ltk::img_widget

Struct Image

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pub struct Image {
    pub rgba: Arc<Vec<u8>>,
    pub width: u32,
    pub height: u32,
    pub cover: bool,
    pub display_size: Option<(Length, Length)>,
    pub opacity: f32,
}
Expand description

A static image widget that renders RGBA pixel data.

Images are scaled to fill their allocated rect. Alpha blending against the background is handled automatically (straight → premultiplied conversion).

The pixel buffer is shared via Arc so reusing the same image across frames (e.g. a background decoded once at startup) is a cheap pointer copy instead of a full Vec<u8> clone.

// Display at 40 % of the viewport width by 20 % of its height instead of
// the source's intrinsic pixel size — scales across screens with no tweaks.
img_widget( rgba_bytes, width, height )
    .size( Length::vw( 40.0 ), Length::vh( 20.0 ) )
    .opacity( 0.8 )
.into()

Fields§

§rgba: Arc<Vec<u8>>

Raw RGBA pixel data (4 bytes per pixel, straight alpha).

§width: u32

Pixel width of the source image.

§height: u32

Pixel height of the source image.

§cover: bool

When true the image scales to fill the available width (cover mode).

§display_size: Option<(Length, Length)>

Optional explicit display size (Length values, resolved at layout time).

§opacity: f32

Opacity multiplier in [0.0, 1.0]. Default: 1.0.

Implementations§

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impl Image

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pub fn new(rgba: Arc<Vec<u8>>, width: u32, height: u32) -> Self

Create an image from a shared RGBA buffer.

width and height must match the dimensions of rgba.

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pub fn from_path(path: &str) -> Result<Self, Box<dyn Error>>

Load an image from a file path. Supports PNG, JPEG, and other formats supported by the image crate.

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pub fn cover(self) -> Self

Scale the image to fill the available width, preserving aspect ratio (cover mode).

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pub fn size(self, width: impl Into<Length>, height: impl Into<Length>) -> Self

Set an explicit display size. Accepts logical f32 pixels or any Length variant (e.g. Length::vw(13.0) for 13 % of viewport width).

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pub fn opacity(self, o: f32) -> Self

Set the opacity multiplier. Clamped to [0.0, 1.0].

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pub fn preferred_size(&self, max_width: f32, canvas: &Canvas) -> (f32, f32)

Return the preferred (width, height) given available max_width. canvas is used to resolve viewport-relative Length values.

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pub fn draw(&self, canvas: &mut Canvas, rect: Rect)

Draw the image into canvas at rect.

Trait Implementations§

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impl<Msg: Clone> From<Image> for Element<Msg>

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fn from(i: Image) -> Self

Converts to this type from the input type.

Auto Trait Implementations§

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impl Freeze for Image

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impl RefUnwindSafe for Image

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impl Send for Image

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impl Sync for Image

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impl Unpin for Image

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impl UnwindSafe for Image

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