How to detect a mouseButtonPressed event outside a QGraphicsView widget? - python

I have a QGraphicsView widget with a QGraphicsScene set in it. I wish to detect a mouseButtonPressed event anywhere in my application window outside of the QGraphicsView widget.
I tried to install an eventFilter to the central widget of the application as follows:
self.centralwidget.installEventFilter(self)
My QGraphicsView widget is self.viewStartImg. In my eventFilter method, I have the following:
def eventFilter(self, obj, event):
if obj != self.viewStartImg and event.type() == QEvent.MouseButtonPress:
print('Outside the QGraphicsView')
In my application, when I click inside of the QGraphicsView, I still get 'Outside the QGraphicsView' printed out. I believe that's happening because QGraphicsView is a child of the centralWidget, but I am not sure.
Any alternate method of achieving this functionality is highly appreciated!

There are several ways to achieve this. One way would be to subclass QGraphicsView and override mousePressEvent in the subclass. Another possibility is to install an event filter on the view object. For the first method you would do something like this
from PyQt5 import QtWidgets, QtCore
class MyView(QtWidgets.QGraphicsView):
def mousePressEvent(self, event):
print('mouse pressed inside view')
event.accept()
class MyWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.central = QtWidgets.QWidget(self)
self.view = MyView(self.central)
self.scene = QtWidgets.QGraphicsScene()
self.view.setScene(self.scene)
hlayout = QtWidgets.QHBoxLayout(self.central)
hlayout.setContentsMargins(50,50,50,50)
hlayout.addWidget(self.view)
self.setCentralWidget(self.central)
def mousePressEvent(self, event):
print('mouse pressed ouside view')
event.accept()
if __name__ == "__main__" :
app = QtWidgets.QApplication([])
win = MyWindow()
win.show()
app.exec()
And for the second one
class MyWindow(QtWidgets.QMainWindow):
money_changed = QtCore.pyqtSignal(int)
def __init__(self):
super().__init__()
self.central = QtWidgets.QWidget(self)
self.view = QtWidgets.QGraphicsView(self.central)
self.scene = QtWidgets.QGraphicsScene()
self.view.setScene(self.scene)
hlayout = QtWidgets.QHBoxLayout(self.central)
hlayout.setContentsMargins(50,50,50,50)
hlayout.addWidget(self.view)
self.setCentralWidget(self.central)
self.view.installEventFilter(self)
def mousePressEvent(self, event):
print('mouse pressed ouside view')
event.accept()
def eventFilter(self, object, event):
if object == self.view and event.type() == QtCore.QEvent.MouseButtonPress:
print('mouse pressed inside view')
return True
return super().eventFilter(object, event)

It may not be exactly what you're looking for, but I recently needed to register when the user clicked outside my widget and used this method:
def event(self, event):
if event == None:
return False
if event.type() == QtCore.QEvent.WindowDeactivate:
print "Clicked outside"
self.main_widget.close()
return super(_ComboBoxPlusDialog, self).event(event)
I used this to close the window, as you can see. So it only registers the outside click once. I used this to get around an issue with Qt.Popup disabling input for the IME.

Related

KeyPressEvent with Qwidget is not working?

