Fix wasm check

crates/egui/src/atomics/atom_widget.rs

@@ -0,0 +1,111 @@
+use crate::{AtomKind, AtomLayout, Atoms, Button, Context, Frame, Id, Response, Ui, Widget};
+
+// We would rename AtomLayout to AtomElement or similar, and it would be the "container" element
+type AtomElement<'a> = AtomLayout<'a>;
+
+trait AtomWidget {
+    fn show(self, ui: &mut AtomUi, response: Response) -> AtomElement;
+}
+
+impl<'a> AtomWidget for Button<'a> {
+    // We could pass in the response via Context::read_response for convenience,
+    fn show(self, ui: &mut AtomUi, response: Response) -> AtomElement {
+        // self.atom_ui(ui) // this should return the AtomElement instead
+    }
+}
+
+/// The [Ui] equivalent. Instead of producing a list of shapes to paint, it produces a tree of
+/// [AtomElement]s to layout and paint
+struct AtomUi<'a> {
+    // This would probably just be another AtomElement and there would be a AtomKind::Layout
+    content: AtomElement<'a>,
+    id: Id,
+    next_id: usize,
+    context: Context,
+}
+
+impl AtomUi {
+    pub fn new(context: Context) -> Self {
+        AtomUi {
+            content: AtomElement::default(),
+            id: Id::new(0),
+            next_id: 0,
+            context,
+        }
+    }
+
+    pub fn scope(&mut self, layout: AtomElement, content: impl FnOnce(&mut AtomUi)) {}
+
+    pub fn horizontal(&mut self, content: impl FnOnce(&mut AtomUi)) {
+        let layout = AtomElement::default();
+        //.direction(egui::Direction::LeftToRight); We don't have a Direction yet
+        self.scope(layout, content);
+    }
+
+    pub fn vertical(&mut self, content: impl FnOnce(&mut AtomUi)) {
+        let layout = AtomElement::default();
+        //.direction(egui::Direction::TopDown); We don't have a Direction yet
+        self.scope(layout, content);
+    }
+
+    fn next_id(&mut self) -> Id {
+        let id = self.id.with(self.next_id);
+        self.next_id += 1;
+        id
+    }
+
+    pub fn add(&mut self, widget: impl AtomWidget<'_>) {
+        let id = self.next_id();
+        // It would be really convenient if this could return a "default" response instead of Option
+        let response = self.context.read_response(id);
+
+        // TODO: We need a AtomKind::AtomElement or similar
+        self.content
+            .push_right(widget.show(self, response.unwrap()));
+    }
+}
+
+impl Widget for AtomUi {
+    /// This is where the actual layout and rendering happens.
+    /// This could be a advanced version of our current `AtomLayout`
+    /// (we could draw inspiration from https://github.com/nicbarker/clay),
+    /// or could be based on e.g. `taffy`.
+    ///
+    /// Since we now have a tree of elements, we can do fancy multipass measuring and layouting.
+    /// Everything that `taffy` can do should be possible.
+    ///
+    /// We'd probably want to do some kind of caching here so we don't have to re-layout parts of the
+    /// tree that haven't changed. (Taffy has built in support for that, I believe.)
+    fn ui(self, ui: &mut Ui) -> Response {
+        self.content.show(ui).response
+    }
+}
+
+pub fn my_single_pass_ui(ui: &mut Ui) {
+    // Ideally there would be something like this:
+    // let mut atom_ui = ui.atom_ui(AtomElement::default().vertical());
+    // the atom ui should inherit the UiStack, Style, Id, etc...
+    let mut atom_ui = AtomUi::new(ui.ctx().clone());
+
+    // Then we can build our element tree
+    my_atom_ui(&mut atom_ui);
+
+    // And add it to our classic ui
+    ui.add(atom_ui);
+}
+
+/// The atom-based uis could feel very similar to the classic uis
+pub fn my_atom_ui(ui: &mut AtomUi) {
+    ui.add(Button::new("Atom Widget Button!"));
+
+    ui.horizontal(|ui| {
+        ui.add(Button::new("Button 2"));
+    });
+
+    // If we add a AtomKind::Ui(&dyn Widget) we could even integrate these both ways. Lifetimes
+    // could get baaad though, ideally we would evaluate closures as soon as they are added to the
+    // AtomElement. We could call the single pass ui based on the rect from last frame.
+    ui.add(AtomKind::ui(|ui: &mut Ui| {
+        my_single_pass_ui(ui);
+    }))
+}

crates/egui/src/atomics/mod.rs

@@ -1,7 +1,9 @@
 mod atom;
+mod atom_element;
 mod atom_ext;
 mod atom_kind;
 mod atom_layout;
+mod atom_widget;
 mod atoms;
 mod sized_atom;
 mod sized_atom_kind;