Make RichText richer (strong, weak, code, underline, …)

egui/src/widget_text.rs

@@ -9,9 +9,17 @@ use crate::{style::WidgetVisuals, text::LayoutJob, Color32, Galley, Pos2, TextSt
 #[derive(Default)]
 pub struct RichText {
     text: String,
+    wrap: Option<bool>,
     text_style: Option<TextStyle>,
+    background_color: Color32,
     text_color: Option<Color32>,
-    wrap: Option<bool>,
+    code: bool,
+    strong: bool,
+    weak: bool,
+    strikethrough: bool,
+    underline: bool,
+    italics: bool,
+    raised: bool,
 }
 
 impl RichText {
@@ -23,6 +31,19 @@ impl RichText {
         }
     }
 
+    /// If `true`, the text will wrap at the `max_width`.
+    ///
+    /// By default [`Self::wrap`] will be true in vertical layouts
+    /// and horizontal layouts with wrapping,
+    /// and false on non-wrapping horizontal layouts.
+    ///
+    /// Note that any `\n` in the text will always produce a new line.
+    #[inline]
+    pub fn wrap(mut self, wrap: bool) -> Self {
+        self.wrap = Some(wrap);
+        self
+    }
+
     #[inline]
     pub fn text(&self) -> &str {
         &self.text
@@ -54,26 +75,86 @@ impl RichText {
         self.text_style(TextStyle::Monospace)
     }
 
-    /// Override text color.
+    /// Monospace label with different background color.
     #[inline]
-    pub fn color(mut self, color: impl Into<Color32>) -> Self {
-        self.text_color = Some(color.into());
+    pub fn code(mut self) -> Self {
+        self.code = true;
+        self.text_style(TextStyle::Monospace)
+    }
+
+    /// Extra strong text (stronger color).
+    #[inline]
+    pub fn strong(mut self) -> Self {
+        self.strong = true;
         self
     }
 
-    /// If `true`, the text will wrap at the `max_width`.
+    /// Extra weak text (fainter color).
+    #[inline]
+    pub fn weak(mut self) -> Self {
+        self.weak = true;
+        self
+    }
+
+    /// Draw a line under the text.
     ///
-    /// By default [`Self::wrap`] will be true in vertical layouts
-    /// and horizontal layouts with wrapping,
-    /// and false on non-wrapping horizontal layouts.
+    /// If you want to control the line color, use [`LayoutJob`] instead.
+    #[inline]
+    pub fn underline(mut self) -> Self {
+        self.underline = true;
+        self
+    }
+
+    /// Draw a line through the text, crossing it out.
     ///
-    /// Note that any `\n` in the text will always produce a new line.
+    /// If you want to control the strikethrough line color, use [`LayoutJob`] instead.
     #[inline]
-    pub fn wrap(mut self, wrap: bool) -> Self {
-        self.wrap = Some(wrap);
+    pub fn strikethrough(mut self) -> Self {
+        self.strikethrough = true;
+        self
+    }
+
+    /// Tilt the characters to the right.
+    #[inline]
+    pub fn italics(mut self) -> Self {
+        self.italics = true;
         self
     }
 
+    /// Smaller text.
+    #[inline]
+    pub fn small(self) -> Self {
+        self.text_style(TextStyle::Small)
+    }
+
+    /// For e.g. exponents.
+    #[inline]
+    pub fn small_raised(self) -> Self {
+        self.text_style(TextStyle::Small).raised()
+    }
+
+    /// Align text to top. Only applicable together with [`Self::small()`].
+    #[inline]
+    pub fn raised(mut self) -> Self {
+        self.raised = true;
+        self
+    }
+
+    /// Fill-color behind the text.
+    #[inline]
+    pub fn background_color(mut self, background_color: impl Into<Color32>) -> Self {
+        self.background_color = background_color.into();
+        self
+    }
+
+    /// Override text color.
+    #[inline]
+    pub fn color(mut self, color: impl Into<Color32>) -> Self {
+        self.text_color = Some(color.into());
+        self
+    }
+
+    /// Read the font height of the selected text style.
     pub fn font_height(&self, fonts: &epaint::text::Fonts, style: &crate::Style) -> f32 {
         let text_style = self
             .text_style
@@ -82,46 +163,98 @@ impl RichText {
         fonts.row_height(text_style)
     }
 
