Enum tui_textarea::Scrolling

#[non_exhaustive]
pub enum Scrolling {
    Delta {
        rows: i16,
        cols: i16,
    },
    PageDown,
    PageUp,
    HalfPageDown,
    HalfPageUp,
}

Specify how to scroll the textarea.

This type is marked as #[non_exhaustive] since more variations may be supported in the future. Note that the cursor will not move until it goes out the viewport. See also: [TextArea::scroll]

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Delta

Fields

rows: i16

cols: i16

Scroll the textarea by rows (vertically) and columns (horizontally). Passing positive scroll amounts to rows and cols scolls it to down and right. Negative integers means the opposite directions. (i16, i16) pair can be converted into Scrolling::Delta where 1st element means rows and 2nd means columns.

use tui_textarea::{TextArea, Scrolling};

// Let's say terminal height is 8.

// Create textarea with 20 lines "0", "1", "2", "3", ...
let mut textarea: TextArea = (0..20).into_iter().map(|i| i.to_string()).collect();

// Scroll down by 2 lines.
textarea.scroll(Scrolling::Delta{rows: 2, cols: 0});
assert_eq!(textarea.cursor(), (2, 0));

// (1, 0) is converted into Scrolling::Delta{rows: 1, cols: 0}
textarea.scroll((1, 0));
assert_eq!(textarea.cursor(), (3, 0));

PageDown

Scroll down the textarea by one page.

use tui_textarea::{TextArea, Scrolling};

// Let's say terminal height is 8.

// Create textarea with 20 lines "0", "1", "2", "3", ...
let mut textarea: TextArea = (0..20).into_iter().map(|i| i.to_string()).collect();

// Scroll down by one page (8 lines)
textarea.scroll(Scrolling::PageDown);
assert_eq!(textarea.cursor(), (8, 0));
textarea.scroll(Scrolling::PageDown);
assert_eq!(textarea.cursor(), (16, 0));
textarea.scroll(Scrolling::PageDown);
assert_eq!(textarea.cursor(), (19, 0)); // Reached bottom of the textarea

PageUp

Scroll up the textarea by one page.

use tui_textarea::{TextArea, Scrolling, CursorMove};

// Let's say terminal height is 8.

// Create textarea with 20 lines "0", "1", "2", "3", ...
let mut textarea: TextArea = (0..20).into_iter().map(|i| i.to_string()).collect();

// Go to the last line at first
textarea.move_cursor(CursorMove::Bottom);
assert_eq!(textarea.cursor(), (19, 0));

// Scroll up by one page (8 lines)
textarea.scroll(Scrolling::PageUp);
assert_eq!(textarea.cursor(), (11, 0));
textarea.scroll(Scrolling::PageUp);
assert_eq!(textarea.cursor(), (7, 0)); // Reached top of the textarea

HalfPageDown

Scroll down the textarea by half of the page.

use tui_textarea::{TextArea, Scrolling};

// Let's say terminal height is 8.

// Create textarea with 10 lines "0", "1", "2", "3", ...
let mut textarea: TextArea = (0..10).into_iter().map(|i| i.to_string()).collect();

// Scroll down by half-page (4 lines)
textarea.scroll(Scrolling::HalfPageDown);
assert_eq!(textarea.cursor(), (4, 0));
textarea.scroll(Scrolling::HalfPageDown);
assert_eq!(textarea.cursor(), (8, 0));
textarea.scroll(Scrolling::HalfPageDown);
assert_eq!(textarea.cursor(), (9, 0)); // Reached bottom of the textarea

HalfPageUp

Scroll up the textarea by half of the page.

use tui_textarea::{TextArea, Scrolling, CursorMove};

// Let's say terminal height is 8.

// Create textarea with 20 lines "0", "1", "2", "3", ...
let mut textarea: TextArea = (0..20).into_iter().map(|i| i.to_string()).collect();

// Go to the last line at first
textarea.move_cursor(CursorMove::Bottom);
assert_eq!(textarea.cursor(), (19, 0));

// Scroll up by half-page (4 lines)
textarea.scroll(Scrolling::HalfPageUp);
assert_eq!(textarea.cursor(), (15, 0));
textarea.scroll(Scrolling::HalfPageUp);
assert_eq!(textarea.cursor(), (11, 0));

Trait Implementations

impl From<(i16, i16)> for Scrolling

fn from((rows, cols): (i16, i16)) -> Self

Converts to this type from the input type.