Make pencil the default tool

Cargo.toml

@@ -12,22 +12,25 @@ targets = ["x86_64-unknown-linux-gnu", "wasm32-unknown-unknown"]
 pinenote = []
 
 [dependencies]
-egui = "0.31"
-egui_extras = { version = "0.31", features = ["svg"] }
-eframe = { version = "0.31", default-features = false, features = [
+egui = "0.32"
+egui_extras = { version = "0.32", features = ["svg"] }
+egui_glow = "0.32"
+eframe = { version = "0.32", default-features = false, features = [
     "glow",           # alt: "wgpu".
     "persistence",
     "wayland",
 ] }
 log = "0.4.27"
 serde = { version = "1.0.219", features = ["derive"] }
-egui_glow = "0.31.1"
 rfd = { version = "0.15.3", default-features = false, features = ["gtk3"] }
 rand = "0.9.1"
 eyre = "0.6.12"
 half = "2.6.0"
 zerocopy = { version = "0.8.25", features = ["derive", "std"] }
 base64 = "0.22.1"
+chrono = { version = "0.4.41", features = ["serde"] }
+notify = "8.1.0"
+arboard = "3.6.0"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 env_logger = "0.11.8"
@@ -39,13 +42,14 @@ wasm-bindgen-futures = "0.4.50"
 web-sys = "0.3.77"
 
 [patch.crates-io]
-egui =   { git = "https://github.com/emilk/egui", rev = "f2ce6424f3a32f47308fb9871d540c01377b2cd9" }
-eframe = { git = "https://github.com/emilk/egui", rev = "f2ce6424f3a32f47308fb9871d540c01377b2cd9" }
+# egui = { path = "../egui/crates/egui" }
+# eframe = { path = "../egui/crates/eframe" }
 
 [dev-dependencies]
 insta = { version = "1.43.1", features = ["yaml"] }
-# egui = { path = "../egui/crates/egui" }
-# eframe = { path = "../egui/crates/eframe" }
+
+[lints.clippy]
+unnecessary_lazy_evaluations = "allow"
 
 [profile.release]
 opt-level = 2 # fast and small wasm

src/app.rs

@@ -1,16 +1,24 @@
 use std::{
     fs,
+    io::Read,
     path::PathBuf,
     sync::{Arc, mpsc},
     thread::JoinHandle,
     time::{Duration, Instant},
 };
 
-use crate::{file_editor::FileEditor, folder::Folder, preferences::Preferences, util::GuiSender};
-use egui::{
-    Align, Button, Context, FontData, FontDefinitions, Image, Key, Modifiers, PointerButton,
-    RichText, ScrollArea, Widget, include_image,
+use crate::{
+    file_editor::{FileEditor, SaveStatus},
+    folder::Folder,
+    preferences::Preferences,
+    text_styles::{H1, H1_MONO, H2, H2_MONO, H3, H3_MONO, H4, H4_MONO, H5, H5_MONO, H6, H6_MONO},
+    util::{GuiSender, file_mtime, log_error},
 };
+use egui::{
+    Align, Button, Context, FontData, FontDefinitions, FontFamily, FontId, Frame, Image, Key,
+    Modifiers, PointerButton, RichText, ScrollArea, Theme, Widget, include_image,
+};
+use eyre::eyre;
 
 #[derive(serde::Deserialize, serde::Serialize)]
 #[serde(default)]
@@ -40,7 +48,7 @@ pub struct Jobs {
 }
 
 impl Jobs {
-    fn start(&mut self, ctx: &Context, job: impl FnOnce() -> Option<Action> + Send + 'static) {
+    pub fn start(&mut self, ctx: &Context, job: impl FnOnce() -> Option<Action> + Send + 'static) {
         let ctx = ctx.clone();
         let actions_tx = self.actions_tx.clone();
         self.handles.push(std::thread::spawn(move || {
@@ -73,9 +81,21 @@ impl Tab {
         }
     }
 
-    pub fn is_dirty(&self) -> bool {
+    pub fn notice_symbol(&self) -> Option<&'static str> {
         match self {
-            Tab::File(file_editor) => file_editor.is_dirty,
+            Tab::File(file_editor) => match file_editor.save_status() {
+                SaveStatus::Synced => None,
+                SaveStatus::NoFile => Some("?"),
+                SaveStatus::FileOutdated => Some("*"),
+                SaveStatus::BufferOutdated => Some("!"),
+                SaveStatus::Desynced => Some("!!"),
+            },
+        }
+    }
+
+    pub fn save(&mut self, ctx: &Context, jobs: &mut Jobs) {
+        match self {
+            Tab::File(file_editor) => file_editor.save(ctx, jobs),
         }
     }
 }
@@ -171,17 +191,39 @@ impl App {
         .map(|(name, data)| (name.to_string(), Arc::new(FontData::from_static(data))))
         .collect();
 
-        fonts.families.insert(
-            egui::FontFamily::Proportional,
-            vec!["IosevkaAile-Regular".into()],
-        );
+        fonts
+            .families
+            .insert(FontFamily::Proportional, vec!["IosevkaAile-Regular".into()]);
 
         fonts
             .families
-            .insert(egui::FontFamily::Monospace, vec!["Iosevka-Thin".into()]);
+            .insert(FontFamily::Monospace, vec!["Iosevka-Thin".into()]);
 
         cc.egui_ctx.set_fonts(fonts);
 
+        // markdown font styles
+        for theme in [Theme::Dark, Theme::Light] {
+            cc.egui_ctx.style_mut_of(theme, |style| {
+                for (name, size, family) in [
+                    (H1, 28.0, FontFamily::Proportional),
+                    (H2, 26.0, FontFamily::Proportional),
+                    (H3, 24.0, FontFamily::Proportional),
+                    (H4, 22.0, FontFamily::Proportional),
+                    (H5, 20.0, FontFamily::Proportional),
+                    (H6, 18.0, FontFamily::Proportional),
+                    (H1_MONO, 28.0, FontFamily::Monospace),
+                    (H2_MONO, 26.0, FontFamily::Monospace),
+                    (H3_MONO, 24.0, FontFamily::Monospace),
+                    (H4_MONO, 22.0, FontFamily::Monospace),
+                    (H5_MONO, 20.0, FontFamily::Monospace),
+                    (H6_MONO, 18.0, FontFamily::Monospace),
+                ] {
+                    let name = egui::TextStyle::Name(name.into());
+                    style.text_styles.insert(name, FontId { size, family });
+                }
+            });
+        }
+
         // enable features on egui_extras to add more image types
         egui_extras::install_image_loaders(&cc.egui_ctx);
 
@@ -253,7 +295,7 @@ impl eframe::App for App {
         });
 
         egui::TopBottomPanel::top("top_panel").show(ctx, |ui| {
-            egui::containers::menu::Bar::new().ui(ui, |ui| {
+            egui::MenuBar::new().ui(ui, |ui| {
                 // NOTE: no File->Quit on web pages!
                 ui.menu_button("Menu ⚙", |ui| {
                     ui.label(RichText::new("Action").weak());
@@ -268,11 +310,18 @@ impl eframe::App for App {
                         self.jobs.start(ui.ctx(), move || {
                             let file_path = rfd::FileDialog::new().pick_file()?;
 
-                            let text = fs::read_to_string(&file_path)
+                            let mut file = fs::File::open(&file_path)
+                                .inspect_err(|e| log::error!("Failed to open {file_path:?}: {e}"))
+                                .ok()?;
+
+                            let mtime = log_error(eyre!("file_path:?"), || file_mtime(&file))?;
+
+                            let mut text = String::new();
+                            file.read_to_string(&mut text)
                                 .inspect_err(|e| log::error!("Failed to read {file_path:?}: {e}"))
                                 .ok()?;
 
-                            let editor = FileEditor::from_file(file_path, &text);
+                            let editor = FileEditor::from_file(file_path, &text, mtime);
                             Some(Action::OpenFile(editor))
                         });
                     }
@@ -364,8 +413,8 @@ impl eframe::App for App {
                         let selected = self.open_tab_index == Some(i);
                         let mut button = Button::new(tab.title()).selected(selected);
 
-                        if tab.is_dirty() {
-                            button = button.right_text(RichText::new("*").strong())
+                        if let Some(symbol) = tab.notice_symbol() {
+                            button = button.right_text(RichText::new(symbol).strong())
                         }
 
                         let response = ui.add(button);
@@ -396,13 +445,22 @@ impl eframe::App for App {
                         if let Some(file_path) = response.open_file {
                             let file_path = file_path.to_owned();
                             self.jobs.start(ui.ctx(), move || {
-                                let text = fs::read_to_string(&file_path)
+                                let mut file = fs::File::open(&file_path)
+                                    .inspect_err(|e| {
+                                        log::error!("Failed to open {file_path:?}: {e}")
+                                    })
+                                    .ok()?;
+
+                                let mtime = log_error(eyre!("file_path:?"), || file_mtime(&file))?;
+
+                                let mut text = String::new();
+                                file.read_to_string(&mut text)
                                     .inspect_err(|e| {
                                         log::error!("Failed to read {file_path:?}: {e}")
                                     })
                                     .ok()?;
 
-                                let editor = FileEditor::from_file(file_path, &text);
+                                let editor = FileEditor::from_file(file_path, &text, mtime);
                                 Some(Action::OpenFile(editor))
                             });
                         }
@@ -413,19 +471,24 @@ impl eframe::App for App {
                 });
             });
 
-        egui::CentralPanel::default().show(ctx, |ui| {
-            if let Some(Tab::File(file_editor)) = self
-                .open_tab_index
-                .and_then(|i| self.tabs.get_mut(i))
-                .map(|(_tab_id, tab)| tab)
-            {
-                file_editor.show(ui, &self.preferences);
-            }
+        egui::CentralPanel::default()
+            .frame(Frame {
+                fill: ctx.style().visuals.window_fill(),
+                ..Frame::central_panel(&ctx.style())
+            })
+            .show(ctx, |ui| {
+                if let Some(Tab::File(file_editor)) = self
+                    .open_tab_index
+                    .and_then(|i| self.tabs.get_mut(i))
+                    .map(|(_tab_id, tab)| tab)
+                {
+                    file_editor.show(ui, &self.preferences);
+                }
 
-            ui.with_layout(egui::Layout::bottom_up(Align::LEFT), |ui| {
-                egui::warn_if_debug_build(ui);
+                ui.with_layout(egui::Layout::bottom_up(Align::LEFT), |ui| {
+                    egui::warn_if_debug_build(ui);
+                });
             });
-        });
     }
 }
 
@@ -448,29 +511,13 @@ impl App {
     }
 
     fn save_active_tab(&mut self, ctx: &Context) {
-        let open_file = self
+        let open_tab = self
             .open_tab_index
             .and_then(|i| self.tabs.get_mut(i))
-            .map(|(id, tab)| match tab {
-                Tab::File(file_editor) => (*id, file_editor),
-            })
-            .and_then(|(_, file_editor)| {
-                file_editor
-                    .path()
-                    .map(ToOwned::to_owned)
-                    .zip(Some(file_editor))
-            });
+            .map(|(_id, tab)| tab);
 
