I'm trying to catch a closeEvent for several dockWidgets that get added dynamically to a QMainWindow. It is unclear to me how I can figure out which widget has been closed.. Here's an simplified example:
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.leftDockWidget = QtGui.QDockWidget('pick tool', self)
self.leftDockWidget.setWidget( QtGui.QLabel('a dock widget') )
self.addDockWidget( QtCore.Qt.LeftDockWidgetArea, self.leftDockWidget )
self.leftDockWidget.closeEvent = self.dockWidgetCloseEvent
self.show()
def dockWidgetCloseEvent(self, event):
print event
# how to get sender widget ?
event.sender() doesn't seem to exist..
any ideas ?
thanks
One way to achieve what you want would be to use an event filter:
from PyQt4 import QtGui, QtCore
class Example(QtGui.QMainWindow):
def __init__(self):
super(Example, self).__init__()
self.leftDockWidget = QtGui.QDockWidget('pick tool', self)
self.leftDockWidget.setWidget(QtGui.QLabel('a dock widget'))
self.addDockWidget(QtCore.Qt.LeftDockWidgetArea, self.leftDockWidget)
self.leftDockWidget.installEventFilter(self)
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.Close and
isinstance(source, QtGui.QDockWidget)):
print source.windowTitle()
return super(Example, self).eventFilter(source, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Example()
window.show()
sys.exit(app.exec_())
def dockWidgetCloseEvent(self, event):
self.sender()
Related
Don't know exactly how to give the parameters of QMouseEvent class. Should I create new class to implement a QMouseEvent into my QTextEdit?
class Test(QMainWindow):
def __init__(self):
super().__init__()
self.txt = QTextEdit(self)
self.txt.setMouseTracking(True)
self.txt.mouseReleaseEvent(QMouseEvent())
class Test2(QTextEdit):
def __init__(self):
super().__init__()
def mouseReleaseEvent(self, e):
print("text edit is clicked")
ui = Test()
ui.show()
Since many times it is asked how to detect the events that affect a widget then in this answer I will detail the solution and it will be used as a canonical answer for future questions.
To detect an event from a widget there are several solutions:
- Override a method
If the widget has a method that handles that event then an option is to override that method and associate it with a signal so that other objects can be notified.
In the particular case of the mouse release event, this is handled by the mouseReleaseEvent method.
from PyQt5 import QtCore, QtWidgets
class TextEdit(QtWidgets.QTextEdit):
released = QtCore.pyqtSignal()
def mouseReleaseEvent(self, event):
super().mouseReleaseEvent(event)
self.released.emit()
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.textedit = TextEdit()
self.textedit.released.connect(self.handle_released)
self.setCentralWidget(self.textedit)
#QtCore.pyqtSlot()
def handle_released(self):
print("released")
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
- Use an event filter
Qt allows you to monitor the events using an event filter, so you can take advantage of this feature to emit a signal in a similar way to the previous solution.
In the case of classes that inherit from QAbstractScrollArea, the mouse methods are transmitted to the viewport, so that object must be monitored.
from PyQt5 import QtCore, QtWidgets
class ReleaseFilter(QtCore.QObject):
released = QtCore.pyqtSignal()
def __init__(self, widget):
super().__init__(widget)
self._widget = widget
self.widget.installEventFilter(self)
#property
def widget(self):
return self._widget
def eventFilter(self, obj, event):
if obj is self.widget and event.type() == QtCore.QEvent.MouseButtonRelease:
self.released.emit()
return super().eventFilter(obj, event)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.textedit = QtWidgets.QTextEdit()
rf = ReleaseFilter(self.textedit.viewport())
rf.released.connect(self.handle_released)
self.setCentralWidget(self.textedit)
#QtCore.pyqtSlot()
def handle_released(self):
print("released")
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
I have to activate some function, when the cursor is moving. So, I used self.setMouseTracking(True) in MainWidget. But in this way mouseMoveEvent() works only when there is an empty form under cursor. I tried to create another widget over main, but it doesnt work at all.
class ClickButton(QPushButton):
def __init__(self, text, window):
...
def run(self):
...
class Window(QWidget):
def __init__(self):
super().__init__()
self.setGeometry(0, 0, 1000, 1000)
self.setMouseTracking(True)
self.clickers = [ClickButton('OK', self) for i in range(8)]
def mouseMoveEvent(self, ev):
for e in self.clickers:
e.run()
Whats to do?
If you want to detect the position of the mouse even when the mouse is on top of a child, a possible option is to use an event filter.
from PyQt5 import QtCore, QtGui, QtWidgets
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
w_ = QtWidgets.QWidget()
lay_w = QtWidgets.QHBoxLayout(w_)
for c in (QtWidgets.QPushButton(), QtWidgets.QLineEdit()):
lay_w.addWidget(c)
lay = QtWidgets.QVBoxLayout(self)
for w in (QtWidgets.QPushButton(), QtWidgets.QLineEdit(), QtWidgets.QTextEdit(), w_):
lay.addWidget(w)
for ws in self.findChildren(QtWidgets.QWidget) + [self]:
ws.setMouseTracking(True)
ws.installEventFilter(self)
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.MouseMove:
p_respect_to_window = self.mapFromGlobal(obj.mapToGlobal(event.pos()))
print(p_respect_to_window)
return super(Widget, self).eventFilter(obj, event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
On the other hand if you only want to do it in only one type of custom widget it is better to overwrite the mouseMoveEvent method of the custom widget:
from PyQt5 import QtCore, QtGui, QtWidgets
class ClickButton(QtWidgets.QPushButton):
def __init__(self, text, parent=None):
super(ClickButton, self).__init__(text=text, parent=parent)
self.setMouseTracking(True)
def mouseMoveEvent(self, event):
self.run()
super(ClickButton, self).mouseMoveEvent(event)
def run(self):
print("call to run function in button{} and time: {}".format(self.text(),
QtCore.QDateTime.currentDateTime().toString()))
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
lay = QtWidgets.QVBoxLayout(self)
for i in range(10):
w = ClickButton(str(i), self)
lay.addWidget(w)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
How can I get the value returned from mousePressEvent of a widget and apply it to another widget?
