feat: refresh_strategy and post_refresh()

[limikael]

Area

lokinit

Problem

Currently, lokinit is continuously emitting update and render events. For a game that is usually the sole focus of a user, and where things are constantly moving on screen, this makes sense. For other types of apps (like a chat app), it takes up unnecessary CPU.

Suggested solution

It would be nice if there was a setting to just have it emit such events when a redraw is needed. This is similar to e.g. ControlFlow in winit and the EventPump in SDL. From the programmer's perspective we could do this by having a setting refresh_strategy: RefreshStrategy in Conf, where RefreshStrategy is an enum with the values Continuous or Requested. The default would be Continuous, in which case things would work the same as they do now. If the refresh strategy is requested, the update and draw events would only be sent if needed (e.g. when the app is started, or if it has been minimized and then restored). There would also be a post_refresh function on the window module that manually triggers the update and draw events to be sent.

As an implementation note, it is important that the post_refresh function makes sure that the update happens after any pending events.

Also, in order to be able to roll the feature out quicker we can see it as a kind of "hint". I.e., we don't need to have it on all platforms before we merge the code into mainline.

Alternatives

No response

Additional information

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Checks

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