Triggering code on Pythonista focus lost

nfmusician

I've got an app using a TextView for editing plaintext files that has a save button. In the case that focus is lost from the Pythonista app as a whole (not just the TextView itself) while the file is unsaved, is there a way to catch this and trigger an automatic save before the app sleeps?

stephen

@nfmusician

Here u go!

console.set_idle_timer_disabled(flag):

Disable or enable the idle timer (which puts the device to sleep after a certain period of inactivity).

console.is_in_background():

Return True if the app is currently running in the background, False otherwise.

JonB

The method using a timer to periodically check whether the app is in the background ought to work. Check once every 30 seconds, perhaps. It might not be a bad idea to just perpetually save to a file after certain periods of inactivity -- at least to a temporary file. In your delegate method, you could first call the ui.cancel_delays(), then call ui.delay(your_save_func, 30).

That way everytime you edit, after you stop typing, 30 seconds later the file gets saved. That should work in the background as well, I think (but test it).

As an alternative, you can register a callback for notifications when the app is sent to the background -- so that you call for function immediately.

mikael

@nfmusician, if you want to use the ”always saved” option that @Jonb suggested, here’s a version that calls the save 1 second after you have stopped typing.


from functools import partial
import ui

class Delegate:
    
    save_delay = 1
    
    def textview_did_change(self, textview):
        ui.cancel_delays()
        ui.delay(
            partial(self.save, textview),
            self.save_delay)
        
    def save(self, textview):
        print('Saving', textview)
    
tv = ui.TextView(delegate=Delegate())
tv.present('fullscreen')

cvp

@mikael said:

from functools import partial

Didn't know this partial. I often have searched a way with ui.delay calling a function with arguments, without using globals. Thanks to remember me that I don't know a lot about Python 😢