egui_cable 0.9.0

A generic and extensible data-oriented widget for connecting ports by cables
Documentation 
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use std::fmt::Debug;
use std::hash::Hash;

use egui::{Vec2, Widget};

use crate::{
    custom_widget::CustomWidget, default_port::DefaultPort, id::Id, plug::DraggedPlug,
    port_params::PortParams, state::State,
};

pub type PortId = Id;

#[derive(Debug)]
pub struct Port {
    port_id: PortId,
    widget: Option<CustomWidget>,
}

impl Port {
    pub fn new<T: Hash + Eq + Debug + Send + Sync + 'static>(port_id: T) -> Self {
        Port {
            port_id: PortId::new(port_id),
            widget: None,
        }
    }

    pub fn widget(mut self, widget: impl Into<CustomWidget>) -> Self {
        self.widget = Some(widget.into());
        self
    }
}

impl Widget for Port {
    fn ui(self, ui: &mut egui::Ui) -> egui::Response {
        ui.push_id(self.port_id.clone(), |ui| {
            // This widget is not need to use egui::Area

            let mut state = State::get_cloned(ui);

            // Render port with params
            PortParams {
                hovered: state.hovered_port_id() == Some(self.port_id.clone()),
            }
            .set(ui);
            let response = self.widget.unwrap_or_else(|| DefaultPort.into()).ui(ui);

            // advance generation if this port is rendered twice
            state.advance_generation_if_twice(self.port_id.clone());
            // update port's position used for plug rendering
            state.update_port_pos(self.port_id.clone(), response.rect.left_top());

            let dragged_plug = state.dragged_plug().unwrap_or(DraggedPlug {
                pos: egui::pos2(-100.0, -100.0), // far
                size: Vec2::ZERO,
            });

            // distance between the port and the dragged plug
            let distance_sq = response.rect.center().distance_sq(dragged_plug.pos);
            let min_length = |vec: Vec2| vec.x.min(vec.y);
            let close_distance =
                (min_length(response.rect.size()) + min_length(dragged_plug.size)) / 2.0;

            // distance required because `response.hovered()` always returns false when plug is interacted
            let hovered = response.hovered() || distance_sq < close_distance.powi(2);

            // update hovered port id used for cable connection
            if hovered {
                state.update_hovered_port_id(self.port_id);
            }

            // finally update the state
            state.store_to(ui);

            response
        })
        .inner
    }
}