Add support for footer styles

src/markdown/process.rs

@@ -201,8 +201,7 @@ impl<'a> MarkdownProcessor<'a> {
             let formatted = formatted.trim_end();
             self.slide_operations.push(RenderOperation::RenderPreformattedLine {
                 text: formatted.into(),
-                // TODO: remove once measuring character widths is in place
+                unformatted_length: original.len(),
-                original_length: original.len(),
                 block_length,
             });
             self.push_line_break();

src/presentation.rs

@@ -82,5 +82,5 @@ pub enum RenderOperation {
     RenderSeparator,
     RenderLineBreak,
     RenderImage(Image),
-    RenderPreformattedLine { text: String, original_length: usize, block_length: usize },
+    RenderPreformattedLine { text: String, unformatted_length: usize, block_length: usize },
 }

src/render/draw.rs

@@ -42,10 +42,12 @@ where
         let slide_drawer = SlideDrawer { handle: &mut self.handle, theme, dimensions: slide_dimensions };
         slide_drawer.render_slide(slide)?;
 
-        if let Some(template) = &theme.styles.footer.template {
+        let rendered_footer = theme.styles.footer.render(
-            let current_slide = (presentation.current_slide_index() + 1).to_string();
+            presentation.current_slide_index(),
-            let total_slides = presentation.total_slides().to_string();
+            presentation.total_slides(),
-            let footer = template.replace("{current_slide}", &current_slide).replace("{total_slides}", &total_slides);
+            dimensions.columns as usize,
+        );
+        if let Some(footer) = rendered_footer {
             self.handle.queue(cursor::MoveTo(0, dimensions.rows - 1))?;
             self.handle.queue(style::Print(footer))?;
         }
@@ -97,8 +99,8 @@ where
             RenderOperation::RenderSeparator => self.render_separator(),
             RenderOperation::RenderLineBreak => self.render_line_break(),
             RenderOperation::RenderImage(image) => self.render_image(image),
-            RenderOperation::RenderPreformattedLine { text, original_length, block_length } => {
+            RenderOperation::RenderPreformattedLine { text, unformatted_length, block_length } => {
-                self.render_preformatted_line(text, *original_length, *block_length)
+                self.render_preformatted_line(text, *unformatted_length, *block_length)
             }
         }
     }
@@ -142,7 +144,7 @@ where
         Ok(())
     }
 
-    fn render_preformatted_line(&mut self, text: &str, original_length: usize, block_length: usize) -> DrawResult {
+    fn render_preformatted_line(&mut self, text: &str, unformatted_length: usize, block_length: usize) -> DrawResult {
         let style = self.theme.alignment(&ElementType::Code);
         let start_column = match *style {
             Alignment::Left { margin } => margin,
@@ -155,7 +157,7 @@ where
         self.handle.queue(cursor::MoveToColumn(start_column))?;
 
         let max_line_length = (self.dimensions.columns - start_column * 2) as usize;
-        let until_right_edge = max_line_length.saturating_sub(original_length);
+        let until_right_edge = max_line_length.saturating_sub(unformatted_length);
         // Pad this code block with spaces so we get a nice little rectangle.
         self.handle.queue(style::Print(&text))?;
         self.handle.queue(style::Print(" ".repeat(until_right_edge)))?;

src/theme.rs

@@ -142,10 +142,38 @@ pub struct AuthorStyle {
     pub positioning: AuthorPositioning,
 }
 
-#[derive(Debug, Default, Deserialize)]
+#[derive(Debug, Deserialize)]
-pub struct FooterStyle {
+#[serde(tag = "style", rename_all = "snake_case")]
-    #[serde(default = "default_footer_template")]
+pub enum FooterStyle {
-    pub template: Option<String>,
+    Template { format: String },
+    ProgressBar,
+    Empty,
+}
+
+impl Default for FooterStyle {
+    fn default() -> Self {
+        Self::Template { format: " {current_slide} / {total_slides}".to_string() }
+    }
+}
+
+impl FooterStyle {
+    pub fn render(&self, current_slide: usize, total_slides: usize, total_columns: usize) -> Option<String> {
+        match self {
+            FooterStyle::Template { format } => {
+                let current_slide = (current_slide + 1).to_string();
+                let total_slides = total_slides.to_string();
+                let footer = format.replace("{current_slide}", &current_slide).replace("{total_slides}", &total_slides);
+                Some(footer)
+            }
+            FooterStyle::ProgressBar => {
+                let progress_ratio = (current_slide + 1) as f64 / total_slides as f64;
+                let columns_ratio = (total_columns as f64 * progress_ratio).ceil();
+                let bar = "█".repeat(columns_ratio as usize);
+                Some(bar)
+            }
+            FooterStyle::Empty => None,
+        }
+    }
 }
 
 #[derive(Debug, Default, Deserialize)]
@@ -191,10 +219,6 @@ pub enum AuthorPositioning {
     PageBottom,
 }
 
-fn default_footer_template() -> Option<String> {
-    Some("{current_slide} / {total_slides}".to_string())
-}
-
 #[cfg(test)]
 mod test {
     use super::*;

themes/dark.yaml

@@ -36,3 +36,5 @@ styles:
       prefix: "░░░░░░"
     h6:
       prefix: "░░░░░░░"
+  footer: 
+    style: progress_bar