Add Widget and Node

Cargo.lock

@@ -80,6 +80,12 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "arrayvec"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96d30a06541fbafbc7f82ed10c06164cfbd2c401138f6addd8404629c4b16711"
+
 [[package]]
 name = "async-trait"
 version = "0.1.77"
@@ -454,6 +460,12 @@ version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4271d37baee1b8c7e4b708028c57d816cf9d2434acb33a549475f78c181f6253"
 
+[[package]]
+name = "grid"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d196ffc1627db18a531359249b2bf8416178d84b729f3cebeb278f285fb9b58c"
+
 [[package]]
 name = "h2"
 version = "0.4.2"
@@ -1027,6 +1039,7 @@ dependencies = [
  "anyhow",
  "image",
  "palette",
+ "taffy",
 ]
 
 [[package]]
@@ -1073,6 +1086,15 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "slotmap"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbff4acf519f630b3a3ddcfaea6c06b42174d9a44bc70c620e9ed1649d58b82a"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.13.1"
@@ -1121,6 +1143,19 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
 
+[[package]]
+name = "taffy"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fddbee94e20bc4612dcb789953324236eebd4fc6a08c650ccbf7f615e59a0d6a"
+dependencies = [
+ "arrayvec",
+ "grid",
+ "num-traits",
+ "serde",
+ "slotmap",
+]
+
 [[package]]
 name = "tiff"
 version = "0.9.1"
@@ -1236,6 +1271,12 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
 
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"

showbits-common/Cargo.toml

@@ -8,5 +8,10 @@ anyhow.workspace = true
 image.workspace = true
 palette.workspace = true
 
+[dependencies.taffy]
+version = "0.4.0"
+default-features = false
+features = ["std", "taffy_tree", "flexbox", "grid", "block_layout"]
+
 [lints]
 workspace = true

showbits-common/src/lib.rs

@@ -1,5 +1,7 @@
-pub use crate::{rect::*, vec2::*, view::*};
+pub use crate::{node::*, rect::*, vec2::*, view::*, widget::*};
 
+mod node;
 mod rect;
 mod vec2;
 mod view;
+mod widget;

showbits-common/src/node.rs

@@ -0,0 +1,30 @@
+use taffy::{NodeId, Style, TaffyResult, TaffyTree};
+
+use crate::Widget;
+
+pub struct Node {
+    layout: Style,
+    children: Vec<NodeId>,
+    widget: Option<Box<dyn Widget>>,
+}
+
+impl Node {
+    pub fn empty() -> Self {
+        Self {
+            layout: Style::default(),
+            children: vec![],
+            widget: None,
+        }
+    }
+
+    pub fn widget<W: Widget + 'static>(mut self, widget: W) -> Self {
+        self.widget = Some(Box::new(widget));
+        self
+    }
+
+    pub fn register(self, tree: &mut TaffyTree<Box<dyn Widget>>) -> TaffyResult<NodeId> {
+        let id = tree.new_with_children(self.layout, &self.children)?;
+        tree.set_node_context(id, self.widget)?;
+        Ok(id)
+    }
+}

showbits-common/src/widget.rs

@@ -0,0 +1,23 @@
+use taffy::{AvailableSpace, Size};
+
+use crate::{Node, View};
+
+pub trait Widget {
+    #[allow(unused_variables)]
+    fn size(&mut self, known: Size<Option<f32>>, available: Size<AvailableSpace>) -> Size<f32> {
+        Size::ZERO
+    }
+
+    fn draw_below(&mut self, view: &mut View<'_>) -> anyhow::Result<()>;
+    fn draw_above(&mut self, view: &mut View<'_>) -> anyhow::Result<()>;
+}
+
+pub trait WidgetExt {
+    fn node(self) -> Node;
+}
+
+impl<W: Widget + 'static> WidgetExt for W {
+    fn node(self) -> Node {
+        Node::empty().widget(self)
+    }
+}