wayland: implement alpha_modifier_v1

src/theme.rs

@@ -1,6 +1,7 @@
 use std::{
     cell::{Cell, RefCell},
     cmp::Ordering,
+    ops::Mul,
 };
 
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -23,6 +24,19 @@ impl Ord for Color {
     }
 }
 
+impl Mul<f32> for Color {
+    type Output = Self;
+
+    fn mul(self, rhs: f32) -> Self::Output {
+        Self {
+            r: self.r * rhs,
+            g: self.g * rhs,
+            b: self.b * rhs,
+            a: self.a * rhs,
+        }
+    }
+}
+
 impl PartialOrd for Color {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
         Some(self.cmp(other))