So I was wondering if someone would be able to help shed a little light for me on something I am working on in Python.
I am creating a program with a Tkinter GUI interface that interacts with a Serial device, and an ADC chip to measure voltage. I want to make sure I properly understand how I'm building the main program loop to keep everything running smoothly. I'm going to lay out how I think the program should run, if anyone has any corrections please throw them at me.
Program is run, GUI Interface initializes
User presses a button
send signal of button through serial
measure/display voltage levels
periodically update voltage display
if button is pressed, return to step 3
Now I know to run my Tkinter GUI I set up mainloop() as the last line of code. Now my question is simply, is that all I will need? Will mainloop() continually update while it waits for another button press, or will I essentially have to creatre an update method that cycles through everything until another button is pressed?
Will mainloop() continually update while it waits for another button press, or will I essentially have to creatre an update method that cycles through everything until another button is pressed?
Not all. That's why you are using tk.Tk().mainloop(). tkinter does this for you. All you are expected to do is implement the functionality that should happen when your button is pressed. tkinter will listen for the button press.
Related
I have one simple question. Is there a way to put some button that will when pressed put everything as it was in moment I started program. Thanks.
I am using a code designed by another person in MAC OS. I am using Windows instead and have slightly modified it, but the problem comes when using the GUI that is created.
I have already dealt with a similar issue with a slider. Once I pressed the slider, I couldn´t release it or press another button. I was forced to quit the GUI and start again. I solved it by changing the event command from EVT_COMMAND_SCROLL to EVT_COMMAND_SCROLL_THUMBTRACK. However I did not understand why it worked in MAC OS and does not work in Windows.
Now, I want to close the GUI with the typical cross inside the red button in the right corner of the window. I can do it if it is the first order I do in the GUI. If I first press any button or slider, the exit button does not work.
It made me consider if a major problem is hidden in the code which I am not seeing. I am new at wxPython, which is the module used in the code.
I just ask for your opinion and hope it is a basic error.
Thanks very much
I want to run my code on raspberry pi which has a touchscreen attached to it. The GUI is made using Tkinter and I want to pop up the system onscreen keyboard when the entry is focused. Here is my current code:
For binding the entry widget with FocusIn event:
self.usernameEntry.bind('<FocusIn>', self.FocusLogin)
For calling the onscreen keyboard installed in the pi:
def FocusLogin(self,event):
os.system('florence')
My problem is that whatever I enter through florence keyboard it never automatically populates the entry widget. It is only after I close the keyboard that I actually see what I typed in. I've tried matchbox-keyboard but it just freezes the whole UI. Florence seems better but it does not update the entry field as I mentioned. I want the UI to automatically show the keys I'm pressing in the entry field.
For someone looking for the answer, I found 2 ways of solving this:
First, use subprocess.popen to create seperate threads of UI and the Keyboard. This works fine on onboard keyboard but florence lags
Second method is to run florence in background before opening the app. Then use
florence hide
florence show
to hide or display florence on the events you want to bind.
I'm in the process of creating a filling program with Python 3.3/Tkinter and have run into an issue that's really stumping me. Basically, I want to prevent button presses from registering while certain processes are taking place. I tried changing the button's state to state='disabled' but this only delays the click from registering until after the function is finished running. In other words, despite the button being "disabled", if it's clicked, the button press will register as soon as it's re-enabled. Please see the example code below.
def Button_Action:
Button.config(state='disabled')
#Activate some hardware that takes a few seconds.
Button.config(state='normal')
So, the question is: How can one selectively ignore button presses in Tkinter/Python 3?
I'm really new to Python and have tried searching for relevant questions to no avail, so please forgive me if this is a stupid question, or has been asked before. Also, I have tested this with both Radiobuttons as well as, standard Buttons (in case that helps).
You can use update method.
def button_action():
b.config(state='disabled')
b.update() # <----------
# Activate some hardware that takes a few seconds.
b.update() # <----------
b.config(state='normal')
The first call to update is to make the button displayed as disabled state.
The second call to update is to handle all pending event (clicks in your case) before enable the button.
BTW, it's normal state, not enabled that make the button back to normal state.
I am writing a python app using Tkinter for buttons and graphics and having trouble getting a timer working, what I need is a sample app that has three buttons and a label.
[start timer] [stop timer] [quit]
When I press the start button a function allows the label to count up from zero every 5 seconds, the stop button stops the timer and the quit button quits the app.
I need to be able to press stop timer and quit at any time, and the time.sleep(5) function locks everything up so I can't use that.
currently i'm using threading.timer(5,do_count_function) and getting nowhere !
I'm a vb.net programmer, so python is a bit new to me, but hey, i'm trying.
Check the .after method of your Tk() object. This allows you to use Tk's timer to fire events within the gui's own loop by giving it a length of time and a callback method.