Enum dispatch time

21 files changed, 245 insertions, 190 deletions

diff --git a/src/app.rs b/src/app.rs
index 2d150ea6..002a4f49 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -29,7 +29,7 @@ use frozen_state::FrozenState;
 use crate::{
     canvas::Painter,
     constants,
-    tuice::{Application, Row},
+    tuice::{Application, Element, Row},
     units::data_units::DataUnit,
     Pid,
 };
@@ -234,12 +234,11 @@ impl Application for AppState {
         self.terminator.load(SeqCst)
     }
 
-    fn view(
-        &mut self,
-    ) -> Box<dyn crate::tuice::Component<Self::Message, crate::tuice::CrosstermBackend>> {
-        Box::new(Row::with_children(vec![crate::tuice::TextTable::new(
+    fn view(&mut self) -> Element<'static, Self::Message> {
+        use crate::tuice::TextTable;
+        Element::from(Row::with_children(vec![Element::from(TextTable::new(
             vec!["A", "B", "C"],
-        )]))
+        ))]))
     }
 
     fn destroy(&mut self) {
diff --git a/src/tuice/application.rs b/src/tuice/application.rs
index b32ff3f6..6fd2e34b 100644
--- a/src/tuice/application.rs
+++ b/src/tuice/application.rs
@@ -2,7 +2,7 @@ use std::{fmt::Debug, sync::mpsc::Receiver};
 
 use super::{
     runtime::{self, RuntimeEvent},
-    Component, Event,
+    Element, Event,
 };
 
 /// An alias to the [`tui::backend::CrosstermBackend`] writing to [`std::io::Stdout`].
@@ -19,7 +19,7 @@ pub trait Application: Sized {
     /// always returning false.
     fn is_terminated(&self) -> bool;
 
-    fn view(&mut self) -> Box<dyn Component<Self::Message, CrosstermBackend>>;
+    fn view(&mut self) -> Element<'static, Self::Message>;
 
     /// To run upon stopping the application.
     fn destroy(&mut self) {}
diff --git a/src/tuice/component.rs b/src/tuice/component.rs
index f4646ac5..131f576c 100644
--- a/src/tuice/component.rs
+++ b/src/tuice/component.rs
@@ -4,18 +4,19 @@ pub use base::*;
 pub mod widget;
 pub use widget::*;
 
+use enum_dispatch::enum_dispatch;
 use tui::{layout::Rect, Frame};
 
-use super::{Bounds, DrawContext, Event, LayoutNode, Size, Status};
+use super::{Bounds, Event, LayoutNode, Size, Status};
 
 /// A component displays information and can be interacted with.
 #[allow(unused_variables)]
-pub trait Component<Message, Backend>
-where
-    Backend: tui::backend::Backend,
-{
+#[enum_dispatch]
+pub trait TmpComponent<Message> {
     /// Draws the component.
-    fn draw(&mut self, area: Rect, context: &DrawContext, frame: &mut Frame<'_, Backend>);
+    fn draw<Backend>(&mut self, area: Rect, frame: &mut Frame<'_, Backend>)
+    where
+        Backend: tui::backend::Backend;
 
     /// How a component should react to an [`Event`].
     ///
diff --git a/src/tuice/component/base/block.rs b/src/tuice/component/base/block.rs
index e2697f1e..2232f9d7 100644
--- a/src/tuice/component/base/block.rs
+++ b/src/tuice/component/base/block.rs
@@ -1,14 +1,14 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Component, DrawContext, Event, Status};
+use crate::tuice::{Event, Status, TmpComponent};
 
 pub struct Block {}
 
-impl<Message, B> Component<Message, B> for Block
-where
-    B: Backend,
-{
-    fn draw(&mut self, _area: Rect, _context: &DrawContext, _frame: &mut Frame<'_, B>) {
+impl<Message> TmpComponent<Message> for Block {
+    fn draw<B>(&mut self, _area: Rect, _frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         todo!()
     }
 
