picocalc-os-rs/user_apps/gallery/src/main.rs

#![no_std]
#![no_main]
#![allow(static_mut_refs)]

extern crate alloc;
use alloc::{format, vec};
use core::panic::PanicInfo;
use embedded_graphics::{
    Drawable, image::Image, mono_font::MonoTextStyle, mono_font::ascii::FONT_6X10,
    pixelcolor::Rgb565, prelude::*, text::Text,
};
use tinybmp::Bmp;
use userlib::{
    display::{Display, SCREEN_HEIGHT, SCREEN_WIDTH},
    fs::{Entries, list_dir, read_file},
    get_key,
    keyboard::{KeyCode, KeyState},
    println,
};

#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    println!("user panic: {} @ {:?}", info.message(), info.location());
    loop {}
}

#[unsafe(no_mangle)]
pub extern "Rust" fn _start() {
    main()
}

pub fn main() {
    println!("Starting Gallery app");
    let mut bmp_buf = vec![0_u8; 100_000];
    let mut display = Display::take().unwrap();

    let grid_cols = 3;
    let grid_rows = 3;
    let cell_width = SCREEN_WIDTH as i32 / grid_cols;
    let cell_height = SCREEN_HEIGHT as i32 / grid_rows;

    let mut images_drawn = 0;

    let mut entries = Entries::new();
    let files_num = list_dir("/images", &mut entries);

    for file in &entries.entries()[2..files_num] {
        if images_drawn >= grid_cols * grid_rows {
            break; // only draw 3x3
        }

        println!("file: {}", file);
        if file.extension().unwrap_or("") == "bmp" || file.extension().unwrap_or("") == "BMP" {
            let file_path = format!("/images/{}", file);

            let read = read_file(&file_path, 0, &mut &mut bmp_buf[..]);
            if read > 0 {
                let bmp = Bmp::from_slice(&bmp_buf).expect("failed to parse bmp");

                let row = images_drawn / grid_cols;
                let col = images_drawn % grid_cols;
                let cell_x = col * cell_width;
                let cell_y = row * cell_height;

                // Center image inside cell
                let bmp_w = bmp.size().width as i32;
                let bmp_h = bmp.size().height as i32;
                let x = cell_x + (cell_width - bmp_w) / 2;
                let y = cell_y + 5; // 5px top margin

                Image::new(&bmp, Point::new(x, y))
                    .draw(&mut display)
                    .unwrap();

                let text_style = MonoTextStyle::new(&FONT_6X10, Rgb565::WHITE);
                let text_y = y + bmp_h + 2; // 2px gap under image
                Text::new(&file.base(), Point::new(cell_x + 2, text_y), text_style)
                    .draw(&mut display)
                    .unwrap();

                images_drawn += 1;
            }
        }
    }

    loop {
        let event = get_key();
        if event.state != KeyState::Idle {
            match event.key {
                KeyCode::Esc => return,
                _ => (),
            }
        };
    }
}