reactivity base

src/layout/ui.rs

@@ -0,0 +1,101 @@
+use crate::{
+    primitive::{Painter, Primitives},
+    util::{IDTracker, ID},
+    HashMap, Widget, WidgetId, WidgetLike, WidgetRef,
+};
+use std::{
+    any::{Any, TypeId},
+    cell::RefCell,
+    rc::Rc,
+};
+
+pub struct UI {
+    ids: IDTracker,
+    base: Option<WidgetId>,
+    pub widgets: Widgets,
+}
+
+pub struct Widgets(HashMap<ID, Box<dyn Widget>>);
+
+#[derive(Clone)]
+pub struct UIBuilder {
+    ui: Rc<RefCell<UI>>,
+}
+
+impl From<UI> for UIBuilder {
+    fn from(ui: UI) -> Self {
+        UIBuilder {
+            ui: Rc::new(RefCell::new(ui)),
+        }
+    }
+}
+
+impl UIBuilder {
+    pub fn add<W: Widget>(&mut self, w: W) -> WidgetRef<W> {
+        WidgetRef::new(self.clone(), [self.push(w)])
+    }
+
+    pub fn push<W: Widget>(&mut self, w: W) -> WidgetId {
+        let mut ui = self.ui.borrow_mut();
+        let id = ui.ids.next();
+        ui.widgets.insert(id.duplicate(), w);
+        WidgetId::new(id, TypeId::of::<W>())
+    }
+
+    pub fn finish<WL: WidgetLike<W>, W>(mut self, base: WL) -> UI {
+        let base = base.id(&mut self).erase_type();
+        let mut ui = Rc::into_inner(self.ui).unwrap().into_inner();
+        ui.base = Some(base);
+        ui
+    }
+}
+
+impl UI {
+    pub fn build() -> UIBuilder {
+        Self::empty().into()
+    }
+
+    pub fn empty() -> Self {
+        Self {
+            ids: IDTracker::new(),
+            base: None,
+            widgets: Widgets::new(),
+        }
+    }
+
+    pub fn to_primitives(&self) -> Primitives {
+        let mut painter = Painter::new(&self.widgets);
+        if let Some(base) = &self.base {
+            painter.draw(base);
+        }
+        painter.finish()
+    }
+}
+
+impl Widgets {
+    fn new() -> Self {
+        Self(HashMap::new())
+    }
+
+    pub fn get(&self, id: &WidgetId) -> &dyn Widget {
+        self.0.get(&id.id).unwrap().as_ref()
+    }
+
+    pub fn get_mut<W: Widget>(&mut self, id: &WidgetId<W>) -> Option<&mut W> {
+        self.0.get_mut(&id.id).unwrap().as_any_mut().downcast_mut()
+    }
+
+    pub fn insert(&mut self, id: ID, widget: impl Widget) {
+        self.0.insert(id, Box::new(widget));
+    }
+
+    pub fn insert_any(&mut self, id: ID, widget: Box<dyn Widget>) {
+        self.0.insert(id, widget);
+    }
+}
+
+impl dyn Widget {
+    pub fn as_any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+}