diff --git a/src/tuice/component/base/carousel.rs b/src/tuice/component/base/carousel.rs
index 2169f9d0..62407c9c 100644
--- a/src/tuice/component/base/carousel.rs
+++ b/src/tuice/component/base/carousel.rs
@@ -1,14 +1,14 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Component, DrawContext, Event, Status};
+use crate::tuice::{Event, Status, TmpComponent};
 
 pub struct Carousel {}
 
-impl<Message, B> Component<Message, B> for Carousel
-where
-    B: Backend,
-{
-    fn draw(&mut self, _area: Rect, _context: &DrawContext, _frame: &mut Frame<'_, B>) {
+impl<Message> TmpComponent<Message> for Carousel {
+    fn draw<B>(&mut self, _area: Rect, _frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         todo!()
     }
 
diff --git a/src/tuice/component/base/column.rs b/src/tuice/component/base/column.rs
index 3c15f893..5fdae3dc 100644
--- a/src/tuice/component/base/column.rs
+++ b/src/tuice/component/base/column.rs
@@ -1,14 +1,14 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Component, DrawContext, Event, Status};
+use crate::tuice::{Event, Status, TmpComponent};
 
 pub struct Column {}
 
-impl<Message, B> Component<Message, B> for Column
-where
-    B: Backend,
-{
-    fn draw(&mut self, _area: Rect, _context: &DrawContext, _frame: &mut Frame<'_, B>) {
+impl<Message> TmpComponent<Message> for Column {
+    fn draw<B>(&mut self, _area: Rect, _frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         todo!()
     }
 
diff --git a/src/tuice/component/base/container.rs b/src/tuice/component/base/container.rs
index a2c28750..f085349e 100644
--- a/src/tuice/component/base/container.rs
+++ b/src/tuice/component/base/container.rs
@@ -1,34 +1,47 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Bounds, Component, DrawContext, Event, Length, Size, Status, LayoutNode};
+use crate::tuice::{Bounds, Element, Event, LayoutNode, Size, Status, TmpComponent};
 
-pub struct Container<'a, Message, B>
-where
-    B: Backend,
-{
-    width: Length,
-    height: Length,
-    child: Box<dyn Component<Message, B> + 'a>,
+/// A [`Container`] just contains a child, as well as being able to be sized.
+///
+/// Inspired by Flutter's [Container class](https://api.flutter.dev/flutter/widgets/Container-class.html).
+#[derive(Default)]
+pub struct Container<'a, Message> {
+    width: Option<u16>,
+    height: Option<u16>,
+    child: Option<Box<Element<'a, Message>>>,
 }
 
-impl<'a, Message, B> Container<'a, Message, B>
-where
-    B: Backend,
-{
-    pub fn new(child: Box<dyn Component<Message, B> + 'a>) -> Self {
+impl<'a, Message> Container<'a, Message> {
+    pub fn with_child(child: Element<'a, Message>) -> Self {
         Self {
-            width: Length::Flex,
-            height: Length::Flex,
-            child,
+            width: None,
+            height: None,
+            child: Some(child.into()),
         }
     }
+
+    pub fn child(mut self, child: Option<Element<'a, Message>>) -> Self {
+        self.child = child.map(|c| c.into());
+        self
+    }
+
+    pub fn width(mut self, width: Option<u16>) -> Self {
+        self.width = width;
+        self
+    }
+
+    pub fn height(mut self, height: Option<u16>) -> Self {
+        self.height = height;
+        self
+    }
 }
 
-impl<'a, Message, B> Component<Message, B> for Container<'a, Message, B>
-where
-    B: Backend,
-{
-    fn draw(&mut self, area: Rect, _context: &DrawContext, _frame: &mut Frame<'_, B>) {
+impl<'a, Message> TmpComponent<Message> for Container<'a, Message> {
+    fn draw<B>(&mut self, area: Rect, _frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         todo!()
     }
 
@@ -37,30 +50,39 @@ where
     }
 
     fn layout(&self, bounds: Bounds, node: &mut LayoutNode) -> Size {
-        let width = match self.width {
-            Length::Flex => {
-                todo!()
-            }
-            Length::FlexRatio(ratio) => {
-                todo!()
-            }
-            Length::Fixed(length) => length.clamp(bounds.min_width, bounds.max_width),
-            Length::Child => {
-                todo!()
-            }
-        };
+        let (width, height) = if let Some(child) = &self.child {
+            let mut child_node = LayoutNode::default();
 
