egui-data-table 0.10.0

use egui::scroll_area::ScrollBarVisibility;
use egui::{Response, Sense, Widget};
use egui_data_table::{
    viewer::{default_hotkeys, CellWriteContext, DecodeErrorBehavior, RowCodec, UiActionContext},
    RowViewer,
};
use std::fmt::{Display, Formatter};
use std::str::FromStr;
use std::{borrow::Cow, iter::repeat_with};

/* ----------------------------------------- Columns -------------------------------------------- */

mod columns {

    // column indices
    // columns can easily be reordered simply by changing the values of these indices.
    pub const NAME: usize = 0;
    pub const AGE: usize = 1;
    pub const GENDER: usize = 2;
    pub const IS_STUDENT: usize = 3;
    pub const GRADE: usize = 4;
    pub const ROW_LOCKED: usize = 5;

    /// count of columns
    pub const COLUMN_COUNT: usize = 6;

    pub const COLUMN_NAMES: [&str; COLUMN_COUNT] = [
        "Name (Click to sort)",
        "Age",
        "Gender",
        "Is Student (Not sortable)",
        "Grade",
        "Row locked",
    ];
}
use columns::*;

/* ----------------------------------------- Data Scheme ---------------------------------------- */

struct Viewer {
    name_filter: String,
    row_protection: bool,
    hotkeys: Vec<(egui::KeyboardShortcut, egui_data_table::UiAction)>,
}

#[derive(Debug, Clone)]
struct Row {
    name: String,
    age: i32,
    gender: Option<Gender>,
    is_student: bool,
    grade: Grade,
    row_locked: bool,
}

impl Default for Row {
    fn default() -> Self {
        Row {
            name: "".to_string(),
            age: 0,
            gender: None,
            is_student: false,
            grade: Grade::F,
            row_locked: false,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
enum Grade {
    A,
    B,
    C,
    D,
    E,
    F,
}

impl Display for Grade {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            Grade::A => write!(f, "A"),
            Grade::B => write!(f, "B"),
            Grade::C => write!(f, "C"),
            Grade::D => write!(f, "D"),
            Grade::E => write!(f, "E"),
            Grade::F => write!(f, "F"),
        }
    }
}

impl TryFrom<i32> for Grade {
    type Error = ();

    fn try_from(input: i32) -> Result<Self, Self::Error> {
        let value = match input {
            0 => Grade::A,
            1 => Grade::B,
            2 => Grade::C,
            3 => Grade::D,
            4 => Grade::E,
            5 => Grade::F,
            _ => return Err(()),
        };
        Ok(value)
    }
}

impl FromStr for Grade {
    type Err = ();

    fn from_str(input: &str) -> Result<Self, Self::Err> {
        let value = match input {
            "A" => Grade::A,
            "B" => Grade::B,
            "C" => Grade::C,
            "D" => Grade::D,
            "E" => Grade::E,
            "F" => Grade::F,
            _ => return Err(()),
        };

        Ok(value)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
enum Gender {
    Male,
    Female,
}

impl Display for Gender {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            Gender::Male => write!(f, "Male"),
            Gender::Female => write!(f, "Female"),
        }
    }
}

impl FromStr for Gender {
    type Err = ();

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "Male" => Ok(Gender::Male),
            "Female" => Ok(Gender::Female),
            _ => Err(()),
        }
    }
}

/* -------------------------------------------- Codec ------------------------------------------- */

struct Codec;

impl RowCodec<Row> for Codec {
    type DeserializeError = &'static str;

    fn encode_column(&mut self, src_row: &Row, column: usize, dst: &mut String) {
        match column {
            NAME => dst.push_str(&src_row.name),
            AGE => dst.push_str(&src_row.age.to_string()),
            IS_STUDENT => dst.push_str(&src_row.is_student.to_string()),
            GRADE => dst.push_str(src_row.grade.to_string().as_str()),
            ROW_LOCKED => dst.push_str(&src_row.row_locked.to_string()),
            GENDER => {
                if let Some(g) = &src_row.gender {
                    dst.push_str(&g.to_string());
                }
            }
            _ => unreachable!(),
        }
    }

    fn decode_column(
        &mut self,
        src_data: &str,
        column: usize,
        dst_row: &mut Row,
    ) -> Result<(), DecodeErrorBehavior> {
        match column {
            NAME => dst_row.name.replace_range(.., src_data),
            AGE => dst_row.age = src_data.parse().map_err(|_| DecodeErrorBehavior::SkipRow)?,
            IS_STUDENT => {
                dst_row.is_student = src_data.parse().map_err(|_| DecodeErrorBehavior::SkipRow)?
            }
            GRADE => {
                dst_row.grade = src_data.parse().map_err(|_| DecodeErrorBehavior::SkipRow)?;
            }
            ROW_LOCKED => {
                dst_row.row_locked = src_data.parse().map_err(|_| DecodeErrorBehavior::SkipRow)?
            }
            GENDER => {
                dst_row.gender = src_data.trim().parse().ok();
            }
            _ => unreachable!(),
        }

