feat: add typography style system with profiles, alignment, line spacing, first-line indent

src/app.rs

@@ -1,5 +1,6 @@
 use crate::book::Book;
 use crate::persistence;
+use crate::style::StyleProfile;
 use crate::theme::{self, Settings};
 use eframe::egui;
 use std::path::PathBuf;
@@ -102,6 +103,12 @@ impl App {
         let _ = persistence::save_settings(&self.settings_dir, &self.settings);
     }
 
+    fn active_profile(&self) -> &StyleProfile {
+        let idx = self.settings.profiles.iter().position(|p| p.name == self.settings.active_profile);
+        let idx = idx.unwrap_or(0);
+        &self.settings.profiles[idx]
+    }
+
     fn save_reading_position(&mut self) {
         if let Some(ref path) = self.state.file_path {
             let path_str = path.to_string_lossy().to_string();
@@ -181,6 +188,10 @@ impl eframe::App for App {
             .map(|p| p.to_string_lossy().to_string())
             .unwrap_or_default();
 
+        let mut style = self.active_profile().clone();
+        let theme_copy = self.settings.theme;
+        let use_kraft = self.settings.use_kraft_bg;
+
         egui::CentralPanel::default().show(ctx, |ui| {
             let book = self.state.book.as_mut().unwrap();
             let action = crate::reader::reading_view(
@@ -189,11 +200,11 @@ impl eframe::App for App {
                 &mut self.state.current_section,
                 &mut self.state.current_page,
                 &mut self.state.sidebar_open,
-                &mut self.settings.font_size,
+                &mut style,
-                &self.settings.theme,
+                &theme_copy,
                 &file_path,
                 self.kraft_texture.as_ref(),
-                self.settings.use_kraft_bg,
+                use_kraft,
             );
 
             if action.go_back {
@@ -203,6 +214,14 @@ impl eframe::App for App {
                 self.state.current_page = 0;
             }
 
+            if action.cycle_profile {
+                let idx = self.settings.profiles.iter()
+                    .position(|p| p.name == self.settings.active_profile)
+                    .unwrap_or(0);
+                let next = (idx + 1) % self.settings.profiles.len();
+                self.settings.active_profile = self.settings.profiles[next].name.clone();
+            }
+
             if action.toggle_kraft_bg {
                 self.settings.use_kraft_bg = !self.settings.use_kraft_bg;
             }
@@ -224,6 +243,18 @@ impl eframe::App for App {
             }
         });
 
+        // Sync style changes back to active profile (outside closure)
+        if let Some(p) = self.settings.profiles.iter_mut()
+            .find(|p| p.name == self.settings.active_profile)
+        {
+            p.font_size = style.font_size;
+            p.alignment = style.alignment;
+            p.line_spacing = style.line_spacing;
+            p.paragraph_spacing = style.paragraph_spacing;
+            p.first_line_indent = style.first_line_indent;
+        }
+        self.settings.font_size = style.font_size;
+
         self.save_reading_position();
         self.save_settings();
     }

src/main.rs

@@ -5,6 +5,7 @@ mod book;
 mod font;
 mod persistence;
 mod reader;
+mod style;
 mod texture;
 mod theme;
 

src/reader.rs

@@ -1,10 +1,10 @@
 use eframe::egui;
 use crate::book::Book;
+use crate::style::{StyleProfile, TextAlignment};
 use crate::theme::{self, Theme};
 
-pub fn recalculate_pages(book: &mut Book, font_size: f32, panel_width: f32, panel_height: f32) {
+pub fn recalculate_pages(book: &mut Book, font_size: f32, line_height: f32, panel_width: f32, panel_height: f32) {
     let char_width = font_size * 0.6;
-    let line_height = font_size * 1.5;
     let chars_per_line = if char_width > 0.0 {
         (panel_width / char_width).max(1.0) as usize
     } else {
@@ -26,6 +26,7 @@ pub struct ReaderAction {
     pub toggle_theme: bool,
     pub toggle_bookmark: bool,
     pub toggle_kraft_bg: bool,
+    pub cycle_profile: bool,
     pub page_next: bool,
     pub page_prev: bool,
 }
@@ -36,7 +37,7 @@ pub fn reading_view(
     current_section: &mut usize,
     current_page: &mut usize,
     sidebar_open: &mut bool,
-    font_size: &mut f32,
+    style: &mut StyleProfile,
     theme: &Theme,
     _file_path: &str,
     kraft_texture: Option<&egui::TextureHandle>,
@@ -47,12 +48,14 @@ pub fn reading_view(
         toggle_theme: false,
         toggle_bookmark: false,
         toggle_kraft_bg: false,
+        cycle_profile: false,
         page_next: false,
         page_prev: false,
     };
 
     let panel_size = ui.available_size();
-    recalculate_pages(book, *font_size, panel_size.x, panel_size.y);
+    let line_h = style.line_height();
+    recalculate_pages(book, style.font_size, line_h, panel_size.x, panel_size.y);
 
     let colors = theme::reader_colors(theme);
 