-        let height = match self.height {
-            Length::Flex => {
-                todo!()
-            }
-            Length::FlexRatio(ratio) => {
-                todo!()
-            }
-            Length::Fixed(length) => length.clamp(bounds.min_height, bounds.max_height),
-            Length::Child => {
-                todo!()
+            fn bounds_if_exist(val: Option<u16>, min_bound: u16, max_bound: u16) -> (u16, u16) {
+                if let Some(val) = val {
+                    let val = val.clamp(min_bound, max_bound);
+                    (val, val)
+                } else {
+                    (min_bound, max_bound)
+                }
             }
+
+            let child_bounds = {
+                let (min_width, max_width) =
+                    bounds_if_exist(self.width, bounds.min_width, bounds.max_width);
+                let (min_height, max_height) =
+                    bounds_if_exist(self.height, bounds.min_height, bounds.max_height);
+
+                Bounds {
+                    min_width,
+                    min_height,
+                    max_width,
+                    max_height,
+                }
+            };
+
+            let child_size = child.layout(child_bounds, &mut child_node);
+
+            // Note that this is implicitly bounded by our above calculations,
+            // no need to recheck if it's valid!
+            (child_size.width, child_size.height)
+        } else {
+            (bounds.min_width, bounds.min_height)
         };
 
         Size { height, width }
diff --git a/src/tuice/component/base/flex.rs b/src/tuice/component/base/flex.rs
new file mode 100644
index 00000000..29d4709b
--- /dev/null
+++ b/src/tuice/component/base/flex.rs
@@ -0,0 +1,60 @@
+use tui::{backend::Backend, layout::Rect, Frame};
+
+use crate::tuice::{Bounds, Element, Event, LayoutNode, Size, Status, TmpComponent};
+
+pub struct FlexElement<'a, Message> {
+    /// Represents a ratio with other [`FlexElement`]s on how far to expand.
+    pub flex: u16,
+    element: Element<'a, Message>,
+}
+
+impl<'a, Message> FlexElement<'a, Message> {
+    pub fn new<I: Into<Element<'a, Message>>>(element: I) -> Self {
+        Self {
+            flex: 1,
+            element: element.into(),
+        }
+    }
+
+    pub fn with_flex<I: Into<Element<'a, Message>>>(element: I, flex: u16) -> Self {
+        Self {
+            flex,
+            element: element.into(),
+        }
+    }
+
+    pub fn with_no_flex<I: Into<Element<'a, Message>>>(element: I) -> Self {
+        Self {
+            flex: 0,
+            element: element.into(),
+        }
+    }
+
+    pub fn flex(mut self, flex: u16) -> Self {
+        self.flex = flex;
+        self
+    }
+
+    pub(crate) fn draw<B>(&mut self, area: Rect, frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
+        self.element.draw(area, frame)
+    }
+
+    pub(crate) fn on_event(
+        &mut self, area: Rect, event: Event, messages: &mut Vec<Message>,
+    ) -> Status {
+        self.element.on_event(area, event, messages)
+    }
+
+    pub(crate) fn layout(&self, bounds: Bounds, node: &mut LayoutNode) -> Size {
+        todo!()
+    }
+}
+
+impl<'a, Message> From<Element<'a, Message>> for FlexElement<'a, Message> {
+    fn from(element: Element<'a, Message>) -> Self {
+        Self { flex: 0, element }
+    }
+}
diff --git a/src/tuice/component/base/mod.rs b/src/tuice/component/base/mod.rs
index d2152703..237621a5 100644
--- a/src/tuice/component/base/mod.rs
+++ b/src/tuice/component/base/mod.rs
@@ -16,8 +16,8 @@ pub use block::Block;
 pub mod carousel;
 pub use carousel::Carousel;
 