-        if let Some((file_path, file_editor)) = open_file {
-            file_editor.is_dirty = false;
-            let text = file_editor.to_string();
-            let file_path = file_path.to_owned();
-            self.jobs.start(ctx, move || {
-                if let Err(e) = fs::write(file_path, text.as_bytes()) {
-                    log::error!("{e}");
-                };
-                None
-            });
+        if let Some(open_tab) = open_tab {
+            open_tab.save(ctx, &mut self.jobs);
         }
     }
 }

src/easy_mark/easy_mark_highlighter.rs

@@ -1,245 +0,0 @@
-use egui::text::{CCursorRange, LayoutJob};
-
-use crate::easy_mark::easy_mark_parser;
-
-/// Highlight easymark, memoizing previous output to save CPU.
-///
-/// In practice, the highlighter is fast enough not to need any caching.
-#[derive(Default)]
-pub struct MemoizedHighlighter {
-    style: egui::Style,
-    code: String,
-    output: LayoutJob,
-}
-
-impl MemoizedHighlighter {
-    pub fn highlight(
-        &mut self,
-        egui_style: &egui::Style,
-        code: &str,
-        cursor: Option<CCursorRange>,
-    ) -> LayoutJob {
-        if (&self.style, self.code.as_str()) != (egui_style, code) {
-            self.style = egui_style.clone();
-            code.clone_into(&mut self.code);
-            self.output = highlight_easymark(egui_style, code, cursor);
-        }
-        self.output.clone()
-    }
-}
-
-pub fn highlight_easymark(
-    egui_style: &egui::Style,
-    mut text: &str,
-
-    // TODO: hide special characters where cursor isn't
-    _cursor: Option<CCursorRange>,
-) -> LayoutJob {
-    let mut job = LayoutJob::default();
-    let mut style = easy_mark_parser::Style::default();
-    let mut start_of_line = true;
-
-    const CODE_INDENT: f32 = 10.0;
-
-    while !text.is_empty() {
-        if start_of_line && text.starts_with("```") {
-            let astyle = format_from_style(
-                egui_style,
-                &easy_mark_parser::Style {
-                    code: true,
-                    ..Default::default()
-                },
-            );
-
-            // Render the initial backticks as spaces
-            text = &text[3..];
-            job.append("   ", CODE_INDENT, astyle.clone());
-
-            match text.find("\n```") {
-                Some(n) => {
-                    for line in text[..n + 1].lines() {
-                        job.append(line, CODE_INDENT, astyle.clone());
-                        job.append("\n", 0.0, astyle.clone());
-                    }
-                    // Render the final backticks as spaces
-                    job.append("   ", CODE_INDENT, astyle);
-                    text = &text[n + 4..];
-                }
-                None => {
-                    job.append(text, 0.0, astyle.clone());
-                    text = "";
-                }
-            };
-            style = Default::default();
-            continue;
-        }
-
-        if text.starts_with('`') {
-            style.code = true;
-            let end = text[1..]
-                .find(&['`', '\n'][..])
-                .map_or_else(|| text.len(), |i| i + 2);
-            job.append(&text[..end], 0.0, format_from_style(egui_style, &style));
-            text = &text[end..];
-            style.code = false;
-            continue;
-        }
-
-        let skip;
-
-        // zero-width space
-        let _zws = "\u{200b}";
-
-        let mut apply_basic_style =
-            |text: &mut &str,
-             style: &mut easy_mark_parser::Style,
-             access: fn(&mut easy_mark_parser::Style) -> &mut bool| {
-                let skip = if *access(style) {
-                    // Include the character that is ending this style:
-                    job.append(&text[..1], 0.0, format_from_style(egui_style, style));
-                    *text = &text[1..];
-                    0
-                } else {
-                    1
-                };
-                *access(style) ^= true;
-                skip
-            };
-
-        if text.starts_with('*') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.strong);
-        } else if text.starts_with('/') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.italics);
-        } else if text.starts_with('_') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.underline);
-        } else if text.starts_with('$') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.small);
-        } else if text.starts_with('~') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.strikethrough);
-        } else if text.starts_with('^') {
-            skip = apply_basic_style(&mut text, &mut style, |style| &mut style.raised);
-        } else if text.starts_with('\\') && text.len() >= 2 {
-            skip = 2;
-        } else if start_of_line && text.starts_with(' ') {
-            // we don't preview indentation, because it is confusing
-            skip = 1;
-        } else if start_of_line && text.starts_with("###### ") {
-            style.heading = true;
-            skip = 7;
-        } else if start_of_line && text.starts_with("##### ") {
-            style.heading = true;
-            skip = 6;
-        } else if start_of_line && text.starts_with("#### ") {
-            style.heading = true;
-            skip = 5;
-        } else if start_of_line && text.starts_with("### ") {
-            style.heading = true;
-            skip = 4;
-        } else if start_of_line && text.starts_with("## ") {
-            style.heading = true;
-            skip = 3;
-        } else if start_of_line && text.starts_with("# ") {
-            style.heading = true;
-            skip = 2;
-        } else if start_of_line && text.starts_with("> ") {
-            style.quoted = true;
-            skip = 2;
-            // we don't preview indentation, because it is confusing
-        } else if start_of_line && text.trim_start().starts_with("- ") {
-            job.append("• ", 0.0, format_from_style(egui_style, &style));
-            text = &text[2..];
-            skip = 0;
-            // we don't preview indentation, because it is confusing
-        } else {
-            skip = 0;
-        }
-        // Note: we don't preview underline, strikethrough and italics because it confuses things.
-
-        // Swallow everything up to the next special character:
-        let line_end = text[skip..]
-            .find('\n')
-            .map_or_else(|| text.len(), |i| (skip + i + 1));
-        let end = text[skip..]
-            .find(&['*', '`', '~', '_', '/', '$', '^', '\\', '<', '['][..])
-            .map_or_else(|| text.len(), |i| (skip + i).max(1));
-
-        if line_end <= end {
-            job.append(
-                &text[..line_end],
-                0.0,
-                format_from_style(egui_style, &style),
-            );
-            text = &text[line_end..];
-            start_of_line = true;
-            style = Default::default();
-        } else {
-            job.append(&text[..end], 0.0, format_from_style(egui_style, &style));
-            text = &text[end..];
-            start_of_line = false;
-        }
-    }
-
-    job
-}
-
-fn format_from_style(
-    egui_style: &egui::Style,
-    emark_style: &easy_mark_parser::Style,
-) -> egui::text::TextFormat {
-    use egui::{Align, Color32, Stroke, TextStyle};
-
-    let color = if emark_style.code {
-        egui_style.visuals.strong_text_color() * Color32::from_rgb(0x44, 0xff, 0x44)
-    } else if emark_style.strong || emark_style.heading {
-        egui_style.visuals.strong_text_color()
-    } else if emark_style.quoted {
-        egui_style.visuals.weak_text_color()
-    } else {
-        egui_style.visuals.text_color()
-    };
-
-    let text_style = if emark_style.heading {
-        TextStyle::Heading
-    } else if emark_style.code {
-        TextStyle::Monospace
-    } else if emark_style.small | emark_style.raised {
-        TextStyle::Small
-    } else {
-        TextStyle::Body
-    };
-
-    let background = if emark_style.code {
-        egui_style.visuals.code_bg_color
-    } else {
-        Color32::TRANSPARENT
-    };
-
-    let underline = if emark_style.underline {
-        Stroke::new(1.0, color)
-    } else {
-        Stroke::NONE
-    };
-
-    let strikethrough = if emark_style.strikethrough {
-        Stroke::new(1.0, color)
-    } else {
-        Stroke::NONE
-    };
-
-    let valign = if emark_style.raised {
-        Align::TOP
-    } else {
-        Align::BOTTOM
-    };
-
-    egui::text::TextFormat {
-        font_id: text_style.resolve(egui_style),
-        color,
-        background,
-        italics: emark_style.italics,
-        underline,
-        strikethrough,
-        valign,
-        ..Default::default()
-    }
-}

src/file_editor.rs

@@ -1,57 +1,116 @@
 use std::{
     cmp::Ordering,
     fmt::{self, Display},
+    fs::{self, File},
+    io::Write,
     ops::{Div as _, Sub as _},
     path::{Path, PathBuf},
     str::FromStr,
+    sync::mpsc,
 };
 
+use chrono::{DateTime, Local};
 use egui::{
-    Align, Button, DragAndDrop, Frame, Layout, ScrollArea, Ui, UiBuilder, Vec2, Widget as _, vec2,
+    Align, Button, Context, DragAndDrop, Frame, Layout, ScrollArea, Ui, UiBuilder, Vec2, vec2,
 };
+use eyre::eyre;
+use notify::{EventKind, Watcher};
 
 use crate::{
+    app::Jobs,
     custom_code_block::{MdItem, iter_lines_and_code_blocks},
     handwriting::{self, Handwriting, HandwritingStyle},
     preferences::Preferences,
     text_editor::MdTextEdit,
+    util::{file_mtime, log_error},
 };
 
 #[derive(serde::Deserialize, serde::Serialize)]
 pub struct FileEditor {
     title: String,
-    pub path: Option<PathBuf>,
+
+    path: Option<PathBuf>,
     pub buffer: Vec<BufferItem>,
 
-    /// Whether the file has been edited since it was laste saved to disk.
-    pub is_dirty: bool,
+    pub file_mtime: Option<DateTime<Local>>,
+    pub buffer_mtime: DateTime<Local>,
+
+    // TODO: instantiate these on load
+    #[serde(skip)]
+    inner: Option<Inner>,
+
+    /// The distance to scroll when paging up or down.
+    ///
+    /// This is calculated when the view is rendered.
+    #[serde(skip)]
+    scroll_delta: f32,
+
+    /// Whether the file has been edited since it was last saved to disk.
+    is_dirty: bool,
+}
+
+struct Inner {
+    file_events: mpsc::Receiver<FileEvent>,
+    file_events_tx: mpsc::Sender<FileEvent>,
+    _file_watcher: notify::RecommendedWatcher,
+}
+
+#[derive(Debug)]
+pub enum SaveStatus {
+    /// The contents of the buffer is the same as on disk.
+    Synced,
+
+    /// The contents exits only in memory and has never been saved to disk.
+    NoFile,
+
+    /// The buffer has been edited but not saved to disk.
+    FileOutdated,
+
+    /// The contents on disk has changes that are newer than the buffer.
+    BufferOutdated,
+
+    /// The contents on disk and in the buffer has diverged.
+    Desynced,
+}
+
+#[derive(Debug)]
+enum FileEvent {
+    NewFileMTime(DateTime<Local>),
+    NewBufferMTime(DateTime<Local>),
 }
 
 #[derive(serde::Deserialize, serde::Serialize)]
 pub enum BufferItem {
-    Text(MdTextEdit),
+    Text(Box<MdTextEdit>),
     Handwriting(Box<Handwriting>),
 }
 
 impl FileEditor {
     pub fn new(title: impl Into<String>) -> Self {
-        let buffer = vec![BufferItem::Text(MdTextEdit::new())];
+        let buffer = vec![BufferItem::Text(Box::new(MdTextEdit::new()))];
         Self {
             title: title.into(),
             path: None,
             buffer,
+            file_mtime: None,
+            buffer_mtime: Local::now(),
+            scroll_delta: 0.0,
             is_dirty: false,
+            inner: None,
         }
     }
 
-    pub fn from_file(file_path: PathBuf, contents: &str) -> Self {
+    pub fn from_file(file_path: PathBuf, contents: &str, mtime: DateTime<Local>) -> Self {
         let file_title = file_path
             .file_name()
             .map(|name| name.to_string_lossy().to_string())
             .unwrap_or_else(|| String::from("untitled.md"));
+
         Self {
             title: file_title,
             path: Some(file_path),
+            file_mtime: Some(mtime),
+            buffer_mtime: mtime,
             ..FileEditor::from(contents)
         }
     }
@@ -64,15 +123,66 @@ impl FileEditor {
         self.path.as_deref()
     }
 
+    pub fn save_status(&self) -> SaveStatus {
+        let Some(file_mtime) = self.file_mtime else {
+            return SaveStatus::NoFile;
+        };
+
+        let buffer_is_newer = self.buffer_mtime > file_mtime;
+        let file_is_newer = self.buffer_mtime < file_mtime;
+
+        if buffer_is_newer || (file_is_newer && self.is_dirty) {
+            SaveStatus::Desynced
+        } else if file_is_newer {
+            SaveStatus::BufferOutdated
+        } else if self.is_dirty {
+            SaveStatus::FileOutdated
+        } else {
+            SaveStatus::Synced
+        }
+    }
+
     pub fn show(&mut self, ui: &mut Ui, preferences: &Preferences) {
+        if let Some(path) = &self.path
+            && self.inner.is_none()
+        {
+            self.inner = Some(spawn_file_watcher(path));
+        }
+
+        if let Some(inner) = &mut self.inner {
+            while let Ok(event) = inner.file_events.try_recv() {
+                match event {
+                    FileEvent::NewFileMTime(mtime) => {
+                        self.file_mtime = Some(mtime);
+                    }
+                    FileEvent::NewBufferMTime(mtime) => {
+                        self.buffer_mtime = mtime;
+                        self.file_mtime = Some(mtime);
+                    }
+                }
+            }
+        }
+
         ui.vertical_centered_justified(|ui| {
             ui.heading(&self.title);
 
             const MAX_NOTE_WIDTH: f32 = 600.0;
 
