Add anchor-based TOC navigation: parse #fragment anchors, find exact page within section

src/reader.rs

@@ -11,6 +11,7 @@ fn parse_blocks(raw_text: &str) -> Vec<ContentBlock> {
             continue;
         }
         let mut heading_level = 0u8;
+        let mut anchor: Option<String> = None;
         let mut text = trimmed.to_string();
         if text.contains('\x01') {
             if let Some(pos) = text.find('\x01') {
@@ -20,19 +21,28 @@ fn parse_blocks(raw_text: &str) -> Vec<ContentBlock> {
                     .next()
                     .and_then(|c| c.to_digit(10))
                     .unwrap_or(1) as u8;
+                let after_level = &text[pos + 2..];
+                if let Some(anchor_start) = after_level.find('\x03') {
+                    if let Some(anchor_end) = after_level.find('\x04') {
+                        let anchor_str = &after_level[anchor_start + 1..anchor_end];
+                        anchor = Some(anchor_str.to_string());
+                    }
+                }
                 text.drain(pos..pos + 2);
             }
+            text = text.replace(&['\x03', '\x04'][..], "");
             text = text.replace('\x02', "");
         }
         let text = text.trim().to_string();
         if !text.is_empty() {
-            blocks.push(ContentBlock { text, heading_level });
+            blocks.push(ContentBlock { text, heading_level, anchor });
         }
     }
     if blocks.is_empty() {
         blocks.push(ContentBlock {
             text: String::new(),
             heading_level: 0,
+            anchor: None,
         });
     }
     blocks
@@ -201,6 +211,17 @@ pub fn find_page_by_snippet(section: &crate::book::Section, snippet: &str) -> Op
     None
 }
 
+pub fn find_page_for_anchor(section: &crate::book::Section, anchor: &str) -> Option<usize> {
+    for (block_idx, block) in section.blocks.iter().enumerate() {
+        if let Some(ref a) = block.anchor {
+            if a == anchor {
+                return find_page_for_block(section, block_idx);
+            }
+        }
+    }
+    None
+}
+
 pub struct ReaderAction {
     pub go_back: bool,
     pub toggle_theme: bool,
@@ -212,6 +233,7 @@ pub struct ReaderAction {
     pub page_prev: bool,
     pub toggle_sidebar: bool,
     pub jump_to_section: Option<usize>,
+    pub jump_to_anchor: Option<String>,
 }
 
 pub fn reading_view(
@@ -239,6 +261,7 @@ pub fn reading_view(
         page_prev: false,
         toggle_sidebar: false,
         jump_to_section: None,
+        jump_to_anchor: None,
     };
     let mut jump_to_bookmark: Option<usize> = None;
 
@@ -271,8 +294,9 @@ pub fn reading_view(
                 ui.separator();
                 if sidebar_tab == 0 {
                     egui::ScrollArea::vertical().show(ui, |ui| {
-                        if let Some(section) = render_toc(ui, &book.toc, *current_section) {
+                        if let Some((section, anchor)) = render_toc(ui, &book.toc, *current_section) {
                             action.jump_to_section = Some(section);
+                            action.jump_to_anchor = anchor;
                         }
                     });
                 } else {
@@ -549,8 +573,8 @@ fn render_toc(
     ui: &mut egui::Ui,
     entries: &[crate::book::TocEntry],
     current_section: usize,
-) -> Option<usize> {
-    let mut jump = None;
+) -> Option<(usize, Option<String>)> {
+    let mut jump: Option<(usize, Option<String>)> = None;
     for entry in entries {
         let label_text = egui::RichText::new(&entry.label);
         let response = ui.add(
@@ -559,9 +583,10 @@ fn render_toc(
                 .wrap()
         );
         if response.clicked() {
-            jump = Some(entry.section);
+            jump = Some((entry.section, entry.anchor.clone()));
         }
-        response.on_hover_text(format!("跳转到: {} (章节 {})", entry.label, entry.section));
+        let anchor_info = entry.anchor.as_ref().map(|a| format!(" @{a}")).unwrap_or_default();
+        response.on_hover_text(format!("跳转到: {} (章节 {}{})", entry.label, entry.section, anchor_info));
         if !entry.children.is_empty() {
             ui.indent(&entry.label, |ui| {
                 if let Some(s) = render_toc(ui, &entry.children, current_section) {