Comment by Rohansi
5 hours ago
> Another example: When typing only the newly typed character and caret are rendered. The rest of your entire screen is reused.
You're right that they avoid unnecessary painting but it is not this granular anymore. It used to be but rendering is so much faster these days where it is cheaper to just render a bit more than tracking dirty regions. It's easily visible on Android where you can enable "Show view updates" and see the entire textbox view updates when the cursor flashes. The docs say the same thing.
https://developer.android.com/reference/android/view/View#in...
Wow, that's quite silly - and might partially explain some of the worsening battery life on Android. GTK4 also removes such an API, but just like those docs say, dirty rects are still calculated internally. You can enable the same visual debugging in GTK4 and see that dirty rects are done the same as they always have been.
Chrome on desktop has an option for flashing whenever it paints and it only highlights the line of text you're typing on. So clearly chrome still tracks dirty rects properly.