+            // distance to scroll when paging up or down.
+            let mut scroll_delta = 0.0;
+
+            ui.input_mut(|input| {
+                if input.consume_key(egui::Modifiers::NONE, egui::Key::PageUp) {
+                    scroll_delta += self.scroll_delta;
+                }
+                if input.consume_key(egui::Modifiers::NONE, egui::Key::PageDown) {
+                    scroll_delta -= self.scroll_delta;
+                }
+            });
+
             ui.horizontal(|ui| {
                 ui.label("new");
-                if ui.button("text").clicked() {
+                if ui.button(" text ").clicked() {
                     self.is_dirty = true;
                     self.buffer.push(BufferItem::Text(Default::default()));
                 }
@@ -81,9 +191,23 @@ impl FileEditor {
                     self.buffer
                         .push(BufferItem::Handwriting(Default::default()));
                 }
+
+                ui.add_space(16.0);
+
+                ui.label("scroll");
+                if ui.button("  up  ").clicked() {
+                    scroll_delta += self.scroll_delta;
+                }
+                if ui.button("down").clicked() {
+                    scroll_delta -= self.scroll_delta;
+                }
             });
 
-            ScrollArea::vertical().show(ui, |ui| {
+            let scroll_area = ScrollArea::vertical().show(ui, |ui| {
+                if scroll_delta != 0.0 {
+                    ui.scroll_with_delta(Vec2::new(0.0, scroll_delta));
+                }
+
                 ui.horizontal(|ui| {
                     let side_padding = ui.available_width().sub(MAX_NOTE_WIDTH).max(0.0).div(2.0);
                     ui.add_space(side_padding);
@@ -94,6 +218,8 @@ impl FileEditor {
                     ui.add_space(side_padding);
                 });
             });
+
+            self.scroll_delta = scroll_area.inner_rect.height() * 0.5;
         });
     }
 
@@ -120,25 +246,16 @@ impl FileEditor {
 
             let mut retain = true;
 
-            if is_dragging {
-                let (_, drop) = ui.dnd_drop_zone::<DraggingItem, _>(Frame::NONE, |ui| {
-                    ui.set_min_size(vec2(ui.available_width(), drag_zone_height));
-                });
-                if let Some(drop) = drop {
-                    drop_from_to = Some((drop.index, i));
-                }
-            } else {
-                // the dnd_drop_zone adds 3pts work of extra space
-                ui.add_space(drag_zone_height + 3.0);
-            }
-
+            // Createa horizontal area to draw the buffer item. The three things drawn here are:
+            // - The controls that exist at the left-size of the buffer item, i.e. "up"/"down".
+            // - The buffer item.
+            // - The controls that exist at the right-size of the buffer item, i.e. "delete".
             ui.horizontal(|ui| {
-                // We don't know how tall the buffer item will be, so we'll reserve
-                // some horizontal space here and come back to drawing the dragger
-                // later.
-                let (dragger_id, mut dragger_rect) = ui.allocate_space(Vec2::new(20.0, 1.0));
+                // At this point, we don't know how tall the buffer item will be, so we'll reserve
+                // some horizontal space here and come back to drawing the controls later.
+                let (_id, mut left_controls_rect) = ui.allocate_space(Vec2::new(20.0, 1.0));
 
-                // Leave some space at the end for the delete button..
+                // Leave some space at the end for the delete button.
                 let w = ui.available_width();
                 let item_size = Vec2::new(w - 20.0, 0.0);
 
@@ -161,18 +278,17 @@ impl FileEditor {
                 });
 
                 // Delete-button
-                if ui.button("x").clicked() {
+                if ui.button("⌫").clicked() {
                     retain = false;
                     ui.ctx().request_repaint();
                 }
 
-                // Draw the dragger using the height from the buffer item
-                dragger_rect.set_height(item_response.response.rect.height());
+                left_controls_rect.set_height(item_response.response.rect.height());
 
                 // Controls for moving the buffer item
-                ui.allocate_new_ui(
+                ui.scope_builder(
                     UiBuilder::new()
-                        .max_rect(dragger_rect)
+                        .max_rect(left_controls_rect)
                         .layout(Layout::top_down(Align::Center)),
                     |ui| {
                         let up_button_response = ui.add_enabled(!is_first, Button::new("⇡"));
@@ -180,17 +296,12 @@ impl FileEditor {
                             drop_from_to = Some((i, i - 1));
                         }
 
-                        ui.dnd_drag_source(dragger_id, DraggingItem { index: i }, |ui| {
-                            Button::new("≡")
-                                .min_size(
-                                    // Use all available height, save for the height taken up by
-                                    // the up/down buttons + padding. Assume down-button is the
-                                    // equally tall as the up-button.
-                                    dragger_rect.size()
-                                        - Vec2::Y * (up_button_response.rect.height() * 2.0 + 4.0),
-                                )
-                                .ui(ui);
-                        });
+                        // Add some space so that the next button is drawn
+                        // at the bottom of the buffer item.
+                        ui.add_space(
+                            left_controls_rect.height()
+                                - (up_button_response.rect.height() * 2.0 + 4.0),
+                        );
 
                         if ui.add_enabled(!is_last, Button::new("⇣")).clicked() {
                             drop_from_to = Some((i, i + 2));
@@ -243,6 +354,38 @@ impl FileEditor {
         self.title = title.to_string_lossy().to_string();
         self.path = Some(new_path);
     }
+
+    pub fn set_dirty(&mut self, value: bool) {
+        self.is_dirty = value;
+    }
+
+    pub fn save(&mut self, ctx: &Context, jobs: &mut Jobs) {
+        let Some(file_path) = self.path.clone() else {
+            log::info!("Can't save {}, no path set.", self.title);
+            return;
+        };
+
+        self.is_dirty = false;
+        let text = self.to_string();
+        let inner = self
+            .inner
+            .get_or_insert_with(|| spawn_file_watcher(&file_path));
+        let file_event_tx = inner.file_events_tx.clone();
+
+        jobs.start(ctx, move || {
+            log_error(eyre!("Failed to save file {file_path:?}"), || {
+                let mut file = fs::File::create(file_path)?;
+                file.write_all(text.as_bytes())?;
+                let mtime = file_mtime(&file)?;
+
+                let _ = file_event_tx.send(FileEvent::NewBufferMTime(mtime));
+
+                Ok(())
+            });
+
+            None
+        });
+    }
 }
 
 impl Display for BufferItem {
@@ -280,7 +423,7 @@ impl From<&str> for FileEditor {
             _ => {
                 let mut text_edit = MdTextEdit::new();
                 text_edit.text.push_str(text);
-                buffer.push(BufferItem::Text(text_edit));
+                buffer.push(BufferItem::Text(Box::new(text_edit)));
             }
         };
 
@@ -314,6 +457,40 @@ impl From<&str> for FileEditor {
     }
 }
 
+fn spawn_file_watcher(p: &Path) -> Inner {
+    let (tx, rx) = mpsc::channel();
+
+    let path = p.to_owned();
+    let events_tx = tx.clone();
+    let mut watcher = notify::recommended_watcher(move |event: notify::Result<notify::Event>| {
+        log_error(eyre!("watch {path:?} error"), || {
+            match event?.kind {
+                EventKind::Create(..) | EventKind::Modify(..) | EventKind::Remove(..) => {}
+
+                EventKind::Access(..) | EventKind::Any | EventKind::Other => return Ok(()),
+            }
+
+            let file = File::open(&path)?;
+            let mtime = file_mtime(&file)?;
+
+            let _ = events_tx.send(FileEvent::NewFileMTime(mtime));
+
+            Ok(())
+        });
+    })
+    .unwrap();
+
+    if let Err(e) = watcher.watch(p, notify::RecursiveMode::NonRecursive) {
+        log::error!("Failed to watch {p:?}: {e}");
+    };
+
+    Inner {
+        file_events: rx,
+        file_events_tx: tx,
+        _file_watcher: watcher,
+    }
+}
+
 #[cfg(test)]
 mod test {
 

src/folder.rs

@@ -7,7 +7,7 @@ use std::{
     thread,
 };
 
-use egui::{Response, Ui};
+use egui::{Button, Color32, Response, Stroke, TextWrapMode, Ui, Vec2, Widget};
 use eyre::{Context, OptionExt, eyre};
 use serde::{Deserialize, Serialize};
 
@@ -52,20 +52,59 @@ impl Deref for FolderResponse<'_> {
 impl LoadedFolder {
     pub fn show<'a>(&'a mut self, ui: &mut Ui) -> FolderResponse<'a> {
         let mut open_file = None;
+
+        let draw_highlight = |ui: &mut Ui, rect| {
+            ui.painter().rect(
+                rect,
+                2.0,
+                if ui.visuals().dark_mode {
+                    Color32::from_white_alpha(16)
+                } else {
+                    Color32::from_black_alpha(16)
+                },
+                Stroke::NONE,
+                egui::StrokeKind::Outside,
+            );
+        };
+
         let inner = ui
             .collapsing(&self.name, |ui| {
                 for folder in &mut self.child_folders {
                     open_file = open_file.or(folder.show(ui).open_file);
                 }
 
+                let w = ui.available_width();
+
+                let mut first = true;
+
                 for file in &mut self.child_files {
-                    if ui.button(&file.name).clicked() {
+                    if !first {
+                        ui.add_space(2.0);
+                    }
+                    first = false;
+
+                    let button = Button::new(&file.name)
+                        .min_size(Vec2::new(w, 0.0))
+                        .wrap_mode(TextWrapMode::Truncate)
+                        .frame(false)
+                        .corner_radius(0.0)
+                        .ui(ui);
+
+                    if button.hovered() {
+                        draw_highlight(ui, button.rect);
+                    }
+
+                    if button.clicked() {
                         open_file = Some(file.path.as_path())
                     };
                 }
             })
             .header_response;
 
+        if inner.hovered() {
+            draw_highlight(ui, inner.rect);
+        }
+
         FolderResponse { inner, open_file }
     }
 
@@ -94,12 +133,19 @@ impl LoadedFolder {
                 log::error!("Symlinks not yet supported, skipping {path:?}");
                 continue;
             } else if file_type.is_file() {
-                child_files.push(File { name, path });
+                if filter_file(&name) {
+                    child_files.push(File { name, path });
+                }
             } else if file_type.is_dir() {
-                child_folders.push(Folder::NotLoaded { name, path });
+                if filter_folder(&name) {
+                    child_folders.push(Folder::NotLoaded { name, path });
+                }
             }
         }
 
+        child_folders.sort_by_key(|folder| folder.name().to_owned());
+        child_files.sort_by_key(|file| (!file.name.ends_with(".md"), file.name.clone()));
+
         let folder = LoadedFolder {
             name,
             path,
@@ -216,3 +262,11 @@ impl<'de> Deserialize<'de> for Folder {
         Ok(Folder::NotLoaded { name, path })
     }
 }
+
+fn filter_folder(_folder_name: &str) -> bool {
+    true
+}
+
+fn filter_file(file_name: &str) -> bool {
+    file_name != ".DS_Store"
+}

src/handwriting/canvas_rasterizer.rs

@@ -42,7 +42,7 @@ impl Tile {
 
         Self {
             bounding_box,
-            image: ColorImage::new([CHUNK_SIZE, CHUNK_SIZE], Color32::TRANSPARENT),
+            image: ColorImage::filled([CHUNK_SIZE, CHUNK_SIZE], Color32::TRANSPARENT),
             texture: None,
             texture_is_dirty: false,
         }

src/handwriting/mod.rs

@@ -1,5 +1,6 @@
 mod canvas_rasterizer;
 mod disk_format;
+mod tool;
 
 use std::{
     fmt::{self, Display},
@@ -8,13 +9,14 @@ use std::{
     sync::Arc,
 };
 
