Source code for pyqtgraph.flowchart.Terminal

__all__ = ["Terminal", "TerminalGraphicsItem"]

import weakref

from .. import functions as fn
from ..graphicsItems.GraphicsObject import GraphicsObject
from ..Point import Point
from ..Qt import QtCore, QtGui, QtWidgets

translate = QtCore.QCoreApplication.translate

[docs] class Terminal(object):
[docs] def __init__(self, node, name, io, optional=False, multi=False, pos=None, renamable=False, removable=False, multiable=False, bypass=None): """ Construct a new terminal. ============== ================================================================================= **Arguments:** node the node to which this terminal belongs name string, the name of the terminal io 'in' or 'out' optional bool, whether the node may process without connection to this terminal multi bool, for inputs: whether this terminal may make multiple connections for outputs: whether this terminal creates a different value for each connection pos [x, y], the position of the terminal within its node's boundaries renamable (bool) Whether the terminal can be renamed by the user removable (bool) Whether the terminal can be removed by the user multiable (bool) Whether the user may toggle the *multi* option for this terminal bypass (str) Name of the terminal from which this terminal's value is derived when the Node is in bypass mode. ============== ================================================================================= """ self._io = io self._optional = optional self._multi = multi self._node = weakref.ref(node) self._name = name self._renamable = renamable self._removable = removable self._multiable = multiable self._connections = {} self._graphicsItem = TerminalGraphicsItem(self, parent=self._node().graphicsItem()) self._bypass = bypass if multi: self._value = {} ## dictionary of terminal:value pairs. else: self._value = None self.valueOk = None self.recolor()
[docs] def value(self, term=None): """Return the value this terminal provides for the connected terminal""" if term is None: return self._value if self.isMultiValue(): return self._value.get(term, None) else: return self._value
def bypassValue(self): return self._bypass
[docs] def setValue(self, val, process=True): """If this is a single-value terminal, val should be a single value. If this is a multi-value terminal, val should be a dict of terminal:value pairs""" if not self.isMultiValue(): if fn.eq(val, self._value): return self._value = val else: if not isinstance(self._value, dict): self._value = {} if val is not None: self._value.update(val) self.setValueAcceptable(None) ## by default, input values are 'unchecked' until Node.update(). if self.isInput() and process: self.node().update() self.recolor()
def setOpts(self, **opts): self._renamable = opts.get('renamable', self._renamable) self._removable = opts.get('removable', self._removable) self._multiable = opts.get('multiable', self._multiable) if 'multi' in opts: self.setMultiValue(opts['multi'])
[docs] def connected(self, term): """Called whenever this terminal has been connected to another. (note--this function is called on both terminals)""" if self.isInput() and term.isOutput(): self.inputChanged(term) if self.isOutput() and self.isMultiValue(): self.node().update() self.node().connected(self, term)
[docs] def disconnected(self, term): """Called whenever this terminal has been disconnected from another. (note--this function is called on both terminals)""" if self.isMultiValue() and term in self._value: del self._value[term] self.node().update() else: if self.isInput(): self.setValue(None) self.node().disconnected(self, term)
[docs] def inputChanged(self, term, process=True): """Called whenever there is a change to the input value to this terminal. It may often be useful to override this function.""" if self.isMultiValue(): self.setValue({term: term.value(self)}, process=process) else: self.setValue(term.value(self), process=process)
[docs] def valueIsAcceptable(self): """Returns True->acceptable None->unknown False->Unacceptable""" return self.valueOk
def setValueAcceptable(self, v=True): self.valueOk = v self.recolor() def connections(self): return self._connections def node(self): return self._node() def isInput(self): return self._io == 'in' def isMultiValue(self): return self._multi
[docs] def setMultiValue(self, multi): """Set whether this is a multi-value terminal.""" self._multi = multi if not multi and len(self.inputTerminals()) > 1: self.disconnectAll() for term in self.inputTerminals(): self.inputChanged(term)
def isOutput(self): return self._io == 'out' def isRenamable(self): return self._renamable def isRemovable(self): return self._removable def isMultiable(self): return self._multiable def name(self): return self._name def graphicsItem(self): return self._graphicsItem def isConnected(self): return len(self.connections()) > 0 def connectedTo(self, term): return term in self.connections() def hasInput(self): for t in self.connections(): if t.isOutput(): return True return False
