wxpython call a function when focus of TextCtrl changes - python

Morning, I would like to call a function in my GUI in the event that the content of a TextCtrl is changed. Only after the user leaves the TextCtrl object though, not during editing.
Please can you help me find the right event handler to use, I'm very new to wxpython and I can't even find a list of allowable events.
Many thanks

You can bind the TextCtrl to wx.EVT_TEXT to capture changes to the value and wx.EVT_KILL_FOCUS to trigger an even when the focus changes. Alternatively you could bind it to wx.EVT_SET_FOCUS and save the current TextCtrl value and also bind to it wx.EVT_KILL_FOCUS to and compare the new value to see if it's changed.
------- EDIT -------
WxFormBuilder is fantastic tool for quickly creating basic UIs. It will also show you every event that you can bind to a widget by clicking on the 'events'` tab.

Related

Moving through panes in AUI managed frame

My wx.Frame derived class is managed by AuiManager. I have several panes in this frame (all are derived from wx.Panel and all have wx.TAB_TRAVERSAL flag set). Pressing TAB key on the keyboard moves focus inside every pane correctly. The problem is, I don't know how to (or even if it is possible) move focus to the next pane. Any ideas about this?
P.S. I've tried googling and reading through wxPython docs, but couldn't find any clue.
I try to be as helpful as I can, given the little information you provided. To shift the focus to another Panel use that Panel's SetFocus() function. (See function description in the link)
Your question also seems to imply that you are interested in the key bindings of focus events. To manage the key bindings to focus events in wxpython, please checkout wx.NavigationKeyEvent. This will allow you to get and set the directions and events resulting from your navigation key inputs.
Last, have you tried pressing the [page down] key for switching panes?

Tkinter Listbox - How to disable arrow key selection?

I have a Python 3.7 tkinter GUI, and within the GUI I have implemented up-down arrow key controls for the main part of the application. Next to it I have a list box that also controls the application but in a different way, and by default AFTER a listbox selection has been made the listbox selection will scroll with up and down arrows. So, after I've used the list box in the app, the arrow key triggers an up arrow event in both the main part of the application and in the list box. This triggers my application to respond in the change in list box selection by loading new data into the main app. This is obviously unacceptable.
How can I disable the arrow key controls feature of tkinter's
ListBox?
I've tried configuring the listbox to not take focus, but this doesn't seem to disable the feature.
Edit:
I solved this by binding the list box's FocusIn event to a function that immediately focus's something else. This is far from ideal, as the code now focus's in then changes focus for no reason. If there is a way to disable focus on a widget completely or disable the list box key bindings that would be a preferred solution.
from tkinter import *
class App:
def __init__(self):
self.root = Tk()
self.dummy_widget = Label()
self.lb = ListBox(master=self.root)
self.lb.bind("<FocusIn>", lambda event: self.dummy_widget.focus())
# Additional setup and packing widgets...
if __name__ == '__main__':
mainloop()
This seems very "hacky", although it does the job perfectly.
How can I disable the arrow key controls feature of tkinter's ListBox?
Create your own bindings for the events you want to override, in the widget in which you want them overridden. Do anything you want in that function (including nothing), and then return the string break, which is the documented way to prevent events from being processed any further.
For a more extensive description of how bindings work, see this answer to the question Basic query regarding bindtags in tkinter. It describes how a character is inserted into an entry widget, but the mechanism is identical for all events and widgets in tkinter.