+use arboard::Clipboard;
 use base64::{Engine, prelude::BASE64_STANDARD};
 use canvas_rasterizer::CanvasRasterizer;
 use disk_format::{DiskFormat, RawStroke, RawStrokeHeader, f16_le};
 use egui::{
     Color32, Event, Frame, Id, Mesh, PointerButton, Pos2, Rect, Sense, Shape, Stroke, Theme, Ui,
     Vec2,
-    emath::{self, TSTransform},
+    emath::{self, RectTransform, TSTransform},
     epaint::{TessellationOptions, Tessellator, Vertex},
 };
 use eyre::{Context, bail};
@@ -25,6 +27,8 @@ use zerocopy::{FromBytes, IntoBytes};
 use crate::{custom_code_block::try_from_custom_code_block, rasterizer};
 use crate::{custom_code_block::write_custom_code_block, util::random_id};
 
+use self::tool::{Tool, ToolEvent};
+
 const HANDWRITING_MIN_HEIGHT: f32 = 100.0;
 const HANDWRITING_BOTTOM_PADDING: f32 = 80.0;
 const HANDWRITING_MARGIN: f32 = 0.05;
@@ -77,10 +81,20 @@ struct Ephemeral {
 
     canvas_rasterizer: CanvasRasterizer,
 
+    tool: Tool,
+
+    /// Tool position in canvas space.
+    tool_position: Option<Pos2>,
+
+    /// Tool position last frame, in canvas space.
+    last_tool_position: Option<Pos2>,
+
     /// The stroke that is currently being drawed.
     current_stroke: Vec<Pos2>,
 
     /// The lines that have not been blitted to `texture` yet.
+    ///
+    /// Each pair of [Pos2]s is the start and end of one line.
     unblitted_lines: Vec<[Pos2; 2]>,
 
     tessellator: Option<Tessellator>,
@@ -125,6 +139,9 @@ impl Default for Ephemeral {
         Self {
             id: random_id(),
             canvas_rasterizer: Default::default(),
+            tool: Tool::Pencil,
+            tool_position: None,
+            last_tool_position: None,
             current_stroke: Default::default(),
             tessellator: None,
             mesh: Default::default(),
@@ -163,6 +180,20 @@ impl Handwriting {
                 }
             });
 
+            if ui.button("copy").clicked() {
+                let text = self.to_string();
+                // TODO: move to a job
+                let _ = Clipboard::new().unwrap().set_text(text);
+            }
+
+            let (label, switch_to_tool) = match self.e.tool {
+                Tool::Pencil => ("eraser", Tool::Eraser),
+                Tool::Eraser => ("pencil", Tool::Pencil),
+            };
+            if ui.button(label).clicked() {
+                self.e.tool = switch_to_tool;
+            }
+
             let vertex_count: usize = self.e.mesh.indices.len() / 3;
             ui.label(format!("vertices: {vertex_count}"));
         })
@@ -202,6 +233,8 @@ impl Handwriting {
             emath::RectTransform::from_to(Rect::from_min_size(Pos2::ZERO, size), response.rect);
         let from_screen = to_screen.inverse();
 
+        self.e.last_tool_position = self.e.tool_position;
+
         // Was the user in the process of drawing a stroke last frame?
         let was_drawing = !self.e.current_stroke.is_empty();
 
@@ -261,88 +294,21 @@ impl Handwriting {
 
             // Process input events and turn them into strokes
             for event in events {
-                let last_canvas_pos = self.e.current_stroke.last();
-
-                match event {
-                    Event::PointerMoved(new_position) => {
-                        let new_canvas_pos = from_screen * new_position;
-                        if let Some(&last_canvas_pos) = last_canvas_pos {
-                            if last_canvas_pos != new_canvas_pos {
-                                self.push_to_stroke(new_canvas_pos);
-                                response.mark_changed();
+                let mut last_tool_position = self.e.last_tool_position;
+                process_event(&mut last_tool_position, from_screen, &event, |tool_event| {
+                    self.e.tool_position = tool_event.position();
+                    match self.e.tool {
+                        Tool::Pencil => {
+                            hw_response.changed |= tool::pencil::on_tool_event(self, tool_event);
+                        }
+                        Tool::Eraser => {
+                            if tool::eraser::on_tool_event(self, tool_event) {
+                                self.e.refresh_texture = true;
+                                hw_response.changed = true;
                             }
                         }
                     }
-
-                    Event::MouseMoved(mut delta) => {
-                        if delta.length() == 0.0 {
-                            continue;
-                        }
-
-                        // FIXME: pinenote: MouseMovement delta does *not* take into account screen
-                        // scaling and rotation, so unless you've scaling=1 and no rotation, the
-                        // MouseMoved values will be all wrong.
-                        if cfg!(feature = "pinenote") {
-                            delta /= 1.8;
-                            delta = -delta.rot90();
-                        }
-
-                        if let Some(&last_canvas_pos) = last_canvas_pos {
-                            self.push_to_stroke(last_canvas_pos + delta);
-                            response.mark_changed();
-                        } else {
-                            println!("Got `MouseMoved`, but have no previous pos");
-                        }
-                    }
-
-                    Event::PointerButton {
-                        pos,
-                        button,
-                        pressed,
-                        modifiers: _,
-                    } => match (button, pressed) {
-                        (PointerButton::Primary, true) => {
-                            if last_canvas_pos.is_none() {
-                                self.e.current_stroke.push(from_screen * pos);
-                            }
-                        }
-                        (PointerButton::Primary, false) => {
-                            if last_canvas_pos.is_some() {
-                                self.push_to_stroke(from_screen * pos);
-                                self.commit_current_line(hw_response);
-                                response.mark_changed();
-                            }
-
-                            // Stop reading events.
-                            // TODO: In theory, we can get multiple press->draw->release series
-                            // in the same frame. Should handle this.
-                            break;
-                        }
-                        (_, _) => continue,
-                    },
-
-                    // Stop drawing after pointer disappears or the window is unfocused
-                    // TODO: In theory, we can get multiple press->draw->release series
-                    // in the same frame. Should handle this.
-                    Event::PointerGone | Event::WindowFocused(false) => {
-                        if !self.e.current_stroke.is_empty() {
-                            self.commit_current_line(hw_response);
-                            break;
-                        }
-                    }
-
-                    Event::WindowFocused(true)
-                    | Event::Copy
-                    | Event::Cut
-                    | Event::Paste(..)
-                    | Event::Text(..)
-                    | Event::Key { .. }
-                    | Event::Zoom(..)
-                    | Event::Ime(..)
-                    | Event::Touch { .. }
-                    | Event::MouseWheel { .. }
-                    | Event::Screenshot { .. } => continue,
-                }
+                });
             }
         }
 
@@ -399,6 +365,14 @@ impl Handwriting {
         // Draw the texture
         self.e.canvas_rasterizer.show(ui.ctx(), &painter, mesh_rect);
 
+        if let Some(tool_position) = self.e.tool_position
+            && let Tool::Eraser = self.e.tool
+        {
+            let pos = to_screen * tool_position;
+            let shape = Shape::circle_stroke(pos, tool::eraser::RADIUS, style.stroke);
+            painter.add(shape);
+        }
+
         response
     }
 
@@ -418,7 +392,7 @@ impl Handwriting {
             last_mesh_ctx,
             ..
         } = &mut self.e;
-        // TODO: don't tessellate and rasterize on the GUI thread
+        // TODO: avoid tessellating and rasterizing on the GUI thread
 
         *last_mesh_ctx = Some(mesh_context);
 
@@ -437,10 +411,7 @@ impl Handwriting {
             .iter()
             .chain([&*current_stroke])
             .filter(|stroke| stroke.len() >= 2)
-            .map(|stroke| {
-                //let points: Vec<Pos2> = stroke.iter().map(|&p| to_screen * p).collect();
-                egui::Shape::line(stroke.clone(), style.stroke)
-            })
+            .map(|stroke| egui::Shape::line(stroke.clone(), style.stroke))
             .for_each(|shape| {
                 tessellator.tessellate_shape(shape, mesh);
             });
@@ -473,7 +444,6 @@ impl Handwriting {
         ui.vertical_centered_justified(|ui| {
             self.ui_control(None, ui, &mut response);
 
-            //ui.label("Paint with your mouse/touch!");
             Frame::canvas(ui.style())
                 .corner_radius(20.0)
                 .stroke(Stroke::new(5.0, Color32::from_black_alpha(40)))
@@ -584,6 +554,87 @@ impl Handwriting {
     }
 }
 
+/// Convert [egui::Event]s to [ToolEvent]s.
+fn process_event(
+    last_canvas_pos: &mut Option<Pos2>,
+    from_screen: RectTransform,
+    event: &Event,
+    mut on_tool_event: impl FnMut(ToolEvent),
+) {
+    match event {
+        &Event::PointerMoved(new_position) => {
+            let new_canvas_pos = from_screen * new_position;
+            if last_canvas_pos.is_some() && *last_canvas_pos != Some(new_canvas_pos) {
+                *last_canvas_pos = Some(new_canvas_pos);
+                on_tool_event(ToolEvent::Move { to: new_canvas_pos });
+            }
+        }
+
+        &Event::MouseMoved(mut delta) => {
+            if delta.length() == 0.0 {
+                return;
+            }
+
+            // FIXME: pinenote: MouseMovement delta does *not* take into account screen
+            // scaling and rotation, so unless you've scaling=1 and no rotation, the
+            // MouseMoved values will be all wrong.
+            if cfg!(feature = "pinenote") {
+                delta /= 1.8;
+                delta = -delta.rot90();
+            }
+
+            if let Some(pos) = last_canvas_pos {
+                *pos += delta;
+                on_tool_event(ToolEvent::Move { to: *pos });
+            } else {
+                println!("Got `MouseMoved`, but have no previous pos");
+            }
+        }
+
+        &Event::PointerButton {
+            pos,
+            button,
+            pressed,
+            modifiers: _,
+        } => match (button, pressed) {
+            (PointerButton::Primary, true) => {
+                if last_canvas_pos.is_none() {
+                    let pos = from_screen * pos;
+                    *last_canvas_pos = Some(pos);
+                    on_tool_event(ToolEvent::Press { at: pos });
+                }
+            }
+            (PointerButton::Primary, false) => {
+                if last_canvas_pos.take().is_some() {
+                    let pos = from_screen * pos;
+                    on_tool_event(ToolEvent::Move { to: pos });
+                    on_tool_event(ToolEvent::Release {});
+                }
+            }
+            (_, _) => {}
+        },
+
+        // Stop drawing after pointer disappears or the window is unfocused
+        Event::PointerGone | Event::WindowFocused(false) => {
+            if last_canvas_pos.take().is_some() {
+                on_tool_event(ToolEvent::Release {});
+            }
+        }
+
+        Event::WindowFocused(true)
+        | Event::Copy
+        | Event::Cut
+        | Event::Paste(..)
+        | Event::Text(..)
+        | Event::Key { .. }
+        | Event::Zoom(..)
+        | Event::Ime(..)
+        | Event::Touch { .. }
+        | Event::MouseWheel { .. }
+        | Event::Screenshot { .. } => {}
+    }
+}
+
 fn new_tessellator(pixels_per_point: f32) -> Tessellator {
     Tessellator::new(
         pixels_per_point,
@@ -727,7 +778,9 @@ fn mesh_triangles(mesh: &Mesh) -> impl Iterator<Item = [&Vertex; 3]> + Clone {
 mod test {
     use std::str::FromStr;
 
-    use super::Handwriting;
+    use egui::{Event, Modifiers, PointerButton, Pos2, Rect, emath::RectTransform};
+
+    use super::{Handwriting, process_event};
 
