Trait embedded_graphics_core::text::TextRenderer[−][src]

pub trait TextRenderer {
    type Color: PixelColor;
    fn draw_string<D>(
        &self, 
        text: &str, 
        position: Point, 
        target: &mut D
    ) -> Result<Point, D::Error>
    where
        D: DrawTarget<Color = Self::Color>;

    fn draw_whitespace<D>(
        &self, 
        width: u32, 
        position: Point, 
        target: &mut D
    ) -> Result<Point, D::Error>
    where
        D: DrawTarget<Color = Self::Color>;

    fn measure_string(&self, text: &str, position: Point) -> TextMetrics;

    fn vertical_offset(
        &self, 
        position: Point, 
        vertical_alignment: VerticalAlignment
    ) -> Point;

    fn line_height(&self) -> u32;
}

Text renderer.

The TextRenderer trait is used to integrate text renderers into embedded-graphics. Users should not call it directly and instead use the functions provided by the Text type.

Associated Types

type Color: PixelColor[src]

Color type.

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Required methods

fn draw_string<D>(
    &self,
    text: &str,
    position: Point,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, [src]

Draws a string.

The interpretation of the y coordinate of position is dependent on the implementation and can, for example, be the top edge of the bounding box or a point on the baseline. The caller must ensure that the coordinate is first converted with the vertical_offset method.

The method returns the start position of the next character to allow chaining of multiple draw calls.

Implementation notes

This method must not interpret any control characters and only render a single line of text. Any control character in the text should be handled the same way as any other character that isn't included in the font.

fn draw_whitespace<D>(
    &self,
    width: u32,
    position: Point,
    target: &mut D
) -> Result<Point, D::Error> where
    D: DrawTarget<Color = Self::Color>, [src]

Draws whitespace of the given width.

The interpretation of the y coordinate of position is dependent on the implementation and can, for example, be the top edge of the bounding box or a point on the baseline. The caller must ensure that the coordinate is first converted with the vertical_offset method.

The method returns the start position of the next character to allow chaining of multiple draw calls.

fn measure_string(&self, text: &str, position: Point) -> TextMetrics[src]

Returns the text metrics for a string.

The interpretation of the y coordinate of position is dependent on the implementation and can, for example, be the top edge of the bounding box or a point on the baseline. The caller must ensure that the coordinate is first converted with the vertical_offset method.

The returned bounding box is zero sized, if the text is completely transparent.

Implementation notes

This method must not interpret any control characters and only render a single line of text. Any control character in the text should be handled the same way as any other character that isn't included in the font.

fn vertical_offset(
    &self,
    position: Point,
    vertical_alignment: VerticalAlignment
) -> Point[src]

Offsets the point to apply the vertical alignment.

fn line_height(&self) -> u32[src]

Returns the line height.

The line height is defined as the vertical distance between the baseline of two adjacent lines in pixels.

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Implementors

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