I have two custom widgets (two classes based on QtGui.QWidget). In __init__ of QtGui.QMainWindow I create their instances:
self.MyWidget1 = MyWidget1()
self.MyWidget2 = MyWidget2()
There are also two buttons (QtGui.QPushButton) in __init__ part, and there are two slots when user clicks each of them:
def clickButton1(self):
self.setCentralWidget(self.MyWidget1)
def clickButton2(self):
self.setCentralWidget(self.MyWidget2)
But it works only on first click and then PyQt says that underlying widget (MyWidget1 or MyWidget2) was deleted. I think it was done by sip module. Is there a way to prevent deleting widgets after reseting of central widget? Thanks!
I think it's almost impossible.
From setCentralWidget docs:
Note: QMainWindow takes ownership of the widget pointer and deletes it at the appropriate time.
So, you should create new MyWidget instance.
def clickButton2(self):
self.setCentralWidget(MyWidget2())
But the right way of doing such things is to use QStackedWidget
Related
I recently decided to create a small application that simply reads the files in a compressed file and renames them. I went through several UI modules and decided to use PyQt6.
To achieve this, I first created a QWidget that holds the widgets QPushButton and QLineEdit.
The user then types the new name into the QLineEdit widget and select the QPushButton if the file has to be excluded.
Now, this widget that was created will be added into a QVBoxLayout which is then set as the QScrollArea layout.
Here's my problem:
Once I was done creating the scroll area and the list, I wanted to retrieve the content of each widget. For this purpose, I use the findChild method. But it only returns the address of the object.
Is there any way to get the text stored in QLineEdit of each widget? Is it possible to retrieve the text just by knowing its address?
Here's what I tried:
for index in range(self.layout.count()):
widget = self.layout.itemAt(index).widget()
nameFromLineEdit = widget.findChild(QLineEdit).text()
print(nameFromLineEdit)
I inherited from QGraphicsItemGroup and made a class that keeps a pointer to its contained items so that I can later refer to them and change properties. It has an ellipse item and a line item and I want only the ellipse to be clickable. I need that press event of the ellipse to propagate to the QGraphicsView so that I can send a signal to some surrounding widgets.
So far I tried inheriting also from QGraphicsObject to have signals available but got stuck with ambigous base error when trying to use scene->addItem. I tried casting to QGraphicsItemGroup but I still get the error. I also tried inheriting from QObject with no success.
I'm new to QGraphics and I know the QGraphics framework has a lot of tools for user interaction and even interaction between GraphicsItems but this is really kicking my butt.
What would be the proper way to get this behavior?
Create a separate "emitter" class
To allow your subclass of QGraphicsItemGroup to emit signals, you can create a separate "emitter" class that inherits from QObject. Then, you can add an instance of this emitter class within your subclass of QGraphicsItemGroup. The emitter object can then emit signals for your subclass as needed.
QGraphicsItemGroup is treated as a single item
Unfortunately, an instance of QGraphicsItemGroup is treated as a single item, so each mousePressEvent will belong to the entire group rather than one of the members of that group (i.e., the ellipse item or the line item). If you want the mousePressEvent to behave differently depending on which item is clicked, they will need to be separate items, or you could try using line->setParentItem(ellipse) to link up the 2 items without using QGraphicsItemGroup.
I am designing a interface with QtDesigner and editing its functionalities with PyQt. One of the widgets that i created has several pushButtons and i want them all to have the property Checkable = True.
So currently what i am doing is:
class MyWidget(QWidget):
def __init__(self):
super(MyWidget, self).__init__()
uic.loadUi('./my_widget.ui', self)
self.pushButton_X.setCheckable(True)
self.pushButton_Y.setCheckable(True)
self.pushButton_Z.setCheckable(True)
self.pushButton_ETC.setCheckable(True)
self.show()
Is there any way i can do something like:
pushbuttons_list = self.get_all_pushbuttons()
for i in pushbuttons_list:
i.setCheckable(True)
?
Im trying the answers to this question but i keep getting
> File "./testing_class.py", line 12, in __init__
items = (self.layout.itemAt(i) for i in range(self.layout.count()))
AttributeError: 'builtin_function_or_method' object has no attribute 'count'
Your example failed because all Qt properties can be accessed by calling the attribute (see the parentheses used for self.layout()):
items = (self.layout().itemAt(i) for i in range(self.layout().count()))
Note that this will only get access to the layout items, not the widgets they might (or might not) contain. For this, using comprehensions will only complicate things unnecessarily, as one-liners should be used only as long as they keep the code readable; the comprehension above is already complex enough, and since you will need to cycle through all items anyway, there's little use in it. Just use a for loop, which is far more readable:
for i in range(self.layout().count()):
widget = self.layout().itemAt(i).widget()
if isinstance(widget, QPushButton):
widget.setCheckable(True)
Note that if you have several buttons that you want checkable and you are doing this only to avoid manually setting the checkable property for all of them, you can just use the extended selection mode that is common for all UI elements that allow selection by keeping pressed Ctrl when clicking multiple objects.