     #[test]
     fn serialize_handwriting() {
@@ -741,4 +794,194 @@ mod test {
             Handwriting::from_str(&serialized).expect("Handwriting must de/serialize correctly");
         insta::assert_debug_snapshot!("deserialized handwriting", deserialized.strokes);
     }
+
+    const TEST_EVENTS: &[Event] = &[
+        Event::PointerMoved(Pos2::new(749.9, 225.6)),
+        Event::PointerButton {
+            pos: Pos2::new(749.9, 225.6),
+            button: PointerButton::Primary,
+            pressed: true,
+            modifiers: Modifiers::NONE,
+        },
+        Event::PointerMoved(Pos2::new(749.9, 225.7)),
+        Event::PointerMoved(Pos2::new(749.9, 226.4)),
+        Event::PointerMoved(Pos2::new(750.2, 228.4)),
+        Event::PointerMoved(Pos2::new(751.0, 231.3)),
+        Event::PointerMoved(Pos2::new(752.6, 234.4)),
+        Event::PointerMoved(Pos2::new(754.1, 237.7)),
+        Event::PointerMoved(Pos2::new(755.8, 241.1)),
+        Event::PointerMoved(Pos2::new(757.7, 244.4)),
+        Event::PointerMoved(Pos2::new(759.3, 247.4)),
+        Event::PointerMoved(Pos2::new(760.8, 250.2)),
+        Event::PointerMoved(Pos2::new(762.8, 253.4)),
+        Event::PointerMoved(Pos2::new(765.1, 256.8)),
+        Event::PointerMoved(Pos2::new(767.7, 260.2)),
+        Event::PointerMoved(Pos2::new(771.2, 264.3)),
+        Event::PointerMoved(Pos2::new(774.6, 267.9)),
+        Event::PointerMoved(Pos2::new(778.2, 271.2)),
+        Event::PointerMoved(Pos2::new(782.7, 275.2)),
+        Event::PointerMoved(Pos2::new(786.7, 278.5)),
+        Event::PointerMoved(Pos2::new(790.4, 280.8)),
+        Event::PointerMoved(Pos2::new(794.1, 282.6)),
+        Event::PointerMoved(Pos2::new(797.9, 283.9)),
+        Event::PointerMoved(Pos2::new(801.9, 284.8)),
+        Event::PointerMoved(Pos2::new(805.9, 285.5)),
+        Event::PointerMoved(Pos2::new(810.2, 285.8)),
+        Event::PointerMoved(Pos2::new(814.5, 285.8)),
+        Event::PointerMoved(Pos2::new(818.2, 285.6)),
+        Event::PointerMoved(Pos2::new(821.6, 284.5)),
+        Event::PointerMoved(Pos2::new(824.7, 283.0)),
+        Event::PointerMoved(Pos2::new(827.5, 281.4)),
+        Event::PointerMoved(Pos2::new(830.4, 279.6)),
+        Event::PointerMoved(Pos2::new(833.4, 277.7)),
+        Event::PointerMoved(Pos2::new(836.1, 275.7)),
+        Event::PointerMoved(Pos2::new(838.6, 273.6)),
+        Event::PointerMoved(Pos2::new(840.9, 271.7)),
+        Event::PointerMoved(Pos2::new(843.0, 269.6)),
+        Event::PointerMoved(Pos2::new(845.4, 267.2)),
+        Event::PointerMoved(Pos2::new(847.7, 265.1)),
+        Event::PointerMoved(Pos2::new(849.8, 262.7)),
+        Event::PointerMoved(Pos2::new(852.0, 260.0)),
+        Event::PointerMoved(Pos2::new(854.3, 256.8)),
+        Event::PointerMoved(Pos2::new(856.3, 253.4)),
+        Event::PointerMoved(Pos2::new(858.2, 250.1)),
+        Event::PointerMoved(Pos2::new(860.0, 247.1)),
+        Event::PointerMoved(Pos2::new(861.5, 244.3)),
+        Event::PointerMoved(Pos2::new(862.8, 242.0)),
+        Event::PointerMoved(Pos2::new(864.1, 240.1)),
+        Event::PointerMoved(Pos2::new(865.0, 238.2)),
+        Event::PointerMoved(Pos2::new(865.8, 236.6)),
+        Event::PointerMoved(Pos2::new(866.5, 234.9)),
+        Event::PointerMoved(Pos2::new(867.1, 233.1)),
+        Event::PointerMoved(Pos2::new(867.8, 231.4)),
+        Event::PointerMoved(Pos2::new(868.4, 229.8)),
+        Event::PointerMoved(Pos2::new(868.7, 228.4)),
+        Event::PointerMoved(Pos2::new(868.9, 227.2)),
+        Event::PointerMoved(Pos2::new(869.1, 226.2)),
+        Event::PointerMoved(Pos2::new(869.1, 225.1)),
+        Event::PointerMoved(Pos2::new(869.1, 224.1)),
+        Event::PointerMoved(Pos2::new(869.1, 223.4)),
+        Event::PointerMoved(Pos2::new(869.1, 222.8)),
+        Event::PointerMoved(Pos2::new(869.1, 222.4)),
+        Event::PointerMoved(Pos2::new(869.1, 222.4)),
+        // Event::PointerButton {
+        //     pos: Pos2::new(869.1, 222.4),
+        //     button: PointerButton::Primary,
+        //     pressed: false,
+        //     modifiers: Modifiers::NONE,
+        // },
+        Event::PointerGone,
+        Event::PointerMoved(Pos2::new(779.3, 158.6)),
+        // --
+        // FIXME: This line looks weird. Probably because of a bug in the rasterizer when the X-coord is all the same.
+        Event::PointerButton {
+            pos: Pos2::new(779.3, 158.6),
+            button: PointerButton::Primary,
+            pressed: true,
+            modifiers: Modifiers::NONE,
+        },
+        Event::PointerMoved(Pos2::new(779.3, 159.0)),
+        Event::PointerMoved(Pos2::new(779.3, 160.9)),
+        Event::PointerMoved(Pos2::new(779.3, 164.6)),
+        Event::PointerMoved(Pos2::new(779.3, 169.6)),
+        Event::PointerMoved(Pos2::new(779.3, 175.2)),
+        Event::PointerMoved(Pos2::new(779.3, 180.3)),
+        Event::PointerMoved(Pos2::new(779.3, 185.0)),
+        Event::PointerMoved(Pos2::new(779.3, 189.4)),
+        Event::PointerMoved(Pos2::new(779.3, 192.8)),
+        Event::PointerMoved(Pos2::new(779.3, 194.9)),
+        Event::PointerMoved(Pos2::new(779.3, 196.1)),
+        Event::PointerMoved(Pos2::new(779.3, 197.0)),
+        Event::PointerMoved(Pos2::new(779.3, 197.6)),
+        Event::PointerMoved(Pos2::new(779.3, 198.1)),
+        Event::PointerMoved(Pos2::new(779.3, 198.5)),
+        Event::PointerMoved(Pos2::new(779.3, 198.8)),
+        Event::PointerMoved(Pos2::new(779.3, 199.0)),
+        Event::PointerMoved(Pos2::new(779.3, 199.2)),
+        Event::PointerMoved(Pos2::new(779.3, 199.2)),
+        Event::PointerButton {
+            pos: Pos2::new(779.3, 199.2),
+            button: PointerButton::Primary,
+            pressed: false,
+            modifiers: Modifiers::NONE,
+        },
+        // --
+        Event::PointerMoved(Pos2::new(841.5, 159.2)),
+        Event::PointerButton {
+            pos: Pos2::new(841.5, 159.2),
+            button: PointerButton::Primary,
+            pressed: true,
+            modifiers: Modifiers::NONE,
+        },
+        Event::PointerMoved(Pos2::new(841.5, 159.3)),
+        Event::PointerMoved(Pos2::new(841.5, 159.7)),
+        Event::PointerMoved(Pos2::new(841.5, 160.5)),
+        Event::PointerMoved(Pos2::new(841.5, 162.4)),
+        Event::PointerMoved(Pos2::new(841.5, 165.1)),
+        Event::PointerMoved(Pos2::new(841.5, 168.4)),
+        Event::PointerMoved(Pos2::new(841.5, 171.6)),
+        Event::PointerMoved(Pos2::new(841.5, 174.4)),
+        Event::PointerMoved(Pos2::new(841.5, 177.1)),
+        Event::PointerMoved(Pos2::new(841.5, 179.3)),
+        Event::PointerMoved(Pos2::new(841.5, 180.9)),
+        Event::PointerMoved(Pos2::new(841.5, 182.4)),
+        Event::PointerMoved(Pos2::new(841.5, 183.5)),
+        Event::PointerMoved(Pos2::new(841.5, 184.5)),
+        Event::PointerMoved(Pos2::new(841.5, 185.6)),
+        Event::PointerMoved(Pos2::new(841.5, 187.0)),
+        Event::PointerMoved(Pos2::new(841.5, 188.6)),
+        Event::PointerMoved(Pos2::new(841.5, 190.3)),
+        Event::PointerMoved(Pos2::new(841.5, 191.8)),
+        Event::PointerMoved(Pos2::new(841.3, 192.7)),
+        Event::PointerMoved(Pos2::new(841.0, 193.3)),
+        Event::PointerMoved(Pos2::new(841.0, 193.7)),
+        Event::PointerMoved(Pos2::new(841.1, 193.9)),
+        Event::PointerMoved(Pos2::new(841.3, 193.9)),
+        Event::PointerMoved(Pos2::new(841.4, 194.0)),
+        Event::PointerMoved(Pos2::new(841.4, 194.2)),
+        Event::PointerMoved(Pos2::new(841.4, 194.6)),
+        Event::PointerMoved(Pos2::new(841.4, 194.9)),
+        Event::PointerMoved(Pos2::new(841.4, 195.1)),
+        Event::PointerMoved(Pos2::new(841.4, 195.1)),
+        Event::PointerButton {
+            pos: Pos2::new(841.4, 195.1),
+            button: PointerButton::Primary,
+            pressed: false,
+            modifiers: Modifiers::NONE,
+        },
+    ];
+
+    fn from_screen() -> RectTransform {
+        RectTransform::from_to(
+            Rect::from_two_pos(Pos2::new(570.0, 145.1), Pos2::new(1116.4, 245.1)),
+            Rect::from_two_pos(Pos2::new(0.0, 0.0), Pos2::new(546.4, 100.0)),
+        )
+    }
+
+    #[test]
+    fn handle_input() {
+        let mut tool_events = vec![];
+        let mut last_pos = None;
+        let from_screen = from_screen();
+        for event in TEST_EVENTS {
+            process_event(&mut last_pos, from_screen, event, |tool_event| {
+                tool_events.push(tool_event)
+            });
+        }
+        insta::assert_yaml_snapshot!(tool_events);
+    }
+
+    #[test]
+    fn input_to_handwriting() {
+        let mut handwriting = Handwriting::default();
+        let mut last_pos = None;
+        let from_screen = from_screen();
+        for event in TEST_EVENTS {
+            process_event(&mut last_pos, from_screen, event, |tool_event| {
+                handwriting.on_tool_event(tool_event);
+            });
+        }
+        let serialized = handwriting.to_string();
+        insta::assert_snapshot!("input events to handwriting", serialized);
+    }
 }

