class PlotSelectionTool(PlotTool):
"""
A tool for selecting a region on a plot.
"""
#: Selection modes
Rect, Lasso = 1, 2
#: Selection was started by the user.
selectionStarted = Signal(QPainterPath)
#: The current selection has been updated
selectionUpdated = Signal(QPainterPath)
#: The selection has finished (user has released the mouse button)
selectionFinished = Signal(QPainterPath)
def __init__(self, parent=None, selectionMode=Rect, **kwargs):
super().__init__(parent, **kwargs)
self.__mode = selectionMode
self.__path = None
self.__item = None
def setSelectionMode(self, mode):
"""
Set the selection mode (rectangular or lasso selection).
Parameters
----------
mode : int
PlotSelectionTool.Rect or PlotSelectionTool.Lasso
"""
assert mode in {PlotSelectionTool.Rect, PlotSelectionTool.Lasso}
if self.__mode != mode:
if self.__path is not None:
self.selectionFinished.emit()
self.__mode = mode
self.__path = None
def selectionMode(self):
"""
Return the current selection mode.
"""
return self.__mode
def selectionShape(self):
"""
Return the current selection shape.
This is the area selected/drawn by the user.
Returns
-------
shape : QPainterPath
The selection shape in view coordinates.
"""
if self.__path is not None:
shape = QPainterPath(self.__path)
shape.closeSubpath()
else:
shape = QPainterPath()
viewbox = self.viewBox()
if viewbox is None:
return QPainterPath()
return viewbox.childGroup.mapFromParent(shape)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
pos = event.pos()
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(pos, pos)
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path = QPainterPath()
self.__path.moveTo(event.pos())
self.selectionStarted.emit(self.selectionShape())
self.__updategraphics()
event.accept()
return True
else:
return False
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(event.buttonDownPos(Qt.LeftButton), event.pos())
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path.lineTo(event.pos())
self.selectionUpdated.emit(self.selectionShape())
self.__updategraphics()
event.accept()
return True
else:
return False
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(event.buttonDownPos(Qt.LeftButton), event.pos())
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path.lineTo(event.pos())
self.selectionFinished.emit(self.selectionShape())
self.__path = QPainterPath()
self.__updategraphics()
event.accept()
return True
else:
return False
def __updategraphics(self):
viewbox = self.viewBox()
if viewbox is None:
return
if self.__path.isEmpty():
if self.__item is not None:
self.__item.setParentItem(None)
viewbox.removeItem(self.__item)
if self.__item.scene():
self.__item.scene().removeItem(self.__item)
self.__item = None
else:
if self.__item is None:
item = QtGui.QGraphicsPathItem()
color = QtGui.QColor(Qt.yellow)
item.setPen(QtGui.QPen(color, 0))
color.setAlpha(50)
item.setBrush(QtGui.QBrush(color))
self.__item = item
viewbox.addItem(item)
self.__item.setPath(self.selectionShape())
class GraphicsPathObject(QGraphicsObject):
"""A QGraphicsObject subclass implementing an interface similar to
QGraphicsPathItem, and also adding a positionChanged() signal
"""
positionChanged = Signal([], ["QPointF"])
def __init__(self, parent=None, **kwargs):
QGraphicsObject.__init__(self, parent, **kwargs)
self.setFlag(QGraphicsObject.ItemSendsGeometryChanges)
self.__path = QPainterPath()
self.__brush = QBrush(Qt.NoBrush)
self.__pen = QPen()
self.__boundingRect = None
def setPath(self, path):
"""Set the items `path` (:class:`QPainterPath`).
"""
if not isinstance(path, QPainterPath):
raise TypeError("%r, 'QPainterPath' expected" % type(path))
if self.__path != path:
self.prepareGeometryChange()
# Need to store a copy of object so the shape can't be mutated
# without properly updating the geometry.
self.__path = QPainterPath(path)
self.__boundingRect = None
self.update()
def path(self):
"""Return the items path.
"""
return QPainterPath(self.__path)
def setBrush(self, brush):
"""Set the items `brush` (:class:`QBrush`)
"""
if not isinstance(brush, QBrush):
brush = QBrush(brush)
if self.__brush != brush:
self.__brush = QBrush(brush)
self.update()
def brush(self):
"""Return the items brush.