The property editor will automatically show all common properties for the selected widgets, and apply the changed property to all of them.
Another option is to use findChildren():
for button in self.findChildren(QPushButton, Qt.FindDirectChildrenOnly):
button.setCheckable(True)
The Qt.FindDirectChildrenOnly flag is required whenever you have complex layouts that have nested widgets containing other buttons, if you remove that you will find any push button that exists inside the window (or the widget referenced as self).
Finally, buttons can be part of a QButtonGroup, which can also be created in Designer. Just select all buttons (as explained above), right click on one of them and select "Assign to button group", and then:
for button in self.buttonGroup.buttons():
button.setCheckable(True)
Note that the self.buttonGroup above is the object name assigned by Designer, if you change it or you create more than one, ensure that the reference matches it.
In PyQt, I have a dialog that spawns another dialog (when you click a button to do so in the first dialog). I want to maintain a strong parent-child relationship, for garbage collection purposes, and to make the .findChild and .findChildren functions usable.
The root of the question may be: how do you use .setParent() but still have the object in question be shown as a separate window, rather than shown within the parent widget?
The 'parent' dialog (actually a container widget within a tab within a dialog) is 'newEntryWidget'. It spawns 'clueDialog' when a signal (not shown here) calls newEntryWidget.quickTextClueAction as a slot. Visually, clueDialog should be a "top level window" with its own banner, its own window attributes (I want to keep it on top of everything else), etc.
class newEntryWidget(QWidget,Ui_newEntryWidget):
def __init__(self,parent,sec=0,formattedLocString='',fleet='',dev='',origLocString='',amendFlag=False,amendRow=None):
QDialog.__init__(self)
self.parent=parent # just an attribute; not the same as setParent
...
...
def quickTextClueAction(self):
self.newClueDialog=clueDialog(self,self.ui.timeField.text(),self.ui.teamField.text(),self.ui.radioLocField.text(),lastClueNumber+1)
self.newClueDialog.show()
class clueDialog(QDialog,Ui_clueDialog):
def __init__(self,parent,t,callsign,radioLoc,newClueNumber):
QDialog.__init__(self)
self.parent=parent # just an attribute; not the same as setParent
...
...
Right now, since I am using self.parent=parent, which is just an attribute and not true "parent/child relationship" in Qt terms, clueDialog does display as a top level window, which is what I want:
But, if I add 'self.setParent(parent)' in the clueDialog init function, I get this:
How can I preserve the top-level-window behavior, and have the real-honest-parent-child-relationship so that .findChild(clueDialog) will work from within the newEntryWidget object?
Ultimately, I want to enforce that the newEntryWidget object should not be closed if it still has and 'child' clueDialogs open.
Instead of calling .setParent, call QDialog.__init__(self, parent) which constructs the clue dialog with a parent from the beginning. Setting it this way allows Qt establishes the parent-child relationship at the beginning of clueDialog's lifetime.
I believe this will fix both your issues: 1) the clue window frame, caption, etc. will be painted, 2) you will be able to iterate for proper children of newEntry.
I have a GUI based in Python 3 and tkinter that has a big ttk.Treeview. I have defined methods for row selection (one click) and opening an advanced info panel (double-click). I need to ensure that, after being double-clicked, for the next one or two seconds, the Treeview state won't be changed by another click. Is it possible to deactivate Treeview mouse bindings, like what we do with buttons?
Doing a little more research, I was able to come up with a solution for this. I just created an empty method that is called when the tree widget is supposed to be inactive. So, we can use something like this to "unbind" all the mouse events and re-bind them a few seconds later, as needed:
def nothing(self, *event):
""" # Hacking moment: A function that does nothing, for those times you need it...
"""
pass
def bind_tree(self):
""" # Bind mouse and keyboard events to their respective functions or methods...
"""
self.tree.bind('<<TreeviewSelect>>', self.selectItem_popup)
self.tree.bind('<Double-1>', self.show_details)
self.tree.bind("<Button-2>", self.popupMenu)
self.tree.bind("<Button-3>", self.popupMenu)
def unbind_tree(self):
""" # Unbind all mouse and keyboard events, by binding them to an empty method...
"""
self.tree.bind('<<TreeviewSelect>>', self.nothing)
self.tree.bind('<Double-1>', self.nothing)
self.tree.bind("<Button-2>", self.nothing)
self.tree.bind("<Button-3>", self.nothing)
Then, in the rest of the code, We only need to call bind_tree() and unbind_tree() as needed.
This worked for me:
tree.bind("<ButtonRelease-1>", my_select_function)
# Do some stuff
tree.unbind("<ButtonRelease-1>")