class LinkCurveItem(QGraphicsPathItem):
"""
Link curve item. The main component of a :class:`LinkItem`.
"""
def __init__(self, parent):
# type: (QGraphicsItem) -> None
super().__init__(parent)
self.setAcceptedMouseButtons(Qt.NoButton)
self.setAcceptHoverEvents(True)
self.__animationEnabled = False
self.__hover = False
self.__enabled = True
self.__shape = None # type: Optional[QPainterPath]
self.__curvepath = QPainterPath()
self.__curvepath_disabled = None # type: Optional[QPainterPath]
self.__pen = self.pen()
self.setPen(QPen(QBrush(QColor("#9CACB4")), 2.0))
self.shadow = QGraphicsDropShadowEffect(blurRadius=5,
color=QColor(SHADOW_COLOR),
offset=QPointF(0, 0))
self.setGraphicsEffect(self.shadow)
self.shadow.setEnabled(False)
self.__blurAnimation = QPropertyAnimation(self.shadow, b"blurRadius")
self.__blurAnimation.setDuration(50)
self.__blurAnimation.finished.connect(self.__on_finished)
def setCurvePath(self, path):
# type: (QPainterPath) -> None
if path != self.__curvepath:
self.prepareGeometryChange()
self.__curvepath = QPainterPath(path)
self.__curvepath_disabled = None
self.__shape = None
self.__update()
def curvePath(self):
# type: () -> QPainterPath
return QPainterPath(self.__curvepath)
def setHoverState(self, state):
# type: (bool) -> None
self.prepareGeometryChange()
self.__hover = state
self.__update()
def setLinkEnabled(self, state):
# type: (bool) -> None
self.prepareGeometryChange()
self.__enabled = state
self.__update()
def isLinkEnabled(self):
# type: () -> bool
return self.__enabled
def setPen(self, pen):
# type: (QPen) -> None
if self.__pen != pen:
self.prepareGeometryChange()
self.__pen = QPen(pen)
self.__shape = None
super().setPen(self.__pen)
def shape(self):
# type: () -> QPainterPath
if self.__shape is None:
path = self.curvePath()
pen = QPen(self.pen())
pen.setWidthF(max(pen.widthF(), 25.0))
pen.setStyle(Qt.SolidLine)
self.__shape = stroke_path(path, pen)
return self.__shape
def setPath(self, path):
# type: (QPainterPath) -> None
self.__shape = None
super().setPath(path)
def setAnimationEnabled(self, enabled):
# type: (bool) -> None
"""
Set the link item animation enabled.
"""
if self.__animationEnabled != enabled:
self.__animationEnabled = enabled
def __update(self):
# type: () -> None
radius = 5 if self.__hover else 0
if radius != 0 and not self.shadow.isEnabled():
self.shadow.setEnabled(True)
if self.__animationEnabled:
if self.__blurAnimation.state() == QPropertyAnimation.Running:
self.__blurAnimation.pause()
self.__blurAnimation.setStartValue(self.shadow.blurRadius())
self.__blurAnimation.setEndValue(radius)
self.__blurAnimation.start()
else:
self.shadow.setBlurRadius(radius)
basecurve = self.__curvepath
link_enabled = self.__enabled
if link_enabled:
path = basecurve
else:
if self.__curvepath_disabled is None:
self.__curvepath_disabled = path_link_disabled(basecurve)
path = self.__curvepath_disabled
self.setPath(path)
def __on_finished(self):
if self.shadow.blurRadius() == 0:
self.shadow.setEnabled(False)
class SplitterResizer(QObject):
"""
An object able to control the size of a widget in a QSplitter instance.
"""
def __init__(self, parent=None, **kwargs):
# type: (Optional[QObject], Any) -> None
super().__init__(parent, **kwargs)
self.__splitter = None # type: Optional[QSplitter]
self.__widget = None # type: Optional[QWidget]
self.__updateOnShow = True # Need __update on next show event
self.__animationEnabled = True
self.__size = -1
self.__expanded = False
self.__animation = QPropertyAnimation(
self, b"size_", self, duration=200
)
self.__action = QAction("toggle-expanded", self, checkable=True)
self.__action.triggered[bool].connect(self.setExpanded)
def setSize(self, size):
# type: (int) -> None
"""
Set the size of the controlled widget (either width or height
depending on the orientation).
.. note::
The controlled widget's size is only updated when it it is shown.
"""
if self.__size != size:
self.__size = size
self.__update()
def size(self):
# type: () -> int
"""
Return the size of the widget in the splitter (either height of
width) depending on the splitter orientation.
"""
if self.__splitter and self.__widget:
index = self.__splitter.indexOf(self.__widget)
sizes = self.__splitter.sizes()
return sizes[index]
else:
return -1
size_ = Property(int, fget=size, fset=setSize)
def setAnimationEnabled(self, enable):
# type: (bool) -> None
"""Enable/disable animation."""
self.__animation.setDuration(0 if enable else 200)
def animationEnabled(self):
# type: () -> bool
return self.__animation.duration() == 0
def setSplitterAndWidget(self, splitter, widget):
# type: (QSplitter, QWidget) -> None
"""Set the QSplitter and QWidget instance the resizer should control.
.. note:: the widget must be in the splitter.
"""
if splitter and widget and not splitter.indexOf(widget) > 0:
raise ValueError("Widget must be in a splitter.")
if self.__widget is not None:
self.__widget.removeEventFilter(self)
if self.__splitter is not None:
self.__splitter.removeEventFilter(self)
self.__splitter = splitter
self.__widget = widget
if widget is not None:
widget.installEventFilter(self)
if splitter is not None:
splitter.installEventFilter(self)
self.__update()
size = self.size()
if self.__expanded and size == 0:
self.open()
elif not self.__expanded and size > 0:
self.close()
def toggleExpandedAction(self):
# type: () -> QAction
"""Return a QAction that can be used to toggle expanded state.
"""
return self.__action
def toogleExpandedAction(self):
warnings.warn(
"'toogleExpandedAction is deprecated, use 'toggleExpandedAction' "
"instead.", DeprecationWarning, stacklevel=2
)
return self.toggleExpandedAction()
def open(self):
# type: () -> None
"""Open the controlled widget (expand it to sizeHint).
"""
self.__expanded = True
self.__action.setChecked(True)
if self.__splitter is None or self.__widget is None:
return
hint = self.__widget.sizeHint()
if self.__splitter.orientation() == Qt.Vertical:
end = hint.height()
else:
end = hint.width()
self.__animation.setStartValue(0)
self.__animation.setEndValue(end)
self.__animation.start()
def close(self):
# type: () -> None
"""Close the controlled widget (shrink to size 0).
