Struct MarginManager 

pub struct MarginManager {
    pub left_config: MarginConfig,
    pub right_config: MarginConfig,
    /* private fields */
}

Manages margins and annotations for a buffer This is similar to OverlayManager - a general-purpose primitive for margin decorations

Line indicators use byte-position markers that automatically adjust when the buffer is edited. This ensures indicators stay anchored to the content they represent.

Fields

left_config: MarginConfig

Configuration for left margin

right_config: MarginConfig

Configuration for right margin

Implementations

impl MarginManager

pub fn new() -> Self

Create a new margin manager with default settings

pub fn without_line_numbers() -> Self

Create a margin manager with line numbers disabled

pub fn adjust_for_insert(&mut self, position: usize, length: usize)

Adjust all indicator markers after an insertion Call this when text is inserted into the buffer

pub fn adjust_for_delete(&mut self, position: usize, length: usize)

Adjust all indicator markers after a deletion Call this when text is deleted from the buffer

pub fn set_line_indicator( &mut self, byte_offset: usize, namespace: String, indicator: LineIndicator, ) -> MarkerId

Set a line indicator at a byte position for a specific namespace

The indicator is anchored to the byte position and will automatically shift when text is inserted or deleted before it.

Returns the marker ID that can be used to remove or update the indicator.

pub fn remove_line_indicator(&mut self, marker_id: MarkerId, namespace: &str)

Remove line indicator for a specific namespace at a marker

pub fn clear_line_indicators_for_namespace(&mut self, namespace: &str)

Clear all line indicators for a specific namespace

pub fn get_line_indicator( &self, line: usize, get_line_fn: impl Fn(usize) -> usize, ) -> Option<&LineIndicator>

Get the line indicator for a specific line number

This looks up all indicators whose markers resolve to the given line. Returns the highest priority indicator if multiple exist on the same line.

Note: This is O(n) in the number of indicators. For rendering, prefer get_indicators_in_viewport which is more efficient.

pub fn get_indicators_for_viewport( &self, viewport_start: usize, viewport_end: usize, get_line_fn: impl Fn(usize) -> usize, ) -> BTreeMap<usize, LineIndicator>

Get indicators within a viewport byte range

Only queries markers within viewport_start..viewport_end, avoiding iteration over the entire indicator set.

Returns a map of line_number -> highest priority indicator for that line. The get_line_fn converts byte offsets to line numbers.

pub fn get_indicator_position(&self, marker_id: MarkerId) -> Option<usize>

Get the byte position of a line indicator’s marker.

Returns the current byte offset for the given marker ID, or None if the marker doesn’t exist. Useful for testing that marker positions survive undo/redo correctly.

pub fn query_indicator_range( &self, start: usize, end: usize, ) -> Vec<(MarkerId, usize, usize)>

Query indicator markers in a byte range. Returns (MarkerId, start, end) tuples for markers in the range.

pub fn set_indicator_position( &mut self, marker_id: MarkerId, new_position: usize, )

Move a line indicator’s marker to a new byte position.

This is a no-op if the marker doesn’t exist in the indicator markers. Used to restore displaced markers after undo.

pub fn add_annotation(&mut self, annotation: MarginAnnotation)

Add an annotation to a margin

pub fn remove_by_id(&mut self, id: &str)

Remove all annotations with a specific ID

pub fn remove_at_line(&mut self, line: usize, position: MarginPosition)

Remove all annotations at a specific line

pub fn clear_position(&mut self, position: MarginPosition)

Clear all annotations in a position

pub fn clear_all(&mut self)

Clear all annotations

pub fn get_at_line( &self, line: usize, position: MarginPosition, ) -> Option<&[MarginAnnotation]>

Get all annotations at a specific line

pub fn render_line( &self, line: usize, position: MarginPosition, _buffer_total_lines: usize, show_line_numbers: bool, ) -> MarginContent

Get the content to render for a specific line in a margin. If show_line_numbers is true and position is Left, includes line number.

pub fn update_width_for_buffer( &mut self, buffer_total_lines: usize, show_line_numbers: bool, )

Update the left margin width based on buffer size. Only adjusts width when show_line_numbers is true.

pub fn left_total_width(&self) -> usize

Get the total width of the left margin (including separator) The separator includes the diagnostic indicator when present

pub fn right_total_width(&self) -> usize

Get the total width of the right margin (including separator)

pub fn configure_for_line_numbers(&mut self, show_line_numbers: bool)

Configure left margin layout for line number visibility.

This adjusts left_config.enabled and left_config.width so that left_total_width() returns the correct gutter size for the given show_line_numbers setting. Called at render time with the per-split line number state.

pub fn annotation_count(&self, position: MarginPosition) -> usize

Get the number of annotations in a position

Trait Implementations

impl Debug for MarginManager

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

Formats the value using the given formatter.

impl Default for MarginManager

fn default() -> Self

Returns the “default value” for a type.