-pub mod sized_box;
-pub use sized_box::SizedBox;
-
 pub mod container;
 pub use container::Container;
+
+pub mod flex;
+pub use flex::*;
diff --git a/src/tuice/component/base/row.rs b/src/tuice/component/base/row.rs
index dcdbf5d2..93c5b317 100644
--- a/src/tuice/component/base/row.rs
+++ b/src/tuice/component/base/row.rs
@@ -1,42 +1,59 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Bounds, Component, DrawContext, Event, Size, Status};
+use crate::tuice::{Bounds, Event, FlexElement, LayoutNode, Size, Status, TmpComponent};
 
 #[derive(Default)]
-pub struct Row<'a, Message, B>
-where
-    B: Backend,
-{
-    children: Vec<Box<dyn Component<Message, B> + 'a>>, // FIXME: For performance purposes, let's cheat and use enum-dispatch
+pub struct Row<'a, Message> {
+    children: Vec<FlexElement<'a, Message>>,
 }
 
-impl<'a, Message, B> Row<'a, Message, B>
-where
-    B: Backend,
-{
+impl<'a, Message> Row<'a, Message> {
     /// Creates a new [`Row`] with the given children.
     pub fn with_children<C>(children: Vec<C>) -> Self
     where
-        C: Into<Box<dyn Component<Message, B> + 'a>>,
+        C: Into<FlexElement<'a, Message>>,
     {
         Self {
             children: children.into_iter().map(Into::into).collect(),
         }
     }
+
+    pub fn with_child(mut self) -> Self {
+        self
+    }
+
+    pub fn with_flex_child(mut self) -> Self {
+        self
+    }
 }
 
-impl<'a, Message, B> Component<Message, B> for Row<'a, Message, B>
-where
-    B: Backend,
-{
-    fn draw(&mut self, area: Rect, context: &DrawContext, frame: &mut Frame<'_, B>) {
+impl<'a, Message> TmpComponent<Message> for Row<'a, Message> {
+    fn draw<B>(&mut self, area: Rect, frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         self.children.iter_mut().for_each(|child| {
-            // TODO: This is just temp! We need layout!
-            child.draw(area, context, frame);
+            child.draw(area, frame);
         })
     }
 
     fn on_event(&mut self, _area: Rect, _event: Event, _messages: &mut Vec<Message>) -> Status {
         Status::Ignored
     }
+
+    fn layout(&self, bounds: Bounds, node: &mut LayoutNode) -> Size {
+        let mut remaining_bounds = bounds;
+
+        let child_nodes: Vec<LayoutNode> = self
+            .children
+            .iter()
+            .map(|child| {
+                let mut child_node = LayoutNode::default();
+                let size = child.layout(remaining_bounds, &mut child_node);
+                child_node
+            })
+            .collect();
+
+        todo!()
+    }
 }
diff --git a/src/tuice/component/base/shortcut.rs b/src/tuice/component/base/shortcut.rs
index 9c70d10c..b17ac0dd 100644
--- a/src/tuice/component/base/shortcut.rs
+++ b/src/tuice/component/base/shortcut.rs
@@ -1,17 +1,17 @@
 use tui::{backend::Backend, layout::Rect, Frame};
 
-use crate::tuice::{Component, DrawContext, Event, Status};
+use crate::tuice::{Event, Status, TmpComponent};
 
 /// A [`Component`] to handle keyboard shortcuts and assign actions to them.
 ///
 /// Inspired by [Flutter's approach](https://docs.flutter.dev/development/ui/advanced/actions_and_shortcuts).
 pub struct Shortcut {}
 
-impl<Message, B> Component<Message, B> for Shortcut
-where
-    B: Backend,
-{
-    fn draw(&mut self, _area: Rect, _context: &DrawContext, _frame: &mut Frame<'_, B>) {
+impl<Message> TmpComponent<Message> for Shortcut {
+    fn draw<B>(&mut self, _area: Rect, _frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         todo!()
     }
 