If I press any key, nothing will happen. How to implement it? And I notice if I pressed some key, (at first time/Very Beggning/first character), it take some more time to display that pressed Character in textbox.How to resolve it?
from PyQt5 import QtWidgets,QtCore,QtGui
class MyKey(QtWidgets.QWidget):
def __init__(self):
super(). __init__()
self.setWindowTitle(" My Key Board")
self.ui()
def ui(self):
self.tb = QtWidgets.QLineEdit()
self.vb = QtWidgets.QVBoxLayout()
self.vb.addWidget(self.tb)
self.setLayout(self.vb)
def keyPressEvent(self, e):
print("key pressed")
print(e.key())
if type(e) == QtGui.QKeyEvent:
if e.key() == QtCore.Qt.Key_A:
print("ypu pressed 'A'")
if __name__ == "__main__":
import sys
myapp = QtWidgets.QApplication(sys.argv)
mywindow = MyKey()
mywindow.show()
sys.exit(myapp.exec_())
In Qt the KeyPressEvent is only sent to the widget that has the focus and if it consumes it then the event is not sent to the parent widgets otherwise the parent widget is also notified.
In this case, the QLineEdit is the widget that has the focus and consumes the events that have text, numbers and some special keys, so the parent widgets will not be notified in those cases. There are other keys that are not consumed by QLineEdit such as F2, Escape, etc that are received by the parent widget.
If you want to listen to a special key or combination of keys then you must use a QShortcut but because the OP wants to listen to all the events then a possible solution is to install an eventfilter to the QWindow associated with the window that if it receives the keyboard event when the window has the focus no matter which widget has the focus.
from PyQt5 import QtWidgets, QtCore, QtGui
class MyKey(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.setWindowTitle(" My Key Board")
self.ui()
def ui(self):
self.tb = QtWidgets.QLineEdit()
vb = QtWidgets.QVBoxLayout(self)
vb.addWidget(self.tb)
def handle_key_press(self, key, text):
if key == QtCore.Qt.Key_A:
print("ypu pressed 'A'")
class KeyHelper(QtCore.QObject):
key_pressed = QtCore.pyqtSignal(int, str)
def __init__(self, window):
super().__init__(window)
self._window = window
self.window.installEventFilter(self)
#property
def window(self):
return self._window
def eventFilter(self, obj, event):
if obj is self._window and event.type() == QtCore.QEvent.KeyPress:
self.key_pressed.emit(event.key(), event.text())
return super().eventFilter(obj, event)
if __name__ == "__main__":
import sys
myapp = QtWidgets.QApplication(sys.argv)
mywindow = MyKey()
mywindow.show()
helper = KeyHelper(mywindow.windowHandle())
helper.key_pressed.connect(mywindow.handle_key_press)
sys.exit(myapp.exec_())

QComboBox click triggers a leaveEvent on the main QDialog

I am trying to build a hover Dialog but i am stuck at the interaction between QComboBox selection and QDialog's leaveEvent. it looks like when i try to click on combobox to select something, it triggers a leaveEvent which then hides my QDialog. Why is this happening? What can i try to ensure that the Dialog is only hidden when I move my mouse outside of the Dialog?
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
import sys
class hoverDialog(QDialog):
def __init__(self, parent=None):
super().__init__()
self.setAttribute(Qt.WA_DeleteOnClose)
self.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)
self.v = QVBoxLayout()
self.combobox = QComboBox()
self.combobox.addItems(['Work-around','Permanent'])
self.textedit = QPlainTextEdit()
self.v.addWidget(self.combobox)
self.v.addWidget(self.textedit)
self.setLayout(self.v)
#self.setMouseTracking(True)
def leaveEvent(self, event):
self.hide()
return super().leaveEvent(event)
class Table(QWidget):
def __init__(self, parent=None):
super().__init__()
self.label4 = QLabel()
self.label4.setText("hover popup")
self.label4.installEventFilter(self)
self.checkbox1 = QCheckBox()
self.pushButton3 = QPushButton()
self.pushButton3.setText('Generate')
self.pushButton3.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Preferred)
self.pushButton3.clicked.connect(self.buttonPressed)
self.hbox5 = QHBoxLayout()
self.hbox5.addWidget(self.checkbox1)
self.hbox5.addWidget(self.label4)
self.hbox5.addWidget(self.pushButton3)
self.vbox1 = QVBoxLayout()
self.vbox1.addLayout(self.hbox5)
self.setLayout(self.vbox1)
self.autoResolve = hoverDialog(self)
def eventFilter(self, obj, event):
if obj == self.label4 and event.type() == QtCore.QEvent.Enter and self.autoResolve.isHidden():
self.onHovered()
return super().eventFilter(obj, event)
def onHovered(self):
pos = QtGui.QCursor.pos()
self.autoResolve.move(pos)
self.autoResolve.show()
def buttonPressed(self):
if self.checkbox.isChecked():
print('do something..')
if __name__ == '__main__':
app = QApplication(sys.argv)
form = Table()
form.show()
app.exec_()
Looking at the sources, I believe that the origin of the problem is in Qt's behavior whenever a new popup widget is shown.
I cannot guarantee this at 100%, but in any case the simplest solution is to hide the widget only if the combo popup is not shown:
def leaveEvent(self, event):
if not self.combobox.view().isVisible():
self.hide()
Note that your approach is not really perfect: since the dialog could be shown with a geometry that is outside the current mouse position, it will not be able to hide itself until the mouse actually enters it. You should probably filter FocusOut and WindowDeactivate events also.

