Source code for pyqtgraph.graphicsItems.UIGraphicsItem

from ..Qt import QtCore, QtGui
from .GraphicsObject import GraphicsObject

__all__ = ['UIGraphicsItem']
[docs]class UIGraphicsItem(GraphicsObject): """ Base class for graphics items with boundaries relative to a GraphicsView or ViewBox. The purpose of this class is to allow the creation of GraphicsItems which live inside a scalable view, but whose boundaries will always stay fixed relative to the view's boundaries. For example: GridItem, InfiniteLine The view can be specified on initialization or it can be automatically detected when the item is painted. NOTE: Only the item's boundingRect is affected; the item is not transformed in any way. Use viewRangeChanged to respond to changes in the view. """ #sigViewChanged = QtCore.Signal(object) ## emitted whenever the viewport coords have changed
[docs] def __init__(self, bounds=None, parent=None): """ ============== ============================================================================= **Arguments:** bounds QRectF with coordinates relative to view box. The default is QRectF(0,0,1,1), which means the item will have the same bounds as the view. ============== ============================================================================= """ GraphicsObject.__init__(self, parent) self.setFlag(self.GraphicsItemFlag.ItemSendsScenePositionChanges) if bounds is None: self._bounds = QtCore.QRectF(0, 0, 1, 1) else: self._bounds = bounds self._boundingRect = None self._updateView()
def paint(self, *args): ## check for a new view object every time we paint. #self.updateView() pass def itemChange(self, change, value): ret = GraphicsObject.itemChange(self, change, value) if change == self.GraphicsItemChange.ItemScenePositionHasChanged: self.setNewBounds() return ret #def updateView(self): ### called to see whether this item has a new view to connect to ### check for this item's current viewbox or view widget #view = self.getViewBox() #if view is None: ##print " no view" #return #if self._connectedView is not None and view is self._connectedView(): ##print " already have view", view #return ### disconnect from previous view #if self._connectedView is not None: #cv = self._connectedView() #if cv is not None: ##print "disconnect:", self #cv.sigRangeChanged.disconnect(self.viewRangeChanged) ### connect to new view ##print "connect:", self #view.sigRangeChanged.connect(self.viewRangeChanged) #self._connectedView = weakref.ref(view) #self.setNewBounds() def boundingRect(self): if self._boundingRect is None: br = self.viewRect() if br is None: return QtCore.QRectF() else: self._boundingRect = br return QtCore.QRectF(self._boundingRect)
[docs] def dataBounds(self, axis, frac=1.0, orthoRange=None): """Called by ViewBox for determining the auto-range bounds. By default, UIGraphicsItems are excluded from autoRange.""" return None
[docs] def viewRangeChanged(self): """Called when the view widget/viewbox is resized/rescaled""" self.setNewBounds() self.update()
[docs] def setNewBounds(self): """Update the item's bounding rect to match the viewport""" self._boundingRect = None ## invalidate bounding rect, regenerate later if needed. self.prepareGeometryChange()
def setPos(self, *args): GraphicsObject.setPos(self, *args) self.setNewBounds()
[docs] def mouseShape(self): """Return the shape of this item after expanding by 2 pixels""" shape = self.shape() ds = self.mapToDevice(shape) stroker = QtGui.QPainterPathStroker() stroker.setWidh(2) ds2 = stroker.createStroke(ds).united(ds) return self.mapFromDevice(ds2)