Add Shadow to button::Appearance

style/src/button.rs

@@ -1,5 +1,5 @@
 //! Change the apperance of a button.
-use iced_core::{Background, Border, Color, Vector};
+use iced_core::{Background, Border, Color, Shadow, Vector};
 
 /// The appearance of a button.
 #[derive(Debug, Clone, Copy)]
@@ -8,10 +8,12 @@ pub struct Appearance {
     pub shadow_offset: Vector,
     /// The [`Background`] of the button.
     pub background: Option<Background>,
-    /// The [`Border`] of the butoon.
-    pub border: Border,
     /// The text [`Color`] of the button.
     pub text_color: Color,
+    /// The [`Border`] of the buton.
+    pub border: Border,
+    /// The [`Shadow`] of the butoon.
+    pub shadow: Shadow,
 }
 
 impl std::default::Default for Appearance {
@@ -19,8 +21,9 @@ impl std::default::Default for Appearance {
         Self {
             shadow_offset: Vector::default(),
             background: None,
-            border: Border::default(),
             text_color: Color::BLACK,
+            border: Border::default(),
+            shadow: Shadow::default(),
         }
     }
 }

widget/src/button.rs

@@ -391,11 +391,15 @@ where
         style_sheet.active(style)
     };
 
-    if styling.background.is_some() || styling.border.width > 0.0 {
+    if styling.background.is_some()
+        || styling.shadow.color.a > 0.0
+        || styling.border.width > 0.0
+    {
         renderer.fill_quad(
             renderer::Quad {
                 bounds,
                 border: styling.border,
+                shadow: styling.shadow,
                 ..renderer::Quad::default()
             },
             styling