feat: add event, location, and date frontmatter (#317)

Hello!

Closes #312 


This PR adds fields for the presentation `event`, `location`, and
`date`---these are optional fields but are common frontmatter elements,
particularly if the presentation is for a larger conference / event.

Example:
~~~markdown
---
title: How to Think Like a Designer
sub_title: It's easier than you think
event: Laracon US 2024
location: Dallas, TX
date: 2024-08-28
author: Jack McDade
---
~~~

src/presentation.rs

@@ -493,6 +493,18 @@ pub(crate) struct PresentationMetadata {
     #[serde(default)]
     pub(crate) sub_title: Option<String>,
 
+    /// The presentation event.
+    #[serde(default)]
+    pub(crate) event: Option<String>,
+
+    /// The presentation location.
+    #[serde(default)]
+    pub(crate) location: Option<String>,
+
+    /// The presentation date.
+    #[serde(default)]
+    pub(crate) date: Option<String>,
+
     /// The presentation author.
     #[serde(default)]
     pub(crate) author: Option<String>,
@@ -510,6 +522,19 @@ pub(crate) struct PresentationMetadata {
     pub(crate) options: Option<OptionsConfig>,
 }
 
+impl PresentationMetadata {
+    /// Check if this presentation has frontmatter.
+    pub(crate) fn has_frontmatter(&self) -> bool {
+        self.title.is_some()
+            || self.sub_title.is_some()
+            || self.event.is_some()
+            || self.location.is_some()
+            || self.date.is_some()
+            || self.author.is_some()
+            || !self.authors.is_empty()
+    }
+}
+
 /// A presentation's theme metadata.
 #[derive(Clone, Debug, Default, Deserialize)]
 pub(crate) struct PresentationThemeMetadata {

src/processing/builder.rs

@@ -283,11 +283,7 @@ impl<'a> PresentationBuilder<'a> {
         }
         self.footer_context.borrow_mut().author = metadata.author.clone().unwrap_or_default();
         self.set_theme(&metadata.theme)?;
-        if metadata.title.is_some()
-            || metadata.sub_title.is_some()
-            || metadata.author.is_some()
-            || !metadata.authors.is_empty()
-        {
+        if metadata.has_frontmatter() {
             self.push_slide_prelude();
             self.push_intro_slide(metadata);
         }
@@ -336,15 +332,14 @@ impl<'a> PresentationBuilder<'a> {
     }
 
     fn push_intro_slide(&mut self, metadata: PresentationMetadata) {
-        let styles = &self.theme.intro_slide;
-        let title = Text::new(
-            metadata.title.unwrap_or_default().clone(),
-            TextStyle::default().bold().colors(styles.title.colors.clone()),
-        );
-        let sub_title = metadata
-            .sub_title
-            .as_ref()
-            .map(|text| Text::new(text.clone(), TextStyle::default().colors(styles.subtitle.colors.clone())));
+        let styles = self.theme.intro_slide.clone();
+        let create_text =
+            |text: Option<String>, style: TextStyle| -> Option<Text> { text.map(|text| Text::new(text, style)) };
+        let title = create_text(metadata.title, TextStyle::default().bold().colors(styles.title.colors));
+        let sub_title = create_text(metadata.sub_title, TextStyle::default().colors(styles.subtitle.colors));
+        let event = create_text(metadata.event, TextStyle::default().colors(styles.event.colors));
+        let location = create_text(metadata.location, TextStyle::default().colors(styles.location.colors));
+        let date = create_text(metadata.date, TextStyle::default().colors(styles.date.colors));
         let authors: Vec<_> = metadata
             .author
             .into_iter()
@@ -355,11 +350,24 @@ impl<'a> PresentationBuilder<'a> {
             self.slide_state.ignore_footer = true;
         }
         self.chunk_operations.push(RenderOperation::JumpToVerticalCenter);
-        self.push_text(TextBlock::from(title), ElementType::PresentationTitle);
-        self.push_line_break();
-        if let Some(text) = sub_title {
-            self.push_text(TextBlock::from(text), ElementType::PresentationSubTitle);
+        if let Some(title) = title {
+            self.push_line(title, ElementType::PresentationTitle);
+        }
+        if let Some(sub_title) = sub_title {
+            self.push_line(sub_title, ElementType::PresentationSubTitle);
+        }
+        if event.is_some() || location.is_some() || date.is_some() {
             self.push_line_break();
+            self.push_line_break();
+            if let Some(event) = event {
+                self.push_line(event, ElementType::PresentationEvent);
+            }
+            if let Some(location) = location {
+                self.push_line(location, ElementType::PresentationLocation);
+            }
+            if let Some(date) = date {
+                self.push_line(date, ElementType::PresentationDate);
+            }
         }
         if !authors.is_empty() {
             match self.theme.intro_slide.author.positioning {
@@ -373,8 +381,7 @@ impl<'a> PresentationBuilder<'a> {
                 }
             };
             for author in authors {
-                self.push_text(TextBlock::from(author), ElementType::PresentationAuthor);
-                self.push_line_break();
+                self.push_line(author, ElementType::PresentationAuthor);
             }
         }
         self.slide_state.title = Some(TextBlock::from("[Introduction]"));
@@ -671,6 +678,11 @@ impl<'a> PresentationBuilder<'a> {
         self.chunk_operations.push(RenderOperation::SetColors(self.theme.default_style.colors.clone()));
     }
 