"""
self.__expanded = False
self.__action.setChecked(False)
if self.__splitter is None or self.__widget is None:
return
self.__animation.setStartValue(self.size())
self.__animation.setEndValue(0)
self.__animation.start()
def setExpanded(self, expanded):
# type: (bool) -> None
"""Set the expanded state."""
if self.__expanded != expanded:
if expanded:
self.open()
else:
self.close()
def expanded(self):
# type: () -> bool
"""Return the expanded state."""
return self.__expanded
def __update(self):
# type: () -> None
"""Update the splitter sizes."""
if self.__splitter and self.__widget:
if sum(self.__splitter.sizes()) == 0:
# schedule update on next show event
self.__updateOnShow = True
return
splitter = self.__splitter
index = splitter.indexOf(self.__widget)
sizes = splitter.sizes()
current = sizes[index]
diff = current - self.__size
sizes[index] = self.__size
sizes[index - 1] = sizes[index - 1] + diff
self.__splitter.setSizes(sizes)
def eventFilter(self, obj, event):
# type: (QObject, QEvent) -> bool
if event.type() == QEvent.Resize and obj is self.__widget and \
self.__animation.state() == QPropertyAnimation.Stopped:
# Update the expanded state when the user opens/closes the widget
# by dragging the splitter handle.
assert self.__splitter is not None
assert isinstance(event, QResizeEvent)
if self.__splitter.orientation() == Qt.Vertical:
size = event.size().height()
else:
size = event.size().width()
if self.__expanded and size == 0:
self.__action.setChecked(False)
self.__expanded = False
elif not self.__expanded and size > 0:
self.__action.setChecked(True)
self.__expanded = True
if event.type() == QEvent.Show and obj is self.__splitter and \
self.__updateOnShow:
# Update the splitter state after receiving valid geometry
self.__updateOnShow = False
self.__update()
return super().eventFilter(obj, event)
class NodeBodyItem(GraphicsPathObject):
"""
The central part (body) of the `NodeItem`.
"""
def __init__(self, parent=None):
GraphicsPathObject.__init__(self, parent)
assert (isinstance(parent, NodeItem))
self.__processingState = 0
self.__progress = -1
self.__animationEnabled = False
self.__isSelected = False
self.__hasFocus = False
self.__hover = False
self.__shapeRect = QRectF(-10, -10, 20, 20)
self.setAcceptHoverEvents(True)
self.setFlag(QGraphicsItem.ItemSendsScenePositionChanges, True)
self.setFlag(QGraphicsItem.ItemSendsGeometryChanges, True)
self.setPen(QPen(Qt.NoPen))
self.setPalette(default_palette())
self.shadow = QGraphicsDropShadowEffect(
blurRadius=3,
color=QColor(SHADOW_COLOR),
offset=QPointF(0, 0),
)
self.shadow.setEnabled(True)
# An item with the same shape as this object, stacked behind this
# item as a source for QGraphicsDropShadowEffect. Cannot attach
# the effect to this item directly as QGraphicsEffect makes the item
# non devicePixelRatio aware.
shadowitem = GraphicsPathObject(self, objectName="shadow-shape-item")
shadowitem.setPen(Qt.NoPen)
shadowitem.setBrush(QBrush(QColor(SHADOW_COLOR).lighter()))
shadowitem.setGraphicsEffect(self.shadow)
shadowitem.setFlag(QGraphicsItem.ItemStacksBehindParent)
self.__shadow = shadowitem
self.__blurAnimation = QPropertyAnimation(self.shadow, b"blurRadius",
self)
self.__blurAnimation.setDuration(100)
self.__blurAnimation.finished.connect(self.__on_finished)
self.__pingAnimation = QPropertyAnimation(self, b"scale", self)
self.__pingAnimation.setDuration(250)
self.__pingAnimation.setKeyValues([(0.0, 1.0), (0.5, 1.1), (1.0, 1.0)])
# TODO: The body item should allow the setting of arbitrary painter
# paths (for instance rounded rect, ...)
def setShapeRect(self, rect):
"""
Set the item's shape `rect`. The item should be confined within
this rect.
"""
path = QPainterPath()
path.addEllipse(rect)
self.setPath(path)
self.__shadow.setPath(path)
self.__shapeRect = rect
def setPalette(self, palette):
"""
Set the body color palette (:class:`QPalette`).
"""
self.palette = palette
self.__updateBrush()
def setAnimationEnabled(self, enabled):
"""
Set the node animation enabled.
"""
if self.__animationEnabled != enabled:
self.__animationEnabled = enabled
def setProcessingState(self, state):
"""
Set the processing state of the node.
"""
if self.__processingState != state:
self.__processingState = state
if not state and self.__animationEnabled:
self.ping()
def setProgress(self, progress):
"""
Set the progress indicator state of the node. `progress` should
be a number between 0 and 100.
"""
self.__progress = progress
self.update()
def ping(self):
"""
Trigger a 'ping' animation.
"""
animation_restart(self.__pingAnimation)
def hoverEnterEvent(self, event):
self.__hover = True
self.__updateShadowState()
return GraphicsPathObject.hoverEnterEvent(self, event)
def hoverLeaveEvent(self, event):
self.__hover = False
self.__updateShadowState()
return GraphicsPathObject.hoverLeaveEvent(self, event)
def paint(self, painter, option, widget):
"""
Paint the shape and a progress meter.
"""
# Let the default implementation draw the shape
if option.state & QStyle.State_Selected:
# Prevent the default bounding rect selection indicator.
option.state = option.state ^ QStyle.State_Selected
GraphicsPathObject.paint(self, painter, option, widget)
if self.__progress >= 0:
# Draw the progress meter over the shape.
# Set the clip to shape so the meter does not overflow the shape.
painter.save()
painter.setClipPath(self.shape(), Qt.ReplaceClip)
color = self.palette.color(QPalette.ButtonText)
pen = QPen(color, 5)
painter.setPen(pen)
painter.setRenderHints(QPainter.Antialiasing)
span = max(1, int(self.__progress * 57.60))
painter.drawArc(self.__shapeRect, 90 * 16, -span)
painter.restore()
def __updateShadowState(self):
if self.__hasFocus:
color = QColor(FOCUS_OUTLINE_COLOR)
self.setPen(QPen(color, 1.5))
else:
self.setPen(QPen(Qt.NoPen))
radius = 3
enabled = False
if self.__isSelected:
enabled = True
radius = 7
if self.__hover:
radius = 17
enabled = True
if enabled and not self.shadow.isEnabled():
self.shadow.setEnabled(enabled)
if self.__animationEnabled:
if self.__blurAnimation.state() == QPropertyAnimation.Running:
self.__blurAnimation.pause()
self.__blurAnimation.setStartValue(self.shadow.blurRadius())
self.__blurAnimation.setEndValue(radius)
self.__blurAnimation.start()
else:
self.shadow.setBlurRadius(radius)
def __updateBrush(self):
palette = self.palette
if self.__isSelected:
cg = QPalette.Active
else:
cg = QPalette.Inactive
palette.setCurrentColorGroup(cg)
c1 = palette.color(QPalette.Light)
c2 = palette.color(QPalette.Button)
grad = radial_gradient(c2, c1)
self.setBrush(QBrush(grad))
# TODO: The selected and focus states should be set using the
# QStyle flags (State_Selected. State_HasFocus)
def setSelected(self, selected):
"""
Set the `selected` state.
.. note:: The item does not have `QGraphicsItem.ItemIsSelectable` flag.
This property is instead controlled by the parent NodeItem.
"""
self.__isSelected = selected
self.__updateBrush()
def setHasFocus(self, focus):
"""
Set the `has focus` state.
.. note:: The item does not have `QGraphicsItem.ItemIsFocusable` flag.
This property is instead controlled by the parent NodeItem.
"""
self.__hasFocus = focus
self.__updateShadowState()
def __on_finished(self):
if self.shadow.blurRadius() == 0:
self.shadow.setEnabled(False)
class NodeBodyItem(GraphicsPathObject):
"""
The central part (body) of the `NodeItem`.
"""
def __init__(self, parent=None):
GraphicsPathObject.__init__(self, parent)
assert isinstance(parent, NodeItem)
self.__processingState = 0
self.__progress = -1
self.__animationEnabled = False
self.__isSelected = False
self.__hasFocus = False
self.__hover = False
self.__shapeRect = QRectF(-10, -10, 20, 20)
self.setAcceptHoverEvents(True)
self.setFlag(QGraphicsItem.ItemSendsScenePositionChanges, True)
self.setFlag(QGraphicsItem.ItemSendsGeometryChanges, True)
self.setPen(QPen(Qt.NoPen))
self.setPalette(default_palette())
self.shadow = QGraphicsDropShadowEffect(
blurRadius=3,
color=QColor(SHADOW_COLOR),
offset=QPointF(0, 0),
)
self.shadow.setEnabled(True)
# An item with the same shape as this object, stacked behind this
# item as a source for QGraphicsDropShadowEffect. Cannot attach
# the effect to this item directly as QGraphicsEffect makes the item
# non devicePixelRatio aware.
shadowitem = GraphicsPathObject(self, objectName="shadow-shape-item")
shadowitem.setPen(Qt.NoPen)
shadowitem.setBrush(QBrush(QColor(SHADOW_COLOR).lighter()))
shadowitem.setGraphicsEffect(self.shadow)
shadowitem.setFlag(QGraphicsItem.ItemStacksBehindParent)
self.__shadow = shadowitem
self.__blurAnimation = QPropertyAnimation(self.shadow, b"blurRadius",
self)
self.__blurAnimation.setDuration(100)
self.__blurAnimation.finished.connect(self.__on_finished)
self.__pingAnimation = QPropertyAnimation(self, b"scale", self)
self.__pingAnimation.setDuration(250)
self.__pingAnimation.setKeyValues([(0.0, 1.0), (0.5, 1.1), (1.0, 1.0)])
# TODO: The body item should allow the setting of arbitrary painter
# paths (for instance rounded rect, ...)
def setShapeRect(self, rect):
"""
Set the item's shape `rect`. The item should be confined within
this rect.
"""
path = QPainterPath()
path.addEllipse(rect)
self.setPath(path)
self.__shadow.setPath(path)
self.__shapeRect = rect
def setPalette(self, palette):
"""
Set the body color palette (:class:`QPalette`).
"""
self.palette = palette
self.__updateBrush()
def setAnimationEnabled(self, enabled):
"""
Set the node animation enabled.
"""
if self.__animationEnabled != enabled:
self.__animationEnabled = enabled
def setProcessingState(self, state):
"""
Set the processing state of the node.
"""
if self.__processingState != state:
self.__processingState = state
if not state and self.__animationEnabled:
self.ping()
def setProgress(self, progress):
"""
Set the progress indicator state of the node. `progress` should
be a number between 0 and 100.
"""
self.__progress = progress
self.update()
def ping(self):
"""
Trigger a 'ping' animation.
"""
animation_restart(self.__pingAnimation)
def hoverEnterEvent(self, event):
self.__hover = True
self.__updateShadowState()
return GraphicsPathObject.hoverEnterEvent(self, event)
def hoverLeaveEvent(self, event):
self.__hover = False
self.__updateShadowState()
return GraphicsPathObject.hoverLeaveEvent(self, event)
def paint(self, painter, option, widget):
"""
Paint the shape and a progress meter.
"""
# Let the default implementation draw the shape
if option.state & QStyle.State_Selected:
# Prevent the default bounding rect selection indicator.
option.state = option.state ^ QStyle.State_Selected
GraphicsPathObject.paint(self, painter, option, widget)
if self.__progress >= 0:
# Draw the progress meter over the shape.
# Set the clip to shape so the meter does not overflow the shape.
painter.save()
painter.setClipPath(self.shape(), Qt.ReplaceClip)
color = self.palette.color(QPalette.ButtonText)
pen = QPen(color, 5)
painter.setPen(pen)
painter.setRenderHints(QPainter.Antialiasing)
span = max(1, int(self.__progress * 57.60))
painter.drawArc(self.__shapeRect, 90 * 16, -span)
painter.restore()
def __updateShadowState(self):
if self.__hasFocus:
color = QColor(FOCUS_OUTLINE_COLOR)
self.setPen(QPen(color, 1.5))
else:
self.setPen(QPen(Qt.NoPen))
radius = 3
enabled = False
if self.__isSelected:
enabled = True
radius = 7
if self.__hover:
radius = 17
enabled = True
if enabled and not self.shadow.isEnabled():
self.shadow.setEnabled(enabled)
if self.__animationEnabled:
if self.__blurAnimation.state() == QPropertyAnimation.Running:
self.__blurAnimation.pause()
self.__blurAnimation.setStartValue(self.shadow.blurRadius())
self.__blurAnimation.setEndValue(radius)
self.__blurAnimation.start()
else:
self.shadow.setBlurRadius(radius)
def __updateBrush(self):
palette = self.palette
if self.__isSelected:
cg = QPalette.Active
else:
cg = QPalette.Inactive
palette.setCurrentColorGroup(cg)
c1 = palette.color(QPalette.Light)
c2 = palette.color(QPalette.Button)
grad = radial_gradient(c2, c1)
self.setBrush(QBrush(grad))
# TODO: The selected and focus states should be set using the
# QStyle flags (State_Selected. State_HasFocus)
def setSelected(self, selected):
"""
Set the `selected` state.