        Ok(())
    }

    fn create_empty_decoded_row(&mut self) -> Row {
        Row::default()
    }
}

/* ------------------------------------ Viewer Implementation ----------------------------------- */

impl RowViewer<Row> for Viewer {
    fn on_highlight_cell(&mut self, row: &Row, column: usize) {
        log::trace!("cell highlighted: row: {:?}, column: {}", row, column);
    }

    fn try_create_codec(&mut self, _: bool) -> Option<impl RowCodec<Row>> {
        Some(Codec)
    }

    fn num_columns(&mut self) -> usize {
        COLUMN_COUNT
    }

    fn column_name(&mut self, column: usize) -> Cow<'static, str> {
        COLUMN_NAMES[column].into()
    }

    fn is_sortable_column(&mut self, column: usize) -> bool {
        !matches!(column, IS_STUDENT)
    }

    fn is_editable_cell(&mut self, column: usize, _row: usize, row_value: &Row) -> bool {
        let row_locked = row_value.row_locked;
        // allow editing of the locked flag, but prevent editing other columns when locked.
        match column {
            ROW_LOCKED => true,
            _ => !row_locked,
        }
    }

    fn compare_cell(&self, row_l: &Row, row_r: &Row, column: usize) -> std::cmp::Ordering {
        match column {
            NAME => row_l.name.cmp(&row_r.name),
            AGE => row_l.age.cmp(&row_r.age),
            GENDER => row_l.gender.cmp(&row_r.gender),
            GRADE => row_l.grade.cmp(&row_r.grade),
            ROW_LOCKED => row_l.row_locked.cmp(&row_r.row_locked),
            _ => std::cmp::Ordering::Equal,
        }
    }

    fn new_empty_row(&mut self) -> Row {
        Row::default()
    }

    fn set_cell_value(&mut self, src: &Row, dst: &mut Row, column: usize) {
        match column {
            NAME => dst.name.clone_from(&src.name),
            AGE => dst.age = src.age,
            GENDER => dst.gender = src.gender,
            IS_STUDENT => dst.is_student = src.is_student,
            GRADE => dst.grade = src.grade,
            ROW_LOCKED => dst.row_locked = src.row_locked,
            _ => unreachable!(),
        }
    }

    fn confirm_cell_write_by_ui(
        &mut self,
        current: &Row,
        _next: &Row,
        _column: usize,
        _context: CellWriteContext,
    ) -> bool {
        if !self.row_protection {
            return true;
        }

        !current.is_student
    }

    fn confirm_row_deletion_by_ui(&mut self, row: &Row) -> bool {
        if !self.row_protection {
            return true;
        }

        !row.is_student
    }

    fn show_cell_view(&mut self, ui: &mut egui::Ui, row: &Row, column: usize) {
        match column {
            NAME => {
                ui.label(&row.name);
            }
            AGE => {
                ui.label(row.age.to_string());
            }
            GENDER => {
                ui.label(
                    row.gender
                        .map(|gender| gender.to_string())
                        .as_deref()
                        .unwrap_or("Unspecified"),
                );
            }
            IS_STUDENT => {
                ui.add_enabled(false, egui::Checkbox::new(&mut { row.is_student }, ""));
            }
            GRADE => {
                ui.label(row.grade.to_string());
            }
            ROW_LOCKED => {
                ui.add_enabled(false, egui::Checkbox::new(&mut { row.row_locked }, ""));
            }
            _ => unreachable!(),
        }
    }

    fn on_cell_view_response(
        &mut self,
        _row: &Row,
        _column: usize,
        resp: &egui::Response,
    ) -> Option<Box<Row>> {
        resp.dnd_release_payload::<String>().map(|x| {
            Box::new(Row {
                name: (*x).clone(),
                age: 9999,
                gender: Some(Gender::Female),
                is_student: false,
                grade: Grade::A,
                row_locked: false,
            })
        })
    }

    fn show_cell_editor(
        &mut self,
        ui: &mut egui::Ui,
        row: &mut Row,
        column: usize,
    ) -> Option<Response> {
        match column {
            NAME => {
                egui::TextEdit::multiline(&mut row.name)
                    .desired_rows(1)
                    .code_editor()
                    .show(ui)
                    .response
            }
            AGE => ui.add(egui::DragValue::new(&mut row.age).speed(1.0)),
            GENDER => {
                let gender = &mut row.gender;