PyQt5/Python - Multiple keypress events are called with only 1 keypress

So I have the following basic window, my issue is that whenever I press the tab button once it triggers the event twice. Printing "tab" and "keypress" twice. I looked around and all I found about this issue was a C++ answer, I tried to understand the solution but was unable too.
from PyQt5 import QtCore, QtWidgets
class MyWindow(QtWidgets.QMainWindow):
def __init__(self):
super(MyWindow, self).__init__(self)
# Install the event filter that will be used later to detect key presses
QtWidgets.qApp.installEventFilter(self)
self.button = QtGui.QPushButton('Test', self)
self.button.clicked.connect(self.handleButton)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.button)
def handleButton(self):
print("Button")
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.KeyPress:
print("keypress")
if event.key() == QtCore.Qt.Key_Escape:
self.close()
if event.key() == QtCore.Qt.Key_Tab:
print("Tab")
pass
return super(ItemPrice, self).eventFilter(obj, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = MyWindow()
window.show()
sys.exit(app.exec_())
The eventFilter() method needs a boolean result, or 0/1, to return if an event is relevant or not (the filter part). When you return False the event is not blocked, and will hit his target, this lets the application handle the event in a normal way.
In your example, when an expected key is pressed (this is a relevant event), you need to return 1 or True to "intercept" it and prevent the program to handle it, since you provide your own process. In the other cases, you can call the super method like you did :
def eventFilter(self, obj, event):
if event.type() == QtCore.QEvent.KeyPress:
print("keypress")
if event.key() == QtCore.Qt.Key_Escape:
self.close()
return 1
if event.key() == QtCore.Qt.Key_Tab:
print("Tab")
return 1
return super().eventFilter(obj, event)

PyQt4 - Dragging and dropping files into QPushButton

I think the title is fairly self explanatory. I'm working to create a small standalone app that requires the user to drag and drop audio files onto buttons to in turn associate the file with a corresponding button on a piece of hardware by using the filepath, etc...
I've followed a ton of drag and drop tutorials for widgets, and my friend has for lists, however I'm beginning to believe that it can't be done for a button? I'm aware that you can drag and drop text onto a button. I am not fully up to speed with Qt yet so there may just be a glaring error that I'm missing.
Here is the code, many thanks!
import sys
from PyQt4 import QtGui, QtCore
class Button(QtGui.QPushButton):
def __init__(self, parent):
super(Button, self).__init__(parent)
self.setAcceptDrops(True)
self.setDragDropMode(QAbstractItemView.InternalMove)
def dragEnterEvent(self, event):
if event.mimeData().hasUrls():
event.acceptProposedAction()
else:
super(Button, self).dragEnterEvent(event)
def dragMoveEvent(self, event):
super(Button, self).dragMoveEvent(event)
def dropEvent(self, event):
if event.mimeData().hasUrls():
for url in event.mimeData().urls():
path = self.addItem(url.path())
print path
event.acceptProposedAction()
else:
super(Button,self).dropEvent(event)
class MyWindow(QtGui.QWidget):
def __init__(self):
super(MyWindow,self).__init__()
self.setGeometry(100,100,300,400)
self.setWindowTitle("Filenames")
self.btn = QtGui.QPushButton()
self.btn.setGeometry(QtCore.QRect(90, 90, 61, 51))
self.btn.setText("Change Me!")
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.btn)
self.setLayout(layout)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = MyWindow()
window.show()
sys.exit(app.exec_())
There are three problems with your posted code, the main being that you aren't even using the custom Button class that you made. You are adding just a regular button to your window with:
self.btn = QtGui.QPushButton()
instead of:
self.btn = Button(self)
Also, QPushButtons don't have a setDragDropMode() method, so you'll need to comment that line out. I'm not sure what it does anyway.
Also, QPushButton doesn't have an addItem() method so I'm not sure what that's about unless you were planning on implementing it. I replaced it below with just printing the file path.
Here is a working version of your code, that just prints the file path of any file dragged into the button:
import sys
from PyQt4 import QtGui, QtCore
class Button(QtGui.QPushButton):
def __init__(self, parent):
super(Button, self).__init__(parent)
self.setAcceptDrops(True)
#self.setDragDropMode(QAbstractItemView.InternalMove)
def dragEnterEvent(self, event):
if event.mimeData().hasUrls():
event.acceptProposedAction()
else:
super(Button, self).dragEnterEvent(event)
def dragMoveEvent(self, event):
super(Button, self).dragMoveEvent(event)
def dropEvent(self, event):
if event.mimeData().hasUrls():
for url in event.mimeData().urls():
print str(url.toLocalFile())
event.acceptProposedAction()
else:
super(Button,self).dropEvent(event)
class MyWindow(QtGui.QWidget):
def __init__(self):
super(MyWindow,self).__init__()
self.setGeometry(100,100,300,400)
self.setWindowTitle("Filenames")
self.btn = Button(self)
self.btn.setGeometry(QtCore.QRect(90, 90, 61, 51))
self.btn.setText("Change Me!")
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.btn)
self.setLayout(layout)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = MyWindow()
window.show()
sys.exit(app.exec_())

