Merge pull request #1861 from marienz/from-pointers

Support conversion from Fn trait to custom theme

2 files changed, 24 insertions, 31 deletions

diff --git a/examples/scrollable/src/main.rs b/examples/scrollable/src/main.rs
index 97344c94..9d57cb94 100644
--- a/examples/scrollable/src/main.rs
+++ b/examples/scrollable/src/main.rs
@@ -289,18 +289,13 @@ impl Application for ScrollableDemo {
             }
             Direction::Horizontal => {
                 progress_bar(0.0..=1.0, self.current_scroll_offset.x)
-                    .style(theme::ProgressBar::Custom(Box::new(
-                        ProgressBarCustomStyle,
-                    )))
+                    .style(progress_bar_custom_style)
                     .into()
             }
             Direction::Multi => column![
                 progress_bar(0.0..=1.0, self.current_scroll_offset.y),
-                progress_bar(0.0..=1.0, self.current_scroll_offset.x).style(
-                    theme::ProgressBar::Custom(Box::new(
-                        ProgressBarCustomStyle,
-                    ))
-                )
+                progress_bar(0.0..=1.0, self.current_scroll_offset.x)
+                    .style(progress_bar_custom_style)
             ]
             .spacing(10)
             .into(),
@@ -372,16 +367,10 @@ impl scrollable::StyleSheet for ScrollbarCustomStyle {
     }
 }
 
-struct ProgressBarCustomStyle;
-
-impl progress_bar::StyleSheet for ProgressBarCustomStyle {
-    type Style = Theme;
-
-    fn appearance(&self, style: &Self::Style) -> progress_bar::Appearance {
-        progress_bar::Appearance {
-            background: style.extended_palette().background.strong.color.into(),
-            bar: Color::from_rgb8(250, 85, 134).into(),
-            border_radius: 0.0,
-        }
+fn progress_bar_custom_style(theme: &Theme) -> progress_bar::Appearance {
+    progress_bar::Appearance {
+        background: theme.extended_palette().background.strong.color.into(),
+        bar: Color::from_rgb8(250, 85, 134).into(),
+        border_radius: 0.0,
     }
 }
diff --git a/style/src/theme.rs b/style/src/theme.rs
index 6299975d..9500fe9d 100644
--- a/style/src/theme.rs
+++ b/style/src/theme.rs
@@ -105,7 +105,7 @@ impl application::StyleSheet for Theme {
     }
 }
 
-impl application::StyleSheet for fn(&Theme) -> application::Appearance {
+impl<T: Fn(&Theme) -> application::Appearance> application::StyleSheet for T {
     type Style = Theme;
 
     fn appearance(&self, style: &Self::Style) -> application::Appearance {
@@ -113,8 +113,10 @@ impl application::StyleSheet for fn(&Theme) -> application::Appearance {
     }
 }
 
-impl From<fn(&Theme) -> application::Appearance> for Application {
-    fn from(f: fn(&Theme) -> application::Appearance) -> Self {
+impl<T: Fn(&Theme) -> application::Appearance + 'static> From<T>
+    for Application
+{
+    fn from(f: T) -> Self {
         Self::Custom(Box::new(f))
     }
 }
@@ -363,8 +365,8 @@ pub enum Container {
     Custom(Box<dyn container::StyleSheet<Style = Theme>>),
 }
 
-impl From<fn(&Theme) -> container::Appearance> for Container {
-    fn from(f: fn(&Theme) -> container::Appearance) -> Self {
+impl<T: Fn(&Theme) -> container::Appearance + 'static> From<T> for Container {
+    fn from(f: T) -> Self {
         Self::Custom(Box::new(f))
     }
 }
@@ -391,7 +393,7 @@ impl container::StyleSheet for Theme {
     }
 }
 
-impl container::StyleSheet for fn(&Theme) -> container::Appearance {
+impl<T: Fn(&Theme) -> container::Appearance> container::StyleSheet for T {
     type Style = Theme;
 
     fn appearance(&self, style: &Self::Style) -> container::Appearance {
@@ -777,8 +779,10 @@ pub enum ProgressBar {
     Custom(Box<dyn progress_bar::StyleSheet<Style = Theme>>),
 }
 
-impl From<fn(&Theme) -> progress_bar::Appearance> for ProgressBar {
-    fn from(f: fn(&Theme) -> progress_bar::Appearance) -> Self {
+impl<T: Fn(&Theme) -> progress_bar::Appearance + 'static> From<T>
+    for ProgressBar
+{
+    fn from(f: T) -> Self {
         Self::Custom(Box::new(f))
     }
 }
@@ -808,7 +812,7 @@ impl progress_bar::StyleSheet for Theme {
     }
 }
 
-impl progress_bar::StyleSheet for fn(&Theme) -> progress_bar::Appearance {
+impl<T: Fn(&Theme) -> progress_bar::Appearance> progress_bar::StyleSheet for T {
     type Style = Theme;
 
     fn appearance(&self, style: &Self::Style) -> progress_bar::Appearance {
@@ -826,8 +830,8 @@ pub enum Rule {
     Custom(Box<dyn rule::StyleSheet<Style = Theme>>),
 }
 
-impl From<fn(&Theme) -> rule::Appearance> for Rule {
-    fn from(f: fn(&Theme) -> rule::Appearance) -> Self {
+impl<T: Fn(&Theme) -> rule::Appearance + 'static> From<T> for Rule {
+    fn from(f: T) -> Self {
         Self::Custom(Box::new(f))
     }
 }
@@ -850,7 +854,7 @@ impl rule::StyleSheet for Theme {
     }
 }
 
-impl rule::StyleSheet for fn(&Theme) -> rule::Appearance {
+impl<T: Fn(&Theme) -> rule::Appearance> rule::StyleSheet for T {
     type Style = Theme;
 
     fn appearance(&self, style: &Self::Style) -> rule::Appearance {