Struct DisplayContext 

pub struct DisplayContext { /* private fields */ }

Available on crate feature debug-window only.

Handle for displaying images from a background thread.

Obtained inside the closure passed to DebugDisplay::run(). All methods are safe to call from the background thread.

Examples

use fovea_display::{DebugDisplay, Identity};
use fovea::image::Image;
use fovea::pixel::Srgba8;

DebugDisplay::run(|ctx| {
    let img = Image::fill(100, 100, Srgba8::new(255, 0, 0, 255));
    ctx.show("Red", &img, Identity);
    ctx.wait_key();
});

Implementations

impl DisplayContext

pub fn show<V, S>(&self, title: &str, image: &V, strategy: S)

where V: ImageView, V::Pixel: Copy, S: DisplayStrategy<V::Pixel>,

Display an image in a window with the given title.

Converts the image to a framebuffer using the given strategy on the calling thread, then sends the framebuffer to the event loop for display. If a window with this title already exists, its contents are updated; otherwise a new window is created.

This method is non-blocking — it returns immediately after sending the command.

Type parameters

• V: Any ImageView — owned images, ROIs, tiled views, etc.
• S: A DisplayStrategy that can convert V’s pixel type.

pub fn wait_key(&self) -> Option<KeyCode>

Block until a key is pressed in any window.

Returns the KeyCode of the pressed key, or None if all windows were closed or the event loop exited.

Examples

use fovea_display::{DebugDisplay, Identity};
use fovea::image::Image;
use fovea::pixel::Srgba8;

DebugDisplay::run(|ctx| {
    let img = Image::fill(100, 100, Srgba8::new(0, 255, 0, 255));
    ctx.show("Green", &img, Identity);
    match ctx.wait_key() {
        Some(key) => println!("Key pressed: {:?}", key),
        None => println!("All windows closed"),
    }
});

pub fn wait_key_timeout(&self, timeout: Duration) -> Option<KeyCode>

Block until a key is pressed, with a timeout.

Returns Some(key) if a key was pressed within the timeout, None if the timeout elapsed or all windows were closed.

pub fn exit(&self)

Request the event loop to close all windows and exit.

This is called automatically when the user closure returns, but can be called explicitly if needed.

impl DisplayContext

pub fn show_histogram<S, V>(&self, title: &str, h: &Histogram<S, V>)

Display a histogram inside a DebugDisplay::run session, using default render options.

Non-blocking. Uses the same window-update semantics as DisplayContext::show: passing the same title again updates the existing window in place.

pub fn show_histogram_with<S, V>( &self, title: &str, h: &Histogram<S, V>, opts: &HistogramRenderOptions, )

Display a histogram inside a DebugDisplay::run session with custom render options.

pub fn show_histogram_layers( &self, title: &str, layers: &[HistogramLayer<'_>], opts: &HistogramPlotOptions, )

Display a multi-layer histogram inside a DebugDisplay::run session.

Non-blocking. See render_histogram_layers for the rendering model.