RAUI's immediate mode `use_access` allows GUI testing with mock data

immediate_mode_access_and_tests.rs

#[allow(unused_imports)]
use raui_app::prelude::*;
use raui_immediate::*;

mod gui {
    use raui_immediate::*;
    use raui_immediate_widgets::prelude::*;

    pub fn app() {
        nav_content_box((), || {
            tracked_button();
        });
    }

    pub fn tracked_button() {
        if colored_button().trigger_start() {
            // we use access point to some host data
            let clicked = use_access::<bool>("clicked");

            *clicked.write().unwrap() = true;
        }
    }

    fn colored_button() -> ImmediateButton {
        button(NavItemActive, |state| {
            let props = ImageBoxProps::colored(if state.state.trigger {
                Color {
                    r: 0.5,
                    g: 0.0,
                    b: 0.0,
                    a: 1.0,
                }
            } else {
                Color {
                    r: 0.0,
                    g: 0.5,
                    b: 0.0,
                    a: 1.0,
                }
            });

            image_box(props);
        })
    }
}

fn main() {
    let mut clicked = false;

    ImmediateApp::simple("Immediate mode UI - Access and tests", move || {
        // here we register access point to some game state
        let _lifetime = register_access("clicked", &mut clicked);

        gui::app();
    });
}

#[test]
fn test_tracked_button() {
    use raui_core::prelude::*;
    use raui_core::tester::AppCycleTester;

    let mut tester = AppCycleTester::new(
        CoordsMapping::new(Rect {
            left: 0.0,
            right: 1024.0,
            top: 0.0,
            bottom: 576.0,
        }),
        ImmediateContext::default(),
    );
    let mut mock = false;

    tester
        .interactions_engine
        .interact(Interaction::PointerDown(
            PointerButton::Trigger,
            [100.0, 100.0].into(),
        ));

    // since RAUI has deferred UI resolution, signal will take
    // few frames to go through declarative layer to immediate
    // layer and then back to user site.
    for _ in 0..4 {
        tester.run_frame(ImmediateApp::test_frame(|| {
            // and here we register access point to mock data
            let _lifetime = register_access("clicked", &mut mock);

            gui::app();
        }));
    }

    assert_eq!(mock, true);
}