Image not beeing rendered

[Rikorose]

Hi all,

I am trying to render an image from memory via Handle::from_pixels(). However, iced does not show anything but only seems to preserve the space. I am expecting a black image. What am I doing wrong?

Running iced 0.8 on Linux wayland. Also tested with WGPU_BACKEND=vulkan.

// [...]
// Construct a black image
const IMG_TEST1: [u8; 4 * IMG_H * IMG_W] = [255; 4 * IMG_H * IMG_W];

// [...]

    let im = image::Handle::from_pixels(
        IMG_W as u32,
        IMG_H as u32,
        &IMG_TEST1,
    )
    let container = container(
        Image::new(im)
            .width(width)
            .height(height)
            .content_fit(ContentFit::Fill),
    )
    .max_width(width)
    .max_height(height)
    .width(Length::Fill)
    .center_x()
    .center_y()

No black image shown below the title and exit button:

Full Code

#![feature(slice_flatten)]

use std::process::exit;

use iced::widget::{self, column, container, image, text, Container, Image};
use iced::{
    executor, Alignment, Application, Command, ContentFit, Element, Length, Settings, Theme,
};

pub fn main() -> iced::Result {
    ImgView::run(Settings::default())
}

struct ImgView {
    img: image::Handle,
}

#[derive(Debug, Clone, Copy)]
pub enum Message {
    Exit,
}

const IMG_W: usize = 10000;
const IMG_H: usize = 481;
const IMG_TEST1: [u8; 4 * IMG_H * IMG_W] = [0xff; 4 * IMG_H * IMG_W];
const IMG_TEST2: [[[u8; 4]; IMG_H]; IMG_W] = [[[123; 4]; IMG_H]; IMG_W];

impl Application for ImgView {
    type Executor = executor::Default;
    type Message = Message;
    type Theme = Theme;
    type Flags = ();

    fn new(_flags: ()) -> (Self, Command<Message>) {
        (
            Self {
                img: {
                    image::Handle::from_pixels(
                        IMG_W as u32,
                        IMG_H as u32,
                        &IMG_TEST1,
                        // IMG_TEST2.flatten().flatten(),
                    )
                },
            },
            Command::none(),
        )
    }

    fn title(&self) -> String {
        "Iced Image Demo".to_string()
    }

    fn update(&mut self, message: Message) -> Command<Message> {
        match message {
            Message::Exit => {
                exit(0);
            }
        }
    }

    fn view(&self) -> Element<Message> {
        let content = column![
            button("exit").on_press(Message::Exit),
            img_view("Title", self.img.clone(), 1000, 400),
        ]
        .spacing(20)
        .align_items(Alignment::End);

        container(content)
            .padding(50)
            .width(Length::Fill)
            .height(Length::Fill)
            .center_x()
            .center_y()
            .into()
    }
}

fn img_view(title: &str, im: image::Handle, width: u16, height: u16) -> Element<Message> {
    column![
        text(title).size(30).width(Length::Fill),
        img_raw(im, width, height)
    ]
    .max_width(width)
    .width(Length::Fill)
    .into()
}
fn img_raw<'a>(im: image::Handle, width: u16, height: u16) -> Container<'a, Message> {
    container(
        Image::new(im)
            .width(width)
            .height(height)
            .content_fit(ContentFit::Fill),
    )
    .max_width(width)
    .max_height(height)
    .width(Length::Fill)
    .center_x()
    .center_y()
}

fn button(text: &str) -> widget::Button<'_, Message> {
    widget::button(text).padding(10)
}

[hecrj]

You are setting a 255 value for all the channels, which is expected to produce a white image. Try changing the theme to the Dark variant so it becomes visible.

[Rikorose]

I'm dumb -,- Thanks!