I have a QGraphicsScene
with QGraphicsItem
added to it. Suppose I clicked on a map image (QGraphicsItem
) where green circle is drawn. How to get click position in terms of this QGraphicsItem
and not QGraphicsScene
coordinate system.
P.S. Please, don't write code with mouse event handling. Just how to map click position correctly. Thanks in advance.
The idea is to convert the coordinate with respect to the scene to a coordinate with respect to the item.
using the mapFromScene() method of QGraphicsItem:
from PyQt5 import QtCore, QtGui, QtWidgets
import random
class Scene(QtWidgets.QGraphicsScene):
def __init__(self, parent=None):
super(Scene, self).__init__(parent)
pixmap = QtGui.QPixmap(100, 100)
pixmap.fill(QtCore.Qt.red)
self.pixmap_item = self.addPixmap(pixmap)
# random position
self.pixmap_item.setPos(*random.sample(range(-100, 100), 2))
def mousePressEvent(self, event):
items = self.items(event.scenePos())
for item in items:
if item is self.pixmap_item:
print(item.mapFromScene(event.scenePos()))
super(Scene, self).mousePressEvent(event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
scene = Scene()
w = QtWidgets.QGraphicsView(scene)
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
using the mapFromScene() method of QGraphicsItem with mapToScene():
from PyQt5 import QtCore, QtGui, QtWidgets
import random
class View(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(View, self).__init__(QtWidgets.QGraphicsScene(), parent)
pixmap = QtGui.QPixmap(100, 100)
pixmap.fill(QtCore.Qt.red)
self.pixmap_item = self.scene().addPixmap(pixmap)
# random position
self.pixmap_item.setPos(*random.sample(range(-100, 100), 2))
def mousePressEvent(self, event):
items = self.items(event.pos())
for item in items:
if item is self.pixmap_item:
print(item.mapFromScene(self.mapToScene(event.pos())))
super(View, self).mousePressEvent(event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = View()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
from PyQt5 import QtCore, QtGui, QtWidgets
import random
class PixmapItem(QtWidgets.QGraphicsPixmapItem):
def mousePressEvent(self, event):
print(event.pos())
super(PixmapItem, self).mousePressEvent(event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
scene = QtWidgets.QGraphicsScene()
w = QtWidgets.QGraphicsView(scene)
pixmap = QtGui.QPixmap(100, 100)
pixmap.fill(QtCore.Qt.red)
item = PixmapItem(pixmap)
scene.addItem(item)
item.setPos(*random.sample(range(-100, 100), 2))
w.resize(640, 480)
w.show()
sys.exit(app.exec_())