Flesh out the editor example a bit more

core/src/renderer/null.rs

@@ -125,6 +125,10 @@ impl text::Editor for () {
         text::editor::Cursor::Caret(Point::ORIGIN)
     }
 
+    fn cursor_position(&self) -> (usize, usize) {
+        (0, 0)
+    }
+
     fn selection(&self) -> Option<String> {
         None
     }

core/src/text/editor.rs

@@ -12,6 +12,8 @@ pub trait Editor: Sized + Default {
 
     fn cursor(&self) -> Cursor;
 
+    fn cursor_position(&self) -> (usize, usize);
+
     fn selection(&self) -> Option<String>;
 
     fn line(&self, index: usize) -> Option<&str>;
@@ -52,6 +54,12 @@ pub enum Action {
     Drag(Point),
 }
 
+impl Action {
+    pub fn is_edit(&self) -> bool {
+        matches!(self, Self::Edit(_))
+    }
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub enum Edit {
     Insert(char),

examples/editor/Cargo.toml

@@ -7,6 +7,10 @@ publish = false
 
 [dependencies]
 iced.workspace = true
-iced.features = ["advanced", "debug"]
+iced.features = ["advanced", "tokio", "debug"]
 
-syntect = "5.1"
+tokio.workspace = true
+tokio.features = ["fs"]
+
+syntect = "5.1"
+rfd = "0.12"

examples/editor/src/main.rs

@@ -1,70 +1,218 @@
-use iced::widget::{column, horizontal_space, pick_list, row, text_editor};
-use iced::{Element, Font, Length, Sandbox, Settings, Theme};
+use iced::executor;
+use iced::theme::{self, Theme};
+use iced::widget::{
+    button, column, container, horizontal_space, pick_list, row, text,
+    text_editor, tooltip,
+};
+use iced::{Application, Command, Element, Font, Length, Settings};
 
 use highlighter::Highlighter;
 
+use std::ffi;
+use std::io;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
 pub fn main() -> iced::Result {
-    Editor::run(Settings::default())
+    Editor::run(Settings {
+        fonts: vec![include_bytes!("../fonts/icons.ttf").as_slice().into()],
+        default_font: Font {
+            monospaced: true,
+            ..Font::with_name("Hasklug Nerd Font Mono")
+        },
+        ..Settings::default()
+    })
 }
 
 struct Editor {
+    file: Option<PathBuf>,
     content: text_editor::Content,
     theme: highlighter::Theme,
+    is_loading: bool,
+    is_dirty: bool,
 }
 
 #[derive(Debug, Clone)]
 enum Message {
     Edit(text_editor::Action),
     ThemeSelected(highlighter::Theme),
+    NewFile,
+    OpenFile,
+    FileOpened(Result<(PathBuf, Arc<String>), Error>),
+    SaveFile,
+    FileSaved(Result<PathBuf, Error>),
 }
 
-impl Sandbox for Editor {
+impl Application for Editor {
     type Message = Message;
-
-    fn new() -> Self {
-        Self {
-            content: text_editor::Content::with(include_str!("main.rs")),
-            theme: highlighter::Theme::SolarizedDark,
-        }
+    type Theme = Theme;
+    type Executor = executor::Default;
+    type Flags = ();
+
+    fn new(_flags: Self::Flags) -> (Self, Command<Message>) {
+        (
+            Self {
+                file: None,
+                content: text_editor::Content::new(),
+                theme: highlighter::Theme::SolarizedDark,
+                is_loading: true,
+                is_dirty: false,
+            },
+            Command::perform(load_file(default_file()), Message::FileOpened),
+        )
     }
 
     fn title(&self) -> String {
         String::from("Editor - Iced")
     }
 
-    fn update(&mut self, message: Message) {
+    fn update(&mut self, message: Message) -> Command<Message> {
         match message {
             Message::Edit(action) => {
+                self.is_dirty = self.is_dirty || action.is_edit();
+
                 self.content.edit(action);
+
+                Command::none()
             }
             Message::ThemeSelected(theme) => {
                 self.theme = theme;
+
+                Command::none()
+            }
+            Message::NewFile => {
+                if !self.is_loading {
+                    self.file = None;
+                    self.content = text_editor::Content::new();
+                }
+
+                Command::none()
+            }
+            Message::OpenFile => {
+                if self.is_loading {
+                    Command::none()
+                } else {
+                    self.is_loading = true;
+
+                    Command::perform(open_file(), Message::FileOpened)
+                }
+            }
+            Message::FileOpened(result) => {
+                self.is_loading = false;
+                self.is_dirty = false;
+
+                if let Ok((path, contents)) = result {
+                    self.file = Some(path);
+                    self.content = text_editor::Content::with(&contents);
+                }
+
+                Command::none()
+            }
+            Message::SaveFile => {
+                if self.is_loading {
+                    Command::none()
+                } else {
+                    self.is_loading = true;
+
+                    let mut contents = self.content.lines().enumerate().fold(
+                        String::new(),
+                        |mut contents, (i, line)| {
+                            if i > 0 {
+                                contents.push_str("\n");
+                            }
+
+                            contents.push_str(&line);
+
+                            contents
+                        },
+                    );
+
+                    if !contents.ends_with("\n") {
+                        contents.push_str("\n");
+                    }
+
+                    Command::perform(
+                        save_file(self.file.clone(), contents),
+                        Message::FileSaved,
+                    )
+                }
+            }
+            Message::FileSaved(result) => {
+                self.is_loading = false;
+
+                if let Ok(path) = result {
+                    self.file = Some(path);
+                    self.is_dirty = false;
+                }
+
+                Command::none()
             }
         }
     }
 
