fix Draw (redraw)

core/src/ui/mod.rs

@@ -28,7 +28,7 @@ pub trait UiRsc {
     #[allow(unused_variables)]
     fn on_remove(&mut self, id: WidgetId) {}
     #[allow(unused_variables)]
-    fn on_draw(&mut self, active: &ActiveData) {}
+    fn on_draw(&mut self, active: &ActiveData, redrawn: bool) {}
     #[allow(unused_variables)]
     fn on_undraw(&mut self, active: &ActiveData) {}
 

core/src/ui/render_state.rs

@@ -81,10 +81,12 @@ impl UiRenderState {
         old_children: Option<Vec<WidgetId>>,
         rsc: &mut dyn UiRsc,
     ) {
+        let mut redrawn = old_children.is_some();
         let mut old_children = old_children.unwrap_or_default();
         if let Some(active) = self.active.get_mut(&id)
             && !rsc.widgets().needs_redraw.contains(&id)
         {
+            redrawn = true;
             // check to see if we can skip drawing first
             if active.region == region {
                 return;
@@ -149,7 +151,7 @@ impl UiRenderState {
             }
         }
 
-        rsc.on_draw(&active);
+        rsc.on_draw(&active, redrawn);
         self.active.insert(id, active);
     }
 

examples/tabs/main.rs

@@ -148,7 +148,7 @@ impl DefaultAppState for Client {
             .span(Dir::DOWN)
             .add(rsc);
 
-        let main = WidgetPtr::new().add(rsc);
+        let main = WidgetPtr::empty().add(rsc);
 
         let vals = Rc::new(RefCell::new((0, Vec::new())));
         let mut switch_button = |color, to: WeakWidget, label| {

src/default/event.rs

@@ -7,3 +7,7 @@ impl Event for Submit {}
 #[derive(Eq, PartialEq, Hash, Clone)]
 pub struct Edited;
 impl Event for Edited {}
+
+#[derive(Eq, PartialEq, Hash, Clone)]
+pub struct Draw;
+impl Event for Draw {}

src/default/mod.rs

@@ -101,9 +101,21 @@ pub struct DefaultRsc<State: 'static> {
     pub events: EventManager<Self>,
     pub tasks: Tasks<Self>,
     pub state: WidgetState,
+    pub widget_events: Vec<WidgetEvent>,
     _state: PhantomData<State>,
 }
 
+pub struct WidgetEvent {
+    id: WidgetId,
+    ty: WidgetEventType,
+}
+
+pub enum WidgetEventType {
+    Draw,
+    Undraw,
+    Remove,
+}
+
 impl<State> DefaultRsc<State> {
     fn init(window: Arc<Window>) -> (Self, TaskMsgReceiver<Self>) {
         let (tasks, recv) = Tasks::init(window);
@@ -112,6 +124,7 @@ impl<State> DefaultRsc<State> {
                 ui: Default::default(),
                 events: Default::default(),
                 tasks,
+                widget_events: Default::default(),
                 state: Default::default(),
                 _state: Default::default(),
             },
@@ -133,17 +146,31 @@ impl<State> UiRsc for DefaultRsc<State> {
         &mut self.ui
     }
 
-    fn on_draw(&mut self, active: &ActiveData) {
+    fn on_draw(&mut self, active: &ActiveData, redrawn: bool) {
         self.events.draw(active);
+        if !redrawn {
+            self.widget_events.push(WidgetEvent {
+                id: active.id,
+                ty: WidgetEventType::Draw,
+            });
+        }
     }
 
     fn on_undraw(&mut self, active: &ActiveData) {
         self.events.undraw(active);
+        self.widget_events.push(WidgetEvent {
+            id: active.id,
+            ty: WidgetEventType::Undraw,
+        });
     }
 
     fn on_remove(&mut self, id: WidgetId) {
         self.events.remove(id);
         self.state.remove(id);
+        self.widget_events.push(WidgetEvent {
+            id,
+            ty: WidgetEventType::Remove,
+        });
     }
 }
 
@@ -297,6 +324,18 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
             _ => (),
         }
         state.window_event(event, rsc, render);
+
+        let mut events = std::mem::take(&mut rsc.widget_events);
+        for event in events.drain(..) {
+            match event.ty {
+                WidgetEventType::Draw => {
+                    rsc.run_event::<Draw>(event.id, (), state);
+                }
+                _ => (),
+            }
+        }
+        rsc.widget_events = events;
+
         let ui_state = self.state.default_state_mut();
         if render.needs_redraw(&ui_state.root, rsc.widgets()) {
             ui_state.renderer.window().request_redraw();

src/widget/mod.rs

@@ -5,6 +5,7 @@ mod ptr;
 mod rect;
 mod text;
 mod trait_fns;
+mod selector;
 
 pub use image::*;
 pub use mask::*;
@@ -13,3 +14,4 @@ pub use ptr::*;
 pub use rect::*;
 pub use text::*;
 pub use trait_fns::*;
+pub use selector::*;

src/widget/ptr.rs

@@ -30,8 +30,10 @@ impl Widget for WidgetPtr {
 }
 
 impl WidgetPtr {
-    pub fn new() -> Self {
-        Self::default()
+    pub fn new(widget: StrongWidget) -> Self {
+        Self {
+            inner: Some(widget),
+        }
     }
     pub fn empty() -> Self {
         Self {

src/widget/selector.rs

@@ -0,0 +1,48 @@
+use std::hash::Hash;
+
+use iris_core::util::HashMap;
+
+use crate::prelude::*;
+
+pub struct WidgetSelector<T> {
+    current: (T, StrongWidget),
+    map: HashMap<T, StrongWidget>,
+}
+
+impl<T: Hash + Eq> WidgetSelector<T> {
+    pub fn new(key: T, widget: StrongWidget) -> Self {
+        Self {
+            current: (key, widget),
+            map: Default::default(),
+        }
+    }
+
+    pub fn set(&mut self, key: T, widget: StrongWidget) {
+        self.map.insert(key, widget);
+    }
+
+    pub fn select(&mut self, key: T) -> bool {
+        if let Some(val) = self.map.remove(&key) {
+            let mut new = (key, val);
+            std::mem::swap(&mut new, &mut self.current);
+            self.map.insert(new.0, new.1);
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl<T: 'static> Widget for WidgetSelector<T> {
+    fn draw(&mut self, painter: &mut Painter) {
+        painter.widget(&self.current.1);
+    }
+
+    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
+        ctx.width(&self.current.1)
+    }
+
+    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
+        ctx.height(&self.current.1)
+    }
+}