diff --git a/src/tuice/component/base/sized_box.rs b/src/tuice/component/base/sized_box.rs
deleted file mode 100644
index 4f2286b6..00000000
--- a/src/tuice/component/base/sized_box.rs
+++ /dev/null
@@ -1,59 +0,0 @@
-use tui::backend::Backend;
-
-use crate::tuice::{Component, Length};
-
-pub struct SizedBox<'a, Message, B>
-where
-    B: Backend,
-{
-    width: Length,
-    height: Length,
-    child: Box<dyn Component<Message, B> + 'a>,
-}
-
-impl<'a, Message, B> SizedBox<'a, Message, B>
-where
-    B: Backend,
-{
-    /// Creates a new [`SizedBox`] for a child component
-    /// with a [`Length::Flex`] width and height.
-    pub fn new(child: Box<dyn Component<Message, B> + 'a>) -> Self {
-        Self {
-            width: Length::Flex,
-            height: Length::Flex,
-            child,
-        }
-    }
-
-    /// Creates a new [`SizedBox`] for a child component
-    /// with a [`Length::Flex`] height.
-    pub fn with_width(child: Box<dyn Component<Message, B> + 'a>, width: Length) -> Self {
-        Self {
-            width,
-            height: Length::Flex,
-            child,
-        }
-    }
-
-    /// Creates a new [`SizedBox`] for a child component
-    /// with a [`Length::Flex`] width.
-    pub fn with_height(child: Box<dyn Component<Message, B> + 'a>, height: Length) -> Self {
-        Self {
-            width: Length::Flex,
-            height,
-            child,
-        }
-    }
-
-    /// Sets the width of the [`SizedBox`].
-    pub fn width(mut self, width: Length) -> Self {
-        self.width = width;
-        self
-    }
-
-    /// Sets the height of the [`SizedBox`].
-    pub fn height(mut self, height: Length) -> Self {
-        self.height = height;
-        self
-    }
-}
diff --git a/src/tuice/component/base/text_table.rs b/src/tuice/component/base/text_table.rs
index 042e524c..03c45e49 100644
--- a/src/tuice/component/base/text_table.rs
+++ b/src/tuice/component/base/text_table.rs
@@ -14,7 +14,7 @@ use unicode_segmentation::UnicodeSegmentation;
 
 use crate::{
     constants::TABLE_GAP_HEIGHT_LIMIT,
-    tuice::{Component, DrawContext, Event, Status},
+    tuice::{Event, Status, TmpComponent},
 };
 
 pub use self::table_column::{TextColumn, TextColumnConstraint};
@@ -165,21 +165,11 @@ impl<'a, Message> TextTable<'a, Message> {
     }
 }
 
