Struct LineMetric 

pub struct LineMetric {
    pub start_index: usize,
    pub end_index: usize,
    pub baseline: f32,
    pub height: f32,
    pub width: f32,
}

Per-line metrics returned by text measurement.

When the layout engine or hit-testing code needs to know about individual lines of text (e.g., for cursor positioning in a multi-line text field), it calls TextMeasurer::get_line_metrics and receives a Vec<LineMetric>.

Fields

start_index: usize

Byte index where this line starts in the source string.

end_index: usize

Byte index where this line ends in the source string (exclusive).

baseline: f32

Distance from the top of the line to its alphabetic baseline, in logical pixels.

height: f32

Total height of the line (ascent + descent + leading), in logical pixels.

width: f32

Measured width of the line’s content, in logical pixels.