termit-ui 0.0.1

use crate::geometry::*;
use crate::graphics::*;
use crate::input::*;
use crate::widget::*;
use std::io;

pub struct ElementaryWidget {
    pub layout: Box<Layout>,
    pub elements: Vec<Box<LayoutElement>>,
}

impl ElementaryWidget {
    pub fn new() -> Self {
        ElementaryWidget {
            layout: Box::new(FreeLayout),
            elements: vec![],
        }
    }

    pub fn set_layout<L: Layout + 'static>(&mut self, layout: L) {
        self.layout = Box::new(layout);
    }

    pub fn add_element<E: LayoutElement + 'static, I: IntoLayoutElement<E>>(
        &mut self,
        item: I,
    ) -> &Self {
        self.elements.push(Box::new(item.into_layout_element()));
        self
    }

    fn push<F>(&mut self, mut input: Vec<GrinInput>, filter: F, output: &mut Vec<GrinInput>)
    where
        F: for<'r> FnMut(&'r &mut Box<dyn LayoutElement + 'static>) -> bool,
    {
        for mut e in self.elements.iter_mut().rev().filter(filter) {
            input = e.widget_mut().consume(input);
        }
        output.extend(input.into_iter());
    }
}

impl Widget for ElementaryWidget {
    fn arrange(&mut self, window: Window) {
        let size = window.size;
        let total = self.elements.len();
        for (element, i) in self.elements.iter_mut().zip(0..total) {
            let layout = self.layout.layout(size, i, total);
            let relative = element.placement().place(layout);
            trace!("Relative: {:?}", relative);
            let absolute = window.crop(&relative);
            trace!("Absolute: {:?}", absolute);
            element.state_mut().set_area(absolute);
            element.widget_mut().arrange(absolute);
        }
    }

    fn render(&self, painter: &mut Painter) -> io::Result<()> {
        for element in self.elements.iter() {
            let scope = element.state().get_area();
            trace!("Render scope: {:?}", scope);
            element.widget().render(&mut PainterScope::new(
                &mut *painter,
                scope,
                Style::default(),
            ))?;
        }
        Ok(())
    }

    fn consume(&mut self, input: Vec<GrinInput>) -> Vec<GrinInput> {
        let mut output: Vec<GrinInput> = vec![];
        let input = input.into_iter();
        for inp in input {
            match inp {
                GrinInput::Mouse(MouseEvent { action, position }) => {
                    match action {
                        // tell the scrolls only to those under mouse
                        MouseAction::WheelDown | MouseAction::WheelUp => {
                            self.push(
                                vec![GrinInput::Mouse(MouseEvent { action, position })],
                                |el| el.widget().captures(el.state().get_area(), position),
                                &mut output,
                            );
                        }
                        // tell the drag and release to those under mouse as well as the capturing ones
                        MouseAction::Drag | MouseAction::Release => {
                            self.push(
                                vec![GrinInput::Mouse(MouseEvent { action, position })],
                                |el| {
                                    el.widget().captures(el.state().get_area(), position)
                                        || el.state().is_capturing()
                                },
                                &mut output,
                            );
                        }
                        // reset the capturing state with mouse down and tell the capturing ones
                        MouseAction::PressLeft
                        | MouseAction::PressRight
                        | MouseAction::PressMiddle => {
                            for mut el in self.elements.iter_mut().rev() {
                                let state = el.widget().captures(el.state().get_area(), position);
                                el.state_mut().set_capture(state);
                            }
                            self.push(
                                vec![GrinInput::Mouse(MouseEvent { action, position })],
                                |el| el.state().is_capturing(),
                                &mut output,
                            );
                        }
                    };
                }
                inp => {
                    self.push(vec![inp], |el| el.state().is_capturing(), &mut output);
                }
            }
        }

        output
    }
}