iced-widget-kit 0.1.0

//! A horizontal set of [Group]s that adapt their appearance and arrangement when the [Ribbon]
//! is resized.
pub mod group;

pub use group::{Group, Size};

use crate::ribbon::group::is_collapsed;

use iced_core::{
    Background, Border, Clipboard, Color, Element, Event, Font, Gradient, Layout, Length, Padding,
    Pixels, Point, Rectangle, Shadow, Shell, Size as IcedSize, Theme, Vector, Widget,
    gradient::Linear,
    keyboard,
    layout::{self, Limits, Node},
    mouse::{self, Cursor, Interaction},
    overlay,
    renderer::{self, Quad},
    touch,
    widget::{
        Tree,
        tree::{self, Tag},
    },
    window,
};

use core::panic;
use iced_widget::{button, svg, text};
use std::{f32, time::Instant};

const SEPARATOR_WIDTH: f32 = 1.0;

/// A horizontal collection of [`Group`]s which change their appearance and layout
/// when the [`Ribbon`] is resized.
pub struct Ribbon<'a, Id, Message, Theme = iced_widget::Theme, Renderer = iced_widget::Renderer>
where
    Id: Clone + Eq,
    Theme: Catalog + button::Catalog + text::Catalog,
    Renderer: iced_core::Renderer + iced_core::text::Renderer,
{
    groups: Vec<Group<'a, Id, Message, Theme, Renderer>>,
    width: Length,
    height: Length,
    padding: Padding,
    spacing: f32,
    on_group_dropdown_dismiss: Option<OnDismiss<'a, Message>>,
    class: <Theme as Catalog>::Class<'a>,
}

impl<'a, Id, Message, Theme, Renderer> Ribbon<'a, Id, Message, Theme, Renderer>
where
    Id: Clone + Eq,
    Message: 'a + Clone,
    Theme: 'a + Catalog + button::Catalog + svg::Catalog + text::Catalog,
    <Theme as text::Catalog>::Class<'a>: From<text::StyleFn<'a, Theme>>,
    Renderer: 'a + iced_core::Renderer + iced_core::svg::Renderer + iced_core::text::Renderer,
    <Renderer as iced_core::text::Renderer>::Font: From<iced_core::Font>,
    <Renderer as iced_core::text::Renderer>::Paragraph: Clone,
{
    /// Creates a new [`Ribbon`] which the provided [`Group`]s.
    #[must_use]
    pub fn new(groups: impl IntoIterator<Item = Group<'a, Id, Message, Theme, Renderer>>) -> Self {
        Self {
            groups: groups.into_iter().collect(),
            width: Length::Fill,
            height: Length::Shrink,
            padding: Padding::new(4.0),
            spacing: 0.0,
            on_group_dropdown_dismiss: None,
            class: <Theme as Catalog>::default(),
        }
    }

    /// Sets the width of the [`Ribbon`].
    #[must_use]
    pub fn width(mut self, width: impl Into<Length>) -> Self {
        self.width = width.into();
        self
    }

    /// Sets the height of the [`Ribbon`].
    #[must_use]
    pub fn height(mut self, height: impl Into<Length>) -> Self {
        self.height = height.into();
        self
    }

    /// Sets the spacing between [`Group`]s.
    #[must_use]
    pub fn spacing(mut self, amount: impl Into<Pixels>) -> Self {
        self.spacing = amount.into().0;
        self
    }

    /// Sets the [`Padding`] of the [`Ribbon`].
    #[must_use]
    pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self {
        self.padding = padding.into();
        self
    }

    /// Opens the [`Group`] as a dropdown when collapsed.
    ///
    /// # Panics
    /// Panics if no [`Group`] in the [`Ribbon`] has the provided id.
    #[must_use]
    pub fn open_group(mut self, id: Id) -> Self {
        let mut is_found = false;

        for group in &mut self.groups {
            if group.id() == id {
                is_found = true;
                group.open_dropdown();
            } else {
                group.close_dropdown();
            }
        }

        if !is_found {
            panic!("expect group with id")
        };

        self
    }

    /// Sets the message that will be sent when the [`Group`] collapsed dropdown is dismissed.
    #[must_use]
    pub fn on_group_dropdown_dismiss(mut self, on_dismiss: Message) -> Self {
        self.on_group_dropdown_dismiss = Some(OnDismiss::Direct(on_dismiss));
        self
    }