How to change minimize event behavior in PyQt or PySide?

I'm developing a Qt application and changed the closing behavior with the closeEvent virtual function this way:
class MainWindow(QMainWindow):
def closeEvent(self, event):
event.ignore()
self.hide()
self.trayicon.showMessage('Running', 'Running in the background.')
This works as expected. If I remove event.ignore() the application quits as expected, everything is fine.
I want to control the minimize event too, so when the user clicks the minimize button on the title bar, I want to move the window instead of minimize.
I cannot use the hideEvent virtual function, because the event will be sent to the window anyway, so this code:
def hideEvent(self, event):
event.ignore()
self.move(0,0)
moves the window to the top left AND then minimize it. event.ignore() has no effect here, so I tried using QtCore.QObject.event this way:
def event(self, event):
if event.type() == QEvent.WindowStateChange:
if self.isMinimized():
event.ignore()
self.move(0,0)
return True
return False
The window moves but minimizes again. What is wrong with this ? How can I override the minimize event completely ?
Try the changeEvent and filter for WindowMinimized events, something like this:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
from PyQt4 import QtGui, QtCore
class MyWindow(QtGui.QWidget):
def __init__(self, parent=None):
super(MyWindow, self).__init__(parent)
self.systemTrayIcon = QtGui.QSystemTrayIcon(self)
self.systemTrayIcon.setIcon(QtGui.QIcon.fromTheme("face-smile"))
self.systemTrayIcon.setVisible(True)
self.systemTrayIcon.activated.connect(self.on_systemTrayIcon_activated)
self.label = QtGui.QLabel(self)
self.label.setText("Minimize me!")
self.layoutVertical = QtGui.QVBoxLayout(self)
self.layoutVertical.addWidget(self.label)
#QtCore.pyqtSlot(QtGui.QSystemTrayIcon.ActivationReason)
def on_systemTrayIcon_activated(self, reason):
if reason == QtGui.QSystemTrayIcon.DoubleClick:
if self.isHidden():
self.show()
else:
self.hide()
def changeEvent(self, event):
if event.type() == QtCore.QEvent.WindowStateChange:
if self.windowState() & QtCore.Qt.WindowMinimized:
event.ignore()
self.close()
return
super(MyWindow, self).changeEvent(event)
def closeEvent(self, event):
event.ignore()
self.hide()
self.systemTrayIcon.showMessage('Running', 'Running in the background.')
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
app.setApplicationName('MyWindow')
main = MyWindow()
main.show()
sys.exit(app.exec_())

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