                egui::ComboBox::new(ui.id().with("gender"), "".to_string())
                    .selected_text(
                        gender
                            .map(|gender| gender.to_string())
                            .unwrap_or("Unspecified".to_string()),
                    )
                    .show_ui(ui, |ui| {
                        if ui
                            .add(egui::Button::selectable(
                                matches!(gender, Some(gender) if *gender == Gender::Male),
                                "Male",
                            ))
                            .clicked()
                        {
                            *gender = Some(Gender::Male);
                        }
                        if ui
                            .add(egui::Button::selectable(
                                matches!(gender, Some(gender) if *gender == Gender::Female),
                                "Female",
                            ))
                            .clicked()
                        {
                            *gender = Some(Gender::Female);
                        }
                    })
                    .response
            }
            IS_STUDENT => ui.checkbox(&mut row.is_student, ""),
            GRADE => {
                let grade = &mut row.grade;
                ui.horizontal_wrapped(|ui| {
                    ui.radio_value(grade, Grade::A, "A")
                        | ui.radio_value(grade, Grade::B, "B")
                        | ui.radio_value(grade, Grade::C, "C")
                        | ui.radio_value(grade, Grade::D, "D")
                        | ui.radio_value(grade, Grade::E, "E")
                        | ui.radio_value(grade, Grade::F, "F")
                })
                .inner
            }
            ROW_LOCKED => ui.checkbox(&mut row.row_locked, ""),
            _ => unreachable!(),
        }
        .into()
    }

    fn row_filter_hash(&mut self) -> &impl std::hash::Hash {
        &self.name_filter
    }

    fn filter_row(&mut self, row: &Row) -> bool {
        row.name.contains(&self.name_filter)
    }

    fn hotkeys(
        &mut self,
        context: &UiActionContext,
    ) -> Vec<(egui::KeyboardShortcut, egui_data_table::UiAction)> {
        let hotkeys = default_hotkeys(context);
        self.hotkeys.clone_from(&hotkeys);
        hotkeys
    }

    fn persist_ui_state(&self) -> bool {
        true
    }

    fn on_highlight_change(&mut self, highlighted: &[&Row], unhighlighted: &[&Row]) {
        log::trace!("highlight {:?}", highlighted);
        log::trace!("unhighlight {:?}", unhighlighted);
    }

    fn on_row_updated(&mut self, row_index: usize, new_row: &Row, old_row: &Row) {
        log::trace!(
            "row updated. row_id: {}, new_row: {:?}, old_row: {:?}",
            row_index,
            new_row,
            old_row
        );
    }

    fn on_row_inserted(&mut self, row_index: usize, row: &Row) {
        log::trace!("row inserted. row_id: {}, values: {:?}", row_index, row);
    }

    fn on_row_removed(&mut self, row_index: usize, row: &Row) {
        log::trace!("row removed. row_id: {}, values: {:?}", row_index, row);
    }
}

/* ------------------------------------------ View Loop ----------------------------------------- */

struct DemoApp {
    table: egui_data_table::DataTable<Row>,
    viewer: Viewer,
    style_override: egui_data_table::Style,
    scroll_bar_always_visible: bool,
}

impl Default for DemoApp {
    fn default() -> Self {
        Self {
            table: {
                let mut rng = fastrand::Rng::new();
                let mut name_gen = names::Generator::with_naming(names::Name::Numbered);

                repeat_with(move || Row {
                    name: name_gen.next().unwrap(),
                    age: rng.i32(4..31),
                    gender: match rng.i32(0..=2) {
                        0 => None,
                        1 => Some(Gender::Male),
                        2 => Some(Gender::Female),
                        _ => unreachable!(),
                    },
                    is_student: rng.bool(),
                    grade: rng.i32(0..=5).try_into().unwrap_or(Grade::F),
                    row_locked: false,
                })
            }
            .take(100000)
            .collect(),
            viewer: Viewer {
                name_filter: String::new(),
                row_protection: false,
                hotkeys: Vec::new(),
            },
            style_override: Default::default(),
            scroll_bar_always_visible: false,
        }
    }
}

impl eframe::App for DemoApp {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        fn is_send<T: Send>(_: &T) {}
        fn is_sync<T: Sync>(_: &T) {}

        is_send(&self.table);
        is_sync(&self.table);

        egui::TopBottomPanel::top("MenuBar").show(ctx, |ui| {
            egui::MenuBar::new().ui(ui, |ui| {
                ui.hyperlink_to(
                    " kang-sw/egui-data-table",
                    "https://github.com/kang-sw/egui-data-table",
                );

                ui.hyperlink_to(
                    "(source)",
                    "https://github.com/kang-sw/egui-data-table/blob/master/examples/demo.rs",
                );

                ui.separator();

                egui::widgets::global_theme_preference_buttons(ui);

                ui.separator();

                ui.label("Name Filter");
                ui.text_edit_singleline(&mut self.viewer.name_filter);