    /// Sets the message that will be sent when the [`Group`] collapsed dropdown is dismissed.
    ///
    /// This is analogous to [`Ribbon::on_group_dropdown_dismiss`], but using a closure to produce
    /// the message.
    #[must_use]
    pub fn on_group_dropdown_dismiss_with(mut self, on_dismiss: impl Fn() -> Message + 'a) -> Self {
        self.on_group_dropdown_dismiss = Some(OnDismiss::Closure(Box::new(on_dismiss)));
        self
    }

    /// Sets the style of the [`Ribbon`].
    #[must_use]
    pub fn style(mut self, style: impl Fn(&Theme) -> Style + 'a) -> Self
    where
        <Theme as Catalog>::Class<'a>: From<StyleFn<'a, Theme>>,
    {
        self.class = (Box::new(style) as StyleFn<'a, Theme>).into();
        self
    }

    fn total_spacing(&self) -> f32 {
        (self.groups.len() - 1) as f32 * self.spacing
    }

    fn can_shrink(&self, current_sizes: &[group::Size]) -> bool {
        self.groups
            .iter()
            .zip(current_sizes)
            .any(|(group, current_size)| group.shrink_hint(*current_size).is_some())
    }

    fn should_shrink(&mut self, available_width: f32, current_sizes: &[group::Size]) -> bool {
        let groups_width = self
            .groups
            .iter()
            .zip(current_sizes)
            .fold(0.0, |total, (group, size)| {
                total + group.size_width(*size).unwrap()
            })
            + self.total_spacing()
            + self.padding.left
            + self.padding.right;

        (available_width - groups_width) < 0.0 && self.can_shrink(current_sizes)
    }
}

fn group_sizes(tree: &Tree) -> Vec<group::Size> {
    tree.children.iter().map(group::current_size).collect()
}

enum OnDismiss<'a, Message> {
    Direct(Message),
    Closure(Box<dyn Fn() -> Message + 'a>),
}

impl<'a, Message: Clone> OnDismiss<'a, Message> {
    fn get(&self) -> Message {
        match self {
            OnDismiss::Direct(msg) => msg.clone(),
            OnDismiss::Closure(f) => f(),
        }
    }
}

#[derive(Debug, Default)]
struct State {
    now: Option<Instant>,
    open_collapsed_group: Option<usize>,
    available_width: f32,
    group_sizes: Vec<group::Size>,
}

impl<'a, Id, Message, Theme, Renderer> Widget<Message, Theme, Renderer>
    for Ribbon<'a, Id, Message, Theme, Renderer>
where
    Id: Clone + Eq,
    Message: 'a + Clone,
    Theme: 'a + Catalog + button::Catalog + svg::Catalog + text::Catalog,
    Renderer: 'a + iced_core::svg::Renderer + iced_core::text::Renderer,
    <Renderer as iced_core::text::Renderer>::Font: From<iced_core::Font>,
    <Theme as text::Catalog>::Class<'a>: From<text::StyleFn<'a, Theme>>,
    <Renderer as iced_core::text::Renderer>::Paragraph: Clone,
{
    fn tag(&self) -> Tag {
        Tag::of::<State>()
    }

    fn state(&self) -> tree::State {
        tree::State::new(State::default())
    }

    fn children(&self) -> Vec<Tree> {
        self.groups.iter().map(Group::tree).collect()
    }

    fn diff(&self, tree: &mut Tree) {
        tree.diff_children_custom(&self.groups, |tree, group| group.diff(tree), Group::tree);
    }

    fn size(&self) -> IcedSize<Length> {
        IcedSize::new(self.width, self.height)
    }

    fn layout(&mut self, tree: &mut Tree, renderer: &Renderer, limits: &Limits) -> Node {
        let limits = limits.width(self.width).height(self.height);

        let groups_max_height = self.groups.iter_mut().zip(&mut tree.children).fold(
            0.0_f32,
            |max_height, (group, tree)| {
                group
                    .height_check_layout(tree, renderer, &limits)
                    .size()
                    .height
                    .max(max_height)
            },
        );