Here's the widget with the mousePressEvent:
class Text(QTextEdit):
...
def mousePressEvent(self, event):
if event.button()==Qt.LeftButton:
return "test"
Now I want to use the string returned from the event and apply it to another widget:
class OtherWidget(QWidget):
...
self.label=QLabel()
self.label.setText(???) # <=== How to put the string here?
...
How can I do that? I have tried the following but it does not work.
self.label.setText(Text().mousePressEvent())
The events do not return anything for what you point out is impossible, Qt to send information asynchronously uses the signals, in the next part I show an example:
from PyQt5 import QtCore, QtWidgets
class Text(QtWidgets.QTextEdit):
mousePressSignal = QtCore.pyqtSignal(str)
def mousePressEvent(self, event):
if event.button() == QtCore.Qt.LeftButton:
text = "test: {}-{}".format(event.pos().x(), event.pos().y())
self.mousePressSignal.emit(text)
class OtherWidget(QtWidgets.QWidget):
def __init__(self, parent=None):
super(OtherWidget, self).__init__(parent)
self.label = QtWidgets.QLabel()
lay = QtWidgets.QVBoxLayout(self)
lay.addWidget(self.label, alignment=QtCore.Qt.AlignCenter)
#QtCore.pyqtSlot(str)
def setText(self, text):
self.label.setText(text)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
t = Text()
o = OtherWidget()
o.resize(640, 480)
t.mousePressSignal.connect(o.setText)
t.show()
o.show()
sys.exit(app.exec_())
Briefly I want to track mouse coordinate over a QGraphicsView.
This answer works well for a QLabel object, but not works as expected when I switch to QGraphicsView as follows:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.graphicsView = QtGui.QGraphicsView(self)
self.graphicsView.setMouseTracking(True)
self.graphicsView.installEventFilter(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.graphicsView)
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.MouseMove and
source is self.graphicsView):
pos = event.pos()
print('mouse move: (%d, %d)' % (pos.x(), pos.y()))
return QtGui.QWidget.eventFilter(self, source, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
window.resize(200, 100)
sys.exit(app.exec_())
Specifically, it seems like that the event is caught only when my cursor moves accross the border of the QGraphicsView (the black lines).
Could anyone tell me why and is there any better solutions?
For certain widgets, you need to use its viewport instead:
self.graphicsView.viewport().installEventFilter(self)
...
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.MouseMove and
source is self.graphicsView.viewport()):
...
An alternative is to override mouseMoveEvent(event) of QGraphicsView directly.
Example:
from PySide import QtGui
class MyGraphicsView(QtGui.QGraphicsView):
def __init__(self, parent):
QtGui.QGraphicsView.__init__(self, parent)
self.setMouseTracking(True)
def mouseMoveEvent(self, event):
print('mouseMoveEvent: pos {}'.format(event.pos()))
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.graphicsView = MyGraphicsView(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.graphicsView)
app = QtGui.QApplication([])
window = Window()
window.show()
window.resize(200, 100)
app.exec_()
Let's say I created two QObject in my interface (ui). I would like to connect these two widgets and let them controling each other depending on their visual status. If one is hidden, the other one must be visible. And vice versa.
Can you help me ? :)
Thanks !
Nico
Possible solution: Sublclass widgets and override hideEvent and showEvent:
#!/usr/bin/env python
import sys
from PyQt4 import QtCore, QtGui
class CustomWidget(QtGui.QLabel):
signal_hided = QtCore.pyqtSignal()
signal_shown = QtCore.pyqtSignal()
def hideEvent(self, event):
print 'hideEvent'
super(CustomWidget, self).hideEvent(event)
self.signal_hided.emit()
def showEvent(self, event):
print 'showEvent'
super(CustomWidget, self).showEvent(event)
self.signal_shown.emit()
class MainWidget(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.widget1 = CustomWidget('Widget1')
self.widget2 = CustomWidget('Widget2')
# connect signals, so if one widget is hidden then other is shown
self.widget1.signal_hided.connect(self.widget2.show)
self.widget2.signal_hided.connect(self.widget1.show)
self.widget2.signal_shown.connect(self.widget1.hide)
self.widget1.signal_shown.connect(self.widget2.hide)
# some test code
self.button = QtGui.QPushButton('test')
layout = QtGui.QVBoxLayout()
layout.addWidget(self.button)
layout.addWidget(self.widget1)
layout.addWidget(self.widget2)
self.setLayout(layout)
self.button.clicked.connect(self.do_test)
def do_test(self):
if self.widget1.isHidden():
self.widget1.show()
else:
self.widget2.show()
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
widget = MainWidget()
widget.resize(640, 480)
widget.show()
sys.exit(app.exec_())