wip: viewport abstraction for a table view

src/ui/mod.rs

@@ -10,7 +10,7 @@ use ratatui::{
     buffer::Buffer,
     layout::{Constraint, Flex, Layout, Rect},
     style::{Modifier, Style},
-    widgets::{Block, Table, TableState, Widget},
+    widgets::{Block, Table, TableState, Widget, WidgetRef},
 };
 use tui_prompts::{State, Status, TextPrompt, TextState};
 use tui_textarea::{CursorMove, TextArea};
@@ -21,6 +21,7 @@ pub mod render;
 mod test;
 
 use cmd::Cmd;
+use render::Viewport;
 
 #[derive(Default, Debug, PartialEq, Clone)]
 pub enum Modality {
@@ -459,20 +460,16 @@ impl<'ws> Workspace<'ws> {
     ) -> Vec<(Rect, Box<dyn Fn(Rect, &mut Buffer, &mut Self)>)> {
         use ratatui::widgets::StatefulWidget;
         let mut cs = vec![Constraint::Fill(4), Constraint::Fill(30)];
-        let Address { row, col } = self.book.location;
         let mut rs: Vec<Box<dyn Fn(Rect, &mut Buffer, &mut Self)>> = vec![
             Box::new(|rect: Rect, buf: &mut Buffer, ws: &mut Self| ws.text_area.render(rect, buf)),
             Box::new(move |rect: Rect, buf: &mut Buffer, ws: &mut Self| {
                 let sheet_name = ws.book.get_sheet_name().unwrap_or("Unknown");
                 // Table widget display
                 let table_block = Block::bordered().title_top(sheet_name);
-                let table_inner: Table = TryFrom::try_from(&ws.book).expect("");
-                let table = table_inner.block(table_block);
-                // https://docs.rs/ratatui/latest/ratatui/widgets/struct.TableState.html
-                // TODO(zaphar): Apparently scrolling by columns doesn't work?
-                ws.state.table_state.select_cell(Some((row, col)));
-                ws.state.table_state.select_column(Some(col));
-                StatefulWidget::render(table, rect, buf, &mut ws.state.table_state);
+                // TODO(zaphar): We should be smarter about calculating the location properly
+                // Might require viewport state to do properly
+                let viewport = Viewport::new(&ws.book).with_corner(ws.book.location.clone()).block(table_block);
+                viewport.render(rect, buf);
             }),
         ];
 

src/ui/render/mod.rs

@@ -10,6 +10,9 @@ use tui_popup::Popup;
 
 use super::*;
 
+pub mod viewport;
+pub use viewport::Viewport;
+
 impl<'widget, 'ws: 'widget> Widget for &'widget mut Workspace<'ws> {
     fn render(self, area: Rect, buf: &mut ratatui::prelude::Buffer)
     where
@@ -55,6 +58,10 @@ const COLNAMES: [&'static str; 26] = [
     "T", "U", "V", "W", "X", "Y", "Z",
 ];
 
+// TODO(jwall): A Viewport widget where we assume lengths for column
+// sizes would probably help us to manage column scrolling.
+// Could use a ViewportState and stateful rendering.
+
 impl<'t, 'book: 't> TryFrom<&'book Book> for Table<'t> {
     fn try_from(value: &'book Book) -> std::result::Result<Self, Self::Error> {
         // TODO(zaphar): This is apparently expensive. Maybe we can cache it somehow?