        // Calculate if Groups need their group::Size changed
        let previous_available_width = tree.state.downcast_ref::<State>().available_width;
        let available_width = limits.shrink(self.padding).width(self.width).max().width;
        let previous_sizes = &tree.state.downcast_ref::<State>().group_sizes;

        if previous_available_width != available_width || *previous_sizes != group_sizes(tree) {
            let is_group_animating = tree.children.iter().any(|child| {
                let state = child.state.downcast_ref::<group::State>();
                state.is_resizing()
            });

            if !is_group_animating {
                let mut current_sizes = self
                    .groups
                    .iter()
                    .map(|group| group.maximum_size())
                    .collect::<Vec<_>>();

                // Starting from the right, step through each group reducing its size until
                // the Ribbon fits in the available width
                while self.should_shrink(available_width, &current_sizes) {
                    let max_size = self
                        .groups
                        .iter()
                        .zip(&current_sizes)
                        .filter(|(group, current_size)| group.can_shrink(**current_size))
                        .fold(group::Size::Collapsed, |size, (_, current_size)| {
                            group::Size::max(size, *current_size)
                        });

                    for (group, current_size) in
                        self.groups.iter_mut().zip(current_sizes.iter_mut()).rev()
                    {
                        if let Some(size_hint) = group.shrink_hint(*current_size)
                            && *current_size >= max_size
                        {
                            *current_size = size_hint;
                            break;
                        }
                    }
                }

                for (group_tree, size) in tree.children.iter_mut().zip(&current_sizes) {
                    match tree.state.downcast_ref::<State>().now {
                        Some(now) => group::resize(group_tree, *size, now),
                        None => group::resize_fixed(group_tree, *size),
                    }
                }

                let group_sizes = group_sizes(tree);
                let state = tree.state.downcast_mut::<State>();
                state.available_width = available_width;
                state.group_sizes = group_sizes;
            }
        }

        let groups_limits =
            limits.max_height(groups_max_height + self.padding.top + self.padding.bottom);

        layout::padded(
            &groups_limits,
            self.width,
            self.height,
            self.padding,
            |limits| {
                // Interleave groups with separators and position
                let (size, nodes) = self.groups.iter_mut().zip(&mut tree.children).fold(
                    (IcedSize::ZERO, vec![]),
                    |(mut total_size, mut nodes), (group, group_tree)| {
                        let group_node = group
                            .layout(group_tree, renderer, limits)
                            .move_to([total_size.width, 0.0]);

                        let total_width = total_size.width + group_node.size().width;
                        nodes.push(group_node);

                        // Every second node is a separator line node
                        let separator_width = SEPARATOR_WIDTH + self.spacing;

                        let separator_node =
                            Node::new(IcedSize::new(separator_width, limits.max().height))
                                .move_to([total_width, 0.0]);

                        total_size =
                            IcedSize::new(total_width + separator_width, groups_max_height);

                        nodes.push(separator_node);
                        (total_size, nodes)
                    },
                );

                Node::with_children(size, nodes)
            },
        )
    }

    fn operate(
        &mut self,
        tree: &mut Tree,
        layout: Layout<'_>,
        renderer: &Renderer,
        operation: &mut dyn iced_core::widget::Operation,
    ) {
        operation.container(None, layout.bounds());

        operation.traverse(&mut |operation| {
            self.groups
                .iter_mut()
                .zip(&mut tree.children)
                .zip(layout.child(0).children().step_by(2))
                .for_each(|((group, state), layout)| {
                    group.operate(state, layout, renderer, operation);
                });
        });
    }

    fn update(
        &mut self,
        tree: &mut Tree,
        event: &Event,
        layout: Layout<'_>,
        cursor: Cursor,
        renderer: &Renderer,
        clipboard: &mut dyn Clipboard,
        shell: &mut Shell<'_, Message>,
        viewport: &Rectangle,
    ) {
        for ((group, group_tree), layout) in self
            .groups
            .iter_mut()
            .zip(&mut tree.children)
            .zip(layout.child(0).children().step_by(2))
        {
            group.update(
                group_tree, event, layout, cursor, renderer, clipboard, shell, viewport,
            );

            if shell.is_event_captured() {
                return;
            }
        }

        let state = tree.state.downcast_mut::<State>();