.. note:: The item does not have `QGraphicsItem.ItemIsSelectable` flag.
This property is instead controlled by the parent NodeItem.
"""
self.__isSelected = selected
self.__updateBrush()
def setHasFocus(self, focus):
"""
Set the `has focus` state.
.. note:: The item does not have `QGraphicsItem.ItemIsFocusable` flag.
This property is instead controlled by the parent NodeItem.
"""
self.__hasFocus = focus
self.__updateShadowState()
def __on_finished(self):
if self.shadow.blurRadius() == 0:
self.shadow.setEnabled(False)
class SplitterResizer(QObject):
"""
An object able to control the size of a widget in a QSplitter instance.
"""
def __init__(self, parent=None):
super().__init__(parent)
self.__splitter = None
self.__widget = None
self.__updateOnShow = True # Need __update on next show event
self.__animationEnabled = True
self.__size = -1
self.__expanded = False
self.__animation = QPropertyAnimation(
self, b"size_", self, duration=200
)
self.__action = QAction("toogle-expanded", self, checkable=True)
self.__action.triggered[bool].connect(self.setExpanded)
def setSize(self, size):
"""Set the size of the controlled widget (either width or height
depending on the orientation).
.. note::
The controlled widget's size is only updated when it it is shown.
"""
if self.__size != size:
self.__size = size
self.__update()
def size(self):
"""Return the size of the widget in the splitter (either height of
width) depending on the splitter orientation.
"""
if self.__splitter and self.__widget:
index = self.__splitter.indexOf(self.__widget)
sizes = self.__splitter.sizes()
return sizes[index]
else:
return -1
size_ = Property(int, fget=size, fset=setSize)
def setAnimationEnabled(self, enable):
"""Enable/disable animation.
"""
self.__animation.setDuration(0 if enable else 200)
def animationEnabled(self):
return self.__animation.duration() == 0
def setSplitterAndWidget(self, splitter, widget):
"""Set the QSplitter and QWidget instance the resizer should control.
.. note:: the widget must be in the splitter.
"""
if splitter and widget and not splitter.indexOf(widget) > 0:
raise ValueError("Widget must be in a spliter.")
if self.__widget is not None:
self.__widget.removeEventFilter(self)
if self.__splitter is not None:
self.__splitter.removeEventFilter(self)
self.__splitter = splitter
self.__widget = widget
if widget is not None:
widget.installEventFilter(self)
if splitter is not None:
splitter.installEventFilter(self)
self.__update()
size = self.size()
if self.__expanded and size == 0:
self.open()
elif not self.__expanded and size > 0:
self.close()
def toogleExpandedAction(self):
"""Return a QAction that can be used to toggle expanded state.
"""
return self.__action
def open(self):
"""Open the controlled widget (expand it to sizeHint).
"""
self.__expanded = True
self.__action.setChecked(True)
if self.__splitter is None or self.__widget is None:
return
hint = self.__widget.sizeHint()
if self.__splitter.orientation() == Qt.Vertical:
end = hint.height()
else:
end = hint.width()
self.__animation.setStartValue(0)
self.__animation.setEndValue(end)
self.__animation.start()
def close(self):
"""Close the controlled widget (shrink to size 0).
"""
self.__expanded = False
self.__action.setChecked(False)
if self.__splitter is None or self.__widget is None:
return
self.__animation.setStartValue(self.size())
self.__animation.setEndValue(0)
self.__animation.start()
def setExpanded(self, expanded):
"""Set the expanded state.
"""
if self.__expanded != expanded:
if expanded:
self.open()
else:
self.close()
def expanded(self):
"""Return the expanded state.
"""
return self.__expanded
def __update(self):
"""Update the splitter sizes.
"""
if self.__splitter and self.__widget:
if sum(self.__splitter.sizes()) == 0:
# schedule update on next show event
self.__updateOnShow = True
return
splitter = self.__splitter
index = splitter.indexOf(self.__widget)
sizes = splitter.sizes()
current = sizes[index]
diff = current - self.__size
sizes[index] = self.__size
sizes[index - 1] = sizes[index - 1] + diff
self.__splitter.setSizes(sizes)
def eventFilter(self, obj, event):
if event.type() == QEvent.Resize and obj is self.__widget and \
self.__animation.state() == QPropertyAnimation.Stopped:
# Update the expanded state when the user opens/closes the widget
# by dragging the splitter handle.
if self.__splitter.orientation() == Qt.Vertical:
size = event.size().height()
else:
size = event.size().width()
if self.__expanded and size == 0:
self.__action.setChecked(False)
self.__expanded = False
elif not self.__expanded and size > 0:
self.__action.setChecked(True)
self.__expanded = True
if event.type() == QEvent.Show and obj is self.__splitter and \
self.__updateOnShow:
# Update the splitter state after receiving valid geometry
self.__updateOnShow = False
self.__update()
return super().eventFilter(obj, event)
class NodeAnchorItem(GraphicsPathObject):
"""
The left/right widget input/output anchors.
