Scroll should try to show the focused widget on focus change

[maan2003]

Whenever focus is changed, scroll should pan to the widget with the focus. in this example when focusing the textboxes outside the viewport, scroll doesn't move

example to test

use druid::widget::{Flex, Padding, TextBox};
use druid::{AppLauncher, Widget, WidgetExt, WindowDesc};

pub fn main() {
    let window = WindowDesc::new(build_widget());
    AppLauncher::with_window(window)
        .log_to_console()
        .launch("".to_string())
        .expect("launch failed");
}

fn build_widget() -> impl Widget<String> {
    let mut col = Flex::column();
    for _ in 0..30 {
        col.add_child(Padding::new(3.0, TextBox::new()));
    }
    col.scroll()
}

[xarvic]

Maybe this could be done with a notification. Something like ScrollTo: Selector<Rect>. Either with global coordinates or by updating the notification in every WidgetPod it is passed trough.

[maan2003]

global coordinates should be fine. Nested Scrolls will be a good testcase

[xarvic]

Maybe this could be done with a notification. Something like ScrollTo: Selector<Rect>.

I just noticed that FocusChanged is a lifecycle event, hence we can`t send Notifications. We could use Commands but this feels wrong.