        match event {
            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
            | Event::Touch(touch::Event::FingerLifted { .. })
            | Event::Touch(touch::Event::FingerLost { .. }) => {
                state.open_collapsed_group = None;
            }
            Event::Window(window::Event::RedrawRequested(now)) => {
                state.now = Some(*now);
            }
            _ => {}
        }
    }

    fn draw(
        &self,
        tree: &Tree,
        renderer: &mut Renderer,
        theme: &Theme,
        style: &renderer::Style,
        layout: Layout<'_>,
        cursor: Cursor,
        viewport: &Rectangle,
    ) {
        let ribbon_style = <Theme as Catalog>::style(theme, &self.class);
        let groups_bounds = layout.bounds();

        renderer.fill_quad(
            Quad {
                bounds: groups_bounds,
                border: ribbon_style.border,
                shadow: ribbon_style.shadow,
                snap: ribbon_style.snap,
            },
            ribbon_style.background.unwrap_or(Color::TRANSPARENT.into()),
        );

        let mut layouts = layout.child(0).children();
        let mut trees = tree.children.iter();
        let mut next_group_trees = tree.children.iter().skip(1);

        for group in self.groups.iter() {
            let group_tree = trees.next().unwrap();

            // Every odd node is a Group
            group.draw(
                group_tree,
                renderer,
                theme,
                style,
                layouts.next().unwrap(),
                cursor,
                viewport,
            );

            // Every even node is a separator line
            let layout = layouts.next().unwrap();
            let bounds = layout.bounds();

            let is_group_collapsed = is_collapsed(group_tree);
            let is_next_group_collapsed = next_group_trees.next().is_some_and(is_collapsed);

            let x = match (is_group_collapsed, is_next_group_collapsed) {
                (true, _) => bounds.x,
                (_, true) => bounds.x + (bounds.width - 1.0),
                (false, false) => bounds.x + (bounds.width - 1.0) / 2.0,
            };

            renderer.fill_quad(
                Quad {
                    bounds: Rectangle {
                        x,
                        y: bounds.y,
                        width: 1.0,
                        height: bounds.height,
                    },
                    ..Quad::default()
                },
                ribbon_style.separator_color.unwrap_or(Color::TRANSPARENT),
            );
        }
    }

    fn mouse_interaction(
        &self,
        tree: &Tree,
        layout: Layout<'_>,
        cursor: Cursor,
        viewport: &Rectangle,
        renderer: &Renderer,
    ) -> Interaction {
        self.groups
            .iter()
            .zip(&tree.children)
            .zip(layout.child(0).children().step_by(2))
            .map(|((group, tree), layout)| {
                group.mouse_interaction(tree, layout, cursor, viewport, renderer)
            })
            .max()
            .unwrap_or_default()
    }

    fn overlay<'b>(
        &'b mut self,
        tree: &'b mut Tree,
        layout: Layout<'b>,
        renderer: &Renderer,
        viewport: &Rectangle,
        translation: Vector,
    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
        let overlays = self
            .groups
            .iter_mut()
            .zip(&mut tree.children)
            .zip(layout.child(0).children().step_by(2))
            .flat_map(|((group, tree), layout)| {
                if is_collapsed(tree) && group.is_dropdown_open() {
                    Some(overlay::Element::new(Box::new(GroupDropdown {
                        position: layout.position(),
                        tree,
                        group,
                        padding: self.padding,
                        on_dismiss: self.on_group_dropdown_dismiss.as_ref(),
                        class: &self.class,
                    })))
                } else {
                    group.overlay(tree, layout, renderer, viewport, translation)
                }
            })
            .collect();