"""
def __init__(self, parent, **kwargs):
# type: (Optional[QGraphicsItem], Any) -> None
super().__init__(parent, **kwargs)
self.__parentNodeItem = None # type: Optional[NodeItem]
self.setAcceptHoverEvents(True)
self.setPen(QPen(Qt.NoPen))
self.normalBrush = QBrush(QColor("#CDD5D9"))
self.normalHoverBrush = QBrush(QColor("#9CACB4"))
self.connectedBrush = self.normalHoverBrush
self.connectedHoverBrush = QBrush(QColor("#959595"))
self.setBrush(self.normalBrush)
self.__animationEnabled = False
self.__hover = False
# Does this item have any anchored links.
self.anchored = False
if isinstance(parent, NodeItem):
self.__parentNodeItem = parent
else:
self.__parentNodeItem = None
self.__anchorPath = QPainterPath()
self.__points = [] # type: List[AnchorPoint]
self.__pointPositions = [] # type: List[float]
self.__fullStroke = QPainterPath()
self.__dottedStroke = QPainterPath()
self.__shape = None # type: Optional[QPainterPath]
self.shadow = QGraphicsDropShadowEffect(
blurRadius=0,
color=QColor(SHADOW_COLOR),
offset=QPointF(0, 0),
)
# self.setGraphicsEffect(self.shadow)
self.shadow.setEnabled(False)
shadowitem = GraphicsPathObject(self, objectName="shadow-shape-item")
shadowitem.setPen(Qt.NoPen)
shadowitem.setBrush(QBrush(QColor(SHADOW_COLOR)))
shadowitem.setGraphicsEffect(self.shadow)
shadowitem.setFlag(QGraphicsItem.ItemStacksBehindParent)
self.__shadow = shadowitem
self.__blurAnimation = QPropertyAnimation(self.shadow, b"blurRadius",
self)
self.__blurAnimation.setDuration(50)
self.__blurAnimation.finished.connect(self.__on_finished)
def parentNodeItem(self):
# type: () -> Optional['NodeItem']
"""
Return a parent :class:`NodeItem` or ``None`` if this anchor's
parent is not a :class:`NodeItem` instance.
"""
return self.__parentNodeItem
def setAnchorPath(self, path):
# type: (QPainterPath) -> None
"""
Set the anchor's curve path as a :class:`QPainterPath`.
"""
self.__anchorPath = QPainterPath(path)
# Create a stroke of the path.
stroke_path = QPainterPathStroker()
stroke_path.setCapStyle(Qt.RoundCap)
# Shape is wider (bigger mouse hit area - should be settable)
stroke_path.setWidth(25)
self.prepareGeometryChange()
self.__shape = stroke_path.createStroke(path)
# The full stroke
stroke_path.setWidth(3)
self.__fullStroke = stroke_path.createStroke(path)
# The dotted stroke (when not connected to anything)
stroke_path.setDashPattern(Qt.DotLine)
self.__dottedStroke = stroke_path.createStroke(path)
if self.anchored:
assert self.__fullStroke is not None
self.setPath(self.__fullStroke)
self.__shadow.setPath(self.__fullStroke)
brush = self.connectedHoverBrush if self.__hover else self.connectedBrush
self.setBrush(brush)
else:
assert self.__dottedStroke is not None
self.setPath(self.__dottedStroke)
self.__shadow.setPath(self.__dottedStroke)
brush = self.normalHoverBrush if self.__hover else self.normalBrush
self.setBrush(brush)
def anchorPath(self):
# type: () -> QPainterPath
"""
Return the anchor path (:class:`QPainterPath`). This is a curve on
which the anchor points lie.
"""
return QPainterPath(self.__anchorPath)
def setAnchored(self, anchored):
# type: (bool) -> None
"""
Set the items anchored state. When ``False`` the item draws it self
with a dotted stroke.
"""
self.anchored = anchored
if anchored:
self.setPath(self.__fullStroke)
self.__shadow.setPath(self.__fullStroke)
hover = self.__hover and len(
self.__points) > 1 # a stylistic choice
brush = self.connectedHoverBrush if hover else self.connectedBrush
self.setBrush(brush)
else:
self.setPath(self.__dottedStroke)
self.__shadow.setPath(self.__dottedStroke)
brush = self.normalHoverBrush if self.__hover else self.normalBrush
self.setBrush(brush)
def setConnectionHint(self, hint=None):
"""
Set the connection hint. This can be used to indicate if
a connection can be made or not.
"""
raise NotImplementedError
def count(self):
# type: () -> int
"""
Return the number of anchor points.
"""
return len(self.__points)
def addAnchor(self, anchor, position=0.5):
# type: (AnchorPoint, float) -> int
"""
Add a new :class:`AnchorPoint` to this item and return it's index.
The `position` specifies where along the `anchorPath` is the new
point inserted.
"""
return self.insertAnchor(self.count(), anchor, position)
def insertAnchor(self, index, anchor, position=0.5):
# type: (int, AnchorPoint, float) -> int
"""
Insert a new :class:`AnchorPoint` at `index`.
See also
--------
NodeAnchorItem.addAnchor
"""
if anchor in self.__points:
raise ValueError("%s already added." % anchor)
self.__points.insert(index, anchor)
self.__pointPositions.insert(index, position)
anchor.setParentItem(self)
anchor.setPos(self.__anchorPath.pointAtPercent(position))
anchor.destroyed.connect(self.__onAnchorDestroyed)
self.__updatePositions()
self.setAnchored(bool(self.__points))
hover = self.__hover and len(self.__points) > 1 # a stylistic choice
anchor.setHoverState(hover)
return index
def removeAnchor(self, anchor):
# type: (AnchorPoint) -> None
"""
Remove and delete the anchor point.
"""
anchor = self.takeAnchor(anchor)
anchor.hide()
anchor.setParentItem(None)
anchor.deleteLater()
def takeAnchor(self, anchor):
# type: (AnchorPoint) -> AnchorPoint
"""
Remove the anchor but don't delete it.
"""
index = self.__points.index(anchor)
del self.__points[index]
del self.__pointPositions[index]
anchor.destroyed.disconnect(self.__onAnchorDestroyed)
self.__updatePositions()
self.setAnchored(bool(self.__points))
return anchor
def __onAnchorDestroyed(self, anchor):
# type: (QObject) -> None
try:
index = self.__points.index(anchor)
except ValueError:
return
del self.__points[index]
del self.__pointPositions[index]
def anchorPoints(self):
# type: () -> List[AnchorPoint]
"""
Return a list of anchor points.
"""
return list(self.__points)
def anchorPoint(self, index):
# type: (int) -> AnchorPoint
"""
Return the anchor point at `index`.
"""
return self.__points[index]
def setAnchorPositions(self, positions):
# type: (Iterable[float]) -> None
"""
Set the anchor positions in percentages (0..1) along the path curve.
"""
if self.__pointPositions != positions:
self.__pointPositions = list(positions)
self.__updatePositions()
def anchorPositions(self):
# type: () -> List[float]
"""
Return the positions of anchor points as a list of floats where
each float is between 0 and 1 and specifies where along the anchor
path does the point lie (0 is at start 1 is at the end).