@@ -90,10 +93,16 @@ pub fn reading_view(
                         action.toggle_bookmark = true;
                     }
                     if ui.button("A⁻").on_hover_text("缩小字体").clicked() {
-                        *font_size = (*font_size - 2.0).max(10.0);
+                        style.font_size = (style.font_size - 2.0).max(10.0);
                     }
                     if ui.button("A⁺").on_hover_text("放大字体").clicked() {
-                        *font_size = (*font_size + 2.0).min(48.0);
+                        style.font_size = (style.font_size + 2.0).min(48.0);
+                    }
+                    if ui.button(&style.name)
+                        .on_hover_text(format!("样式: {} (点击切换)", style.name))
+                        .clicked()
+                    {
+                        action.cycle_profile = true;
                     }
                     let kraft_icon = if use_kraft_bg { "📄" } else { "📋" };
                     if ui.button(kraft_icon).on_hover_text("牛皮纸背景").clicked() {
@@ -189,15 +198,28 @@ pub fn reading_view(
             if *current_page < section.pages.len().saturating_sub(1) {
                 let start = section.pages[*current_page];
                 let end = section.pages[*current_page + 1];
-                let text: String = section.content.chars().skip(start).take(end - start).collect();
+                let raw_text: String = section.content.chars().skip(start).take(end - start).collect();
-                ui.put(text_rect, |ui: &mut egui::Ui| {
+                let indented = crate::style::apply_indent(&raw_text, style.first_line_indent);
+
+                let align = match style.alignment {
+                    TextAlignment::Left => egui::Align::LEFT,
+                    TextAlignment::Center => egui::Align::Center,
+                    TextAlignment::Right => egui::Align::RIGHT,
+                };
+                ui.allocate_new_ui(egui::UiBuilder::new().max_rect(text_rect), |ui| {
+                    ui.with_layout(
+                        egui::Layout::top_down(align).with_main_justify(false),
+                        |ui| {
                             ui.add(
                                 egui::Label::new(
-                            egui::RichText::new(&text)
+                                    egui::RichText::new(&indented)
-                                .size(*font_size)
+                                        .size(style.font_size)
+                                        .line_height(Some(style.line_height()))
                                         .color(colors.text)
                                 ).wrap()
-                    )
+                            );
+                        },
+                    );
                 });
             }
         }

src/style.rs

@@ -0,0 +1,84 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
+pub enum TextAlignment {
+    Left,
+    Center,
+    Right,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StyleProfile {
+    pub name: String,
+    pub alignment: TextAlignment,
+    pub line_spacing: f32,
+    pub paragraph_spacing: f32,
+    pub first_line_indent: f32,
+    pub font_size: f32,
+}
+
+impl StyleProfile {
+    pub fn presets() -> Vec<StyleProfile> {
+        vec![
+            StyleProfile {
+                name: "Kindle 默认".into(),
+                alignment: TextAlignment::Left,
+                line_spacing: 1.8,
+                paragraph_spacing: 1.0,
+                first_line_indent: 2.0,
+                font_size: 20.0,
+            },
+            StyleProfile {
+                name: "紧凑".into(),
+                alignment: TextAlignment::Left,
+                line_spacing: 1.4,
+                paragraph_spacing: 0.5,
+                first_line_indent: 2.0,
+                font_size: 18.0,
+            },
+            StyleProfile {
+                name: "宽松".into(),
+                alignment: TextAlignment::Left,
+                line_spacing: 2.2,
+                paragraph_spacing: 1.5,
+                first_line_indent: 2.0,
+                font_size: 22.0,
+            },
+            StyleProfile {
+                name: "居中".into(),
+                alignment: TextAlignment::Center,
+                line_spacing: 1.6,
+                paragraph_spacing: 1.0,
+                first_line_indent: 0.0,
+                font_size: 20.0,
+            },
+        ]
+    }
+
+    pub fn line_height(&self) -> f32 {
+        self.font_size * self.line_spacing
+    }
+
+}
+
+pub fn apply_indent(text: &str, indent_chars: f32) -> String {
+    if indent_chars <= 0.0 {
+        return text.to_string();
+    }
+    let indent = "\u{3000}".repeat(indent_chars as usize);
+    let mut result = String::with_capacity(text.len());
+    let mut para_start = true;
+    for ch in text.chars() {
+        if ch == '\n' {
+            result.push('\n');
+            para_start = true;
+        } else if para_start {
+            result.push_str(&indent);
+            result.push(ch);
+            para_start = false;
+        } else {
+            result.push(ch);
+        }
+    }
+    result.trim().to_string()
+}

src/theme.rs

@@ -171,6 +171,8 @@ pub struct Settings {
     pub font_size: f32,
     pub theme: Theme,
     pub use_kraft_bg: bool,
+    pub active_profile: String,
+    pub profiles: Vec<crate::style::StyleProfile>,
     pub recent_files: Vec<String>,
     pub reading_positions: std::collections::HashMap<String, ReadingPosition>,
     pub bookmarks: std::collections::HashMap<String, Vec<Bookmark>>,
@@ -183,6 +185,8 @@ impl Default for Settings {
             font_size: 20.0,
             theme: Theme::Light,
             use_kraft_bg: false,
+            active_profile: "Kindle 默认".into(),
+            profiles: crate::style::StyleProfile::presets(),
             recent_files: Vec::new(),
             reading_positions: std::collections::HashMap::new(),
             bookmarks: std::collections::HashMap::new(),