Struct piet::LineMetric

pub struct LineMetric {
    pub start_offset: usize,
    pub end_offset: usize,
    pub trailing_whitespace: usize,
    pub baseline: f64,
    pub height: f64,
    pub y_offset: f64,
}

Metadata about each line in a text layout.

Fields

start_offset: usize

The start index of this line in the underlying String used to create the TextLayout to which this line belongs.

end_offset: usize

The end index of this line in the underlying String used to create the TextLayout to which this line belongs.

This is the end of an exclusive range; this index is not part of the line.

Includes trailing whitespace.

trailing_whitespace: usize

The length of the trailing whitespace at the end of this line, in utf-8 code units.

When lines are broken on whitespace (as is common), the whitespace is assigned to the end of the preceding line. Reporting the size of the trailing whitespace section lets an API consumer measure and render only the trimmed line up to the whitespace.

baseline: f64

The distance from the top of the line (y_offset) to the baseline.

height: f64

The height of the line.

This value is intended to be used to determine the height of features such as cursors and selection regions. Although it is generally the case that y_offset + height for line n is equal to the y_offset of line n + 1, this is not strictly enforced, and should not be counted on.

y_offset: f64

The y position of the top of this line, relative to the top of the layout.

It should be possible to use this position, in conjunction with height, to determine the region that would be used for things like text selection.

Implementations

impl LineMetric

pub fn range(&self) -> Range<usize>

The utf-8 range in the underlying String used to create the TextLayout to which this line belongs.

Trait Implementations

impl Clone for LineMetric

fn clone(&self) -> LineMetric

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LineMetric

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

Formats the value using the given formatter.

impl Default for LineMetric

fn default() -> LineMetric

Returns the “default value” for a type.

impl PartialEq<LineMetric> for LineMetric

fn eq(&self, other: &LineMetric) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for LineMetric