"""
return list(self.__pointPositions)
def shape(self):
# type: () -> QPainterPath
if self.__shape is not None:
return QPainterPath(self.__shape)
else:
return super().shape()
def boundingRect(self):
if self.__shape is not None:
return self.__shape.controlPointRect()
else:
return GraphicsPathObject.boundingRect(self)
def hoverEnterEvent(self, event):
self.__hover = True
brush = self.connectedHoverBrush if self.anchored else self.normalHoverBrush
self.setBrush(brush)
self.__updateShadowState()
return super().hoverEnterEvent(event)
def hoverLeaveEvent(self, event):
self.__hover = False
brush = self.connectedBrush if self.anchored else self.normalBrush
self.setBrush(brush)
self.__updateShadowState()
return super().hoverLeaveEvent(event)
def setAnimationEnabled(self, enabled):
# type: (bool) -> None
"""
Set the anchor animation enabled.
"""
if self.__animationEnabled != enabled:
self.__animationEnabled = enabled
def __updateShadowState(self):
# type: () -> None
radius = 5 if self.__hover else 0
if radius != 0 and not self.shadow.isEnabled():
self.shadow.setEnabled(True)
if self.__animationEnabled:
if self.__blurAnimation.state() == QPropertyAnimation.Running:
self.__blurAnimation.pause()
self.__blurAnimation.setStartValue(self.shadow.blurRadius())
self.__blurAnimation.setEndValue(radius)
self.__blurAnimation.start()
else:
self.shadow.setBlurRadius(radius)
for anchor in self.anchorPoints():
anchor.setHoverState(self.__hover)
def __updatePositions(self):
# type: () -> None
"""Update anchor points positions.
"""
for point, t in zip(self.__points, self.__pointPositions):
pos = self.__anchorPath.pointAtPercent(t)
point.setPos(pos)
def __on_finished(self):
# type: () -> None
if self.shadow.blurRadius() == 0:
self.shadow.setEnabled(False)
class LinkItem(QGraphicsWidget):
"""
A Link item in the canvas that connects two :class:`.NodeItem`\\s in the
canvas.
The link curve connects two `Anchor` items (see :func:`setSourceItem`
and :func:`setSinkItem`). Once the anchors are set the curve
automatically adjusts its end points whenever the anchors move.
An optional source/sink text item can be displayed above the curve's
central point (:func:`setSourceName`, :func:`setSinkName`)
"""
#: Signal emitted when the item has been activated (double-click)
activated = Signal()
#: Signal emitted the the item's selection state changes.
selectedChanged = Signal(bool)
#: Z value of the item
Z_VALUE = 0
#: Runtime link state value
#: These are pulled from SchemeLink.State for ease of binding to it's
#: state
State = SchemeLink.State
#: The link has no associated state.
NoState = SchemeLink.NoState
#: Link is empty; the source node does not have any value on output
Empty = SchemeLink.Empty
#: Link is active; the source node has a valid value on output
Active = SchemeLink.Active
#: The link is pending; the sink node is scheduled for update
Pending = SchemeLink.Pending
#: The link's input is marked as invalidated (not yet available).
Invalidated = SchemeLink.Invalidated
def __init__(self, parent=None, **kwargs):
# type: (Optional[QGraphicsItem], Any) -> None
self.__boundingRect = None # type: Optional[QRectF]
super().__init__(parent, **kwargs)
self.setAcceptedMouseButtons(Qt.RightButton | Qt.LeftButton)
self.setAcceptHoverEvents(True)
self.__animationEnabled = False
self.setZValue(self.Z_VALUE)
self.sourceItem = None # type: Optional[NodeItem]
self.sourceAnchor = None # type: Optional[AnchorPoint]
self.sinkItem = None # type: Optional[NodeItem]
self.sinkAnchor = None # type: Optional[AnchorPoint]
self.curveItem = LinkCurveItem(self)
self.linkTextItem = GraphicsTextItem(self)
self.linkTextItem.setAcceptedMouseButtons(Qt.NoButton)
self.linkTextItem.setAcceptHoverEvents(False)
self.__sourceName = ""
self.__sinkName = ""
self.__dynamic = False
self.__dynamicEnabled = False
self.__state = LinkItem.NoState
self.__channelNamesVisible = True
self.hover = False
self.channelNameAnim = QPropertyAnimation(self.linkTextItem,
b'opacity', self)
self.channelNameAnim.setDuration(50)
self.prepareGeometryChange()
self.__updatePen()
self.__updatePalette()
self.__updateFont()
def setSourceItem(self, item, signal=None, anchor=None):
# type: (Optional[NodeItem], Optional[OutputSignal], Optional[AnchorPoint]) -> None
"""
Set the source `item` (:class:`.NodeItem`). Use `anchor`
(:class:`.AnchorPoint`) as the curve start point (if ``None`` a new
output anchor will be created using ``item.newOutputAnchor()``).
Setting item to ``None`` and a valid anchor is a valid operation
(for instance while mouse dragging one end of the link).
"""
if item is not None and anchor is not None:
if anchor not in item.outputAnchors():
raise ValueError("Anchor must be belong to the item")
if self.sourceItem != item:
if self.sourceAnchor:
# Remove a previous source item and the corresponding anchor
self.sourceAnchor.scenePositionChanged.disconnect(
self._sourcePosChanged)
if self.sourceItem is not None:
self.sourceItem.removeOutputAnchor(self.sourceAnchor)
self.sourceItem.selectedChanged.disconnect(
self.__updateSelectedState)
self.sourceItem = self.sourceAnchor = None
self.sourceItem = item
if item is not None and anchor is None:
# Create a new output anchor for the item if none is provided.
anchor = item.newOutputAnchor(signal)
if item is not None:
item.selectedChanged.connect(self.__updateSelectedState)
if anchor != self.sourceAnchor:
if self.sourceAnchor is not None:
self.sourceAnchor.scenePositionChanged.disconnect(
self._sourcePosChanged)
self.sourceAnchor = anchor
if self.sourceAnchor is not None:
self.sourceAnchor.scenePositionChanged.connect(
self._sourcePosChanged)
self.__updateCurve()
def setSinkItem(self, item, signal=None, anchor=None):
# type: (Optional[NodeItem], Optional[InputSignal], Optional[AnchorPoint]) -> None
"""
Set the sink `item` (:class:`.NodeItem`). Use `anchor`
(:class:`.AnchorPoint`) as the curve end point (if ``None`` a new
input anchor will be created using ``item.newInputAnchor()``).
Setting item to ``None`` and a valid anchor is a valid operation
(for instance while mouse dragging one and of the link).