src/handwriting/snapshots/inkr__handwriting__test__handle_input.snap

@@ -0,0 +1,455 @@
+---
+source: src/handwriting/mod.rs
+expression: tool_events
+---
+- Press:
+    at:
+      x: 179.90002
+      y: 80.5
+- Move:
+    to:
+      x: 179.90002
+      y: 80.59999
+- Move:
+    to:
+      x: 179.90002
+      y: 81.29999
+- Move:
+    to:
+      x: 180.20001
+      y: 83.29999
+- Move:
+    to:
+      x: 181
+      y: 86.2
+- Move:
+    to:
+      x: 182.59998
+      y: 89.29999
+- Move:
+    to:
+      x: 184.09998
+      y: 92.59999
+- Move:
+    to:
+      x: 185.79999
+      y: 96
+- Move:
+    to:
+      x: 187.70001
+      y: 99.29999
+- Move:
+    to:
+      x: 189.3
+      y: 102.29999
+- Move:
+    to:
+      x: 190.8
+      y: 105.09999
+- Move:
+    to:
+      x: 192.79999
+      y: 108.29998
+- Move:
+    to:
+      x: 195.09998
+      y: 111.69999
+- Move:
+    to:
+      x: 197.70001
+      y: 115.100006
+- Move:
+    to:
+      x: 201.20001
+      y: 119.19998
+- Move:
+    to:
+      x: 204.59998
+      y: 122.799995
+- Move:
+    to:
+      x: 208.20001
+      y: 126.100006
+- Move:
+    to:
+      x: 212.70001
+      y: 130.1
+- Move:
+    to:
+      x: 216.70001
+      y: 133.4
+- Move:
+    to:
+      x: 220.40002
+      y: 135.69998
+- Move:
+    to:
+      x: 224.09998
+      y: 137.5
+- Move:
+    to:
+      x: 227.90002
+      y: 138.79999
+- Move:
+    to:
+      x: 231.90002
+      y: 139.69998
+- Move:
+    to:
+      x: 235.90002
+      y: 140.4
+- Move:
+    to:
+      x: 240.20001
+      y: 140.69998
+- Move:
+    to:
+      x: 244.5
+      y: 140.69998
+- Move:
+    to:
+      x: 248.20001
+      y: 140.5
+- Move:
+    to:
+      x: 251.59996
+      y: 139.4
+- Move:
+    to:
+      x: 254.70001
+      y: 137.9
+- Move:
+    to:
+      x: 257.5
+      y: 136.29999
+- Move:
+    to:
+      x: 260.40002
+      y: 134.5
+- Move:
+    to:
+      x: 263.40002
+      y: 132.6
+- Move:
+    to:
+      x: 266.09998
+      y: 130.6
+- Move:
+    to:
+      x: 268.59998
+      y: 128.5
+- Move:
+    to:
+      x: 270.90002
+      y: 126.600006
+- Move:
+    to:
+      x: 273
+      y: 124.5
+- Move:
+    to:
+      x: 275.40002
+      y: 122.100006
+- Move:
+    to:
+      x: 277.70004
+      y: 120.00001
+- Move:
+    to:
+      x: 279.8
+      y: 117.60001
+- Move:
+    to:
+      x: 282
+      y: 114.899994
+- Move:
+    to:
+      x: 284.3
+      y: 111.69999
+- Move:
+    to:
+      x: 286.3
+      y: 108.29998
+- Move:
+    to:
+      x: 288.2
+      y: 104.99999
+- Move:
+    to:
+      x: 290
+      y: 102
+- Move:
+    to:
+      x: 291.5
+      y: 99.2
+- Move:
+    to:
+      x: 292.8
+      y: 96.899994
+- Move:
+    to:
+      x: 294.09995
+      y: 95
+- Move:
+    to:
+      x: 295
+      y: 93.09999
+- Move:
+    to:
+      x: 295.8
+      y: 91.5
+- Move:
+    to:
+      x: 296.5
+      y: 89.79999
+- Move:
+    to:
+      x: 297.1
+      y: 88
+- Move:
+    to:
+      x: 297.8
+      y: 86.29999
+- Move:
+    to:
+      x: 298.40005
+      y: 84.7
+- Move:
+    to:
+      x: 298.7
+      y: 83.29999
+- Move:
+    to:
+      x: 298.90002
+      y: 82.09999
+- Move:
+    to:
+      x: 299.1
+      y: 81.09999
+- Move:
+    to:
+      x: 299.1
+      y: 80
+- Move:
+    to:
+      x: 299.1
+      y: 79
+- Move:
+    to:
+      x: 299.1
+      y: 78.29999
+- Move:
+    to:
+      x: 299.1
+      y: 77.7
+- Move:
+    to:
+      x: 299.1
+      y: 77.29999
+- Release
+- Press:
+    at:
+      x: 209.29999
+      y: 13.500001
+- Move:
+    to:
+      x: 209.29999
+      y: 13.899994
+- Move:
+    to:
+      x: 209.29999
+      y: 15.799988
+- Move:
+    to:
+      x: 209.29999
+      y: 19.5
+- Move:
+    to:
+      x: 209.29999
+      y: 24.5
+- Move:
+    to:
+      x: 209.29999
+      y: 30.09999
+- Move:
+    to:
+      x: 209.29999
+      y: 35.199997
+- Move:
+    to:
+      x: 209.29999
+      y: 39.899994
+- Move:
+    to:
+      x: 209.29999
+      y: 44.299988
+- Move:
+    to:
+      x: 209.29999
+      y: 47.699997
+- Move:
+    to:
+      x: 209.29999
+      y: 49.799988
+- Move:
+    to:
+      x: 209.29999
+      y: 51
+- Move:
+    to:
+      x: 209.29999
+      y: 51.899994
+- Move:
+    to:
+      x: 209.29999
+      y: 52.499996
+- Move:
+    to:
+      x: 209.29999
+      y: 52.999996
+- Move:
+    to:
+      x: 209.29999
+      y: 53.399994
+- Move:
+    to:
+      x: 209.29999
+      y: 53.699993
+- Move:
+    to:
+      x: 209.29999
+      y: 53.89999
+- Move:
+    to:
+      x: 209.29999
+      y: 54.09999
+- Move:
+    to:
+      x: 209.29999
+      y: 54.09999
+- Release
+- Press:
+    at:
+      x: 271.5
+      y: 14.099991
+- Move:
+    to:
+      x: 271.5
+      y: 14.199998
+- Move:
+    to:
+      x: 271.5
+      y: 14.599991
+- Move:
+    to:
+      x: 271.5
+      y: 15.399994
+- Move:
+    to:
+      x: 271.5
+      y: 17.299988
+- Move:
+    to:
+      x: 271.5
+      y: 20
+- Move:
+    to:
+      x: 271.5
+      y: 23.299988
+- Move:
+    to:
+      x: 271.5
+      y: 26.499998
+- Move:
+    to:
+      x: 271.5
+      y: 29.299986
+- Move:
+    to:
+      x: 271.5
+      y: 32
+- Move:
+    to:
+      x: 271.5
+      y: 34.199997
+- Move:
+    to:
+      x: 271.5
+      y: 35.799988
+- Move:
+    to:
+      x: 271.5
+      y: 37.299988
+- Move:
+    to:
+      x: 271.5
+      y: 38.399994
+- Move:
+    to:
+      x: 271.5
+      y: 39.399994
+- Move:
+    to:
+      x: 271.5
+      y: 40.5
+- Move:
+    to:
+      x: 271.5
+      y: 41.899994
+- Move:
+    to:
+      x: 271.5
+      y: 43.5
+- Move:
+    to:
+      x: 271.5
+      y: 45.199997
+- Move:
+    to:
+      x: 271.5
+      y: 46.699997
+- Move:
+    to:
+      x: 271.3
+      y: 47.59999
+- Move:
+    to:
+      x: 271
+      y: 48.199997
+- Move:
+    to:
+      x: 271
+      y: 48.59999
+- Move:
+    to:
+      x: 271.09998
+      y: 48.799988
+- Move:
+    to:
+      x: 271.3
+      y: 48.799988
+- Move:
+    to:
+      x: 271.40002
+      y: 48.899994
+- Move:
+    to:
+      x: 271.40002
+      y: 49.09999
+- Move:
+    to:
+      x: 271.40002
+      y: 49.5
+- Move:
+    to:
+      x: 271.40002
+      y: 49.799988
+- Move:
+    to:
+      x: 271.40002
+      y: 50
+- Move:
+    to:
+      x: 271.40002
+      y: 50
+- Release

src/handwriting/snapshots/inkr__handwriting__test__input events to handwriting.snap

@@ -0,0 +1,7 @@
+---
+source: src/handwriting/mod.rs
+expression: serialized
+---
+```handwriting
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
+```

src/handwriting/tool/eraser.rs

@@ -0,0 +1,32 @@
+use crate::handwriting::{Handwriting, ToolEvent};
+use egui::Pos2;
+
+pub const RADIUS: f32 = 12.0;
+
+/// Handle a [ToolEvent]. Returns true if a stroke was completed.
+pub fn on_tool_event(handwriting: &mut Handwriting, tool_event: ToolEvent) -> bool {
+    match tool_event {
+        ToolEvent::Press { at } => {
+            erase(handwriting, at, RADIUS)
+        }
+        ToolEvent::Move { to } => {
+            erase(handwriting, to, RADIUS)
+        }
+        ToolEvent::Release => {
+            false            
+        }
+    }
+
+}
+
+fn erase(handwriting: &mut Handwriting, at: Pos2, radius: f32) -> bool {
+    let strokes = handwriting.strokes.len();
+
+    handwriting.strokes.retain(|stroke| {
+        stroke.iter().all(|&point| {
+            (point - at).length() > radius
+        })
+    });
+
+    handwriting.strokes.len() < strokes
+}

src/handwriting/tool/mod.rs

@@ -0,0 +1,28 @@
+pub mod pencil;
+pub mod eraser;
+
+use egui::Pos2;
+use serde::Serialize;
+
+pub enum Tool {
+    Pencil,
+    Eraser,
+}
+
+/// A simple event that can defines how a tool (e.g. the pen) is used on a [Handwriting].
+#[derive(Debug, Serialize, Copy, Clone)]
+pub enum ToolEvent {
+    Press { at: Pos2 },
+    Move { to: Pos2 },
+    Release,
+}
+
+impl ToolEvent {
+    pub const fn position(&self) -> Option<Pos2> {
+        match self {
+            &ToolEvent::Press { at } => Some(at),
+            &ToolEvent::Move { to } => Some(to),
+            ToolEvent::Release => None,
+        }
+    }
+}

src/handwriting/tool/pencil.rs

@@ -0,0 +1,22 @@
+use crate::handwriting::{Handwriting, ToolEvent};
+use std::mem;
+
+/// Handle a [ToolEvent]. Returns true if a stroke was completed.
+pub fn on_tool_event(handwriting: &mut Handwriting, tool_event: ToolEvent) -> bool {
+    match tool_event {
+        ToolEvent::Press { at } => {
+            debug_assert!(handwriting.e.current_stroke.is_empty());
+            handwriting.push_to_stroke(at);
+            false
+        }
+        ToolEvent::Move { to } => {
+            handwriting.push_to_stroke(to);
+            false
+        }
+        ToolEvent::Release => {
+            debug_assert!(!handwriting.e.current_stroke.is_empty());
+            handwriting.strokes.push(mem::take(&mut handwriting.e.current_stroke));
+            true
+        }
+    }
+}

src/lib.rs

@@ -1,5 +1,3 @@
-#![warn(clippy::all, rust_2018_idioms)]
-
 pub mod app;
 pub mod constants;
 pub mod custom_code_block;
@@ -10,6 +8,7 @@ pub mod markdown;
 pub mod preferences;
 pub mod rasterizer;
 pub mod text_editor;
+pub mod text_styles;
 pub mod util;
 
 pub use app::App;

src/markdown/ast.rs

@@ -40,7 +40,7 @@ pub struct Style {
     pub raised: bool,
 }
 
-pub enum MarkdownItem<'a> {
+pub enum Item<'a> {
     Text {
         span: Span<'a>,
         style: Style,

src/markdown/highlighter.rs

@@ -1,10 +1,12 @@
 use egui::text::{CCursorRange, LayoutJob};
 
-use crate::markdown::{
-    span::Span,
-    tokenizer::{Heading, Token, TokenKind, tokenize},
+use crate::{
+    markdown::Heading,
+    text_styles::{H1, H1_MONO, H2, H2_MONO, H3, H3_MONO, H4, H4_MONO, H5, H5_MONO, H6, H6_MONO},
 };
 
+use super::{Item, Style, parse};
+
 /// Highlight markdown, caching previous output to save CPU.
 #[derive(Default)]
 pub struct MemoizedHighlighter {
@@ -13,36 +15,6 @@ pub struct MemoizedHighlighter {
     output: LayoutJob,
 }
 
