Struct ScrollState 

pub struct ScrollState {
    pub scroll_offset: usize,
    pub viewport_height: usize,
    pub total_lines: usize,
    pub current_line: usize,
    pub filter: Option<String>,
    pub filter_mode: bool,
}

Scroll state for markdown rendering.

Manages scroll position, viewport dimensions, and current line for navigation.

Fields

scroll_offset: usize

Current scroll offset (0-indexed, first visible line index).

viewport_height: usize

Height of viewport (number of visible lines).

total_lines: usize

Total number of lines in document.

current_line: usize

Currently selected line (1-indexed, for highlighting).

filter: Option<String>

Current filter text (when in filter mode).

filter_mode: bool

Whether filter mode is currently active.

Implementations

impl ScrollState

pub fn new() -> Self

Create a new scroll state with default settings.

impl ScrollState

pub fn adjust_scroll_for_current_line(&mut self)

Adjust scroll offset to ensure current_line is visible with a margin. Scrolls when the cursor gets within 3 lines of the top/bottom edge.

impl ScrollState

pub fn filter_line_down(&mut self, _filter_text: String)

Move to the next line that matches the filter text.

Arguments

• filter_text - The text to match against (case-insensitive)

This method is used in filter mode to navigate through matching lines. It updates both current_line and scroll_offset to show the next match.

pub fn filter_line_up(&mut self, _filter_text: String)

Move to the previous line that matches the filter text.

Arguments

• filter_text - The text to match against (case-insensitive)

This method is used in filter mode to navigate through matching lines. It updates both current_line and scroll_offset to show the previous match.

impl ScrollState

pub fn is_current_line_visible(&self) -> bool

Check if current line is visible in the viewport.

Returns

true if the current line is within the visible viewport.

impl ScrollState

pub fn line_down(&mut self)

Move current line down (for keyboard navigation).

impl ScrollState

pub fn line_up(&mut self)

Move current line up (for keyboard navigation).

impl ScrollState

pub fn max_scroll_offset(&self) -> usize

Get the maximum valid scroll offset.

Returns

The maximum scroll offset that keeps content visible.

impl ScrollState

pub fn scroll_down(&mut self, amount: usize)

Scroll down by given number of lines.

Arguments

• amount - Number of lines to scroll down.

impl ScrollState

pub fn scroll_percentage(&self) -> f64

Calculate percentage scrolled (0.0 to 1.0).

Returns

The scroll position as a percentage of total scrollable content.

impl ScrollState

pub fn scroll_to_bottom(&mut self)

Move to bottom of document.

impl ScrollState

pub fn scroll_to_top(&mut self)

Move to top of document.

impl ScrollState

pub fn scroll_up(&mut self, amount: usize)

Scroll up by given number of lines.

Arguments

• amount - Number of lines to scroll up.

impl ScrollState

pub fn set_current_line(&mut self, line: usize)

Set current line and adjust scroll to keep it visible.

Arguments

• line - The line number to set as current (1-indexed).

impl ScrollState

pub fn update_total_lines(&mut self, total: usize)

Update total line count.

Arguments

• total - The total number of lines in the document.

impl ScrollState

pub fn update_viewport(&mut self, area: Rect)

Update viewport dimensions.

Arguments

• area - The new viewport area.

impl ScrollState

pub fn visible_range(&self) -> (usize, usize)

Get range of currently visible lines (1-indexed, inclusive).

Returns

A tuple of (start_line, end_line) for visible content.

Trait Implementations

impl Clone for ScrollState

fn clone(&self) -> ScrollState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScrollState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ScrollState

fn default() -> Self

Returns the “default value” for a type.