"""
if item is not None and anchor is not None:
if anchor not in item.inputAnchors():
raise ValueError("Anchor must be belong to the item")
if self.sinkItem != item:
if self.sinkAnchor:
# Remove a previous source item and the corresponding anchor
self.sinkAnchor.scenePositionChanged.disconnect(
self._sinkPosChanged)
if self.sinkItem is not None:
self.sinkItem.removeInputAnchor(self.sinkAnchor)
self.sinkItem.selectedChanged.disconnect(
self.__updateSelectedState)
self.sinkItem = self.sinkAnchor = None
self.sinkItem = item
if item is not None and anchor is None:
# Create a new input anchor for the item if none is provided.
anchor = item.newInputAnchor(signal)
if item is not None:
item.selectedChanged.connect(self.__updateSelectedState)
if self.sinkAnchor != anchor:
if self.sinkAnchor is not None:
self.sinkAnchor.scenePositionChanged.disconnect(
self._sinkPosChanged)
self.sinkAnchor = anchor
if self.sinkAnchor is not None:
self.sinkAnchor.scenePositionChanged.connect(
self._sinkPosChanged)
self.__updateCurve()
def setChannelNamesVisible(self, visible):
# type: (bool) -> None
"""
Set the visibility of the channel name text.
"""
if self.__channelNamesVisible != visible:
self.__channelNamesVisible = visible
self.__initChannelNameOpacity()
def setSourceName(self, name):
# type: (str) -> None
"""
Set the name of the source (used in channel name text).
"""
if self.__sourceName != name:
self.__sourceName = name
self.__updateText()
def sourceName(self):
# type: () -> str
"""
Return the source name.
"""
return self.__sourceName
def setSinkName(self, name):
# type: (str) -> None
"""
Set the name of the sink (used in channel name text).
"""
if self.__sinkName != name:
self.__sinkName = name
self.__updateText()
def sinkName(self):
# type: () -> str
"""
Return the sink name.
"""
return self.__sinkName
def setAnimationEnabled(self, enabled):
# type: (bool) -> None
"""
Set the link item animation enabled state.
"""
if self.__animationEnabled != enabled:
self.__animationEnabled = enabled
self.curveItem.setAnimationEnabled(enabled)
def _sinkPosChanged(self, *arg):
self.__updateCurve()
def _sourcePosChanged(self, *arg):
self.__updateCurve()
def __updateCurve(self):
# type: () -> None
self.prepareGeometryChange()
self.__boundingRect = None
if self.sourceAnchor and self.sinkAnchor:
source_pos = self.sourceAnchor.anchorScenePos()
sink_pos = self.sinkAnchor.anchorScenePos()
source_pos = self.curveItem.mapFromScene(source_pos)
sink_pos = self.curveItem.mapFromScene(sink_pos)
# Adaptive offset for the curve control points to avoid a
# cusp when the two points have the same y coordinate
# and are close together
delta = source_pos - sink_pos
dist = math.sqrt(delta.x()**2 + delta.y()**2)
cp_offset = min(dist / 2.0, 60.0)
# TODO: make the curve tangent orthogonal to the anchors path.
path = QPainterPath()
path.moveTo(source_pos)
path.cubicTo(source_pos + QPointF(cp_offset, 0),
sink_pos - QPointF(cp_offset, 0), sink_pos)
self.curveItem.setCurvePath(path)
self.__updateText()
else:
self.setHoverState(False)
self.curveItem.setPath(QPainterPath())
def __updateText(self):
# type: () -> None
self.prepareGeometryChange()
self.__boundingRect = None
if self.__sourceName or self.__sinkName:
if self.__sourceName != self.__sinkName:
text = ("<nobr>{0}</nobr> \u2192 <nobr>{1}</nobr>".format(
escape(self.__sourceName), escape(self.__sinkName)))
else:
# If the names are the same show only one.
# Is this right? If the sink has two input channels of the
# same type having the name on the link help elucidate
# the scheme.
text = escape(self.__sourceName)
else:
text = ""
self.linkTextItem.setHtml(
'<div align="center" style="font-size: small" >{0}</div>'.format(
text))
path = self.curveItem.curvePath()
# Constrain the text width if it is too long to fit on a single line
# between the two ends
if not path.isEmpty():
# Use the distance between the start/end points as a measure of
# available space
diff = path.pointAtPercent(0.0) - path.pointAtPercent(1.0)
available_width = math.sqrt(diff.x()**2 + diff.y()**2)
# Get the ideal text width if it was unconstrained
doc = self.linkTextItem.document().clone(self)
doc.setTextWidth(-1)
idealwidth = doc.idealWidth()
doc.deleteLater()
# Constrain the text width but not below a certain min width
minwidth = 100
textwidth = max(minwidth, min(available_width, idealwidth))
self.linkTextItem.setTextWidth(textwidth)
else:
# Reset the fixed width
self.linkTextItem.setTextWidth(-1)
if not path.isEmpty():
center = path.pointAtPercent(0.5)
angle = path.angleAtPercent(0.5)
brect = self.linkTextItem.boundingRect()
transform = QTransform()
transform.translate(center.x(), center.y())
# Rotate text to be on top of link
if 90 <= angle < 270:
transform.rotate(180 - angle)
else:
transform.rotate(-angle)
# Center and move above the curve path.
transform.translate(-brect.width() / 2, -brect.height())
self.linkTextItem.setTransform(transform)
def removeLink(self):
# type: () -> None
self.setSinkItem(None)
self.setSourceItem(None)
self.__updateCurve()
def setHoverState(self, state):
# type: (bool) -> None
if self.hover != state:
self.prepareGeometryChange()
self.__boundingRect = None
self.hover = state
if self.sinkAnchor:
self.sinkAnchor.setHoverState(state)
if self.sourceAnchor:
self.sourceAnchor.setHoverState(state)
self.curveItem.setHoverState(state)
self.__updatePen()
self.__updateChannelNameVisibility()
self.__updateZValue()
def __updateZValue(self):
text_ss = self.linkTextItem.styleState()
if self.hover:
text_ss |= QStyle.State_HasFocus
z = 9999
self.linkTextItem.setParentItem(None)
else:
text_ss &= ~QStyle.State_HasFocus
z = self.Z_VALUE
self.linkTextItem.setParentItem(self)
self.linkTextItem.setZValue(z)
self.linkTextItem.setStyleState(text_ss)
def mouseDoubleClickEvent(self, event):
# type: (QGraphicsSceneMouseEvent) -> None
super().mouseDoubleClickEvent(event)
QTimer.singleShot(0, self.activated.emit)
def hoverEnterEvent(self, event):
