on_update() return super().keyPressEvent(ev) def mousePressEvent(self, ev): if ev.button() == QtCore.Qt.MouseButton.LeftButton: self.setTextInteractionFlags(QtCore.Qt.TextInteractionFlag.TextEditorInteraction) self.setFocus(QtCore.Qt.FocusReason.MouseFocusReason) # focus text label elif ev.button() == QtCore.Qt.MouseButton.RightButton: self.setTextInteractionFlags(QtCore.Qt.TextInteractionFlag.NoTextInteraction) #class NodeGraphicsItem(QtWidgets.QGraphicsItem): class NodeGraphicsItem(GraphicsObject): def __init__(self, node): #QtWidgets.QGraphicsItem.__init__(self) GraphicsObject.__init__(self) #QObjectWorkaround.__init__(self) #self.shadow = QtWidgets.QGraphicsDropShadowEffect() #self.shadow.setOffset(5,5) #self.shadow.setBlurRadius(10) #self.setGraphicsEffect(self.shadow) self.pen = fn.mkPen(0,0,0) self.selectPen = fn.mkPen(200,200,200,width=2) self.brush = fn.mkBrush(200, 200, 200, 150) self.hoverBrush = fn.mkBrush(200, 200, 200, 200) self.selectBrush = fn.mkBrush(200, 200, 255, 200) self.hovered = False self.node = node flags = self.GraphicsItemFlag.ItemIsMovable | self.GraphicsItemFlag.ItemIsSelectable | self.GraphicsItemFlag.ItemIsFocusable | self.GraphicsItemFlag.ItemSendsGeometryChanges #flags = self.ItemIsFocusable |self.ItemSendsGeometryChanges self.setFlags(flags) self.bounds = QtCore.QRectF(0, 0, 100, 100) self.nameItem = TextItem(, self, self.labelChanged) self.nameItem.setDefaultTextColor(QtGui.QColor(50, 50, 50)) self.nameItem.moveBy(self.bounds.width()/2. - self.nameItem.boundingRect().width()/2., 0) self._titleOffset = 25 self._nodeOffset = 12 self.updateTerminals() #self.setZValue(10) = None self.buildMenu() def setTitleOffset(self, new_offset): """ This method sets the rendering offset introduced after the title of the node. This method automatically updates the terminal labels. The default for this value is 25px. :param new_offset: The new offset to use in pixels at 100% scale. """ self._titleOffset = new_offset self.updateTerminals() def titleOffset(self): """ This method returns the current title offset in use. :returns: The offset in px. """ return self._titleOffset def setTerminalOffset(self, new_offset): """ This method sets the rendering offset introduced after every terminal of the node. This method automatically updates the terminal labels. The default for this value is 12px. :param new_offset: The new offset to use in pixels at 100% scale. """ self._nodeOffset = new_offset self.updateTerminals() def terminalOffset(self): """ This method returns the current terminal offset in use. :returns: The offset in px. """ return self._nodeOffset #self.node.sigTerminalRenamed.connect(self.updateActionMenu) #def setZValue(self, z): #for t, item in self.terminals.values(): #item.setZValue(z+1) #GraphicsObject.setZValue(self, z) def labelChanged(self): newName = self.nameItem.toPlainText() if newName != self.node.rename(newName) ### re-center the label bounds = self.boundingRect() self.nameItem.setPos(bounds.width()/2. - self.nameItem.boundingRect().width()/2., 0) def setPen(self, *args, **kwargs): self.pen = fn.mkPen(*args, **kwargs) self.update() def setBrush(self, brush): self.brush = brush self.update() def updateTerminals(self): self.terminals = {} inp = self.node.inputs() out = self.node.outputs() maxNode = max(len(inp), len(out)) # calculate new height newHeight = self._titleOffset + maxNode*self._nodeOffset # if current height is not equal to new height, update if not self.bounds.height() == newHeight: self.bounds.setHeight(newHeight) self.update() # Populate inputs y = self._titleOffset for i, t in inp.items(): item = t.graphicsItem() item.setParentItem(self) #item.setZValue(self.zValue()+1) item.setAnchor(0, y) self.terminals[i] = (t, item) y += self._nodeOffset # Populate inputs y = self._titleOffset for i, t in out.items(): item = t.graphicsItem() item.setParentItem(self) item.setZValue(self.zValue()) item.setAnchor(self.bounds.width(), y) self.terminals[i] = (t, item) y += self._nodeOffset #self.buildMenu() def boundingRect(self): return self.bounds.adjusted(-5, -5, 5, 5) def paint(self, p, *args): p.setPen(self.pen) if self.isSelected(): p.setPen(self.selectPen) p.setBrush(self.selectBrush) else: p.setPen(self.pen) if self.hovered: p.setBrush(self.hoverBrush) else: p.setBrush(self.brush) p.drawRect(self.bounds) def mousePressEvent(self, ev): ev.ignore() def mouseClickEvent(self, ev): if ev.button() == QtCore.Qt.MouseButton.LeftButton: ev.accept() sel = self.isSelected() self.setSelected(True) if not sel and self.isSelected(): self.update() elif ev.button() == QtCore.Qt.MouseButton.RightButton: ev.accept() self.raiseContextMenu(ev) def mouseDragEvent(self, ev): if ev.button() == QtCore.Qt.MouseButton.LeftButton: ev.accept() self.setPos(self.pos()+self.mapToParent(ev.pos())-self.mapToParent(ev.lastPos())) def hoverEvent(self, ev): if not ev.isExit() and ev.acceptClicks(QtCore.Qt.MouseButton.LeftButton): ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton) self.hovered = True else: self.hovered = False self.update() def keyPressEvent(self, ev): if ev.key() == QtCore.Qt.Key.Key_Delete or ev.key() == QtCore.Qt.Key.Key_Backspace: ev.accept() if not self.node._allowRemove: return self.node.close() else: ev.ignore() def itemChange(self, change, val): if change == self.GraphicsItemChange.ItemPositionHasChanged: for k, t in self.terminals.items(): t[1].nodeMoved() return GraphicsObject.itemChange(self, change, val) def getMenu(self): return def raiseContextMenu(self, ev): menu = self.scene().addParentContextMenus(self, self.getMenu(), ev) pos = ev.screenPos() menu.popup(QtCore.QPoint(int(pos.x()), int(pos.y()))) def buildMenu(self): = QtWidgets.QMenu()"Context Menu", "Node")) a ="Context Menu","Add input"), self.addInputFromMenu) if not self.node._allowAddInput: a.setEnabled(False) a ="Context Menu", "Add output"), self.addOutputFromMenu) if not self.node._allowAddOutput: a.setEnabled(False) a ="Context Menu", "Remove node"), self.node.close) if not self.node._allowRemove: a.setEnabled(False) def addInputFromMenu(self): ## called when add input is clicked in context menu self.node.addInput(renamable=True, removable=True, multiable=True) def addOutputFromMenu(self): ## called when add output is clicked in context menu self.node.addOutput(renamable=True, removable=True, multiable=False)