"""
return QBrush(self.__brush)
def setPen(self, pen):
"""Set the items outline `pen` (:class:`QPen`).
"""
if not isinstance(pen, QPen):
pen = QPen(pen)
if self.__pen != pen:
self.prepareGeometryChange()
self.__pen = QPen(pen)
self.__boundingRect = None
self.update()
def pen(self):
"""Return the items pen.
"""
return QPen(self.__pen)
def paint(self, painter, option, widget=None):
if self.__path.isEmpty():
return
painter.save()
painter.setPen(self.__pen)
painter.setBrush(self.__brush)
painter.drawPath(self.__path)
painter.restore()
def boundingRect(self):
if self.__boundingRect is None:
br = self.__path.controlPointRect()
pen_w = self.__pen.widthF()
self.__boundingRect = br.adjusted(-pen_w, -pen_w, pen_w, pen_w)
return self.__boundingRect
def shape(self):
return shapeFromPath(self.__path, self.__pen)
def itemChange(self, change, value):
if change == QGraphicsObject.ItemPositionHasChanged:
self.positionChanged.emit()
self.positionChanged[QPointF].emit(value)
return QGraphicsObject.itemChange(self, change, value)
class PlotSelectionTool(PlotTool):
"""
A tool for selecting a region on a plot.
"""
#: Selection modes
Rect, Lasso = 1, 2
#: Selection was started by the user.
selectionStarted = Signal(QPainterPath)
#: The current selection has been updated
selectionUpdated = Signal(QPainterPath)
#: The selection has finished (user has released the mouse button)
selectionFinished = Signal(QPainterPath)
def __init__(self, parent=None, selectionMode=Rect, **kwargs):
super().__init__(parent, **kwargs)
self.__mode = selectionMode
self.__path = None
self.__item = None
def setSelectionMode(self, mode):
"""
Set the selection mode (rectangular or lasso selection).
Parameters
----------
mode : int
PlotSelectionTool.Rect or PlotSelectionTool.Lasso
"""
assert mode in {PlotSelectionTool.Rect, PlotSelectionTool.Lasso}
if self.__mode != mode:
if self.__path is not None:
self.selectionFinished.emit()
self.__mode = mode
self.__path = None
def selectionMode(self):
"""
Return the current selection mode.
"""
return self.__mode
def selectionShape(self):
"""
Return the current selection shape.
This is the area selected/drawn by the user.
Returns
-------
shape : QPainterPath
The selection shape in view coordinates.
"""
if self.__path is not None:
shape = QPainterPath(self.__path)
shape.closeSubpath()
else:
shape = QPainterPath()
viewbox = self.viewBox()
if viewbox is None:
return QPainterPath()
return viewbox.childGroup.mapFromParent(shape)
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
pos = event.pos()
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(pos, pos)
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path = QPainterPath()
self.__path.moveTo(event.pos())
self.selectionStarted.emit(self.selectionShape())
self.__updategraphics()
event.accept()
return True
else:
return False
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(event.buttonDownPos(Qt.LeftButton), event.pos())
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path.lineTo(event.pos())
self.selectionUpdated.emit(self.selectionShape())
self.__updategraphics()
event.accept()
return True
else:
return False
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
if self.__mode == PlotSelectionTool.Rect:
rect = QRectF(event.buttonDownPos(Qt.LeftButton), event.pos())
self.__path = QPainterPath()
self.__path.addRect(rect)
else:
self.__path.lineTo(event.pos())
self.selectionFinished.emit(self.selectionShape())
self.__path = QPainterPath()
self.__updategraphics()
event.accept()
return True
else:
return False
def __updategraphics(self):
viewbox = self.viewBox()
if viewbox is None:
return
if self.__path.isEmpty():
if self.__item is not None:
self.__item.setParentItem(None)
viewbox.removeItem(self.__item)
if self.__item.scene():
self.__item.scene().removeItem(self.__item)
self.__item = None
else:
if self.__item is None:
item = QtGui.QGraphicsPathItem()
color = QtGui.QColor(Qt.yellow)
item.setPen(QtGui.QPen(color, 0))
color.setAlpha(50)
item.setBrush(QtGui.QBrush(color))
self.__item = item
viewbox.addItem(item)
self.__item.setPath(self.selectionShape())
