texture freeing + render updates done a bit nicer

src/layout/ui.rs

@@ -1,8 +1,8 @@
 use image::DynamicImage;
 
 use crate::{
-    ActiveSensors, HashMap, Painter, SensorMap, TextureHandle, TextureUpdates, Textures, Widget,
-    WidgetId, WidgetLike,
+    ActiveSensors, HashMap, Painter, SensorMap, TextureHandle, Textures, Widget, WidgetId,
+    WidgetLike,
     render::Primitives,
     util::{Id, IdTracker},
 };
@@ -16,16 +16,22 @@ pub struct Ui<Ctx> {
     base: Option<WidgetId>,
     widgets: Widgets<Ctx>,
     updates: Vec<WidgetId>,
-    del_recv: Receiver<Id>,
-    del_send: Sender<Id>,
-    primitives: Primitives,
-    textures: Textures,
+    recv: Receiver<UiMsg>,
+    send: UiMsgSender,
+    pub(crate) primitives: Primitives,
+    pub(crate) textures: Textures,
     full_redraw: bool,
 
     pub(super) active_sensors: ActiveSensors,
     pub(super) sensor_map: SensorMap<Ctx>,
 }
 
+pub enum UiMsg {
+    FreeWidget(Id),
+    FreeTexture(u32),
+}
+pub type UiMsgSender = Sender<UiMsg>;
+
 #[derive(Default)]
 pub struct Widgets<Ctx> {
     ids: IdTracker,
@@ -75,15 +81,11 @@ impl<Ctx> Ui<Ctx> {
     }
 
     pub fn id<W: Widget<Ctx>>(&mut self) -> WidgetId<W> {
-        WidgetId::new(
-            self.widgets.reserve(),
-            TypeId::of::<W>(),
-            self.del_send.clone(),
-        )
+        WidgetId::new(self.widgets.reserve(), TypeId::of::<W>(), self.send.clone())
     }
 
     pub fn add_texture(&mut self, image: DynamicImage) -> TextureHandle {
-        self.textures.add(image)
+        self.textures.add(image, self.send.clone())
     }
 
     pub fn redraw_all(&mut self, ctx: &mut Ctx)
@@ -103,33 +105,27 @@ impl<Ctx> Ui<Ctx> {
         self.primitives = painter.finish();
     }
 
-    pub fn update(&mut self, ctx: &mut Ctx) -> UiRenderUpdates
+    pub fn update(&mut self, ctx: &mut Ctx)
     where
         Ctx: 'static,
     {
-        while let Ok(id) = self.del_recv.try_recv() {
-            self.widgets.delete(id);
-        }
+        self.recv_msgs();
 
         if self.full_redraw {
             self.redraw_all(ctx);
             self.full_redraw = false;
-            UiRenderUpdates {
-                primitives: Some(&self.primitives),
-                textures: self.textures.updates(),
-            }
-        } else if self.updates.is_empty() {
-            UiRenderUpdates {
-                primitives: None,
-                textures: self.textures.updates(),
-            }
-        } else {
+        } else if !self.updates.is_empty() {
             // TODO: partial updates
             self.redraw_all(ctx);
             self.updates.drain(..);
-            UiRenderUpdates {
-                primitives: Some(&self.primitives),
-                textures: self.textures.updates(),
+        }
+    }
+
+    fn recv_msgs(&mut self) {
+        while let Ok(msg) = self.recv.try_recv() {
+            match msg {
+                UiMsg::FreeWidget(id) => self.widgets.delete(id),
+                UiMsg::FreeTexture(id) => self.textures.free(id),
             }
         }
     }
@@ -230,13 +226,8 @@ impl<Ctx: 'static> Default for Ui<Ctx> {
             full_redraw: false,
             active_sensors: Default::default(),
             sensor_map: Default::default(),
-            del_send,
-            del_recv,
+            send: del_send,
+            recv: del_recv,
         }
     }
 }
-
-pub struct UiRenderUpdates<'a> {
-    pub primitives: Option<&'a Primitives>,
-    pub textures: TextureUpdates<'a>,
-}