Styling for QR Code using theme framework

style/src/theme.rs

@@ -12,6 +12,7 @@ use crate::menu;
 use crate::pane_grid;
 use crate::pick_list;
 use crate::progress_bar;
+use crate::qr_code;
 use crate::radio;
 use crate::rule;
 use crate::scrollable;
@@ -956,6 +957,46 @@ impl<T: Fn(&Theme) -> progress_bar::Appearance> progress_bar::StyleSheet for T {
     }
 }
 
+/// The style of a QR Code.
+#[derive(Default)]
+pub enum QRCode {
+    /// The default style.
+    #[default]
+    Default,
+    /// A custom style.
+    Custom(Box<dyn qr_code::StyleSheet<Style = Theme>>),
+}
+
+impl<T: Fn(&Theme) -> qr_code::Appearance + 'static> From<T> for QRCode {
+    fn from(f: T) -> Self {
+        Self::Custom(Box::new(f))
+    }
+}
+
+impl qr_code::StyleSheet for Theme {
+    type Style = QRCode;
+
+    fn appearance(&self, style: &Self::Style) -> qr_code::Appearance {
+        let palette = self.palette();
+
+        match style {
+            QRCode::Default => qr_code::Appearance {
+                cell: palette.text,
+                background: palette.background,
+            },
+            QRCode::Custom(custom) => custom.appearance(self),
+        }
+    }
+}
+
+impl<T: Fn(&Theme) -> qr_code::Appearance> qr_code::StyleSheet for T {
+    type Style = Theme;
+
+    fn appearance(&self, style: &Self::Style) -> qr_code::Appearance {
+        (self)(style)
+    }
+}
+
 /// The style of a rule.
 #[derive(Default)]
 pub enum Rule {