[EasyMark] Add support for small and raised text

egui/src/experimental/easy_mark_parser.rs

@@ -13,6 +13,7 @@
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum Item<'a> {
     /// `\n`
+    // TODO: add Style here so empty heading still uses up the right amount of space.
     Newline,
     ///
     Text(Style, &'a str),
@@ -48,6 +49,10 @@ pub struct Style {
     pub strikethrough: bool,
     /// /italics/
     pub italics: bool,
+    /// $small$
+    pub small: bool,
+    /// ^raised^
+    pub raised: bool,
 }
 
 /// Parser for the `EasyMark` markup language.
@@ -292,6 +297,18 @@ impl<'a> Iterator for Parser<'a> {
                 self.style.italics = !self.style.italics;
                 continue;
             }
+            if let Some(rest) = self.s.strip_prefix('$') {
+                self.s = rest;
+                self.start_of_line = false;
+                self.style.small = !self.style.small;
+                continue;
+            }
+            if let Some(rest) = self.s.strip_prefix('^') {
+                self.s = rest;
+                self.start_of_line = false;
+                self.style.raised = !self.style.raised;
+                continue;
+            }
 
             // `<url>` or `[link](url)`
             if let Some(item) = self.url() {
@@ -301,7 +318,7 @@ impl<'a> Iterator for Parser<'a> {
             // Swallow everything up to the next special character:
             let end = self
                 .s
-                .find(&['*', '`', '~', '_', '/', '\\', '<', '[', '\n'][..])
+                .find(&['*', '`', '~', '_', '/', '$', '^', '\\', '<', '[', '\n'][..])
                 .map(|special| special.max(1)) // make sure we swallow at least one character
                 .unwrap_or_else(|| self.s.len());
 

egui/src/experimental/easy_mark_viewer.rs

@@ -87,12 +87,19 @@ fn label_from_style(text: &str, style: &easy_mark::Style) -> Label {
         underline,
         strikethrough,
         italics,
+        small,
+        raised,
     } = *style;
 
+    let small = small || raised; // Raised text is also smaller
+
     let mut label = Label::new(text);
-    if heading {
+    if heading && !small {
         label = label.heading().strong();
     }
+    if small && !heading {
+        label = label.small();
+    }
     if code {
         label = label.code();
     }
@@ -110,6 +117,9 @@ fn label_from_style(text: &str, style: &easy_mark::Style) -> Label {
     if italics {
         label = label.italics();
     }
+    if raised {
+        label = label.raised();
+    }
     label
 }
 

egui/src/widgets/label.rs

@@ -23,6 +23,7 @@ pub struct Label {
     strikethrough: bool,
     underline: bool,
     italics: bool,
+    raised: bool,
 }
 
 impl Label {
@@ -39,6 +40,7 @@ impl Label {
             strikethrough: false,
             underline: false,
             italics: false,
+            raised: false,
         }
     }
 
@@ -112,10 +114,22 @@ impl Label {
         self
     }
 
+    /// Smaller text
     pub fn small(self) -> Self {
         self.text_style(TextStyle::Small)
     }
 
+    /// For e.g. exponents
+    pub fn small_raised(self) -> Self {
+        self.text_style(TextStyle::Small).raised()
+    }
+
+    /// Align text to top. Only applicable together with [`Self::small()`].
+    pub fn raised(mut self) -> Self {
+        self.raised = true;
+        self
+    }
+
     /// Fill-color behind the text
     pub fn background_color(mut self, background_color: impl Into<Color32>) -> Self {
         self.background_color = background_color.into();
@@ -142,7 +156,8 @@ impl Label {
         } else {
             f32::INFINITY
         };
-        font.layout_multiline(self.text.clone(), wrap_width) // TODO: avoid clone
+        let galley = font.layout_multiline(self.text.clone(), wrap_width); // TODO: avoid clone
+        self.valign_galley(ui, text_style, galley)
     }
 
     pub fn font_height(&self, fonts: &epaint::text::Fonts, style: &Style) -> f32 {
@@ -171,6 +186,7 @@ impl Label {
             strikethrough,
             underline,
             italics,
+            raised: _,
             ..
         } = *self;
 