[docs] def inputTerminals(self): """Return the terminal(s) that give input to this one.""" return [t for t in self.connections() if t.isOutput()]
[docs] def dependentNodes(self): """Return the list of nodes which receive input from this terminal.""" return set([t.node() for t in self.connections() if t.isInput()])
def connectTo(self, term, connectionItem=None): try: if self.connectedTo(term): raise Exception('Already connected') if term is self: raise Exception('Not connecting terminal to self') if term.node() is self.node(): raise Exception("Can't connect to terminal on same node.") for t in [self, term]: if t.isInput() and not t._multi and len(t.connections()) > 0: raise Exception("Cannot connect %s <-> %s: Terminal %s is already connected to %s (and does not allow multiple connections)" % (self, term, t, list(t.connections().keys()))) except: if connectionItem is not None: connectionItem.close() raise if connectionItem is None: connectionItem = ConnectionItem(self.graphicsItem(), term.graphicsItem()) self.graphicsItem().getViewBox().addItem(connectionItem) self._connections[term] = connectionItem term._connections[self] = connectionItem self.recolor() self.connected(term) term.connected(self) return connectionItem def disconnectFrom(self, term): if not self.connectedTo(term): return item = self._connections[term] item.close() del self._connections[term] del term._connections[self] self.recolor() term.recolor() self.disconnected(term) term.disconnected(self) def disconnectAll(self): for t in list(self._connections.keys()): self.disconnectFrom(t) def recolor(self, color=None, recurse=True): if color is None: if not self.isConnected(): ## disconnected terminals are black color = QtGui.QColor(0,0,0) elif self.isInput() and not self.hasInput(): ## input terminal with no connected output terminals color = QtGui.QColor(200,200,0) elif self._value is None or fn.eq(self._value, {}): ## terminal is connected but has no data (possibly due to processing error) color = QtGui.QColor(255,255,255) elif self.valueIsAcceptable() is None: ## terminal has data, but it is unknown if the data is ok color = QtGui.QColor(200, 200, 0) elif self.valueIsAcceptable() is True: ## terminal has good input, all ok color = QtGui.QColor(0, 200, 0) else: ## terminal has bad input color = QtGui.QColor(200, 0, 0) self.graphicsItem().setBrush(QtGui.QBrush(color)) if recurse: for t in self.connections(): t.recolor(color, recurse=False) def rename(self, name): oldName = self._name self._name = name self.node().terminalRenamed(self, oldName) self.graphicsItem().termRenamed(name) def __repr__(self): return "<Terminal %s.%s>" % (str(self.node().name()), str( def __hash__(self): return id(self) def close(self): self.disconnectAll() item = self.graphicsItem() if item.scene() is not None: item.scene().removeItem(item) def saveState(self): return {'io': self._io, 'multi': self._multi, 'optional': self._optional, 'renamable': self._renamable, 'removable': self._removable, 'multiable': self._multiable} def __lt__(self, other): """When the terminal is multi value, the data passed to the DatTreeWidget for each input or output, is {Terminal: value}. To make this sortable, we provide the < operator. """ return self._name < other._name
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) class TerminalGraphicsItem(GraphicsObject): def __init__(self, term, parent=None): self.term = term GraphicsObject.__init__(self, parent) self.brush = fn.mkBrush(0,0,0) = QtWidgets.QGraphicsRectItem(0, 0, 10, 10, self) on_update = self.labelChanged if self.term.isRenamable() else None self.label = TextItem(, self, on_update) self.label.setScale(0.7) self.newConnection = None self.setFiltersChildEvents(True) ## to pick up mouse events on the rectitem if self.term.isRenamable(): self.label.setTextInteractionFlags(QtCore.Qt.TextInteractionFlag.TextEditorInteraction) self.setZValue(1) = None def labelChanged(self): newName = self.label.toPlainText() if newName != self.term.rename(newName) def termRenamed(self, name): self.label.setPlainText(name) def setBrush(self, brush): self.brush = brush def disconnect(self, target): self.term.disconnectFrom(target.term) def boundingRect(self): br = lr = self.label.mapRectToParent(self.label.boundingRect()) return br | lr def paint(self, p, *args): pass def setAnchor(self, x, y): pos = QtCore.QPointF(x, y) self.anchorPos = pos br = lr = self.label.mapRectToParent(self.label.boundingRect()) if self.term.isInput():, pos.y()-br.height()/2.) self.label.setPos(pos.x() + br.width(), pos.y() - lr.height()/2.) else:, pos.y()-br.height()/2.) self.label.setPos(pos.x()-br.width()-lr.width(), pos.y()-lr.height()/2.) self.updateConnections() def updateConnections(self): for t, c in self.term.connections().items(): c.updateLine() def mousePressEvent(self, ev): #ev.accept() ev.ignore() ## necessary to allow click/drag events to process correctly def mouseClickEvent(self, ev): if ev.button() == QtCore.Qt.MouseButton.LeftButton: ev.accept() self.label.setFocus(QtCore.Qt.FocusReason.MouseFocusReason) elif