Struct Bitmap 

pub struct Bitmap(/* private fields */);

Raster images from bytes (docs/images.md): decode an encoded PNG or JPEG the app already holds (a download, a file the user picked, a paste) into the platform’s image type, then show it with image(&bitmap) or draw it with Draw::image.

Bitmap is a handle, not the pixels: they live in the toolkit and are released when the last handle drops. Decoding is asynchronous because several backends decode off the main thread. Probe image_decode_support() / image_encode_support() before offering an affordance that depends on either, and image_encode_formats() before offering a format, since every platform here reads more formats than it writes. A decoded image the toolkit holds, released when the last handle drops.

Cheap to clone (an Rc), so several nodes and the canvas can draw the same decode. !Send like everything else that talks to the toolkit.

Implementations

impl Bitmap

pub fn id(&self) -> BitmapId

The id the toolkit knows this image by, which day_spec::ImageSource::Decoded carries.

pub fn info(&self) -> BitmapInfo

Pixel size, scale, format and alpha, read once at decode (docs/images.md).

pub fn properties(&self) -> Option<ImageProperties>

The metadata beyond the pixels: EXIF orientation, DPI, capture time. None where this backend ships no metadata reader; probe Cap::ImageProperties before offering an affordance that needs it.

pub fn encode(&self, spec: EncodeSpec) -> EncodeFuture

Encode back to bytes, in spec’s format. Await it inside day::task.

pub fn encode_async( &self, spec: EncodeSpec, on_done: impl FnOnce(Result<Vec<u8>, ImageError>) + 'static, )

Bitmap::encode’s callback half, for a call site that is not already async.

Trait Implementations

impl Clone for Bitmap

fn clone(&self) -> Bitmap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Bitmap

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

Formats the value using the given formatter.

impl IntoImageSource<ImageValueMark> for &Bitmap

A decoded image draws by id, so several nodes (and the canvas) share one decode. A decoded handle. The piece keeps a clone alive for the node’s life: the closure below owns it, the binding owns the closure, and the node’s scope owns the binding, so the toolkit’s image outlives the view that shows it however the app juggles its own handle. Without this an image(&bitmap) would carry only the id, and on the web the <img> would point at an object URL that release_image had already revoked.

fn into_image_source(self) -> Reactive<ImageSource>

impl PartialEq for Bitmap

Two handles are the same image when they name the same decode.

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

Equality operator ==.

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

Inequality operator !=.