Source code for pyqtgraph.graphicsItems.ArrowItem

from math import hypot

from .. import functions as fn
from ..Qt import QtGui, QtWidgets

__all__ = ['ArrowItem']

[docs] class ArrowItem(QtWidgets.QGraphicsPathItem): """ For displaying scale-invariant arrows. For arrows pointing to a location on a curve, see CurveArrow """
[docs] def __init__(self, parent=None, **opts): """ Arrows can be initialized with any keyword arguments accepted by the setStyle() method. """ self.opts = {} QtWidgets.QGraphicsPathItem.__init__(self, parent) if 'size' in opts: opts['headLen'] = opts['size'] if 'width' in opts: opts['headWidth'] = opts['width'] pos = opts.pop('pos', (0, 0)) defaultOpts = { 'pxMode': True, 'angle': -150, ## If the angle is 0, the arrow points left 'headLen': 20, 'headWidth': None, 'tipAngle': 25, 'baseAngle': 0, 'tailLen': None, 'tailWidth': 3, 'pen': (200,200,200), 'brush': (50,50,200), } defaultOpts.update(opts) self.setStyle(**defaultOpts) # for backward compatibility self.setPos(*pos)
[docs] def setStyle(self, **opts): """ Changes the appearance of the arrow. All arguments are optional: ====================== ================================================= **Keyword Arguments:** angle Orientation of the arrow in degrees. Default is 0; arrow pointing to the left. headLen Length of the arrow head, from tip to base. default=20 headWidth Width of the arrow head at its base. If headWidth is specified, it overrides tipAngle. tipAngle Angle of the tip of the arrow in degrees. Smaller values make a 'sharper' arrow. default=25 baseAngle Angle of the base of the arrow head. Default is 0, which means that the base of the arrow head is perpendicular to the arrow tail. tailLen Length of the arrow tail, measured from the base of the arrow head to the end of the tail. If this value is None, no tail will be drawn. default=None tailWidth Width of the tail. default=3 pen The pen used to draw the outline of the arrow. brush The brush used to fill the arrow. pxMode If True, then the arrow is drawn as a fixed size regardless of the scale of its parents (including the ViewBox zoom level). ====================== ================================================= """ arrowOpts = ['headLen', 'tipAngle', 'baseAngle', 'tailLen', 'tailWidth', 'headWidth'] allowedOpts = ['angle', 'pen', 'brush', 'pxMode'] + arrowOpts needUpdate = False for k,v in opts.items(): if k not in allowedOpts: raise KeyError('Invalid arrow style option "%s"' % k) if self.opts.get(k) != v: needUpdate = True self.opts[k] = v if not needUpdate: return opt = dict([(k,self.opts[k]) for k in arrowOpts if k in self.opts]) tr = QtGui.QTransform() tr.rotate(self.opts['angle']) self.path =**opt)) self.setPath(self.path) self.setPen(fn.mkPen(self.opts['pen'])) self.setBrush(fn.mkBrush(self.opts['brush'])) if self.opts['pxMode']: self.setFlags(self.flags() | self.GraphicsItemFlag.ItemIgnoresTransformations) else: self.setFlags(self.flags() & ~self.GraphicsItemFlag.ItemIgnoresTransformations)
def paint(self, p, *args): p.setRenderHint(QtGui.QPainter.RenderHint.Antialiasing) super().paint(p, *args) #p.setPen(fn.mkPen('r')) #p.setBrush(fn.mkBrush(None)) #p.drawRect(self.boundingRect()) def shape(self): #if not self.opts['pxMode']: #return QtWidgets.QGraphicsPathItem.shape(self) return self.path ## dataBounds and pixelPadding methods are provided to ensure ViewBox can ## properly auto-range def dataBounds(self, ax, frac, orthoRange=None): pw = 0 pen = self.pen() if not pen.isCosmetic(): pw = pen.width() * 0.7072 if self.opts['pxMode']: return [0,0] else: br = self.boundingRect() if ax == 0: return [br.left()-pw, br.right()+pw] else: return [, br.bottom()+pw] def pixelPadding(self): pad = 0 if self.opts['pxMode']: br = self.boundingRect() pad += hypot(br.width(), br.height()) pen = self.pen() if pen.isCosmetic(): pad += max(1, pen.width()) * 0.7072 return pad