src/ui/render/viewport.rs

@@ -0,0 +1,136 @@
+use std::cmp::min;
+
+use anyhow::Result;
+use ratatui::{
+    layout::{Constraint, Flex},
+    style::{Color, Stylize},
+    text::Text,
+    widgets::{Block, Cell, Row, Table, Widget},
+};
+
+use super::{Address, Book};
+
+// NOTE(jwall): This is stolen from ironcalc but ironcalc doesn't expose it
+// publically.
+pub(crate) const LAST_COLUMN: usize = 16_384;
+//pub(crate) const LAST_ROW: usize = 1_048_576;
+
+/// A visible column to show in our Viewport.
+pub struct VisibleColumn {
+    pub idx: usize,
+    pub length: u16,
+}
+
+impl<'a> From<&'a VisibleColumn> for Constraint {
+    fn from(value: &'a VisibleColumn) -> Self {
+        Constraint::Length(value.length as u16)
+    }
+}
+
+/// A renderable viewport over a book.
+pub struct Viewport<'book> {
+    pub(crate) corner: Address,
+    book: &'book Book,
+    block: Option<Block<'book>>,
+}
+
+const COLNAMES: [&'static str; 26] = [
+    "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S",
+    "T", "U", "V", "W", "X", "Y", "Z",
+];
+
+impl<'book> Viewport<'book> {
+    pub fn new(book: &'book Book) -> Self {
+        Self {
+            book,
+            corner: Default::default(),
+            block: None,
+        }
+    }
+
+    pub fn with_corner(mut self, corner: Address) -> Self {
+        self.corner = corner;
+        self
+    }
+
+    fn get_visible_columns(&self, width: u16) -> Result<Vec<VisibleColumn>> {
+        let mut visible = Vec::new();
+        let mut length = 0;
+        for idx in self.corner.col..=LAST_COLUMN {
+            let size = self.book.get_col_size(idx)? as u16;
+            let updated_length = length + size;
+            if updated_length <= width {
+                length = updated_length;
+                visible.push(VisibleColumn { idx, length: size });
+            }
+        }
+        return Ok(visible);
+    }
+
+    pub fn block(mut self, block: Block<'book>) -> Self {
+        self.block = Some(block);
+        self
+    }
+
+    fn to_table<'widget>(&self, width: u16, height: u16) -> Result<Table<'widget>> {
+        let visible_columns = self.get_visible_columns(width)?;
+        let max_row = min(self.corner.row + height as usize, LAST_COLUMN);
+        let rows: Vec<Row> = (self.corner.row..=max_row)
+            .into_iter()
+            .map(|ri| {
+                let mut cells = vec![Cell::new(Text::from(ri.to_string()))];
+                cells.extend(visible_columns.iter().map(|VisibleColumn { idx: ci, length: _, }| {
+                    // TODO(zaphar): Is this safe?
+                    let content = self
+                        .book
+                        .get_cell_addr_rendered(&Address { row: ri, col: *ci })
+                        .unwrap();
+                    let cell = Cell::new(Text::raw(content));
+                    match (self.book.location.row == ri, self.book.location.col == *ci) {
+                        (true, true) => cell.fg(Color::White).underlined(),
+                        _ => cell
+                            .bg(if ri % 2 == 0 {
+                                Color::Rgb(57, 61, 71)
+                            } else {
+                                Color::Rgb(165, 169, 160)
+                            })
+                            .fg(if ri % 2 == 0 {
+                                Color::White
+                            } else {
+                                Color::Rgb(31, 32, 34)
+                            }),
+                    }
+                    .bold()
+                }));
+                Row::new(cells)
+            })
+            .collect();
+        let constraints: Vec<Constraint> = visible_columns.iter()
+            .map(|vc| Constraint::from(vc))
+            .collect();
+        let mut header = Vec::with_capacity(constraints.len());
+        header.push(Cell::new(""));
+        header.extend((self.corner.col..constraints.len()).map(|i| {
+            let count = (i / 26) + 1;
+            Cell::new(COLNAMES[(i-1) % 26].repeat(count))
+        }));
+        // TODO(zaphar): We should calculate the length from the length of the stringified version of the
+        // row indexes.
+        let mut col_constraints = vec![Constraint::Length(5)];
+        col_constraints.extend(constraints.into_iter());
+        Ok(Table::new(rows, col_constraints)
+            .header(Row::new(header).underlined())
+            .column_spacing(1)
+            .flex(Flex::Start))
+    }
+}
+
+impl<'book> Widget for Viewport<'book> {
+    fn render(self, area: ratatui::prelude::Rect, buf: &mut ratatui::prelude::Buffer) {
+        let mut table = self.to_table(area.width, area.height).expect("Failed to turn viewport into a table.");
+        if let Some(block) = self.block {
+            table = table.block(block);
+        }
+        table.render(area, buf);
+    }
+}

tmp.bash

@@ -0,0 +1,9 @@
+set -ue
+set -o pipefail
+export BUILD_ARG_one="widget"
+export BUILD_ARG_two="acme"
+VALS=()
+printenv | grep BUILD_ARG | while read line;do
+  VALS+=($line)
+done
+echo "${VALS[*]}"