chore: toggle soft line breaks

README.md

@@ -288,6 +288,7 @@ file-picker-width = "75%"    # width of the file picker (fuzzy + file browser)
 toc-filelist-width = "25%"   # width of the TOC and file-list side panels
 main-line-numbers = false    # show line numbers in the main document by default
 code-line-numbers = true     # show line numbers inside fenced code blocks
+keep-soft-breaks = true      # keep source line breaks inside paragraphs
 tab-title-length = -1        # terminal tab title truncation (min: 20, -1: no truncation)
 file-history-length = 0      # recent file history length (0 disables, max: 50)
 hyper-link-prefix = "#"      # single character before link text ("" for none)
@@ -390,7 +391,7 @@ leaf --theme rose-pine README.md
 | Key | Action | Key | Action |
 |---|---|---|---|
 | `j` / `↓` | Scroll down | `?` | Show help popup |
-| `k` / `↑` | Scroll up | `p` | Show file path |
+| `k` / `↑` | Scroll up | `Shift+B` | Toggle soft breaks |
 | `d` / PgDn | Page down (20 lines) | `Shift+L` | Toggle line numbers |
 | `u` / PgUp | Page up (20 lines) | `Shift+T` | Open theme picker |
 | `g` / Home | Top | `Shift+E` | Open editor picker |
@@ -405,7 +406,8 @@ leaf --theme rose-pine README.md
 | `w` | Toggle watch mode | `Double-Click` (code) | Copy code block |
 | `r` | Force reload (watch mode) | `Shift+Drag` | Select text |
 | `t` | Toggle TOC sidebar | `Option+Drag` | Select text (iTerm2) |
-| `q` | Quit | `Ctrl+Double-Click` | Copy line |
+| `p` | Show file path | `Ctrl+Double-Click` | Copy line |
+| `q` | Quit | | |
 
 ## Features
 

config.toml

@@ -104,6 +104,14 @@ watch = false
 # Default: true
 # code-line-numbers = true
 
+# Keep soft line breaks inside paragraphs
+# Set to false to join paragraph lines and re-wrap them to the content width.
+# Can still be toggled interactively with 'Shift+B'.
+# Priority: LEAF_KEEP_SOFT_BREAKS > this setting > default (true)
+# Accepted env values: 1 = true, 0 = false (other values ignored)
+# Default: true
+# keep-soft-breaks = true
+
 # Maximum tab title length (in characters)
 # Controls the tab title of the terminal: "leaf: <filename>".
 # When the filename is long, it is truncated: "leaf: prefix...ext".

src/app/content.rs

@@ -262,18 +262,9 @@ impl App {
                 self.mode = super::AppMode::Document;
                 let (wrapped, is_code_file) = Self::wrap_as_code_block(src, &ext, ss);
                 self.file_mode = is_code_file;
+                self.plain_text_file = Self::is_plain_text_extension(&ext);
                 self.source = wrapped;
-                let theme = current_syntect_theme(themes);
-                let at = app_theme();
-                let parsed = parse_markdown_with_width(
-                    &self.source,
-                    ss,
-                    theme,
-                    self.render_width,
-                    &at.markdown,
-                    self.file_mode,
-                    self.code_line_numbers,
-                );
+                let parsed = self.parse_current_source(ss, themes);
                 self.invalidate_theme_previews();
                 self.store_current_theme_preview_from(&parsed);
                 self.replace_content(parsed);
@@ -284,26 +275,60 @@ impl App {
     }
 
     pub(crate) fn reparse_source(&mut self, ss: &SyntaxSet, themes: &ThemeSet) {
+        let old_total = self.total();
+        let parsed = self.parse_current_source(ss, themes);
+        let new_total = parsed.lines.len();
+
+        if old_total > 0 {
+            self.scroll = ((self.scroll as f64 / old_total as f64) * new_total as f64) as usize;
+            let vh = self.content_area.height as usize;
+            self.scroll = self.scroll.min(new_total.saturating_sub(vh));
+        }
+
+        self.apply_reparsed(parsed);
+    }
+
+    pub(crate) fn toggle_soft_breaks(&mut self, ss: &SyntaxSet, themes: &ThemeSet) {
+        let keep = !self.keep_soft_breaks();
+        self.soft_breaks_override = Some(keep);
+        let anchor = self.source_line_at(self.scroll);
+        let parsed = self.parse_current_source(ss, themes);
+        let new_total = parsed.lines.len();
+        let map = &parsed.source_line_map;
+        let target = map
+            .iter()
+            .copied()
+            .filter(|&line| line <= anchor)
+            .max()
+            .and_then(|best| map.iter().position(|&line| line == best))
+            .unwrap_or(0);
+        let vh = self.content_area.height as usize;
+        self.scroll = target.min(new_total.saturating_sub(vh));
+
+        self.apply_reparsed(parsed);
+        self.set_soft_break_flash(if keep {
+            super::SoftBreakFlash::Kept
+        } else {
+            super::SoftBreakFlash::Joined
+        });
+    }
+
+    pub(super) fn parse_current_source(&self, ss: &SyntaxSet, themes: &ThemeSet) -> ParseResult {
         let theme = current_syntect_theme(themes);
         let at = app_theme();
-        let old_total = self.total();
-        let parsed = parse_markdown_with_width(
+        parse_markdown_with_width(
             &self.source,
             ss,
             theme,
             self.render_width,
             &at.markdown,
             self.file_mode,
             self.code_line_numbers,
-        );
-        let new_total = parsed.lines.len();
-
-        if old_total > 0 {
-            self.scroll = ((self.scroll as f64 / old_total as f64) * new_total as f64) as usize;
-            let vh = self.content_area.height as usize;
-            self.scroll = self.scroll.min(new_total.saturating_sub(vh));
-        }
+            self.keep_soft_breaks(),
+        )
+    }
 