-    pub fn layout(
+    pub fn layout_job(
         self,
         ui: &Ui,
         wrap_width: f32,
         default_text_style: TextStyle,
-    ) -> WidgetTextGalley {
+    ) -> WidgetTextJob {
+        let text_color = self.get_text_color(ui);
+
         let Self {
             text,
-            text_style,
-            text_color,
             wrap,
+            text_style,
+            background_color,
+            text_color: _, // already used by `get_text_color`
+            code,
+            strong: _, // already used by `get_text_color`
+            weak: _,   // already used by `get_text_color`
+            strikethrough,
+            underline,
+            italics,
+            raised,
         } = self;
 
+        let job_has_color = text_color.is_some();
+        let line_color = text_color.unwrap_or_else(|| ui.visuals().text_color());
+        let text_color = text_color.unwrap_or(crate::Color32::TEMPORARY_COLOR);
+
         let wrap = wrap.unwrap_or_else(|| ui.wrap_text());
         let wrap_width = if wrap { wrap_width } else { f32::INFINITY };
 
         let text_style = text_style
             .or(ui.style().override_text_style)
             .unwrap_or(default_text_style);
 
-        let text_color = text_color.or(ui.visuals().override_text_color);
-
-        if let Some(text_color) = text_color {
-            let galley = ui.fonts().layout(text, text_style, text_color, wrap_width);
+        let mut background_color = background_color;
+        if code {
+            background_color = ui.visuals().code_bg_color;
+        }
+        let underline = if underline {
+            crate::Stroke::new(1.0, line_color)
+        } else {
+            crate::Stroke::none()
+        };
+        let strikethrough = if strikethrough {
+            crate::Stroke::new(1.0, line_color)
+        } else {
+            crate::Stroke::none()
+        };
 
-            WidgetTextGalley {
-                galley,
-                galley_has_color: true,
-            }
+        let valign = if raised {
+            crate::Align::TOP
         } else {
-            let galley = ui
-                .fonts()
-                .layout_delayed_color(text, text_style, wrap_width);
+            ui.layout().vertical_align()
+        };
+
+        let text_format = crate::text::TextFormat {
+            style: text_style,
+            color: text_color,
+            background: background_color,
+            italics,
+            underline,
+            strikethrough,
+            valign,
+        };
+
+        let mut job = LayoutJob::single_section(text, text_format);
+        job.wrap_width = wrap_width;
+
+        WidgetTextJob { job, job_has_color }
+    }
 
-            WidgetTextGalley {
-                galley,
-                galley_has_color: false,
-            }
+    fn get_text_color(&self, ui: &Ui) -> Option<Color32> {
+        if let Some(text_color) = self.text_color {
+            Some(text_color)
+        } else if self.strong {
+            Some(ui.visuals().strong_text_color())
+        } else if self.weak {
+            Some(ui.visuals().weak_text_color())
+        } else {
+            ui.visuals().override_text_color
         }
     }
+
+    pub fn layout(
+        self,
+        ui: &Ui,
+        wrap_width: f32,
+        default_text_style: TextStyle,
+    ) -> WidgetTextGalley {
+        let job = self.layout_job(ui, wrap_width, default_text_style);
+        job.layout(ui.fonts())
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -258,6 +391,24 @@ impl From<Arc<Galley>> for WidgetText {
 
 // ----------------------------------------------------------------------------
 
+pub struct WidgetTextJob {
+    job: LayoutJob,
+    job_has_color: bool,
+}
+
+impl WidgetTextJob {
+    pub fn layout(self, fonts: &crate::text::Fonts) -> WidgetTextGalley {
+        let Self { job, job_has_color } = self;
+        let galley = fonts.layout_job(job);
+        WidgetTextGalley {
+            galley,
+            galley_has_color: job_has_color,
+        }
+    }
+}
+
+// ----------------------------------------------------------------------------
+
 /// Text that has been layed out and ready to be painted.
 pub struct WidgetTextGalley {
     galley: Arc<Galley>,

epaint/src/text/text_layout_types.rs

@@ -118,6 +118,21 @@ impl LayoutJob {
         }
     }
 
+    #[inline]
+    pub fn single_section(text: String, format: TextFormat) -> Self {
+        Self {
+            sections: vec![LayoutSection {
+                leading_space: 0.0,
+                byte_range: 0..text.len(),
+                format,
+            }],
+            text,
+            wrap_width: f32::INFINITY,
+            break_on_newline: true,
+            ..Default::default()
+        }
+    }
+
     #[inline(always)]
     pub fn is_empty(&self) -> bool {
         self.sections.is_empty()