Merge pull request #2508 from iced-rs/feature/rich-text

`rich_text` and `markdown` widgets

Cargo.toml

@@ -34,6 +34,8 @@ svg = ["iced_widget/svg"]
 canvas = ["iced_widget/canvas"]
 # Enables the `QRCode` widget
 qr_code = ["iced_widget/qr_code"]
+# Enables the `markdown` widget
+markdown = ["iced_widget/markdown"]
 # Enables lazy widgets
 lazy = ["iced_widget/lazy"]
 # Enables a debug view in native platforms (press F12)
@@ -51,7 +53,7 @@ web-colors = ["iced_renderer/web-colors"]
 # Enables the WebGL backend, replacing WebGPU
 webgl = ["iced_renderer/webgl"]
 # Enables the syntax `highlighter` module
-highlighter = ["iced_highlighter"]
+highlighter = ["iced_highlighter", "iced_widget/highlighter"]
 # Enables experimental multi-window support.
 multi-window = ["iced_winit/multi-window"]
 # Enables the advanced module
@@ -155,6 +157,7 @@ num-traits = "0.2"
 once_cell = "1.0"
 ouroboros = "0.18"
 palette = "0.7"
+pulldown-cmark = "0.11"
 qrcode = { version = "0.13", default-features = false }
 raw-window-handle = "0.6"
 resvg = "0.42"

core/src/renderer/null.rs

@@ -77,9 +77,14 @@ impl text::Paragraph for () {
 
     fn with_text(_text: Text<&str>) -> Self {}
 
+    fn with_spans(
+        _text: Text<&[text::Span<'_, Self::Font>], Self::Font>,
+    ) -> Self {
+    }
+
     fn resize(&mut self, _new_bounds: Size) {}
 
-    fn compare(&self, _text: Text<&str>) -> text::Difference {
+    fn compare(&self, _text: Text<()>) -> text::Difference {
         text::Difference::None
     }
 

core/src/text.rs

@@ -1,8 +1,7 @@
 //! Draw and interact with text.
-mod paragraph;
-
 pub mod editor;
 pub mod highlighter;
+pub mod paragraph;
 
 pub use editor::Editor;
 pub use highlighter::Highlighter;
@@ -11,6 +10,7 @@ pub use paragraph::Paragraph;
 use crate::alignment;
 use crate::{Color, Pixels, Point, Rectangle, Size};
 
+use std::borrow::Cow;
 use std::hash::{Hash, Hasher};
 
 /// A paragraph.
@@ -221,3 +221,162 @@ pub trait Renderer: crate::Renderer {
         clip_bounds: Rectangle,
     );
 }
+
+/// A span of text.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Span<'a, Font = crate::Font> {
+    /// The [`Fragment`] of text.
+    pub text: Fragment<'a>,
+    /// The size of the [`Span`] in [`Pixels`].
+    pub size: Option<Pixels>,
+    /// The [`LineHeight`] of the [`Span`].
+    pub line_height: Option<LineHeight>,
+    /// The font of the [`Span`].
+    pub font: Option<Font>,
+    /// The [`Color`] of the [`Span`].
+    pub color: Option<Color>,
+}
+
+impl<'a, Font> Span<'a, Font> {
+    /// Creates a new [`Span`] of text with the given text fragment.
+    pub fn new(fragment: impl IntoFragment<'a>) -> Self {
+        Self {
+            text: fragment.into_fragment(),
+            size: None,
+            line_height: None,
+            font: None,
+            color: None,
+        }
+    }
+
+    /// Sets the size of the [`Span`].
+    pub fn size(mut self, size: impl Into<Pixels>) -> Self {
+        self.size = Some(size.into());
+        self
+    }
+
+    /// Sets the [`LineHeight`] of the [`Span`].
+    pub fn line_height(mut self, line_height: impl Into<LineHeight>) -> Self {
+        self.line_height = Some(line_height.into());
+        self
+    }
+
+    /// Sets the font of the [`Span`].
+    pub fn font(mut self, font: impl Into<Font>) -> Self {
+        self.font = Some(font.into());
+        self
+    }
+
+    /// Sets the font of the [`Span`], if any.
+    pub fn font_maybe(mut self, font: Option<impl Into<Font>>) -> Self {
+        self.font = font.map(Into::into);
+        self
+    }
+
+    /// Sets the [`Color`] of the [`Span`].
+    pub fn color(mut self, color: impl Into<Color>) -> Self {
+        self.color = Some(color.into());
+        self
+    }
+
+    /// Sets the [`Color`] of the [`Span`], if any.
+    pub fn color_maybe(mut self, color: Option<impl Into<Color>>) -> Self {
+        self.color = color.map(Into::into);
+        self
+    }
+
+    /// Turns the [`Span`] into a static one.
+    pub fn to_static(self) -> Span<'static, Font> {
+        Span {
+            text: Cow::Owned(self.text.into_owned()),
+            size: self.size,
+            line_height: self.line_height,
+            font: self.font,
+            color: self.color,
+        }
+    }
+}
+
+impl<'a, Font> From<&'a str> for Span<'a, Font> {
+    fn from(value: &'a str) -> Self {
+        Span::new(value)
+    }
+}
+
+/// 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);

core/src/text/paragraph.rs

@@ -1,5 +1,6 @@
+//! Draw paragraphs.
 use crate::alignment;
-use crate::text::{Difference, Hit, Text};
+use crate::text::{Difference, Hit, Span, Text};
 use crate::{Point, Size};
 