        Some(overlay::Group::with_children(overlays).overlay())
    }
}

impl<'a, Id, Message, Theme, Renderer> From<Ribbon<'a, Id, Message, Theme, Renderer>>
    for Element<'a, Message, Theme, Renderer>
where
    Id: 'a + Clone + Eq,
    Message: 'a + Clone,
    Theme: 'a + Catalog + button::Catalog + svg::Catalog + text::Catalog,
    Renderer: 'a + iced_core::svg::Renderer + iced_core::text::Renderer,
    <Renderer as iced_core::text::Renderer>::Font: From<Font>,
    <Theme as text::Catalog>::Class<'a>: From<text::StyleFn<'a, Theme>>,
    <Renderer as iced_core::text::Renderer>::Paragraph: Clone,
{
    fn from(ribbon: Ribbon<'a, Id, Message, Theme, Renderer>) -> Self {
        Element::new(ribbon)
    }
}

struct GroupDropdown<
    'a,
    'b,
    Id,
    Message,
    Theme = iced_core::Theme,
    Renderer = iced_widget::Renderer,
> where
    Id: Clone + Eq,
    Theme: Catalog + button::Catalog + text::Catalog,
    Renderer: iced_core::Renderer + iced_core::text::Renderer,
{
    position: Point,
    tree: &'b mut Tree,
    group: &'b mut Group<'a, Id, Message, Theme, Renderer>,
    padding: Padding,
    on_dismiss: Option<&'b OnDismiss<'b, Message>>,
    class: &'b <Theme as Catalog>::Class<'a>,
}

impl<'a, 'b, Id, Message, Theme, Renderer> overlay::Overlay<Message, Theme, Renderer>
    for GroupDropdown<'a, 'b, Id, Message, Theme, Renderer>
where
    Id: Clone + Eq,
    Message: 'a + Clone,
    Theme: 'a + Catalog + button::Catalog + svg::Catalog + text::Catalog,
    <Theme as text::Catalog>::Class<'a>: From<text::StyleFn<'a, Theme>>,
    Renderer: 'a + iced_core::Renderer + iced_core::svg::Renderer + iced_core::text::Renderer,
    <Renderer as iced_core::text::Renderer>::Font: From<Font>,
    <Renderer as iced_core::text::Renderer>::Paragraph: Clone,
{
    fn update(
        &mut self,
        event: &Event,
        layout: Layout<'_>,
        cursor: Cursor,
        renderer: &Renderer,
        clipboard: &mut dyn Clipboard,
        shell: &mut Shell<'_, Message>,
    ) {
        let bounds = layout.bounds();
        let max_size = self.group.maximum_size();

        self.group.size_update(
            max_size,
            self.tree,
            event,
            layout.child(0),
            cursor,
            renderer,
            clipboard,
            shell,
            &bounds,
        );

        let mut publish_dismiss = || {
            if let Some(on_dismiss) = self.on_dismiss {
                shell.publish(on_dismiss.get());
            }
        };

        if cursor.position_over(bounds).is_none() {
            match event {
                Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
                | Event::Touch(touch::Event::FingerLifted { .. })
                | Event::Window(window::Event::Resized(_)) => publish_dismiss(),
                Event::Keyboard(keyboard::Event::KeyPressed { key, .. })
                    if *key == keyboard::Key::Named(keyboard::key::Named::Escape) =>
                {
                    publish_dismiss()
                }

                _ => {}
            }
        }
    }

    fn layout(&mut self, renderer: &Renderer, bounds: IcedSize) -> layout::Node {
        let limits = Limits::new(IcedSize::ZERO, bounds);

        let mut node = layout::padded(
            &limits,
            Length::Shrink,
            Length::Shrink,
            self.padding,
            |limits| {
                self.group
                    .size_layout(self.group.maximum_size(), true, self.tree, renderer, limits)
            },
        );

        let size = node.size();

        // Try to stay inside borders
        let mut position = Point::new(self.position.x, self.position.y + size.height);

        if position.x + size.width > bounds.width {
            position.x = f32::max(0.0, bounds.width - size.width);
        }
        if position.y + size.height > bounds.height {
            position.y = f32::max(0.0, bounds.height - size.height);
        }

        node.move_to_mut(position);
        node
    }

    fn draw(
        &self,
        renderer: &mut Renderer,
        theme: &Theme,
        style: &renderer::Style,
        layout: Layout<'_>,
        cursor: Cursor,
    ) {
        let bounds = layout.bounds();
        let background_style = <Theme as Catalog>::style(theme, self.class);

        renderer.fill_quad(
            renderer::Quad {
                bounds,
                border: background_style.border,
                shadow: background_style.shadow,
                snap: background_style.snap,
            },
            background_style
                .background
                .unwrap_or(Color::TRANSPARENT.into()),
        );

        let max_size = self.group.maximum_size();
        let layout = layout.child(0);
        let bounds = layout.bounds();

        self.group.size_draw(
            max_size, self.tree, renderer, theme, style, layout, cursor, &bounds,
        );
    }

    fn mouse_interaction(
        &self,
        layout: Layout<'_>,
        cursor: Cursor,
        renderer: &Renderer,
    ) -> Interaction {
        self.group.size_mouse_interaction(
            self.group.maximum_size(),
            self.tree,
            layout.child(0),
            cursor,
            &layout.bounds(),
            renderer,
        )
    }
}