                ui.add(egui::Button::new("Drag me and drop on any cell").sense(Sense::drag()))
                    .on_hover_text(
                        "Dropping this will replace the cell \
                        content with some predefined value.",
                    )
                    .dnd_set_drag_payload(String::from("Hallo~"));

                ui.menu_button("🎌 Flags", |ui| {
                    ui.checkbox(&mut self.viewer.row_protection, "Row Protection")
                        .on_hover_text(
                            "If checked, any rows `Is Student` marked \
                        won't be deleted or overwritten by UI actions.",
                        );

                    ui.checkbox(
                        &mut self.style_override.single_click_edit_mode,
                        "Single Click Edit",
                    )
                    .on_hover_text("If checked, cells will be edited with a single click.");

                    ui.checkbox(&mut self.style_override.auto_shrink.x, "Auto-shrink X");
                    ui.checkbox(&mut self.style_override.auto_shrink.y, "Auto-shrink Y");

                    ui.checkbox(
                        &mut self.scroll_bar_always_visible,
                        "Scrollbar always visible",
                    );

                    if ui.button("Shuffle Rows").clicked() {
                        fastrand::shuffle(&mut self.table);
                    }
                })
            })
        });

        egui::TopBottomPanel::bottom("bottom_panel").show(ctx, |ui| {
            egui::Sides::new().show(
                ui,
                |_ui| {},
                |ui| {
                    let mut has_modifications = self.table.has_user_modification();
                    ui.add_enabled(
                        false,
                        egui::Checkbox::new(&mut has_modifications, "Has modifications"),
                    );

                    ui.add_enabled_ui(has_modifications, |ui| {
                        if ui.button("Clear").clicked() {
                            self.table.clear_user_modification_flag();
                        }
                    });
                },
            );
        });

        egui::SidePanel::left("Hotkeys")
            .default_width(500.)
            .show(ctx, |ui| {
                ui.vertical_centered_justified(|ui| {
                    ui.heading("Hotkeys");
                    ui.separator();
                    ui.add_space(0.);

                    for (k, a) in &self.viewer.hotkeys {
                        egui::Button::new(format!("{a:?}"))
                            .shortcut_text(ctx.format_shortcut(k))
                            .wrap_mode(egui::TextWrapMode::Wrap)
                            .sense(Sense::hover())
                            .ui(ui);
                    }
                });
            });

        egui::CentralPanel::default().show(ctx, |ui| {
            match self.scroll_bar_always_visible {
                true => {
                    ui.style_mut().spacing.scroll = egui::style::ScrollStyle::solid();
                    self.style_override.scroll_bar_visibility = ScrollBarVisibility::AlwaysVisible;
                }
                false => {
                    ui.style_mut().spacing.scroll = egui::style::ScrollStyle::floating();
                    self.style_override.scroll_bar_visibility =
                        ScrollBarVisibility::VisibleWhenNeeded;
                }
            };

            ui.add(
                egui_data_table::Renderer::new(&mut self.table, &mut self.viewer)
                    .with_style(self.style_override),
            )
        });
    }
}

/* --------------------------------------- App Entrypoint --------------------------------------- */

#[cfg(not(target_arch = "wasm32"))]
fn main() {
    use eframe::App;
    env_logger::init();

    eframe::run_simple_native(
        "Spreadsheet Demo",
        eframe::NativeOptions {
            centered: true,
            ..Default::default()
        },
        {
            let mut app = DemoApp::default();
            move |ctx, frame| {
                app.update(ctx, frame);
            }
        },
    )
    .unwrap();
}

// When compiling to web using trunk:
#[cfg(target_arch = "wasm32")]
fn main() {
    use eframe::wasm_bindgen::JsCast as _;

    // Redirect `log` message to `console.log` and friends:
    eframe::WebLogger::init(log::LevelFilter::Debug).ok();

    let web_options = eframe::WebOptions::default();

    wasm_bindgen_futures::spawn_local(async {
        let document = web_sys::window()
            .expect("No window")
            .document()
            .expect("No document");

        let canvas = document
            .get_element_by_id("the_canvas_id")
            .expect("Failed to find the_canvas_id")
            .dyn_into::<web_sys::HtmlCanvasElement>()
            .expect("the_canvas_id was not a HtmlCanvasElement");

        let start_result = eframe::WebRunner::new()
            .start(
                canvas,
                web_options,
                Box::new(|_cc| Ok(Box::new(DemoApp::default()))),
            )
            .await;

        // Remove the loading text and spinner:
        if let Some(loading_text) = document.get_element_by_id("loading_text") {
            match start_result {
                Ok(_) => {
                    loading_text.remove();
                }
                Err(e) => {
                    loading_text.set_inner_html(
                        "<p> The app has crashed. See the developer console for details. </p>",
                    );
                    panic!("Failed to start eframe: {e:?}");
                }
            }
        }
    });
}