I've got a qTreeWidget-based interface where I double click on individual items to toggle them on and off. However, I'd like to be able to bulk-toggle them by selecting multiple objects and double clicking them, but when you double click on any item you immediately lose the multi-selection.
Does anyone know a way around this?
Many thanks for your time,
Nick
The first step would be to setup an event that fires whenever an item is double clicked, like so:
treeWidget.itemDoubleClicked.connect(onClickItem)
where onClickItem is:
def onClickItem(item):
print('Text of first column in item is ', item.text(0))
Of course you'll want to do something a bit more fancy inside onClickItem().
The selection/deselection of items is controlled by the mouse-press event, which obviously happens before the double-click is registered. So you need to "eat" the mouse-press at the appropriate moment.
This example allows double-clicking when the meta-key is pressed:
from PySide import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
super(Window, self).__init__()
self.tree = QtGui.QTreeWidget(self)
for text in 'One Two Three Four'.split():
parent = QtGui.QTreeWidgetItem(self.tree, [text])
for text in 'Red Blue Green'.split():
child = QtGui.QTreeWidgetItem(parent, [text])
parent.setExpanded(True)
self.tree.setSelectionMode(QtGui.QAbstractItemView.MultiSelection)
self.tree.viewport().installEventFilter(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.tree)
def eventFilter(self, source, event):
if (source is self.tree.viewport() and
isinstance(event, QtGui.QMouseEvent) and
event.modifiers() == QtCore.Qt.MetaModifier):
if event.type() == QtCore.QEvent.MouseButtonDblClick:
print('meta-double-click')
return True
if event.type() == QtCore.QEvent.MouseButtonPress:
# kill selection when meta-key is also pressed
return True
return super(Window, self).eventFilter(source, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.setGeometry(800, 300, 300, 300)
window.show()
sys.exit(app.exec_())
Related
Is there a signal/event I can make use of for the QMenu tear-off?
I have a QMenu subclass in which it has .setTearOffEnabled(True), but I would like to set this tear-off to always be on the top if the user clicks on the tear-off 'bar'.
I am unable to utilise QtCore.Qt.WindowStaysOnTopHint, as this will result in my menu already being in the tear-off state.
For example: if my main tool area is bigger than the tear-off, and I click on my main tool, the tear-off window will be behind it.
In the following code the clicked signal is emitted when the tear off (dotted lines) is pressed:
import sys
from PyQt5 import QtCore, QtWidgets
class Menu(QtWidgets.QMenu):
clicked = QtCore.pyqtSignal()
def mouseReleaseEvent(self, event):
if self.isTearOffEnabled():
tearRect = QtCore.QRect(
0,
0,
self.width(),
self.style().pixelMetric(
QtWidgets.QStyle.PM_MenuTearoffHeight, None, self
),
)
if tearRect.contains(event.pos()):
self.clicked.emit()
QtCore.QTimer.singleShot(0, self.after_clicked)
super(Menu, self).mouseReleaseEvent(event)
#QtCore.pyqtSlot()
def after_clicked(self):
tornPopup = None
for tl in QtWidgets.QApplication.topLevelWidgets():
if tl.metaObject().className() == "QTornOffMenu":
tornPopup = tl
break
if tornPopup is not None:
print("This is the tornPopup: ", tornPopup)
tornPopup.setWindowFlag(QtCore.Qt.WindowStaysOnTopHint)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
w = QtWidgets.QMainWindow(parent=None)
menu = Menu("Menu", tearOffEnabled=True)
menu.clicked.connect(lambda: print("clicked"))
w.menuBar().addMenu(menu)
for i in range(5):
action = QtWidgets.QAction("action{}".format(i), w)
menu.addAction(action)
w.show()
sys.exit(app.exec_())
When a menu is torn off, it is hidden and Qt replaces it with a copy created from an internal subclass of QMenu. So to set the WindowStaysOnTopHint on a torn off menu, you would first need to find a way to get a reference to it. One way to do this would be to set an event-filter on the application object and watch for child events of the right type:
class MenuWatcher(QtCore.QObject):
def __init__(self, parent=None):
super().__init__(parent)
QtWidgets.qApp.installEventFilter(self)
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.ChildAdded and
event.child().metaObject().className() == 'QTornOffMenu'):
event.child().setWindowFlag(QtCore.Qt.WindowStaysOnTopHint)
return super().eventFilter(source, event)
This class will operate on all torn-off menus created in the application.
