Config to prevent excessive redrawing

Is your feature request related to a problem? Please describe. Some users have described excessive updates of the ePaper screen, even with fps set to 0.0. Partial updates are less intrusive but on full refresh displays it can cause a lot of blinking. Either way, it affects the lifespan of the ePaper display. With more plugins come more updates to 'status' or custom controls.

Describe the solution you'd like A way of limiting the display changes to an ePaper display: "only update every x seconds, but only if changes have occurred"

Setup: Config says "only update once every 10 seconds, max" The update refers to a significant update that would cause the screen to change (by default anything except uptime and name)

Scenario: an update occurs multiple times within the 10 second period

An update occurs, updates the display.
Another update occurs, but within the 10 second timeframe. No redraw of the display occurs.
Yet another update occurs, but within the 10 second timeframe. No redraw of the display occurs.
The 10 second timeframe is hit: View.py knows that updates have occurred - updates the display.

Scenario: Updates outside the 10 second period

An update occurs, causing a redraw
11 seconds later there is an update - the device immediately redraws the screen and the 10 second window begins again.

Scenario: The setting is set to 0 or is missing:

The device behaves as it currently does based on the fps setting, allowing backward compatibility with older configs

There is a side issue here - we don't want the web UI to be restricted to this - the PNG should be updated based on the fps setting. Therefore I'd see the config for this setting going in the ui.display area of the config.

Describe alternatives you've considered I've not found a way to prevent this without affecting the web ui too, or the refresh happens every x seconds regardless of updates (ie setting fps>0.0)

evilsocket / pwnagotchi

Config to prevent excessive redrawing #628