/// The appearance of a [`Ribbon`].
#[derive(Debug, Clone, Copy, PartialEq, Default)]
pub struct Style {
    /// The [`Background`] of the [`Ribbon`].
    pub background: Option<Background>,
    /// The [`Border`] of the [`Ribbon`].
    pub border: Border,
    /// The [`Shadow`] of the [`Ribbon`].
    pub shadow: Shadow,
    /// The color of the separator between groups.
    pub separator_color: Option<Color>,
    /// Whether the [`Ribbon`] should be snapped to the pixel grid.
    pub snap: bool,
}

impl Style {
    /// Updates the border of the [`Style`].
    pub fn border(self, border: impl Into<Border>) -> Self {
        Self {
            border: border.into(),
            ..self
        }
    }

    /// Updates the background of the [`Style`].
    pub fn background(self, background: impl Into<Background>) -> Self {
        Self {
            background: Some(background.into()),
            ..self
        }
    }

    /// Updates the shadow of the [`Style`].
    pub fn shadow(self, shadow: impl Into<Shadow>) -> Self {
        Self {
            shadow: shadow.into(),
            ..self
        }
    }

    /// Update the separator color.
    pub fn separator_color(self, color: Color) -> Self {
        Self {
            separator_color: Some(color),
            ..self
        }
    }
}

impl From<Color> for Style {
    fn from(color: Color) -> Self {
        Self::default().background(color)
    }
}

impl From<Gradient> for Style {
    fn from(gradient: Gradient) -> Self {
        Self::default().background(gradient)
    }
}

impl From<Linear> for Style {
    fn from(gradient: Linear) -> Self {
        Self::default().background(gradient)
    }
}

/// The theme catalog of a [`Ribbon`].
pub trait Catalog {
    /// The item class of the [`Catalog`].
    type Class<'a>;

    /// The default class produced by the [`Catalog`].
    fn default<'a>() -> Self::Class<'a>;

    /// The [`Style`] of a class.
    fn style(&self, class: &Self::Class<'_>) -> Style;
}

/// A styling function for a [`Ribbon`].
pub type StyleFn<'a, Theme> = Box<dyn Fn(&Theme) -> Style + 'a>;

impl<Theme> From<Style> for StyleFn<'_, Theme> {
    fn from(style: Style) -> Self {
        Box::new(move |_theme| style)
    }
}

impl Catalog for Theme {
    type Class<'a> = StyleFn<'a, Self>;

    fn default<'a>() -> Self::Class<'a> {
        Box::new(|_| Style::default())
    }

    fn style(&self, class: &Self::Class<'_>) -> Style {
        class(self)
    }
}

pub fn group<'a, Id, Message, Theme, Renderer>(
    id: Id,
    header: impl text::IntoFragment<'a>,
    content: impl Fn(Size) -> Option<Element<'a, Message, Theme, Renderer>> + 'a,
) -> Group<'a, Id, Message, Theme, Renderer>
where
    Id: Clone + Eq,
    Message: 'a + Clone,
    Theme: 'a + button::Catalog + svg::Catalog + text::Catalog,
    <Theme as svg::Catalog>::Class<'a>: From<svg::StyleFn<'a, Theme>>,
    <Theme as text::Catalog>::Class<'a>: From<text::StyleFn<'a, Theme>>,
    Renderer: 'a + iced_core::Renderer + iced_core::svg::Renderer + iced_core::text::Renderer,
    <Renderer as iced_core::text::Renderer>::Font: From<Font>,
    <Renderer as iced_core::text::Renderer>::Paragraph: Clone,
{
    Group::new(id, header, content)
}