However, if the event-filtering was done by the source menu class, its own torn-off menu could be identified by comparing menu-items:
class Menu(QtWidgets.QMenu):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setTearOffEnabled(True)
QtWidgets.qApp.installEventFilter(self)
def eventFilter(self, source, event):
if event.type() == QtCore.QEvent.ChildAdded:
child = event.child()
if (child.metaObject().className() == 'QTornOffMenu' and
all(a is b for a, b in zip(child.actions(), self.actions()))):
child.setWindowFlag(QtCore.Qt.WindowStaysOnTopHint)
return super().eventFilter(source, event)
I have searched a lot but I am unable to find a solution for doing this.
I have a QListWidget which will populate a list of values. I need to implement a "select all" as default behaviour in the list.
I have already used MultiSelection and that works well, but the need is to avoid clicking on each item, in case the user wants to do the update on all items listed.
Can someone help me understand how to do this?
Use QtWidgets.QAbstractItemView.ExtendedSelection
When the user selects an item in the usual way, the selection is cleared and the new item selected. However, if the user presses the Ctrl key when clicking on an item, the clicked item gets toggled and all other items are left untouched. If the user presses the Shift key while clicking on an item, all items between the current item and the clicked item are selected or unselected, depending on the state of the clicked item. Multiple items can be selected by dragging the mouse over them.
import sys
from PyQt5 import QtWidgets
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = QtWidgets.QListWidget()
for i in range(12):
w.addItem('Item {}'.format(i))
w.setSelectionMode(QtWidgets.QAbstractItemView.ExtendedSelection)
#w.setSelectionMode(QtWidgets.QAbstractItemView.MultiSelection)
w.show()
sys.exit(app.exec_())
From what I understand you want to implement a function that selects all items, the solution is to iterate using the setSelected() method of QListWidget as shown below:
import sys
from PyQt4 import QtCore, QtGui
class ListWidget(QtGui.QListWidget):
def __init__(self, parent=None):
super(ListWidget, self).__init__(parent)
self.setSelectionMode(QtGui.QListWidget.MultiSelection)
#QtCore.pyqtSlot()
def selectAll(self):
for i in range(self.count()):
it = self.item(i)
if it is not None:
it.setSelected(True)
#QtCore.pyqtSlot()
def clearSelection(self):
for i in range(self.count()):
it = self.item(i)
if it is not None:
it.setSelected(False)
class Widget(QtGui.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
lay = QtGui.QVBoxLayout(self)
button_sel = QtGui.QPushButton("Select All")
button_unsel = QtGui.QPushButton("Clear Selection")
self.list_widget = ListWidget()
for letter in "ABCDEFGHIJKLMNOPQRSTUVWXYZ":
it = QtGui.QListWidgetItem(letter)
self.list_widget.addItem(it)
button_sel.clicked.connect(self.list_widget.selectAll)
button_unsel.clicked.connect(self.list_widget.clearSelection)
lay.addWidget(button_sel)
lay.addWidget(button_unsel)
lay.addWidget(self.list_widget)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
Is it possible to change the text alignment of a QComboBox that is not not editable? This answer achieves this by making the QComboBox editable
How to center text in QComboBox?
However, I don't want that because with that change, the clickable part of the ComboBox to trigger the list is now only the arrow on the right, whereas before the entire area was clickable and triggers the drop down menu.
The answer is partly already given in the linked question How to center text in QComboBox?
What remains is to make the read-only object clickable. This can be done as suggested here.
...giving you the following code:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
layout = QtGui.QVBoxLayout(self)
self.combo = QtGui.QComboBox()
self.combo.setEditable(True)
self.ledit = self.combo.lineEdit()
self.ledit.setAlignment(QtCore.Qt.AlignCenter)
# as suggested in the comment to
# https://stackoverflow.com/questions/23770287/how-to-center-text-in-qcombobox
self.ledit.setReadOnly(True) #
self.combo.addItems('One Two Three Four Five'.split())
layout.addWidget(self.combo)
self.clickable(self.combo).connect(self.combo.showPopup)
self.clickable(self.ledit).connect(self.combo.showPopup)
def clickable(self,widget):
""" class taken from
https://wiki.python.org/moin/PyQt/Making%20non-clickable%20widgets%20clickable """
class Filter(QtCore.QObject):
clicked = QtCore.pyqtSignal()
def eventFilter(self, obj, event):
if obj == widget:
if event.type() == QtCore.QEvent.MouseButtonRelease:
if obj.rect().contains(event.pos()):
self.clicked.emit()
# The developer can opt for .emit(obj) to get the object within the slot.
return True
return False
filter = Filter(widget)
widget.installEventFilter(filter)
return filter.clicked
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
I have 2 QTextEdit widgets and I need to put whatever is entered in the first to the second on a press of the enter key (Return).... I am not able to implement it please help?