+    fn push_line(&mut self, text: Text, element_type: ElementType) {
+        self.push_text(TextBlock::from(text), element_type);
+        self.push_line_break();
+    }
+
     fn push_text(&mut self, text: TextBlock, element_type: ElementType) {
         let alignment = self.theme.alignment(&element_type);
         self.push_aligned_text(text, alignment);
@@ -1084,6 +1096,15 @@ struct StrictPresentationMetadata {
     #[serde(default)]
     sub_title: Option<String>,
 
+    #[serde(default)]
+    event: Option<String>,
+
+    #[serde(default)]
+    location: Option<String>,
+
+    #[serde(default)]
+    date: Option<String>,
+
     #[serde(default)]
     author: Option<String>,
 
@@ -1099,8 +1120,9 @@ struct StrictPresentationMetadata {
 
 impl From<StrictPresentationMetadata> for PresentationMetadata {
     fn from(strict: StrictPresentationMetadata) -> Self {
-        let StrictPresentationMetadata { title, sub_title, author, authors, theme, options } = strict;
-        Self { title, sub_title, author, authors, theme, options }
+        let StrictPresentationMetadata { title, sub_title, event, location, date, author, authors, theme, options } =
+            strict;
+        Self { title, sub_title, event, location, date, author, authors, theme, options }
     }
 }
 

src/theme.rs

@@ -206,6 +206,9 @@ impl PresentationTheme {
             Code => &self.code.alignment,
             PresentationTitle => &self.intro_slide.title.alignment,
             PresentationSubTitle => &self.intro_slide.subtitle.alignment,
+            PresentationEvent => &self.intro_slide.event.alignment,
+            PresentationLocation => &self.intro_slide.location.alignment,
+            PresentationDate => &self.intro_slide.date.alignment,
             PresentationAuthor => &self.intro_slide.author.alignment,
             Table => &self.table,
             BlockQuote => &self.block_quote.alignment,
@@ -336,6 +339,18 @@ pub(crate) struct IntroSlideStyle {
     #[serde(default)]
     pub(crate) subtitle: BasicStyle,
 
+    /// The style of the event line.
+    #[serde(default)]
+    pub(crate) event: BasicStyle,
+
+    /// The style of the location line.
+    #[serde(default)]
+    pub(crate) location: BasicStyle,
+
+    /// The style of the date line.
+    #[serde(default)]
+    pub(crate) date: BasicStyle,
+
     /// The style of the author line.
     #[serde(default)]
     pub(crate) author: AuthorStyle,
@@ -580,6 +595,9 @@ pub(crate) enum ElementType {
     Code,
     PresentationTitle,
     PresentationSubTitle,
+    PresentationEvent,
+    PresentationLocation,
+    PresentationDate,
     PresentationAuthor,
     Table,
     BlockQuote,

themes/catppuccin-frappe.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -48,6 +49,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "85c1dc"
+  event:
+    alignment: center
+    colors:
+      foreground: "a6d189"
+  location:
+    alignment: center
+    colors:
+      foreground: "85c1dc"
+  date:
+    alignment: center
+    colors:
+      foreground: "e5c890"
   author:
     alignment: center
     colors:

themes/catppuccin-latte.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -48,6 +49,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "209fb5"
+  event:
+    alignment: center
+    colors:
+      foreground: "40a02b"
+  location:
+    alignment: center
+    colors:
+      foreground: "209fb5"
+  date:
+    alignment: center
+    colors:
+      foreground: "df8e1d"
   author:
     alignment: center
     colors:

themes/catppuccin-macchiato.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -48,6 +49,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "7dc4e4"
+  event:
+    alignment: center
+    colors:
+      foreground: "a6da95"
+  location:
+    alignment: center
+    colors:
+      foreground: "7dc4e4"
+  date:
+    alignment: center
+    colors:
+      foreground: "eed49f"
   author:
     alignment: center
     colors:

themes/catppuccin-mocha.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -48,6 +49,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "74c7ec"
+  event:
+    alignment: center
+    colors:
+      foreground: "a6e3a1"
+  location:
+    alignment: center
+    colors:
+      foreground: "74c7ec"
+  date:
+    alignment: center
+    colors:
+      foreground: "f9e2af"
   author:
     alignment: center
     colors:

themes/dark.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -49,6 +50,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "a5d7e8"
+  event:
+    alignment: center
+    colors:
+      foreground: "b4ccff"
+  location:
+    alignment: center
+    colors:
+      foreground: "a5d7e8"
+  date:
+    alignment: center
+    colors:
+      foreground: "ee9322"
   author:
     alignment: center
     colors:
@@ -93,7 +106,7 @@ typst:
     foreground: "f0f0f0"
     background: "292e42"
 
-footer: 
+footer:
   style: progress_bar
   colors:
     foreground: "7aa2f7"

themes/light.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -49,6 +50,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "8e9aaf"
+  event:
+    alignment: center
+    colors:
+      foreground: "52b788"
+  location:
+    alignment: center
+    colors:
+      foreground: "f77f00"
+  date:
+    alignment: center
+    colors:
+      foreground: "f77f00"
   author:
     alignment: center
     colors:
@@ -93,7 +106,7 @@ typst:
     foreground: "212529"
     background: "e9ecef"
 
-footer: 
+footer:
   style: progress_bar
   colors:
     foreground: "7aa2f7"

themes/terminal-dark.yaml

@@ -1,9 +1,10 @@
+---
 default:
   margin:
     percent: 8
   colors:
     foreground: null
-    background: null 
+    background: null
 
 slide_title:
   alignment: center
@@ -47,6 +48,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: blue
+  event:
+    alignment: center
+    colors:
+      foreground: green
+  location:
+    alignment: center
+    colors:
+      foreground: blue
+  date:
+    alignment: center
+    colors:
+      foreground: yellow
   author:
     alignment: center
     colors:
@@ -91,7 +104,7 @@ typst:
     foreground: "f0f0f0"
     background: "292e42"
 
-footer: 
+footer:
   style: progress_bar
   colors:
     foreground: blue

themes/terminal-light.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -47,6 +48,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: dark_blue
+  event:
+    alignment: center
+    colors:
+      foreground: dark_green
+  location:
+    alignment: center
+    colors:
+      foreground: dark_blue
+  date:
+    alignment: center
+    colors:
+      foreground: dark_yellow
   author:
     alignment: center
     colors:
@@ -91,7 +104,7 @@ typst:
     foreground: "212529"
     background: "e9ecef"
 
-footer: 
+footer:
   style: progress_bar
   colors:
     foreground: dark_blue

themes/tokyonight-storm.yaml

@@ -1,3 +1,4 @@
+---
 default:
   margin:
     percent: 8
@@ -49,6 +50,18 @@ intro_slide:
     alignment: center
     colors:
       foreground: "a9b1d6"
+  event:
+    alignment: center
+    colors:
+      foreground: "7aa2f7"
+  location:
+    alignment: center
+    colors:
+      foreground: "a9b1d6"
+  date:
+    alignment: center
+    colors:
+      foreground: "e0af68"
   author:
     alignment: center
     colors:
@@ -93,7 +106,7 @@ typst:
     foreground: "f0f0f0"
     background: "545c7e"
 
-footer: 
+footer:
   style: progress_bar
   colors:
     foreground: "7aa2f7"