Widget::full_control_redraw

+ transparent containers show their shadows properly

src/context.rs

@@ -575,10 +575,8 @@ impl<'context, 'window, 'clip, 'gfx, 'pass> GraphicsContext<'context, 'window, '
     /// Updates `self` to have `opacity`.
     ///
     /// This setting will be mixed with the current opacity value.
-    #[must_use]
-    pub fn with_opacity(mut self, opacity: impl Into<ZeroToOne>) -> Self {
+    pub fn apply_opacity(&mut self, opacity: impl Into<ZeroToOne>) {
         self.gfx.opacity *= opacity.into();
-        self
     }
 
     /// Returns a new graphics context that renders to the `clip` rectangle.
@@ -668,15 +666,20 @@ impl<'context, 'window, 'clip, 'gfx, 'pass> GraphicsContext<'context, 'window, '
             "redraw called without set_widget_layout"
         );
 
-        let background = self.get(&WidgetBackground);
-        self.fill(background);
-
-        self.apply_current_font_settings();
-
         self.current_node
             .tree
             .note_widget_rendered(self.current_node.node_id);
-        self.current_node.clone().lock().as_widget().redraw(self);
+        let widget = self.current_node.clone();
+        let mut widget = widget.lock();
+        if !widget.as_widget().full_control_redraw() {
+            let background = self.get(&WidgetBackground);
+            self.fill(background);
+
+            self.apply_current_font_settings();
+            self.apply_opacity(self.get(&Opacity));
+        }
+
+        widget.as_widget().redraw(self);
     }
 }
 

src/widget.rs

@@ -63,6 +63,22 @@ pub trait Widget: Send + UnwindSafe + Debug + 'static {
         Debug::fmt(self, f)
     }
 
+    /// Returns true if this widget handles all built-in style components that
+    /// apply.
+    ///
+    /// These components are:
+    ///
+    /// - [`Opacity`](crate::styles::components::Opacity)
+    /// - [`WidgetBackground`](crate::styles::components::WidgetBackground)
+    /// - [`FontFamily`]
+    /// - [`TextSize`]
+    /// - [`LineHeight`]
+    /// - [`FontStyle`]
+    /// - [`FontWeight`]
+    fn full_control_redraw(&self) -> bool {
+        false
+    }
+
     /// Layout this widget and returns the ideal size based on its contents and
     /// the `available_space`.
     #[allow(unused_variables)]

src/widgets/container.rs

@@ -8,7 +8,7 @@ use kludgine::shapes::{CornerRadii, PathBuilder, Shape};
 use kludgine::Color;
 
 use crate::context::{EventContext, GraphicsContext, LayoutContext, WidgetContext};
-use crate::styles::components::{CornerRadius, IntrinsicPadding, SurfaceColor};
+use crate::styles::components::{CornerRadius, IntrinsicPadding, Opacity, SurfaceColor};
 use crate::styles::{Component, ContainerLevel, Dimension, Edges, RequireInvalidation, Styles};
 use crate::value::{Dynamic, IntoValue, Value};
 use crate::widget::{MakeWidget, RootBehavior, Widget, WidgetInstance, WidgetRef};
@@ -211,9 +211,16 @@ impl Widget for Container {
             .finish()
     }
 
+    fn full_control_redraw(&self) -> bool {
+        true
+    }
+
     #[allow(clippy::too_many_lines)]
     fn redraw(&mut self, context: &mut GraphicsContext<'_, '_, '_, '_, '_>) {
+        let opacity = context.get(&Opacity);
+
         let background = self.effective_background_color(context);
+        let background = background.with_alpha_f32(background.alpha_f32() * *opacity);
         if background.alpha() > 0 {
             let shadow = self.effective_shadow(context).into_px(context.gfx.scale());
 

src/widgets/layers.rs

@@ -9,7 +9,7 @@ use intentional::Assert;
 use kludgine::figures::units::{Px, UPx};
 use kludgine::figures::{IntoSigned, IntoUnsigned, Point, Rect, Size, Zero};
 
-use crate::animation::easings::{EaseInQuadradic, EaseOutQuadradic};
+use crate::animation::easings::EaseOutQuadradic;
 use crate::animation::{AnimationTarget, Spawn, ZeroToOne};
 use crate::context::{AsEventContext, EventContext, GraphicsContext, LayoutContext};
 use crate::value::{Dynamic, DynamicGuard, Generation, IntoValue, Value};
@@ -205,7 +205,9 @@ impl Widget for OverlayLayer {
             };
 
             let opacity = child.opacity.get_tracking_refresh(context);
-            context.for_other(mounted).with_opacity(opacity).redraw();
+            let mut context = context.for_other(mounted);
+            context.apply_opacity(opacity);
+            context.redraw();
         }
     }