ev.button() == QtCore.Qt.MouseButton.RightButton: ev.accept() self.raiseContextMenu(ev) def raiseContextMenu(self, ev): ## only raise menu if this terminal is removable menu = self.getMenu() menu = self.scene().addParentContextMenus(self, menu, ev) pos = ev.screenPos() menu.popup(QtCore.QPoint(int(pos.x()), int(pos.y()))) def getMenu(self): if is None: = QtWidgets.QMenu()"Context Menu", "Terminal")) remAct = QtGui.QAction(translate("Context Menu", "Remove terminal"), remAct.triggered.connect(self.removeSelf) = remAct if not self.term.isRemovable(): remAct.setEnabled(False) multiAct = QtGui.QAction(translate("Context Menu", "Multi-value"), multiAct.setCheckable(True) multiAct.setChecked(self.term.isMultiValue()) multiAct.setEnabled(self.term.isMultiable()) multiAct.triggered.connect(self.toggleMulti) = multiAct if self.term.isMultiable(): multiAct.setEnabled = False return def toggleMulti(self): multi = self.term.setMultiValue(multi) def removeSelf(self): self.term.node().removeTerminal(self.term) def mouseDragEvent(self, ev): if ev.button() != QtCore.Qt.MouseButton.LeftButton: ev.ignore() return ev.accept() if ev.isStart(): if self.newConnection is None: self.newConnection = ConnectionItem(self) #self.scene().addItem(self.newConnection) self.getViewBox().addItem(self.newConnection) #self.newConnection.setParentItem(self.parent().parent()) self.newConnection.setTarget(self.mapToView(ev.pos())) elif ev.isFinish(): if self.newConnection is not None: items = self.scene().items(ev.scenePos()) gotTarget = False for i in items: if isinstance(i, TerminalGraphicsItem): self.newConnection.setTarget(i) try: self.term.connectTo(i.term, self.newConnection) gotTarget = True except: self.scene().removeItem(self.newConnection) self.newConnection = None raise break if not gotTarget: self.newConnection.close() self.newConnection = None else: if self.newConnection is not None: self.newConnection.setTarget(self.mapToView(ev.pos())) def hoverEvent(self, ev): if not ev.isExit() and ev.acceptDrags(QtCore.Qt.MouseButton.LeftButton): ev.acceptClicks(QtCore.Qt.MouseButton.LeftButton) ## we don't use the click, but we also don't want anyone else to use it. ev.acceptClicks(QtCore.Qt.MouseButton.RightButton)'w')) else: self.update() def connectPoint(self): ## return the connect position of this terminal in view coords return self.mapToView(self.mapFromItem(, def nodeMoved(self): for t, item in self.term.connections().items(): item.updateLine() class ConnectionItem(GraphicsObject): def __init__(self, source, target=None): GraphicsObject.__init__(self) self.setFlags( self.GraphicsItemFlag.ItemIsSelectable | self.GraphicsItemFlag.ItemIsFocusable ) self.source = source = target self.length = 0 self.hovered = False self.path = None self.shapePath = None = { 'shape': 'line', 'color': (100, 100, 250), 'width': 1.0, 'hoverColor': (150, 150, 250), 'hoverWidth': 1.0, 'selectedColor': (200, 200, 0), 'selectedWidth': 3.0, } self.source.getViewBox().addItem(self) self.updateLine() self.setZValue(0) def close(self): if self.scene() is not None: self.scene().removeItem(self) def setTarget(self, target): = target self.updateLine() def setStyle(self, **kwds): if 'shape' in kwds: self.updateLine() else: self.update() def updateLine(self): start = Point(self.source.connectPoint()) if isinstance(, TerminalGraphicsItem): stop = Point( elif isinstance(, QtCore.QPointF): stop = Point( else: return self.prepareGeometryChange() self.path = self.generatePath(start, stop) self.shapePath = None self.update() def generatePath(self, start, stop): path = QtGui.QPainterPath() path.moveTo(start) if['shape'] == 'line': path.lineTo(stop) elif['shape'] == 'cubic': path.cubicTo(Point(stop.x(), start.y()), Point(start.x(), stop.y()), Point(stop.x(), stop.y())) else: raise Exception('Invalid shape "%s"; options are "line" or "cubic"' %['shape']) return path def keyPressEvent(self, ev): if not self.isSelected(): ev.ignore() return if ev.key() == QtCore.Qt.Key.Key_Delete or ev.key() == QtCore.Qt.Key.Key_Backspace: self.source.disconnect( ev.accept() else: ev.ignore() 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) self.setFocus() if not sel and self.isSelected(): self.update() def hoverEvent(self, ev): if (not ev.isExit()) and ev.acceptClicks(QtCore.Qt.MouseButton.LeftButton): self.hovered = True else: self.hovered = False self.update() def boundingRect(self): return self.shape().boundingRect() def viewRangeChanged(self): self.shapePath = None self.prepareGeometryChange() def shape(self): if self.shapePath is None: if self.path is None: return QtGui.QPainterPath() stroker = QtGui.QPainterPathStroker() px = self.pixelWidth() stroker.setWidth(px*8) self.shapePath = stroker.createStroke(self.path) return self.shapePath def paint(self, p, *args): if self.isSelected(): p.setPen(fn.mkPen(['selectedColor'],['selectedWidth'])) else: if self.hovered: p.setPen(fn.mkPen(['hoverColor'],['hoverWidth'])) else: p.setPen(fn.mkPen(['color'],['width'])) p.drawPath(self.path)