# type: (QGraphicsSceneHoverEvent) -> None
# Hover enter event happens when the mouse enters any child object
# but we only want to show the 'hovered' shadow when the mouse
# is over the 'curveItem', so we install self as an event filter
# on the LinkCurveItem and listen to its hover events.
self.curveItem.installSceneEventFilter(self)
return super().hoverEnterEvent(event)
def hoverLeaveEvent(self, event):
# type: (QGraphicsSceneHoverEvent) -> None
# Remove the event filter to prevent unnecessary work in
# scene event filter when not needed
self.curveItem.removeSceneEventFilter(self)
return super().hoverLeaveEvent(event)
def __initChannelNameOpacity(self):
if self.__channelNamesVisible:
self.linkTextItem.setOpacity(1)
else:
self.linkTextItem.setOpacity(0)
def __updateChannelNameVisibility(self):
if self.__channelNamesVisible:
return
enabled = self.hover or self.isSelected() or self.__isSelectedImplicit(
)
targetOpacity = 1 if enabled else 0
if not self.__animationEnabled:
self.linkTextItem.setOpacity(targetOpacity)
else:
if self.channelNameAnim.state() == QPropertyAnimation.Running:
self.channelNameAnim.stop()
self.channelNameAnim.setStartValue(self.linkTextItem.opacity())
self.channelNameAnim.setEndValue(targetOpacity)
self.channelNameAnim.start()
def changeEvent(self, event):
# type: (QEvent) -> None
if event.type() == QEvent.PaletteChange:
self.__updatePalette()
elif event.type() == QEvent.FontChange:
self.__updateFont()
super().changeEvent(event)
def sceneEventFilter(self, obj, event):
# type: (QGraphicsItem, QEvent) -> bool
if obj is self.curveItem:
if event.type() == QEvent.GraphicsSceneHoverEnter:
self.setHoverState(True)
elif event.type() == QEvent.GraphicsSceneHoverLeave:
self.setHoverState(False)
return super().sceneEventFilter(obj, event)
def boundingRect(self):
# type: () -> QRectF
if self.__boundingRect is None:
self.__boundingRect = self.childrenBoundingRect()
return self.__boundingRect
def shape(self):
# type: () -> QPainterPath
return self.curveItem.shape()
def setEnabled(self, enabled):
# type: (bool) -> None
"""
Reimplemented from :class:`QGraphicWidget`
Set link enabled state. When disabled the link is rendered with a
dashed line.
"""
# This getter/setter pair override a property from the base class.
# They should be renamed to e.g. setLinkEnabled/linkEnabled
self.curveItem.setLinkEnabled(enabled)
def isEnabled(self):
# type: () -> bool
return self.curveItem.isLinkEnabled()
def setDynamicEnabled(self, enabled):
# type: (bool) -> None
"""
Set the link's dynamic enabled state.
If the link is `dynamic` it will be rendered in red/green color
respectively depending on the state of the dynamic enabled state.
"""
if self.__dynamicEnabled != enabled:
self.__dynamicEnabled = enabled
if self.__dynamic:
self.__updatePen()
def isDynamicEnabled(self):
# type: () -> bool
"""
Is the link dynamic enabled.
"""
return self.__dynamicEnabled
def setDynamic(self, dynamic):
# type: (bool) -> None
"""
Mark the link as dynamic (i.e. it responds to
:func:`setDynamicEnabled`).
"""
if self.__dynamic != dynamic:
self.__dynamic = dynamic
self.__updatePen()
def isDynamic(self):
# type: () -> bool
"""
Is the link dynamic.
"""
return self.__dynamic
def setRuntimeState(self, state):
# type: (_State) -> None
"""
Style the link appropriate to the LinkItem.State
Parameters
----------
state : LinkItem.State
"""
if self.__state != state:
self.__state = state
self.__updateAnchors()
self.__updatePen()
def runtimeState(self):
# type: () -> _State
return self.__state
def __updatePen(self):
# type: () -> None
self.prepareGeometryChange()
self.__boundingRect = None
if self.__dynamic:
if self.__dynamicEnabled:
color = QColor(0, 150, 0, 150)
else:
color = QColor(150, 0, 0, 150)
normal = QPen(QBrush(color), 2.0)
hover = QPen(QBrush(color.darker(120)), 2.0)
else:
normal = QPen(QBrush(QColor("#9CACB4")), 2.0)
hover = QPen(QBrush(QColor("#959595")), 2.0)
if self.__state & LinkItem.Empty:
pen_style = Qt.DashLine
else:
pen_style = Qt.SolidLine
normal.setStyle(pen_style)
hover.setStyle(pen_style)
if self.hover or self.isSelected():
pen = hover
else:
pen = normal
self.curveItem.setPen(pen)
def __updatePalette(self):
# type: () -> None
self.linkTextItem.setDefaultTextColor(self.palette().color(
QPalette.Text))
def __updateFont(self):
# type: () -> None
font = self.font()
# linkTextItem will be rotated. Hinting causes bad positioning under
# rotation so we prefer to disable it. This is only a hint, on windows
# (DirectWrite engine) vertical hinting is still performed.
font.setHintingPreference(QFont.PreferNoHinting)
self.linkTextItem.setFont(font)
def __updateAnchors(self):
state = QStyle.State(0)
if self.hover:
state |= QStyle.State_MouseOver
if self.isSelected() or self.__isSelectedImplicit():
state |= QStyle.State_Selected
if self.sinkAnchor is not None:
self.sinkAnchor.indicator.setStyleState(state)
self.sinkAnchor.indicator.setLinkState(self.__state)
if self.sourceAnchor is not None:
self.sourceAnchor.indicator.setStyleState(state)
self.sourceAnchor.indicator.setLinkState(self.__state)
def __updateSelectedState(self):
selected = self.isSelected() or self.__isSelectedImplicit()
self.linkTextItem.setSelectionState(selected)
self.__updatePen()
self.__updateAnchors()
self.__updateChannelNameVisibility()
self.curveItem.setSelectionState(selected)
def __isSelectedImplicit(self):
source, sink = self.sourceItem, self.sinkItem
return (source is not None and source.isSelected() and sink is not None
and sink.isSelected())
def itemChange(self, change: QGraphicsItem.GraphicsItemChange,
value: Any) -> Any:
if change == QGraphicsItem.ItemSelectedHasChanged:
self.__updateSelectedState()
self.selectedChanged.emit(value)
return super().itemChange(change, value)