-impl<'a, Message, B> From<TextTable<'a, Message>> for Box<dyn Component<Message, B> + 'a>
-where
-    Message: 'a,
-    B: Backend,
-{
-    fn from(table: TextTable<'a, Message>) -> Self {
-        Box::new(table)
-    }
-}
-
-impl<'a, Message, B> Component<Message, B> for TextTable<'a, Message>
-where
-    B: Backend,
-{
-    fn draw(&mut self, area: Rect, context: &DrawContext, frame: &mut Frame<'_, B>) {
+impl<'a, Message> TmpComponent<Message> for TextTable<'a, Message> {
+    fn draw<B>(&mut self, area: Rect, frame: &mut Frame<'_, B>)
+    where
+        B: Backend,
+    {
         self.table_gap = if !self.show_gap
             || (self.rows.len() + 2 > area.height.into() && area.height < TABLE_GAP_HEIGHT_LIMIT)
         {
diff --git a/src/tuice/component/widget/mod.rs b/src/tuice/component/widget/mod.rs
index e69de29b..8b137891 100644
--- a/src/tuice/component/widget/mod.rs
+++ b/src/tuice/component/widget/mod.rs
@@ -0,0 +1 @@
+
diff --git a/src/tuice/draw_context.rs b/src/tuice/draw_context.rs
deleted file mode 100644
index 2815d9a7..00000000
--- a/src/tuice/draw_context.rs
+++ /dev/null
@@ -1 +0,0 @@
-pub struct DrawContext {}
diff --git a/src/tuice/element.rs b/src/tuice/element.rs
new file mode 100644
index 00000000..1148df98
--- /dev/null
+++ b/src/tuice/element.rs
@@ -0,0 +1,19 @@
+use enum_dispatch::enum_dispatch;
+use tui::{layout::Rect, Frame};
+
+use super::{
+    Block, Bounds, Carousel, Column, Container, Event, LayoutNode, Row, Shortcut, Size, Status,
+    TextTable, TmpComponent,
+};
+
+/// An [`Element`] is an instantiated [`Component`].
+#[enum_dispatch(TmpComponent<Message>)]
+pub enum Element<'a, Message> {
+    Block,
+    Carousel,
+    Column,
+    Container(Container<'a, Message>),
+    Row(Row<'a, Message>),
+    Shortcut,
+    TextTable(TextTable<'a, Message>),
+}
diff --git a/src/tuice/layout/bounds.rs b/src/tuice/layout/bounds.rs
index 59fe3ff2..15cf7dcc 100644
--- a/src/tuice/layout/bounds.rs
+++ b/src/tuice/layout/bounds.rs
@@ -2,6 +2,7 @@
 ///
 /// These are sent from a parent component to a child to determine the [`Size`](super::Size)
 /// of a child, which is passed back up to the parent.
+#[derive(Clone, Copy, Default)]
 pub struct Bounds {
     /// The minimal width available.
     pub min_width: u16,
@@ -15,3 +16,14 @@ pub struct Bounds {
     /// The maximal height available.
     pub max_height: u16,
 }
+
+impl Bounds {
+    pub fn with_two_bounds(width: u16, height: u16) -> Self {
+        Self {
+            min_width: width,
+            min_height: height,
+            max_width: width,
+            max_height: height,
+        }
+    }
+}
diff --git a/src/tuice/layout/build_layout.rs b/src/tuice/layout/build_layout.rs
index 6d8c59fb..709eed49 100644
--- a/src/tuice/layout/build_layout.rs
+++ b/src/tuice/layout/build_layout.rs
@@ -1,13 +1,8 @@
 use tui::layout::Rect;
 
-use crate::tuice::{Bounds, Component, LayoutNode};
+use crate::tuice::{Bounds, Element, LayoutNode, TmpComponent};
 
-pub fn build_layout_tree<Message, Backend>(
-    area: Rect, root: &Box<dyn Component<Message, Backend>>,
-) -> LayoutNode
-where
-    Backend: tui::backend::Backend,
-{
+pub fn build_layout_tree<Message>(area: Rect, root: &Element<'_, Message>) -> LayoutNode {
     let mut root_layout_node = LayoutNode::from_area(area);
     let bounds = Bounds {
         min_width: 0,
@@ -16,7 +11,7 @@ where
         max_height: area.height,
     };
 
-    root.layout(bounds, &mut root_layout_node);
+    let _ = root.layout(bounds, &mut root_layout_node);
 
     root_layout_node
 }
diff --git a/src/tuice/mod.rs b/src/tuice/mod.rs
index 3a942e2f..3a33cc60 100644
--- a/src/tuice/mod.rs
+++ b/src/tuice/mod.rs
@@ -15,5 +15,5 @@ pub use runtime::RuntimeEvent;
 pub mod layout;
 pub use layout::*;
 
-pub mod draw_context;
-pub use draw_context::*;
+pub mod element;
+pub use element::*;
diff --git a/src/tuice/runtime.rs b/src/tuice/runtime.rs
index dddb1722..5c22697e 100644
--- a/src/tuice/runtime.rs
+++ b/src/tuice/runtime.rs
@@ -4,7 +4,7 @@ use tui::layout::Rect;
 
 use crate::tuice::Status;
 
-use super::{Application, Event};
+use super::{Application, Event, TmpComponent};
 
 #[derive(Clone, Copy, Debug)]
 pub enum RuntimeEvent<Message> {
diff --git a/src/units/data_units.rs b/src/units/data_units.rs
index ce8f4867..d0b7c1e1 100644
--- a/src/units/data_units.rs
+++ b/src/units/data_units.rs
@@ -3,4 +3,3 @@ pub enum DataUnit {
     Byte,
     Bit,
 }
-