+    fn apply_reparsed(&mut self, parsed: ParseResult) {
         self.invalidate_theme_previews();
         self.store_current_theme_preview_from(&parsed);
         self.replace_content(parsed);

src/app/flash.rs

@@ -50,6 +50,12 @@ pub(crate) enum HistoryFlash {
     LengthCapped { was: i32 },
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum SoftBreakFlash {
+    Kept,
+    Joined,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum DiffFlash {
     SearchInPreview,
@@ -231,4 +237,16 @@ impl App {
     pub(crate) fn clear_diff_flash(&mut self) {
         self.diff_flash = None;
     }
+
+    pub(crate) fn set_soft_break_flash(&mut self, flash: SoftBreakFlash) {
+        self.soft_break_flash = Some((flash, Instant::now()));
+    }
+
+    pub(crate) fn soft_break_flash(&self) -> Option<(&SoftBreakFlash, &Instant)> {
+        self.soft_break_flash.as_ref().map(|(f, t)| (f, t))
+    }
+
+    pub(crate) fn clear_soft_break_flash(&mut self) {
+        self.soft_break_flash = None;
+    }
 }

src/app/io_picker.rs

@@ -25,6 +25,10 @@ impl App {
         format!("````{ext}\n{src}\n````")
     }
 
+    pub(crate) fn is_plain_text_extension(ext: &str) -> bool {
+        !ext.is_empty() && !Self::is_markdown_extension(ext)
+    }
+
     pub(crate) fn wrap_as_code_block(src: String, ext: &str, ss: &SyntaxSet) -> (String, bool) {
         if Self::is_markdown_extension(ext) || !Self::has_code_syntax(ext, ss) {
             (src, false)

src/app/mod.rs

@@ -63,8 +63,8 @@ pub(crate) use diff_preview::{fetch_before, reconstruct_after_from_hunks};
 
 mod flash;
 pub(crate) use flash::{
-    CodeBlockFlash, DiffFlash, EditorFlash, HistoryFlash, LinkFlash, PathFlash, WatchFlash,
-    COPY_HIGHLIGHT_DURATION_MS, FLASH_DURATION_MS,
+    CodeBlockFlash, DiffFlash, EditorFlash, HistoryFlash, LinkFlash, PathFlash, SoftBreakFlash,
+    WatchFlash, COPY_HIGHLIGHT_DURATION_MS, FLASH_DURATION_MS,
 };
 
 mod text_copy;
@@ -133,6 +133,7 @@ pub(crate) struct StatusCacheKey {
     code_block_flash_active: bool,
     history_flash_active: bool,
     diff_flash_active: bool,
+    soft_break_flash_active: bool,
     preview_reconstruct_error: bool,
     mouse_capture: bool,
     toc_scroll_hint_visible: bool,
@@ -196,6 +197,7 @@ pub(crate) struct App {
     pub(super) file_history_length: Option<i32>,
     pub(super) history_flash: Option<(HistoryFlash, std::time::Instant)>,
     pub(super) diff_flash: Option<(DiffFlash, std::time::Instant)>,
+    pub(super) soft_break_flash: Option<(SoftBreakFlash, std::time::Instant)>,
     pub(super) syntax_set: Option<std::sync::Arc<syntect::parsing::SyntaxSet>>,
     pub(super) diff_highlight: Option<(
         std::sync::Arc<syntect::parsing::SyntaxSet>,
@@ -238,6 +240,9 @@ pub(crate) struct App {
     reverse_mode: bool,
     pub(super) file_mode: bool,
     pub(super) code_line_numbers: bool,
+    keep_soft_breaks_pref: bool,
+    soft_breaks_override: Option<bool>,
+    pub(super) plain_text_file: bool,
     scroll_with_enter: bool,
     page_scroll_size: crate::config::PageScrollSize,
     max_width: Option<usize>,
@@ -381,6 +386,7 @@ impl App {
             file_history_length: None,
             history_flash: None,
             diff_flash: None,
+            soft_break_flash: None,
             syntax_set: None,
             diff_highlight: None,
             history_error_receiver: None,
@@ -429,6 +435,9 @@ impl App {
             reverse_mode: false,
             file_mode: false,
             code_line_numbers: true,
+            keep_soft_breaks_pref: true,
+            soft_breaks_override: None,
+            plain_text_file: false,
             scroll_with_enter: false,
             page_scroll_size: crate::config::PageScrollSize::default(),
             max_width: None,
@@ -471,6 +480,26 @@ impl App {
         self.code_line_numbers = value;
     }
 
