Add Theme selector to layout example

examples/layout/src/main.rs

@@ -1,8 +1,8 @@
 use iced::executor;
 use iced::keyboard;
 use iced::widget::{
-    button, checkbox, column, container, horizontal_space, row, text,
+    button, checkbox, column, container, horizontal_space, pick_list, row,
-    vertical_rule,
+    text, vertical_rule,
 };
 use iced::{
     color, Alignment, Application, Color, Command, Element, Font, Length,
@@ -17,13 +17,15 @@ pub fn main() -> iced::Result {
 struct Layout {
     example: Example,
     explain: bool,
+    theme: Theme,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone)]
 enum Message {
     Next,
     Previous,
     ExplainToggled(bool),
+    ThemeSelected(Theme),
 }
 
 impl Application for Layout {
@@ -37,6 +39,7 @@ impl Application for Layout {
             Self {
                 example: Example::default(),
                 explain: false,
+                theme: Theme::Light,
             },
             Command::none(),
         )
@@ -57,6 +60,9 @@ impl Application for Layout {
             Message::ExplainToggled(explain) => {
                 self.explain = explain;
             }
+            Message::ThemeSelected(theme) => {
+                self.theme = theme;
+            }
         }
 
         Command::none()
@@ -75,7 +81,13 @@ impl Application for Layout {
             text(self.example.title).size(20).font(Font::MONOSPACE),
             horizontal_space(Length::Fill),
             checkbox("Explain", self.explain, Message::ExplainToggled),
+            pick_list(
+                Theme::ALL,
+                Some(self.theme.clone()),
+                Message::ThemeSelected
+            ),
         ]
+        .spacing(20)
         .align_items(Alignment::Center);
 
         let example = container(if self.explain {
@@ -115,7 +127,7 @@ impl Application for Layout {
     }
 
     fn theme(&self) -> Theme {
-        Theme::Dark
+        self.theme.clone()
     }
 }
 

examples/styling/src/main.rs

@@ -53,13 +53,16 @@ impl Sandbox for Styling {
                 self.theme = match theme {
                     ThemeType::Light => Theme::Light,
                     ThemeType::Dark => Theme::Dark,
-                    ThemeType::Custom => Theme::custom(theme::Palette {
+                    ThemeType::Custom => Theme::custom(
-                        background: Color::from_rgb(1.0, 0.9, 1.0),
+                        String::from("Custom"),
-                        text: Color::BLACK,
+                        theme::Palette {
-                        primary: Color::from_rgb(0.5, 0.5, 0.0),
+                            background: Color::from_rgb(1.0, 0.9, 1.0),
-                        success: Color::from_rgb(0.0, 1.0, 0.0),
+                            text: Color::BLACK,
-                        danger: Color::from_rgb(1.0, 0.0, 0.0),
+                            primary: Color::from_rgb(0.5, 0.5, 0.0),
-                    }),
+                            success: Color::from_rgb(0.0, 1.0, 0.0),
+                            danger: Color::from_rgb(1.0, 0.0, 0.0),
+                        },
+                    ),
                 }
             }
             Message::InputChanged(value) => self.input_value = value,

style/src/theme.rs

@@ -23,6 +23,7 @@ use crate::toggler;
 
 use iced_core::{Background, Color, Vector};
 
+use std::fmt;
 use std::rc::Rc;
 
 /// A built-in theme.
@@ -38,18 +39,22 @@ pub enum Theme {
 }
 
 impl Theme {
+    /// A list with all the defined themes.
+    pub const ALL: &'static [Self] = &[Self::Light, Self::Dark];
+
     /// Creates a new custom [`Theme`] from the given [`Palette`].
-    pub fn custom(palette: Palette) -> Self {
+    pub fn custom(name: String, palette: Palette) -> Self {
-        Self::custom_with_fn(palette, palette::Extended::generate)
+        Self::custom_with_fn(name, palette, palette::Extended::generate)
     }
 
     /// Creates a new custom [`Theme`] from the given [`Palette`], with
     /// a custom generator of a [`palette::Extended`].
     pub fn custom_with_fn(
+        name: String,
         palette: Palette,
         generate: impl FnOnce(Palette) -> palette::Extended,
     ) -> Self {
-        Self::Custom(Box::new(Custom::with_fn(palette, generate)))
+        Self::Custom(Box::new(Custom::with_fn(name, palette, generate)))
     }
 
     /// Returns the [`Palette`] of the [`Theme`].
@@ -71,32 +76,51 @@ impl Theme {
     }
 }
 
+impl fmt::Display for Theme {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Light => write!(f, "Light"),
+            Self::Dark => write!(f, "Dark"),
+            Self::Custom(custom) => custom.fmt(f),
+        }
+    }
+}
+
 /// A [`Theme`] with a customized [`Palette`].
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Custom {
+    name: String,
     palette: Palette,
     extended: palette::Extended,
 }
 
 impl Custom {
     /// Creates a [`Custom`] theme from the given [`Palette`].
-    pub fn new(palette: Palette) -> Self {
+    pub fn new(name: String, palette: Palette) -> Self {
-        Self::with_fn(palette, palette::Extended::generate)
+        Self::with_fn(name, palette, palette::Extended::generate)
     }
 
     /// Creates a [`Custom`] theme from the given [`Palette`] with
     /// a custom generator of a [`palette::Extended`].
     pub fn with_fn(
+        name: String,
         palette: Palette,
         generate: impl FnOnce(Palette) -> palette::Extended,
     ) -> Self {
         Self {
+            name,
             palette,
             extended: generate(palette),
         }
     }
 }
 
+impl fmt::Display for Custom {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.name)
+    }
+}
+
 /// The style of an application.
 #[derive(Default)]
 pub enum Application {

widget/src/helpers.rs

@@ -271,7 +271,7 @@ pub fn pick_list<'a, Message, Renderer, T>(
     on_selected: impl Fn(T) -> Message + 'a,
 ) -> PickList<'a, T, Message, Renderer>
 where
-    T: ToString + Eq + 'static,
+    T: ToString + PartialEq + 'static,
     [T]: ToOwned<Owned = Vec<T>>,
     Renderer: core::text::Renderer,
     Renderer::Theme: pick_list::StyleSheet

widget/src/pick_list.rs

@@ -45,7 +45,7 @@ where
 
 impl<'a, T: 'a, Message, Renderer> PickList<'a, T, Message, Renderer>
 where
-    T: ToString + Eq,
+    T: ToString + PartialEq,
     [T]: ToOwned<Owned = Vec<T>>,
     Renderer: text::Renderer,
     Renderer::Theme: StyleSheet
@@ -145,7 +145,7 @@ where
 impl<'a, T: 'a, Message, Renderer> Widget<Message, Renderer>
     for PickList<'a, T, Message, Renderer>
 where
-    T: Clone + ToString + Eq + 'static,
+    T: Clone + ToString + PartialEq + 'static,
     [T]: ToOwned<Owned = Vec<T>>,
     Message: 'a,
     Renderer: text::Renderer + 'a,
@@ -281,7 +281,7 @@ where
 impl<'a, T: 'a, Message, Renderer> From<PickList<'a, T, Message, Renderer>>
     for Element<'a, Message, Renderer>
 where
-    T: Clone + ToString + Eq + 'static,
+    T: Clone + ToString + PartialEq + 'static,
     [T]: ToOwned<Owned = Vec<T>>,
     Message: 'a,
     Renderer: text::Renderer + 'a,