-#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
-pub struct Style {
-    /// # heading (large text)
-    pub heading: Option<Heading>,
-
-    /// > quoted (slightly dimmer color or other font style)
-    pub quoted: bool,
-
-    /// `code` (monospace, some other color)
-    pub code: bool,
-
-    /// self.strong* (emphasized, e.g. bold)
-    pub strong: bool,
-
-    /// _underline_
-    pub underline: bool,
-
-    /// ~strikethrough~
-    pub strikethrough: bool,
-
-    /// /italics/
-    pub italics: bool,
-
-    /// $small$
-    pub small: bool,
-
-    /// ^raised^
-    pub raised: bool,
-}
-
 impl MemoizedHighlighter {
     pub fn highlight(
         &mut self,
@@ -67,189 +39,87 @@ pub fn highlight_markdown(
     _cursor: Option<CCursorRange>,
 ) -> LayoutJob {
     let mut job = LayoutJob::default();
-    let mut style = Style::default();
+    let code_style = Style {
+        code: true,
+        ..Default::default()
+    };
 
-    let mut prev = TokenKind::Newline;
-
-    let tokens: Vec<_> = tokenize(text).collect();
-    let mut tokens = &tokens[..];
-
-    const CODE_INDENT: f32 = 10.0;
-
-    while !tokens.is_empty() {
-        let token = tokens.first().unwrap();
-        tokens = &tokens[1..];
-
-        let start_of_line = prev == TokenKind::Newline;
-        prev = token.kind;
-
-        let mut basic_style: Option<fn(&mut Style) -> &mut bool> = None;
-
-        match token.kind {
-            TokenKind::CodeBlock if start_of_line => {
-                let span = collect_until(
-                    token,
-                    &mut tokens,
-                    series([TokenKind::Newline, TokenKind::CodeBlock]),
-                );
-
-                let code_style = format_from_style(
-                    egui_style,
-                    &Style {
-                        code: true,
-                        ..Default::default()
-                    },
-                );
-
-                job.append(&*span, CODE_INDENT, code_style.clone());
-                style = Default::default();
-                continue;
+    for item in parse(text) {
+        match item {
+            Item::Text { span, style } => {
+                job.append(&span, 0.0, format_from_style(egui_style, &style));
             }
-
-            TokenKind::Newline => style = Style::default(),
-
-            TokenKind::Strong => basic_style = Some(|s| &mut s.strong),
-            TokenKind::Italic => basic_style = Some(|s| &mut s.italics),
-            TokenKind::Strikethrough => basic_style = Some(|s| &mut s.strikethrough),
-
-            TokenKind::CodeBlock | TokenKind::Mono => {
-                style.code = true;
-                let span = collect_until(
-                    token,
-                    &mut tokens,
-                    any_of([TokenKind::Mono, TokenKind::CodeBlock, TokenKind::Newline]),
-                );
-                job.append(&*span, 0.0, format_from_style(egui_style, &style));
-                style.code = false;
-                continue;
+            Item::CodeBlock {
+                all,
+                language: _, // TODO
+                code: _,     // TODO
+            } => {
+                job.append(&all, 100.0, format_from_style(egui_style, &code_style));
             }
-
-            // TODO: different heading strengths
-            TokenKind::Heading(h) if start_of_line => style.heading = Some(h),
-            TokenKind::Quote if start_of_line => style.quoted = true,
-
-            // TODO: indented list entries
-            TokenKind::ListEntry if start_of_line => {
-                job.append("• ", 0.0, format_from_style(egui_style, &style));
-                continue;
-            }
-
-            TokenKind::Text
-            // the following tokens are only richly rendered if encountered e.g. at start_of_line.
-            | TokenKind::Indentation
-            | TokenKind::ListEntry
-            | TokenKind::Heading(..)
-            | TokenKind::Quote => {}
         }
-
-        // if we encountered a marker for Bold, Italic, or Strikethrough, toggle that style and
-        // render the token with the style enabled.
-        if let Some(basic_style) = basic_style {
-            let mut tmp_style = style;
-            *basic_style(&mut tmp_style) = true;
-            *basic_style(&mut style) ^= true; // toggle
-            job.append(&token.span, 0.0, format_from_style(egui_style, &tmp_style));
-            continue;
-        }
-
-        job.append(&token.span, 0.0, format_from_style(egui_style, &style));
     }
 
     job
 }
 
-fn series<'a, const N: usize>(of: [TokenKind; N]) -> impl FnMut(&[Token<'a>; N]) -> bool {
-    move |token| {
-        of.iter()
-            .zip(token)
-            .all(|(kind, token)| kind == &token.kind)
-    }
-}
-
-fn any_of<'a, const N: usize>(these: [TokenKind; N]) -> impl FnMut(&[Token<'a>; 1]) -> bool {
-    move |[token]| these.contains(&token.kind)
-}
-
-/// Collect all tokens up to and including `pattern`, and merge them into a signle span.
-///
-/// `N` determines how many specific and consecutive tokens we are looking for.
-/// i.e. if we were looking for a [TokenKind::Newline] followed by a [TokenKind::Quote], `N`
-/// would equal `2`.
-///
-/// `pattern` is a function that accepts an array of `N` tokens and returns `true` if they match,
-/// i.e. if we should stop collecting. [any_of] and [series] can help to construct this function.
-///
-/// The collected tokens will be split off the head of the slice referred to by `tokens`.
-///
-/// # Panic
-/// Panics if `tokens` does not contain only consecutive adjacent spans.
-fn collect_until<'a, const N: usize>(
-    token: &Token<'a>,
-    tokens: &mut &[Token<'a>],
-    pattern: impl FnMut(&[Token<'a>; N]) -> bool,
-) -> Span<'a>
-where
-    for<'b> &'b [Token<'a>; N]: TryFrom<&'b [Token<'a>]>,
-{
-    let mut windows = tokens
-        .windows(N)
-        .map(|slice| <&[Token<'a>; N]>::try_from(slice).ok().unwrap());
-
-    let split_at = match windows.position(pattern) {
-        Some(i) => i + N,
-        None => tokens.len(), // consume everything
-    };
-
-    let (consume, keep) = tokens.split_at(split_at);
-    *tokens = keep;
-
-    consume
-        .iter()
-        .fold(token.span.clone(), |span: Span<'_>, token| {
-            span.try_merge(&token.span).unwrap()
-        })
-}
-
-fn format_from_style(egui_style: &egui::Style, emark_style: &Style) -> egui::text::TextFormat {
+fn format_from_style(egui_style: &egui::Style, style: &Style) -> egui::text::TextFormat {
     use egui::{Align, Color32, Stroke, TextStyle};
 
-    let color = if emark_style.strong || emark_style.heading.is_some() {
+    let color = if style.code {
+        egui_style.visuals.strong_text_color() * Color32::GREEN
+    } else if style.strong || style.heading.is_some() {
         egui_style.visuals.strong_text_color()
-    } else if emark_style.quoted {
+    } else if style.quoted {
         egui_style.visuals.weak_text_color()
     } else {
         egui_style.visuals.text_color()
     };
 
-    let text_style = if emark_style.heading.is_some() {
-        TextStyle::Heading
-    } else if emark_style.code {
+    let text_style = if let Some(heading) = style.heading {
+        let text_style = match (heading, style.code) {
+            (Heading::H1, false) => H1,
+            (Heading::H2, false) => H2,
+            (Heading::H3, false) => H3,
+            (Heading::H4, false) => H4,
+            (Heading::H5, false) => H5,
+            (Heading::H6, false) => H6,
+
+            (Heading::H1, true) => H1_MONO,
+            (Heading::H2, true) => H2_MONO,
+            (Heading::H3, true) => H3_MONO,
+            (Heading::H4, true) => H4_MONO,
+            (Heading::H5, true) => H5_MONO,
+            (Heading::H6, true) => H6_MONO,
+        };
+
+        TextStyle::Name(text_style.into())
+    } else if style.code {
         TextStyle::Monospace
-    } else if emark_style.small | emark_style.raised {
+    } else if style.small | style.raised {
         TextStyle::Small
     } else {
         TextStyle::Body
     };
 
-    let background = if emark_style.code {
+    let background = if style.code {
         egui_style.visuals.code_bg_color
     } else {
         Color32::TRANSPARENT
     };
 
-    let underline = if emark_style.underline {
+    let underline = if style.underline {
         Stroke::new(1.0, color)
     } else {
         Stroke::NONE
     };
 
-    let strikethrough = if emark_style.strikethrough {
+    let strikethrough = if style.strikethrough {
         Stroke::new(1.0, color)
     } else {
         Stroke::NONE
     };
 
-    let valign = if emark_style.raised {
+    let valign = if style.raised {
         Align::TOP
     } else {
         Align::BOTTOM
@@ -259,7 +129,7 @@ fn format_from_style(egui_style: &egui::Style, emark_style: &Style) -> egui::tex
         font_id: text_style.resolve(egui_style),
         color,
         background,
-        italics: emark_style.italics,
+        italics: style.italics,
         underline,
         strikethrough,
         valign,

src/markdown/mod.rs

@@ -1,7 +1,11 @@
+mod ast;
 mod highlighter;
+mod parser;
 mod span;
 mod tokenizer;
 
+pub use ast::*;
 pub use highlighter::*;
+pub use parser::*;
 pub use span::*;
 pub use tokenizer::*;

src/markdown/parser.rs

@@ -0,0 +1,170 @@
+use std::iter::{self, once};
+
+use crate::markdown::Style;
+
+use super::{Item, Span, Token, TokenKind, tokenize};
+
+pub fn parse(text: &str) -> Vec<Item<'_>> {
+    let tokens: Vec<_> = tokenize(text).collect();
+    parse_tokens(&tokens)
+}
+
+pub fn parse_tokens<'a>(mut tokens: &[Token<'a>]) -> Vec<Item<'a>> {
+    // pretend that the first token was preceeded by a newline.
+    // means we don't have to handle the first token as a special case.
+    let mut prev = TokenKind::Newline;
+
+    let mut style = Style::default();
+
+    iter::from_fn(move || {
+        if tokens.is_empty() {
+            return None;
+        }
+
+        let token = tokens.first().unwrap();
+        tokens = &tokens[1..];
+
+        let start_of_line = prev == TokenKind::Newline;
+        prev = token.kind;
+
+        let mut basic_style: Option<fn(&mut Style) -> &mut bool> = None;
+
+        match token.kind {
+            TokenKind::CodeBlock if start_of_line => {
+                let language = collect_until(
+                    None,
+                    &mut tokens,
+                    any_of([TokenKind::Newline]),
+                );
+
+                let code = collect_until(
+                    None,
+                    &mut tokens,
+                    series([TokenKind::Newline, TokenKind::CodeBlock]),
+                );
+
+                let all = [
+                    &token.span,
+                    &language,
+                    &code,
+                ].into_iter().fold(Span::empty(), |a, b| a.try_merge(b).unwrap());
+
+                let language = language.trim_end_matches("\n");
+                let code = code.trim_end_matches("\n```");
+
+                return Some(Item::CodeBlock { all, language, code });
+            }
+
+            TokenKind::Newline => style = Style::default(),
+
+            TokenKind::Strong => basic_style = Some(|s| &mut s.strong),
+            TokenKind::Italic => basic_style = Some(|s| &mut s.italics),
+            TokenKind::Strikethrough => basic_style = Some(|s| &mut s.strikethrough),
+
+            TokenKind::CodeBlock | TokenKind::Mono => {
+                let span = collect_until(
+                    Some(token),
+                    &mut tokens,
+                    any_of([TokenKind::Mono, TokenKind::CodeBlock, TokenKind::Newline]),
+                );
+
+                let mut style = style;
+                style.code = true;
+
+                return Some(Item::Text { span, style });
+            }
+
+            // TODO: different heading strengths
+            TokenKind::Heading(h) if start_of_line => style.heading = Some(h),
+            TokenKind::Quote if start_of_line => style.quoted = true,
+
+            // TODO: replace dashes with dots
+            //// TODO: indented list entries
+            //TokenKind::ListEntry if start_of_line => {
+            //    job.append("• ", 0.0, format_from_style(egui_style, &style));
+            //    continue;
+            //}
+
+            TokenKind::Text
+            // the following tokens are only richly rendered if encountered e.g. at start_of_line.
+            | TokenKind::Indentation
+            | TokenKind::ListEntry
+            | TokenKind::Heading(..)
+            | TokenKind::Quote => {}
+        }
+
+        // if we encountered a marker for Bold, Italic, or Strikethrough, toggle that style and
+        // render the token with the style enabled.
+        if let Some(basic_style) = basic_style {
+            let mut tmp_style = style;
+            *basic_style(&mut tmp_style) = true;
+            *basic_style(&mut style) ^= true; // toggle
+            return Some(Item::Text {
+                span: token.span.clone(),
+                style: tmp_style,
+            });
+        }
+
+        Some(Item::Text {
+            span: token.span.clone(),
+            style,
+        })
+    })
+    .collect()
+}
+
+fn series<'a, const N: usize>(of: [TokenKind; N]) -> impl FnMut(&[Token<'a>; N]) -> bool {
+    move |token| {
+        of.iter()
+            .zip(token)
+            .all(|(kind, token)| kind == &token.kind)
+    }
+}
+
+fn any_of<'a, const N: usize>(these: [TokenKind; N]) -> impl FnMut(&[Token<'a>; 1]) -> bool {
+    move |[token]| these.contains(&token.kind)
+}
+
+/// Collect all tokens up to and including `pattern`, and merge them into a signle span.
+///
+/// `N` determines how many specific and consecutive tokens we are looking for.
+/// i.e. if we were looking for a [TokenKind::Newline] followed by a [TokenKind::Quote], `N`
+/// would equal `2`.
+///
+/// `pattern` is a function that accepts an array of `N` tokens and returns `true` if they match,
+/// i.e. if we should stop collecting. [any_of] and [series] can help to construct this function.
+///
+/// The collected tokens will be split off the head of the slice referred to by `tokens`.
+///
+/// # Panic
+/// Panics if `tokens` does not contain only consecutive adjacent spans.
+fn collect_until<'a, const N: usize>(
+    first_token: Option<&Token<'a>>,
+    tokens: &mut &[Token<'a>],
+    pattern: impl FnMut(&[Token<'a>; N]) -> bool,
+) -> Span<'a>
+where
+    // &[T; N]: TryFrom<&[T]>
+    for<'b> &'b [Token<'a>; N]: TryFrom<&'b [Token<'a>]>,
+{
+    let mut windows = tokens.windows(N).map(|slice| {
+        <&[Token<'a>; N]>::try_from(slice)
+            .ok()
+            .expect("`windows` promises to return slices of length N")
+    });
+
+    let split_at = match windows.position(pattern) {
+        Some(i) => i + N,
+        None => tokens.len(), // consume everything
+    };
+
+    let (consume, keep) = tokens.split_at(split_at);
+    *tokens = keep;
+
+    once(first_token)
+        .flatten()
+        .chain(consume)
+        .fold(Span::empty(), |span: Span<'_>, token| {
+            span.try_merge(&token.span).unwrap()
+        })
+}