     fn view(&self) -> Element<Message> {
+        let controls = row![
+            action(new_icon(), "New file", Some(Message::NewFile)),
+            action(
+                open_icon(),
+                "Open file",
+                (!self.is_loading).then_some(Message::OpenFile)
+            ),
+            action(
+                save_icon(),
+                "Save file",
+                self.is_dirty.then_some(Message::SaveFile)
+            ),
+            horizontal_space(Length::Fill),
+            pick_list(
+                highlighter::Theme::ALL,
+                Some(self.theme),
+                Message::ThemeSelected
+            )
+            .text_size(14)
+            .padding([5, 10])
+        ]
+        .spacing(10);
+
+        let status = row![
+            text(if let Some(path) = &self.file {
+                let path = path.display().to_string();
+
+                if path.len() > 60 {
+                    format!("...{}", &path[path.len() - 40..])
+                } else {
+                    path
+                }
+            } else {
+                String::from("New file")
+            }),
+            horizontal_space(Length::Fill),
+            text({
+                let (line, column) = self.content.cursor_position();
+
+                format!("{}:{}", line + 1, column + 1)
+            })
+        ]
+        .spacing(10);
+
         column![
-            row![
-                horizontal_space(Length::Fill),
-                pick_list(
-                    highlighter::Theme::ALL,
-                    Some(self.theme),
-                    Message::ThemeSelected
-                )
-                .padding([5, 10])
-            ]
-            .spacing(10),
+            controls,
             text_editor(&self.content)
                 .on_edit(Message::Edit)
-                .font(Font::with_name("Hasklug Nerd Font Mono"))
                 .highlight::<Highlighter>(highlighter::Settings {
                     theme: self.theme,
-                    extension: String::from("rs"),
+                    extension: self
+                        .file
+                        .as_deref()
+                        .and_then(Path::extension)
+                        .and_then(ffi::OsStr::to_str)
+                        .map(str::to_string)
+                        .unwrap_or(String::from("rs")),
                 }),
+            status,
         ]
         .spacing(10)
-        .padding(20)
+        .padding(10)
         .into()
     }
 
@@ -73,6 +221,97 @@ impl Sandbox for Editor {
     }
 }
 
+#[derive(Debug, Clone)]
+pub enum Error {
+    DialogClosed,
+    IoError(io::ErrorKind),
+}
+
+fn default_file() -> PathBuf {
+    PathBuf::from(format!("{}/src/main.rs", env!("CARGO_MANIFEST_DIR")))
+}
+
+async fn open_file() -> Result<(PathBuf, Arc<String>), Error> {
+    let picked_file = rfd::AsyncFileDialog::new()
+        .set_title("Open a text file...")
+        .pick_file()
+        .await
+        .ok_or(Error::DialogClosed)?;
+
+    load_file(picked_file.path().to_owned()).await
+}
+
+async fn load_file(path: PathBuf) -> Result<(PathBuf, Arc<String>), Error> {
+    let contents = tokio::fs::read_to_string(&path)
+        .await
+        .map(Arc::new)
+        .map_err(|error| Error::IoError(error.kind()))?;
+
+    Ok((path, contents))
+}
+
+async fn save_file(
+    path: Option<PathBuf>,
+    contents: String,
+) -> Result<PathBuf, Error> {
+    let path = if let Some(path) = path {
+        path
+    } else {
+        rfd::AsyncFileDialog::new()
+            .save_file()
+            .await
+            .as_ref()
+            .map(rfd::FileHandle::path)
+            .map(Path::to_owned)
+            .ok_or(Error::DialogClosed)?
+    };
+
+    let _ = tokio::fs::write(&path, contents)
+        .await
+        .map_err(|error| Error::IoError(error.kind()))?;
+
+    Ok(path)
+}
+
+fn action<'a, Message: Clone + 'a>(
+    content: impl Into<Element<'a, Message>>,
+    label: &'a str,
+    on_press: Option<Message>,
+) -> Element<'a, Message> {
+    let action =
+        button(container(content).width(Length::Fill).center_x()).width(40);
+
+    if let Some(on_press) = on_press {
+        tooltip(
+            action.on_press(on_press),
+            label,
+            tooltip::Position::FollowCursor,
+        )
+        .style(theme::Container::Box)
+        .into()
+    } else {
+        action.style(theme::Button::Secondary).into()
+    }
+}
+
+fn new_icon<'a, Message>() -> Element<'a, Message> {
+    icon('\u{0e800}')
+}
+
+fn save_icon<'a, Message>() -> Element<'a, Message> {
+    icon('\u{0e801}')
+}
+
+fn open_icon<'a, Message>() -> Element<'a, Message> {
+    icon('\u{0f115}')
+}
+
+fn icon<'a, Message>(codepoint: char) -> Element<'a, Message> {
+    const ICON_FONT: Font = Font::with_name("editor-icons");
+
+    text(codepoint).font(ICON_FONT).into()
+}
+
 mod highlighter {
     use iced::advanced::text::highlighter;
     use iced::widget::text_editor;