I know I need to use KeyPressEvent but I don't understand how to use it only for the QTextEdit??
self.textEdit = QtGui.QTextEdit(self.widget)
self.textEdit.setMinimumSize(QtCore.QSize(201, 291))
self.textEdit.setMaximumSize(QtCore.QSize(201, 291))
self.textEdit.setObjectName("textEdit")
self.textEdit.setReadOnly(True)
self.verticalLayout.addWidget(self.textEdit)
self.textEdit_2 = QtGui.QTextEdit(self.widget)
self.textEdit_2.setMinimumSize(QtCore.QSize(201, 41))
self.textEdit_2.setMaximumSize(QtCore.QSize(201, 41))
self.textEdit_2.setObjectName("textEdit_2")
self.textEdit_2.setFocusPolicy(Qt.StrongFocus)
self.verticalLayout.addWidget(self.textEdit_2)
Any help is appreciated I am stuck.....
Use the viewportEvent (inherited from QAbstractScrollArea)
self.textEdit.viewportEvent.connect(self.copy_the_text)
def copy_the_text(self, event):
if isinstance(event, QtGui.QKeyEvent): # as viewportEvent gets *all* events
if event.key() == Qt.Key_Return or event.key() == Qt.Key_Enter:
# copy the text from textEdit to textEdit_2
You can use Qt.Key_Enter but I think you probably want Qt.Key_Return
EDIT
If you are using an older version of PySide without new style signals and slots you'll need to use
self.connect(self.textEdit, SIGNAL("viewportEvent(event)"), self.copy_the_text)
Here is a small example that shows QLineEdit and its returnPressed signal. Upon pressing return the text in the QLineEdit will be appended to the QTextEdit:
import sys
from PySide import QtGui
class Window(QtGui.QWidget):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.output = QtGui.QTextEdit()
self.output.setReadOnly(True)
self.input = QtGui.QLineEdit()
self.input.returnPressed.connect(self.addInput)
self.input.setPlaceholderText('input here')
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.output)
layout.addWidget(self.input)
def addInput(self):
# skip empty text
if self.input.text():
self.output.append(self.input.text())
# clear the QLineEdit for new input
self.input.clear()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = Window()
w.show()
sys.exit(app.exec_())
I have a GraphicScene inside a QGraphicView populated with many rectangles (items). I would like each rectangle to respond to the mouse click but I'm not able to find the hook to attach the event handler to the correct object and to get the event propagated to it.
I attached an event handler to the scene:
scene.event = myfunction
and it worked (it was firing every event) but I was unable to attach the same function to one of its children. Can you give me an insight on where to search for such an entry point?
So - I'm not really sure what you're doing there, but I can't think of anything in PyQt where you should be mapping a custom function directly to a scene's event method.
Do you have an actual example?
If you're doing:
scene.mousePressEvent = my_mouse_function
Then that is not how you want to do that.
You can look into using an event filters (http://doc.qt.nokia.com/4.7-snapshot/eventsandfilters.html#event-filters).
Best way to get what you want is to subclass the QGraphicsItem (whichever one you are using - QGraphicsRectItem, QGraphicsPathItem, etc.) and overload the mousePressEvent method on it.
http://doc.qt.nokia.com/4.7-snapshot/qgraphicsitem.html#mousePressEvent
For instance:
from PyQt4.QtGui import QGraphicsRectItem
class MyItem(QGraphicsRectItem):
def mousePressEvent(self, event):
super(MyItem, self).mousePressEvent(event)
print 'overloaded'
scene.addItem(MyItem())
Either subclass the view, scene, item etc and reimplement mousePressEvent and/or mouseReleaseEvent; or install an event filter on those items.
For an example that uses an event filter on a scene, see this answer.
Here's a demo which reimplements mouseReleaseEvent on the view:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.view = View(self)
self.label = QtGui.QLabel(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.view)
layout.addWidget(self.label)
class View(QtGui.QGraphicsView):
def __init__(self, parent):
QtGui.QGraphicsView.__init__(self, parent)
self.setScene(QtGui.QGraphicsScene(self))
for index, name in enumerate('One Two Three Four Five'.split()):
item = QtGui.QGraphicsRectItem(
index * 60, index * 60, 50, 50)
item.setData(0, name)
self.scene().addItem(item)
def mouseReleaseEvent(self, event):
pos = event.pos()
item = self.itemAt(pos)
if item is not None:
text = 'Rectangle <b>%s</b>' % item.data(0).toString()
else:
text = 'No Rectangle (%d, %d)' % (pos.x(), pos.y())
self.parent().label.setText(text)
QtGui.QGraphicsView.mouseReleaseEvent(self, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.resize(400, 400)
window.show()
sys.exit(app.exec_())