src/markdown/span.rs

@@ -3,6 +3,8 @@ use std::{
     ops::{Deref, Range},
 };
 
+use eyre::{bail, eyre};
+
 #[derive(Clone, Eq, PartialEq)]
 pub struct Span<'a> {
     complete_str: &'a str,
@@ -17,6 +19,13 @@ impl<'a> Span<'a> {
         }
     }
 
+    pub const fn empty() -> Self {
+        Span {
+            complete_str: "",
+            range: 0..0,
+        }
+    }
+
     pub fn get(&self, slice: Range<usize>) -> Option<Self> {
         let start = self.range.start.checked_add(slice.start)?;
         let end = self.range.start.checked_add(slice.end)?;
@@ -41,26 +50,49 @@ impl<'a> Span<'a> {
         Some((head, tail))
     }
 
+    pub fn trim_end_matches(&self, p: &str) -> Self {
+        if !self.ends_with(p) {
+            return self.clone();
+        }
+
+        Self {
+            range: self.range.start..self.range.end - p.len(),
+            complete_str: self.complete_str,
+        }
+    }
+
     /// Try to merge the spans.
     ///
+    /// If either spans is empty, this just returns the other one.
     /// This only works if spans are pointing into the same backing buffer, and are adjacent.
-    pub fn try_merge(&self, other: &Self) -> Option<Self> {
+    pub fn try_merge(&self, other: &Self) -> eyre::Result<Self> {
+        if self.is_empty() {
+            return Ok(other.clone());
+        }
+
+        if other.is_empty() {
+            return Ok(self.clone());
+        }
+
         if self.complete_str.as_ptr() != other.complete_str.as_ptr() {
-            return None;
+            bail!("Can't merge different strings");
         }
 
         if self.range.end == other.range.start {
-            Some(Self {
+            Ok(Self {
                 range: self.range.start..other.range.end,
                 ..*self
             })
         } else if self.range.start == other.range.end {
-            Some(Self {
+            Ok(Self {
                 range: other.range.start..self.range.end,
                 ..*self
             })
         } else {
-            None
+            Err(eyre!("String: {:?}", self.complete_str)
+                .wrap_err(eyre!("Span 2: {:?}", other.deref()))
+                .wrap_err(eyre!("Span 1: {:?}", self.deref()))
+                .wrap_err("Can't merge disjoint string spans"))
         }
     }
 }

src/markdown/tokenizer.rs

@@ -1,16 +1,6 @@
 use std::iter;
 
-use super::span::Span;
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Heading {
-    H6,
-    H5,
-    H4,
-    H3,
-    H2,
-    H1,
-}
+use super::{Heading, span::Span};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum TokenKind {
@@ -41,7 +31,7 @@ pub enum TokenKind {
     Text,
 }
 
-const TOKENS: &[(&'static str, TokenKind)] = &[
+const TOKENS: &[(&str, TokenKind)] = &[
     ("\n", TokenKind::Newline),
     ("######", TokenKind::Heading(Heading::H6)),
     ("#####", TokenKind::Heading(Heading::H5)),

src/preferences.rs

@@ -1,4 +1,4 @@
-use egui::{Color32, Context, RichText, Theme, Ui, Visuals};
+use egui::{Color32, Context, RichText, Theme, Ui, Visuals, style::ScrollAnimation};
 use serde::{Deserialize, Serialize};
 
 #[derive(Serialize, Deserialize)]
@@ -14,7 +14,7 @@ pub struct Preferences {
     pub hide_handwriting_cursor: bool,
 
     #[serde(skip)]
-    has_applied_theme: bool,
+    has_applied_prefs: bool,
 }
 
 impl Default for Preferences {
@@ -22,7 +22,7 @@ impl Default for Preferences {
         Self {
             animations: true,
             high_contrast: false,
-            has_applied_theme: false,
+            has_applied_prefs: false,
             hide_handwriting_cursor: false,
         }
     }
@@ -31,13 +31,30 @@ impl Default for Preferences {
 impl Preferences {
     /// Apply preferences, if they haven't already been applied.
     pub fn apply(&mut self, ctx: &Context) {
-        if !self.has_applied_theme {
-            self.has_applied_theme = true;
+        if !self.has_applied_prefs {
+            self.has_applied_prefs = true;
+
+            let scroll_animation = if self.animations {
+                ScrollAnimation::default()
+            } else {
+                ScrollAnimation::none()
+            };
+
+            for theme in [Theme::Dark, Theme::Light] {
+                ctx.style_mut_of(theme, |style| {
+                    style.scroll_animation = scroll_animation;
+                });
+            }
 
             let mut dark_visuals = Visuals::dark();
             let mut light_visuals = Visuals::light();
 
-            dark_visuals.code_bg_color = Color32::BLACK;
+            dark_visuals.window_fill = Color32::from_rgb(0x1e, 0x1e, 0x1e);
+            dark_visuals.panel_fill = Color32::from_rgb(0x26, 0x26, 0x26);
+
+            light_visuals.window_fill = Color32::WHITE;
+            light_visuals.panel_fill = Color32::from_rgb(0xf6, 0xf6, 0xf6);
+
             dark_visuals.code_bg_color = Color32::BLACK;
             light_visuals.code_bg_color = Color32::WHITE;
 
@@ -71,11 +88,15 @@ impl Preferences {
     pub fn show(&mut self, ui: &mut Ui) {
         ui.label(RichText::new("Prefs").weak());
 
-        ui.toggle_value(&mut self.animations, "Animations");
+        let animations_toggle = ui.toggle_value(&mut self.animations, "Animations");
+        if animations_toggle.clicked() {
+            self.has_applied_prefs = false;
+            self.apply(ui.ctx());
+        }
 
         let high_contrast_toggle = ui.toggle_value(&mut self.high_contrast, "High Contrast");
         if high_contrast_toggle.clicked() {
-            self.has_applied_theme = false;
+            self.has_applied_prefs = false;
             self.apply(ui.ctx());
         }
 

src/rasterizer.rs

@@ -22,7 +22,7 @@ pub fn rasterize<'a, Blend: BlendFn>(
     point_to_pixel: TSTransform,
     triangles: impl Iterator<Item = [&'a Vertex; 3]>,
 ) -> ColorImage {
-    let mut image = ColorImage::new([width, height], Color32::TRANSPARENT);
+    let mut image = ColorImage::filled([width, height], Color32::TRANSPARENT);
     rasterize_onto::<Blend>(&mut image, point_to_pixel, triangles);
     image
 }
@@ -90,10 +90,10 @@ pub fn rasterize_onto<'a, Blend: BlendFn>(
 /// Rasterize a single triangles onto an image,
 ///
 /// Triangle positions must be in image-local point-coords.
-pub fn rasterize_triangle_onto<'a, Blend: BlendFn>(
+pub fn rasterize_triangle_onto<Blend: BlendFn>(
     image: &mut ColorImage,
     point_to_pixel: TSTransform,
-    triangle: [&'a Vertex; 3],
+    triangle: [&Vertex; 3],
 ) {
     rasterize_onto::<Blend>(image, point_to_pixel, [triangle].into_iter());
 }
@@ -140,8 +140,7 @@ impl PxBoundingBox {
     }
 
     pub fn is_disjoint_from(&self, other: &PxBoundingBox) -> bool {
-        false
-            || self.x_from > other.x_to
+        self.x_from > other.x_to
             || self.y_from > other.y_to
             || other.x_from > self.x_to
             || other.y_from > self.y_to

src/text_styles.rs

@@ -0,0 +1,14 @@
+//! Name of custom [egui::TextStyle]s
+
+pub const H1: &str = "H1";
+pub const H2: &str = "H2";
+pub const H3: &str = "H3";
+pub const H4: &str = "H4";
+pub const H5: &str = "H5";
+pub const H6: &str = "H6";
+pub const H1_MONO: &str = "H1-mono";
+pub const H2_MONO: &str = "H2-mono";
+pub const H3_MONO: &str = "H3-mono";
+pub const H4_MONO: &str = "H4-mono";
+pub const H5_MONO: &str = "H5-mono";
+pub const H6_MONO: &str = "H6-mono";

src/util.rs

@@ -1,6 +1,8 @@
-use std::sync::mpsc;
+use std::{fs::File, os::unix::fs::MetadataExt as _, sync::mpsc};
 
+use chrono::{DateTime, Local};
 use egui::Id;
+use eyre::{Context, ContextCompat};
 use rand::{Rng, rng};
 
 pub fn random_id() -> Id {
@@ -28,3 +30,27 @@ impl<T> GuiSender<T> {
         Ok(())
     }
 }
+
+#[track_caller]
+pub fn log_error<T>(chain: eyre::Report, f: impl FnOnce() -> eyre::Result<T>) -> Option<T> {
+    f().map_err(|e| e.wrap_err(chain))
+        .inspect_err(|e| log::error!("{e}"))
+        .ok()
+}
+
+pub fn file_mtime(file: &File) -> eyre::Result<DateTime<Local>> {
+    (move || {
+        let meta = file.metadata().wrap_err("Failed to stat file")?;
+
+        let sec = meta.mtime();
+        let nsec = meta
+            .mtime_nsec()
+            .try_into()
+            .wrap_err("Nanoseconds overflowed")?;
+
+        DateTime::from_timestamp(sec, nsec)
+            .wrap_err("Bad timestamp")
+            .map(Into::into)
+    })()
+    .wrap_err("Failed to get file mtime")
+}