Implement rich_text widget and markdown example

core/src/widget/text.rs

@@ -11,8 +11,6 @@ use crate::{
     Widget,
 };
 
-use std::borrow::Cow;
-
 pub use text::{LineHeight, Shaping};
 
 /// A paragraph of text.
@@ -22,7 +20,7 @@ where
     Theme: Catalog,
     Renderer: text::Renderer,
 {
-    fragment: Fragment<'a>,
+    fragment: text::Fragment<'a>,
     size: Option<Pixels>,
     line_height: LineHeight,
     width: Length,
@@ -40,7 +38,7 @@ where
     Renderer: text::Renderer,
 {
     /// Create a new fragment of [`Text`] with the given contents.
-    pub fn new(fragment: impl IntoFragment<'a>) -> Self {
+    pub fn new(fragment: impl text::IntoFragment<'a>) -> Self {
         Text {
             fragment: fragment.into_fragment(),
             size: None,
@@ -216,7 +214,7 @@ where
         let state = tree.state.downcast_ref::<State<Renderer::Paragraph>>();
         let style = theme.style(&self.class);
 
-        draw(renderer, defaults, layout, state, style, viewport);
+        draw(renderer, defaults, layout, state.0.raw(), style, viewport);
     }
 }
 
@@ -275,13 +273,12 @@ pub fn draw<Renderer>(
     renderer: &mut Renderer,
     style: &renderer::Style,
     layout: Layout<'_>,
-    state: &State<Renderer::Paragraph>,
+    paragraph: &Renderer::Paragraph,
     appearance: Style,
     viewport: &Rectangle,
 ) where
     Renderer: text::Renderer,
 {
-    let State(ref paragraph) = state;
     let bounds = layout.bounds();
 
     let x = match paragraph.horizontal_alignment() {
@@ -297,7 +294,7 @@ pub fn draw<Renderer>(
     };
 
     renderer.fill_paragraph(
-        paragraph.raw(),
+        paragraph,
         Point::new(x, y),
         appearance.color.unwrap_or(style.text_color),
         *viewport,
@@ -415,81 +412,3 @@ pub fn danger(theme: &Theme) -> Style {
         color: Some(theme.palette().danger),
     }
 }
-
-/// A fragment of [`Text`].
-///
-/// This is just an alias to a string that may be either
-/// borrowed or owned.
-pub type Fragment<'a> = Cow<'a, str>;
-
-/// A trait for converting a value to some text [`Fragment`].
-pub trait IntoFragment<'a> {
-    /// Converts the value to some text [`Fragment`].
-    fn into_fragment(self) -> Fragment<'a>;
-}
-
-impl<'a> IntoFragment<'a> for Fragment<'a> {
-    fn into_fragment(self) -> Fragment<'a> {
-        self
-    }
-}
-
-impl<'a, 'b> IntoFragment<'a> for &'a Fragment<'b> {
-    fn into_fragment(self) -> Fragment<'a> {
-        Fragment::Borrowed(self)
-    }
-}
-
-impl<'a> IntoFragment<'a> for &'a str {
-    fn into_fragment(self) -> Fragment<'a> {
-        Fragment::Borrowed(self)
-    }
-}
-
-impl<'a> IntoFragment<'a> for &'a String {
-    fn into_fragment(self) -> Fragment<'a> {
-        Fragment::Borrowed(self.as_str())
-    }
-}
-
-impl<'a> IntoFragment<'a> for String {
-    fn into_fragment(self) -> Fragment<'a> {
-        Fragment::Owned(self)
-    }
-}
-
-macro_rules! into_fragment {
-    ($type:ty) => {
-        impl<'a> IntoFragment<'a> for $type {
-            fn into_fragment(self) -> Fragment<'a> {
-                Fragment::Owned(self.to_string())
-            }
-        }
-
-        impl<'a> IntoFragment<'a> for &$type {
-            fn into_fragment(self) -> Fragment<'a> {
-                Fragment::Owned(self.to_string())
-            }
-        }
-    };
-}
-
-into_fragment!(char);
-into_fragment!(bool);
-
-into_fragment!(u8);
-into_fragment!(u16);
-into_fragment!(u32);
-into_fragment!(u64);
-into_fragment!(u128);
-into_fragment!(usize);
-
-into_fragment!(i8);
-into_fragment!(i16);
-into_fragment!(i32);
-into_fragment!(i64);
-into_fragment!(i128);
-into_fragment!(isize);
-
-into_fragment!(f32);
-into_fragment!(f64);