+    pub(crate) fn set_keep_soft_breaks(&mut self, value: bool) {
+        self.keep_soft_breaks_pref = value;
+    }
+
+    pub(crate) fn set_plain_text_file(&mut self, value: bool) {
+        self.plain_text_file = value;
+    }
+
+    pub(crate) fn default_keep_soft_breaks(pref: bool, plain_text_file: bool) -> bool {
+        pref || plain_text_file
+    }
+
+    pub(crate) fn keep_soft_breaks(&self) -> bool {
+        self.soft_breaks_override
+            .unwrap_or(Self::default_keep_soft_breaks(
+                self.keep_soft_breaks_pref,
+                self.plain_text_file,
+            ))
+    }
+
     pub(crate) fn set_scroll_with_enter(&mut self, value: bool) {
         self.scroll_with_enter = value;
     }
@@ -909,6 +938,11 @@ impl App {
                 .as_ref()
                 .map(|(_, t)| t.elapsed() < Duration::from_millis(FLASH_DURATION_MS))
                 .unwrap_or(false),
+            soft_break_flash_active: self
+                .soft_break_flash
+                .as_ref()
+                .map(|(_, t)| t.elapsed() < Duration::from_millis(FLASH_DURATION_MS))
+                .unwrap_or(false),
             preview_reconstruct_error: self.is_diff_preview_reconstruction_error(),
             mouse_capture: self.mouse_capture,
             toc_scroll_hint_visible: self.is_toc_scroll_hint_visible(),

src/app/theme_picker.rs

@@ -1,8 +1,8 @@
 use crate::{
-    markdown::{parse_markdown_with_width, ParseResult},
+    markdown::ParseResult,
     theme::{
-        app_theme, current_syntect_theme, current_theme_selection, set_theme_preset,
-        set_theme_selection, theme_preset_index, ThemePreset, ThemeSelection, THEME_PRESETS,
+        current_syntect_theme, current_theme_selection, set_theme_preset, set_theme_selection,
+        theme_preset_index, ThemePreset, ThemeSelection, THEME_PRESETS,
     },
 };
 use syntect::{highlighting::ThemeSet, parsing::SyntaxSet};
@@ -116,17 +116,7 @@ impl App {
             return;
         }
 
-        let theme = current_syntect_theme(themes);
-        let at = app_theme();
-        let parsed = parse_markdown_with_width(
-            &self.source,
-            ss,
-            theme,
-            self.render_width,
-            &at.markdown,
-            self.file_mode,
-            self.code_line_numbers,
-        );
+        let parsed = self.parse_current_source(ss, themes);
         self.store_theme_preview(preset, parsed.clone());
         self.replace_content(parsed);
     }
@@ -145,17 +135,7 @@ impl App {
             if let Some(parsed) = self.theme_picker.original_preview.take() {
                 self.replace_content(parsed);
             } else {
-                let theme = current_syntect_theme(themes);
-                let at = app_theme();
-                let parsed = parse_markdown_with_width(
-                    &self.source,
-                    ss,
-                    theme,
-                    self.render_width,
-                    &at.markdown,
-                    self.file_mode,
-                    self.code_line_numbers,
-                );
+                let parsed = self.parse_current_source(ss, themes);
                 self.replace_content(parsed);
             }
         }

src/config.rs

@@ -68,6 +68,8 @@ pub(crate) struct LeafConfig {
     pub(crate) file_history_length: Option<i32>,
     #[serde(rename = "hyper-link-prefix")]
     pub(crate) hyper_link_prefix: Option<String>,
+    #[serde(rename = "keep-soft-breaks")]
+    pub(crate) keep_soft_breaks: Option<bool>,
     #[serde(rename = "scroll-with-enter")]
     pub(crate) scroll_with_enter: Option<bool>,
     #[serde(