 /// A text paragraph.
@@ -10,12 +11,15 @@ pub trait Paragraph: Sized + Default {
     /// Creates a new [`Paragraph`] laid out with the given [`Text`].
     fn with_text(text: Text<&str, Self::Font>) -> Self;
 
+    /// Creates a new [`Paragraph`] laid out with the given [`Text`].
+    fn with_spans(text: Text<&[Span<'_, Self::Font>], Self::Font>) -> Self;
+
     /// Lays out the [`Paragraph`] with some new boundaries.
     fn resize(&mut self, new_bounds: Size);
 
     /// Compares the [`Paragraph`] with some desired [`Text`] and returns the
     /// [`Difference`].
-    fn compare(&self, text: Text<&str, Self::Font>) -> Difference;
+    fn compare(&self, text: Text<(), Self::Font>) -> Difference;
 
     /// Returns the horizontal alignment of the [`Paragraph`].
     fn horizontal_alignment(&self) -> alignment::Horizontal;
@@ -34,26 +38,87 @@ pub trait Paragraph: Sized + Default {
     /// Returns the distance to the given grapheme index in the [`Paragraph`].
     fn grapheme_position(&self, line: usize, index: usize) -> Option<Point>;
 
-    /// Updates the [`Paragraph`] to match the given [`Text`], if needed.
-    fn update(&mut self, text: Text<&str, Self::Font>) {
-        match self.compare(text) {
+    /// Returns the minimum width that can fit the contents of the [`Paragraph`].
+    fn min_width(&self) -> f32 {
+        self.min_bounds().width
+    }
+
+    /// Returns the minimum height that can fit the contents of the [`Paragraph`].
+    fn min_height(&self) -> f32 {
+        self.min_bounds().height
+    }
+}
+
+/// A [`Paragraph`] of plain text.
+#[derive(Debug, Clone, Default)]
+pub struct Plain<P: Paragraph> {
+    raw: P,
+    content: String,
+}
+
+impl<P: Paragraph> Plain<P> {
+    /// Creates a new [`Plain`] paragraph.
+    pub fn new(text: Text<&str, P::Font>) -> Self {
+        let content = text.content.to_owned();
+
+        Self {
+            raw: P::with_text(text),
+            content,
+        }
+    }
+
+    /// Updates the plain [`Paragraph`] to match the given [`Text`], if needed.
+    pub fn update(&mut self, text: Text<&str, P::Font>) {
+        if self.content != text.content {
+            text.content.clone_into(&mut self.content);
+            self.raw = P::with_text(text);
+            return;
+        }
+
+        match self.raw.compare(Text {
+            content: (),
+            bounds: text.bounds,
+            size: text.size,
+            line_height: text.line_height,
+            font: text.font,
+            horizontal_alignment: text.horizontal_alignment,
+            vertical_alignment: text.vertical_alignment,
+            shaping: text.shaping,
+        }) {
             Difference::None => {}
             Difference::Bounds => {
-                self.resize(text.bounds);
+                self.raw.resize(text.bounds);
             }
             Difference::Shape => {
-                *self = Self::with_text(text);
+                self.raw = P::with_text(text);
             }
         }
     }
 
-    /// Returns the minimum width that can fit the contents of the [`Paragraph`].
-    fn min_width(&self) -> f32 {
-        self.min_bounds().width
+    /// Returns the horizontal alignment of the [`Paragraph`].
+    pub fn horizontal_alignment(&self) -> alignment::Horizontal {
+        self.raw.horizontal_alignment()
     }
 
-    /// Returns the minimum height that can fit the contents of the [`Paragraph`].
-    fn min_height(&self) -> f32 {
-        self.min_bounds().height
+    /// Returns the vertical alignment of the [`Paragraph`].
+    pub fn vertical_alignment(&self) -> alignment::Vertical {
+        self.raw.vertical_alignment()
+    }
+
+    /// Returns the minimum boundaries that can fit the contents of the
+    /// [`Paragraph`].
+    pub fn min_bounds(&self) -> Size {
+        self.raw.min_bounds()
+    }
+
+    /// Returns the minimum width that can fit the contents of the
+    /// [`Paragraph`].
+    pub fn min_width(&self) -> f32 {
+        self.raw.min_width()
+    }
+
+    /// Returns the cached [`Paragraph`].
+    pub fn raw(&self) -> &P {
+        &self.raw
     }
 }