wxpython SearchCtrl two events triggered

I am using a SearchCtrl with a dropdown menu and I'm having some trouble with the events. When I click the little arrow next to the search button, the EVT_SEARCHCTRL_SEARCH_BTN is triggered, which is not what I want. I only want the EVT_MENU_RANGE to be triggered after I clicked an item, and not also the EVT_SEARCHCTRL_SEARCH_BTN before i click it.
self.search_ctrl = wx.SearchCtrl(self.panel_1, -1,
style=wx.TE_PROCESS_ENTER)
self.search_menu = wx.Menu()
self.search_items = {"text1":"value1", "text2":"value2"}
for txt in self.search_items:
self.search_menu.Append(-1, txt)
self.search_ctrl.SetMenu(self.search_menu)
self.Bind(wx.EVT_SEARCHCTRL_SEARCH_BTN, self.search, self.search_ctrl)
self.Bind(wx.EVT_MENU_RANGE, self.onSearchMenu)
Although I should probably add id's to the menu bind, this isn't causing the problem. The code works as expected when I comment out the search button bind.
UPDATE
Apparently this isn't a problem, but a 'feature' of the searchctrl. I tried the wxpython demo and the menu also showed up if I just clicked the search button, and not the arrow. It is apparently one button, instead of the two i thought it was.
Is there a way to accomplish my original request? Do i have to manually modify a textctrl, or is there an other solution?
All the examples I've seen suggest you need to specify a range of IDs when you call your menu bind.
Maybe by default it binds to something unexpected... ?
Edit - In light of your update, it seems likely that you're going to need to make a custom control to me..

Qt - Temporarily disable all events or window functionality?

I have a Qt program with many buttons, user-interactable widgets, etc.
At one stage in the program, I would like all the widgets to temporarily 'stop working'; stop behaving to mouse clicks and instead pass the event on to one function.
(This is so the User can select a widget to perform meta operations. Part explanation here: Get variable name of Qt Widget (for use in Stylesheet)? )
The User would pick a widget (to do stuff with) by clicking it, and of course clicking a button must not cause the button's bound function to run.
What is the correct (most abstracted, sensible) method of doing this?
(which doesn't involve too much new code. ie; not subclassing every widget)
Is there anything in Qt designed for this?
So far, I am able to retrieve a list of all the widgets in the program (by calling
QObject.findChildren(QtGui.QWidget)
so the solution can incorporate this.
My current horrible ideas are;
Some how dealing with all the applications events all the time in one
function and not letting through the events when I need the
application to be dormant.
When I need dormancy, make a new transparent widget which recieves
mouse clicks and stretch it over the entire window. Take coordinates
of click and figure out the widget underneath.
Somehow create a new 'shell' instance of the window.
THANKS!
(Sorry for the terrible write-up; in a slight rush)
python 2.7.2
PyQt4
Windows 7
You can intercept events send to specific widgets with QObject::installEventFilter.
graphite answered this one first so give credit where credit is due.
For an actual example in PySide, here's an example you might draw some useful code from:
my_app.py
from KeyPressEater import KeyPressEater
if __name__ == "__main__":
app = QApplication(sys.argv)
eater = KeyPressEater()
app.installEventFilter(eater)
KeyPressEater.py
class KeyPressEater(QObject):
# subclassing for eventFilter
def eventFilter(self, obj, event):
if self.ignore_input:
# swallow events
pass
else:
# bubble events
return QObject.eventFilter(self,obj,event)

How do I prevent Qt buttons from appearing in a separate frame?

I'm working on a PyQt application. Currently, there's a status panel (defined as a QWidget) which contains a QHBoxLayout. This layout is frequently updated with QPushButtons created by another portion of the application.
Whenever the buttons which appear need to change (which is rather frequently) an update effect gets called. The existing buttons are deleted from the layout (by calling layout.removeWidget(button) and then button.setParent(None)) and the new buttons are added to the layout.
Generally, this works. But occasionally, when I call button.setParent(None) on the button to delete, it causes it to pop out of the application and start floating in its own stand-alone frame.
How can I remove a button from the layout and ensure it doesn't start floating?
You should call the button's close() method. If you want it to be deleted when you close it, you can set the Qt.WA_DeleteOnClose attribute:
button.setAttribute(Qt.WA_DeleteOnClose)
Try calling QWidget::hide() on the button before removing from the layout if you don't want to delete your button.

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