Inactivate pyside-generated windows for the duration of background task - python

I have a simple gui application written in python with pyside. There is a main window and also some modal QDialogs. Depending on the user's actions in some of these dialogs, the application might have to connect to a database and perform corresponding tasks in it.
The problem is: database actions might take a few seconds to complete and my users tend to think that the program is stuck, so they start furiously clicking around and mashing keys. To prevent this erratic behavior I want to deactivate all the windows and display some loading symbol to calm things down.
What I need to create (left - normal state, right - busy state):
This is not the actual app, just an approximate schema of what I want to achieve.
I think some kind of QMovie should do the trick, but I have no idea how to cover a dialog with semi-transparent white and to display the loading symbol on top of it. I am also considering QProgressBar, but I am not sure if it's the right solution for the task.
I would appreciate any advice or a link to similar tasks solved (for some reason I was unable to google anything relevant myself, maybe I am using wrong keywords).

Generally, the way you would do this is with some sort of progress indicator, either a QProgressBar or a QProgressDialog.
With the QProgressDialog, you can launch it modally to prevent users from interacting with the base QDialog or QMainWindow.
Either way, you should still be doing the slow-running task in another thread; otherwise, the GUI is just going to freeze. The user won't be able to move the window or dialog, it won't respond to their clicks, and any progress updates you're making won't be shown in the GUI.

Related

Background process and tkinter

Looking for help on where to start with this, not too good with Python. What I trying to do is use tkinter for a gui interface but i need to be able to process recieved data and update labels widgets as information changes. I all ready have the communication portion of my program working fine in the shell but when I try to tie it to tkinter it will stop processing as soon as the interface is generated. Anyone have a simple code for me to modify to my needs or point me to a reference example somewhere. Spent days so far trying different options and I still have yet to find something that works.
Thanks for any help
Convert your working program into functions that you can register as callbacks in the tkinter UI (say buttons, or other widgets), that is, make it event-driven, and then, for background processing register some of the functions with the after widget method. The root.mainloop() will never return (only on UI close), use it as the last instruction.
So you can't just write your logic in a top-down structure, and hope that it will work well with the UI. The mainloop will be permanently looping, and will call specific funtions in your code, as appropriate to the received events from the user, or to callbacks you registered to run after some time with after.
See here for the after part
Take a look here for structuring tkinter programs. It should have enough info and links for you to study and learn how to do it in a right way.

How to catch a specific window that could pop-up in any moment

In the app I'm trying to automate there is an error window that could pop-up in literally any moment of application work. Then I need to perform some actions like logging this event and stop next automation steps. So I need to catch this moment. How can I do it?
This window always has the same properties (auto_id) so I can describe it before it exist. I can think of using something like a timer which will always check for existence of this window (with the help of .exists(), I guess). But maybe there is a better way of doing it?

Force update GUI in kivy

I am writing an app in kivy which does cpu-heavy calculations at launch. I want the app to display what it's doing at the moment along with the progress, however, since the main loop is not reached yet, it just displays empty white screen until it finishes working. Can I force kivy to update the interface?
Basically I'm looking for kivy's equivalent of Tkinter's root.update()
I could create a workaround by defining a series of functions with each calling the next one through Clock.schedule_once(nextFunction, 1), but that would be very sloppy.
Thanks in advance.
Leaving aside the question of whether you should be using threading or something instead (which possibly you should), the answer is just that you should move your cpu calculations to somewhere else. Display something simple initially (i.e. returning a simple widget from your build method), then do the calculations after that, such as by clock scheduling them.
Your calculations will still block the gui in this case. You can work around this by doing them in a thread or by manually breaking them up into small pieces that can be sequentially scheduled.
It might be possible to update the gui by manually calling something like Clock.tick(), but I'm not sure if this will work right, and even if so it won't be able to display graphics before they have been initialised.

Daemonize, making program to work in background in python/wx.python

I created an complete logger-type program, that logs the certain data from the internet sources. It's GUI I coded in wx.python, now I want to daemonize it (if it is the right term). The program needs to run in background and user has to have option to call/open GUI when he pleases. How can I achieve this with wx.python?
I wouldn't really "daemonize" it per se. Instead, I would just put it in the system tray...at least, that's what I would do on Windows. I assume you can do something similar on the other OSes. Basically you want to bind the frame to wx.EVT_ICONIZE and in that method, you hide it. Then when the user double-clicks the taskbar icon, you want to show it and probably Raise it too.
There's some badly formatted code here: http://bytes.com/topic/python/answers/699757-wxpython-how-minimize-taskbar (I've used a variation of it myself, so I know it works).
And here's some information on Task bar icons: http://www.blog.pythonlibrary.org/2011/12/13/wxpython-101-creating-taskbar-icons/

wxPython: Minimize a Frame to tray

I am in the process of writing an app that I want to make a GUI for. I've got a little bit of experience with making GUI's in wxpython already, but one thing I have not had to try yet; is minimizing an application to tray. I have been doing my research and figured out how to make the icon, but what I have gotten stuck in the mud with is minimizing the Frame to the tray. I have found no functions that I can use to hide the frame with (wx.Frame.Hide() is not the answer). Do any of you know of any way that I could accomplish this? Thanks!
You need to look at the wxPython demo's source code. Look for the part which mentions the DemoTaskBarIcon. Then you'll want to bind to wx.EVT_ICONIZE. You do end up using the frame's Hide() method within the "iconize" event handler. How else would you hide it? Then to show it again, you'll want to use the menu from your task bar icon (which is technically a system tray icon on Windows). See also:
http://bytes.com/topic/python/answers/699757-wxpython-how-minimize-taskbar
http://wxpython-users.1045709.n5.nabble.com/minimize-to-try-question-td2359957.html

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