@@ -239,6 +255,26 @@ impl Label {
             }
         })
     }
+
+    fn valign_galley(&self, ui: &Ui, text_style: TextStyle, mut galley: Galley) -> Galley {
+        if text_style == TextStyle::Small {
+            // Hacky McHackface strikes again:
+            let dy = if self.raised {
+                -2.0
+            } else {
+                let normal_text_heigth = ui.fonts()[TextStyle::Body].row_height();
+                let font_height = ui.fonts()[text_style].row_height();
+                (normal_text_heigth - font_height) / 2.0 - 1.0 // center
+
+                // normal_text_heigth - font_height // align bottom
+            };
+
+            for row in &mut galley.rows {
+                row.translate_y(dy);
+            }
+        }
+        galley
+    }
 }
 
 impl Widget for Label {
@@ -285,6 +321,8 @@ impl Widget for Label {
                 }
             }
 
+            let galley = self.valign_galley(ui, text_style, galley);
+
             let rect = galley.rows[0].rect().translate(vec2(pos.x, pos.y));
             let mut response = ui.allocate_rect(rect, sense);
             for row in galley.rows.iter().skip(1) {

egui/src/widgets/text_edit.rs

@@ -13,7 +13,7 @@ pub(crate) struct State {
 
 #[derive(Clone, Copy, Debug, Default)]
 #[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
-struct CursorPair {
+pub struct CursorPair {
     /// When selecting with a mouse, this is where the mouse was released.
     /// When moving with e.g. shift+arrows, this is what moves.
     /// Note that the two ends can come in any order, and also be equal (no selection).
@@ -133,6 +133,14 @@ pub struct TextEdit<'t> {
     desired_width: Option<f32>,
     desired_height_rows: usize,
 }
+impl<'t> TextEdit<'t> {
+    pub fn cursor(ui: &Ui, id: Id) -> Option<CursorPair> {
+        ui.memory()
+            .text_edit
+            .get(&id)
+            .and_then(|state| state.cursorp)
+    }
+}
 
 impl<'t> TextEdit<'t> {
     #[deprecated = "Use `TextEdit::singleline` or `TextEdit::multiline` (or the helper `ui.text_edit_singleline`, `ui.text_edit_multiline`) instead"]

egui_demo_lib/src/apps/easy_mark_editor.rs

@@ -37,8 +37,9 @@ impl EasyMarkEditor {
             ScrollArea::auto_sized()
                 .id_source("source")
                 .show(&mut columns[0], |ui| {
-                    // ui.text_edit_multiline(&mut self.code);
                     ui.add(TextEdit::multiline(&mut self.code).text_style(TextStyle::Monospace));
+                    // let cursor = TextEdit::cursor(response.id);
+                    // TODO: cmd-i, cmd-b, etc for italics, bold, ....
                 });
             ScrollArea::auto_sized()
                 .id_source("rendered")
@@ -62,7 +63,7 @@ and is also missing some features.
 
 # At a glance
 - inline text:
-  - normal, `code`, *strong*, ~strikethrough~, _underline_, /italics/
+  - normal, `code`, *strong*, ~strikethrough~, _underline_, /italics/, ^raised^, $small$
   - `\` escapes the next character
   - [hyperlink](https://github.com/emilk/egui)
   - Embedded URL: <https://github.com/emilk/egui>
@@ -72,6 +73,8 @@ and is also missing some features.
 - `- ` bullet list
 - `1. ` numbered list
 - \`\`\` code fence
+- a^2^ + b^2^ = c^2^
+- $Remember to read the small print$
 
 # Design
 > /"Why do what everyone else is doing, when everyone else is already doing it?"
@@ -102,9 +105,11 @@ Escaping the newline effectively ignores it.
 
 The style characters are chosen to be similar to what they are representing:
   `_` = _underline_
-  `~` = ~strikethrough~ (`-` is too common in normal text)
+  `~` = ~strikethrough~ (`-` is used for bullet points)
   `/` = /italics/
   `*` = *strong*
+  `$` = $small$
+  `^` = ^raised^
 
 # TODO
 - Sub-headers (`## h2`, `### h3` etc)
@@ -113,5 +118,9 @@ The style characters are chosen to be similar to what they are representing:
   - centering of images is very desirable
   - captioning (image with a text underneath it)
   - `![caption=My image][width=200][center](url)` ?
+- Nicer URL:s
+  - `<url>` and `[url](url)` do the same thing yet look completely different.
+  - let's keep similarity with images
 - Tables
+- Inspiration: <https://mycorrhiza.lesarbr.es/page/mycomarkup>
 "#;