使用PyQt4的QWidget上的eventFilter [英] eventFilter on a QWidget with PyQt4
问题描述
我有一个包含DrawingPointsWidget
的QMainWindow.此小部件随机绘制红点.通过使用self.installEventFilter(self)
为MouseHovering事件安装事件过滤器并实现eventFilter()
方法,可以在QMainWindow的状态栏中显示鼠标坐标.有用.但是我想在这个红点小部件上获取鼠标坐标,而不是QMainWindow上.因此,我希望当鼠标位于点窗口小部件而不是QMainWindow的左上角时,状态栏显示[0,0].我怎么做?我尝试了self.installEventFilter(points)
,但没有任何反应.
I have a QMainWindow which contains a DrawingPointsWidget
. This widget draws red points randomly. I display the mouse coordinates in the QMainWindow's status bar by installing an event filter for the MouseHovering event using self.installEventFilter(self)
and by implementing the eventFilter()
method . It works. However I want to get the mouse coordinates on this red-points widget, and not on the QMainWindow. So I want the status bar to display [0, 0] when the mouse is at the top-left corner of the points widget, and not of the QMainWindow. How do I do that? I tried self.installEventFilter(points)
but nothing happens.
您会在下面的有效代码块中找到
You wil find below a working chunck of code.
似乎我写了points.installEventFilter(self)
时,检测到了QtCore.Event.MouseButtonPressed
事件,只有HoverMove
未被检测到.因此,在我的DrawingPointsWidget
(是QWidget
)上未检测到HoverMove
事件.
令人惊讶的是,在QPushButton
上也检测到了HoverMove
事件,而QPushButton
也是QWidget
!我需要写button.installEventFilter(self)
It seems that if I write points.installEventFilter(self)
, the QtCore.Event.MouseButtonPressed
event is detected, only the HoverMove
is not. So the HoverMove
event is not detected on my DrawingPointsWidget
which is a QWidget
.
Surprisingly, the HoverMove
event is detected on the QPushButton
which is a QAbstractButton
which is a QWidget
too! I need to write button.installEventFilter(self)
import sys
import random
from PyQt4 import QtGui, QtCore
from PyQt4.QtGui import *
class MainWindow(QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
self.__setUI()
def __setUI(self, appTitle="[default title]"):
self.statusBar()
mainWidget = QWidget()
vbox = QVBoxLayout()
button = QPushButton("Hello")
vbox.addWidget( button )
points = DrawingPointsWidget()
vbox.addWidget(points)
mainWidget.setLayout(vbox)
self.setCentralWidget(mainWidget)
self.installEventFilter(self)
def eventFilter(self, object, event):
if event.type() == QtCore.QEvent.HoverMove:
mousePosition = event.pos()
cursor = QtGui.QCursor()
self.statusBar().showMessage(
"Mouse: [" + mousePosition.x().__str__() + ", " + mousePosition.y().__str__() + "]"
+ "\tCursor: [" + cursor.pos().x().__str__() + ", " + cursor.pos().y().__str__() + "]"
)
return True
elif event.type() == QtCore.QEvent.MouseButtonPress:
print "Mouse pressed"
return True
return False
class DrawingPointsWidget(QWidget):
""
def __init__(self):
super(QWidget, self).__init__()
self.__setUI()
def __setUI(self):
self.setGeometry(300, 300, 280, 170)
self.setWindowTitle('Points')
self.show()
def paintEvent(self, e):
"Re-implemented method"
qp = QtGui.QPainter()
qp.begin(self)
self.drawPoints(qp)
qp.end()
def drawPoints(self, qp):
qp.setPen(QtCore.Qt.red)
"Need to get the size in case the window is resized -> generates a new paint event"
size = self.size()
for i in range(1000):
x = random.randint(1, size.width()-1 )
y = random.randint(1, size.height()-1 )
qp.drawPoint(x, y)
def main():
app = QApplication(sys.argv)
#window = WidgetsWindow2()
window = MainWindow()
window.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main()
推荐答案
首先,需要由您要观看的对象设置事件过滤器:
Firstly, the event filter needs to be set by the object you want to watch:
points.installEventFilter(self)
第二,您需要监听的事件是MouseMove
而不是HoverMove
:
Secondly, the event you need to listen for is MouseMove
not HoverMove
:
if event.type() == QtCore.QEvent.MouseMove:
最后,您需要在目标小部件上启用鼠标跟踪:
Finally, you need to enable mouse-tracking on the target widget:
class DrawingPointsWidget(QWidget):
def __init__(self):
super(QWidget, self).__init__()
self.setMouseTracking(True)
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