Fix TOC issues: add ScrollArea, fix section jump mechanism

src/app.rs

@@ -375,6 +375,15 @@ BgType::Custom(ref path) if !path.is_empty() => {
                 ctx.set_style(theme::create_style(&self.settings.theme));
             }
 
+            if action.toggle_sidebar {
+                self.state.sidebar_open = !self.state.sidebar_open;
+            }
+
+            if let Some(section) = action.jump_to_section {
+                self.state.current_section = section;
+                self.state.current_page = 0;
+            }
+
             if action.page_prev {
                  self.state.prev_page();
              }

src/reader.rs

@@ -210,6 +210,8 @@ pub struct ReaderAction {
     pub switch_font: Option<String>,
     pub page_next: bool,
     pub page_prev: bool,
+    pub toggle_sidebar: bool,
+    pub jump_to_section: Option<usize>,
 }
 
 pub fn reading_view(
@@ -235,6 +237,8 @@ pub fn reading_view(
         switch_font: None,
         page_next: false,
         page_prev: false,
+        toggle_sidebar: false,
+        jump_to_section: None,
     };
     let mut jump_to_bookmark: Option<usize> = None;
 
@@ -266,9 +270,15 @@ pub fn reading_view(
                 });
                 ui.separator();
                 if sidebar_tab == 0 {
-                    render_toc(ui, &book.toc, current_section, current_page);
+                    egui::ScrollArea::vertical().show(ui, |ui| {
+                        if let Some(section) = render_toc(ui, &book.toc, *current_section) {
+                            action.jump_to_section = Some(section);
+                        }
+                    });
                 } else {
+                    egui::ScrollArea::vertical().show(ui, |ui| {
                         render_bookmarks(ui, bookmarks, &mut jump_to_bookmark);
+                    });
                 }
             });
     }
@@ -527,6 +537,9 @@ egui::ComboBox::from_id_salt("bg_type_selector")
         if ui.input(|i| i.key_pressed(egui::Key::ArrowLeft)) {
             action.page_prev = true;
         }
+        if ui.input(|i| i.key_pressed(egui::Key::B)) {
+            action.toggle_sidebar = true;
+        }
     });
 
     (action, jump_to_bookmark)
@@ -535,32 +548,29 @@ egui::ComboBox::from_id_salt("bg_type_selector")
 fn render_toc(
     ui: &mut egui::Ui,
     entries: &[crate::book::TocEntry],
-    current_section: &mut usize,
-    current_page: &mut usize,
-) {
+    current_section: usize,
+) -> Option<usize> {
+    let mut jump = None;
     for entry in entries {
-        let is_current = entry.section == *current_section;
-        let label_text = if is_current {
-            egui::RichText::new(&entry.label).color(egui::Color32::YELLOW).strong()
-        } else {
-            egui::RichText::new(&entry.label)
-        };
+        let label_text = egui::RichText::new(&entry.label);
         let response = ui.add(
             egui::Button::new(label_text)
                 .frame(false)
                 .wrap()
         );
         if response.clicked() {
-            *current_section = entry.section;
-            *current_page = 0;
+            jump = Some(entry.section);
         }
-        response.on_hover_text(format!("跳转到: {}", entry.label));
+        response.on_hover_text(format!("跳转到: {} (章节 {})", entry.label, entry.section));
         if !entry.children.is_empty() {
             ui.indent(&entry.label, |ui| {
-                render_toc(ui, &entry.children, current_section, current_page);
+                if let Some(s) = render_toc(ui, &entry.children, current_section) {
+                    jump = Some(s);
+                }
             });
         }
     }
+    jump
 }
 
 fn render_bookmarks(