Switch to persistent printer with queue

showbits-thermal-printer/src/drawer.rs

@@ -1,3 +1,4 @@
+mod backlog;
 mod calendar;
 mod cells;
 mod chat_message;
@@ -11,21 +12,23 @@ mod typst;
 use showbits_common::widgets::{FontStuff, HasFontStuff};
 use tokio::sync::mpsc;
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
 pub use self::{
-    calendar::CalendarDrawing, cells::CellsDrawing, chat_message::ChatMessageDrawing,
-    egg::EggDrawing, image::ImageDrawing, photo::PhotoDrawing, text::TextDrawing,
-    tictactoe::TicTacToeDrawing, typst::TypstDrawing,
+    backlog::BacklogDrawing, calendar::CalendarDrawing, cells::CellsDrawing,
+    chat_message::ChatMessageDrawing, egg::EggDrawing, image::ImageDrawing, photo::PhotoDrawing,
+    text::TextDrawing, tictactoe::TicTacToeDrawing, typst::TypstDrawing,
 };
 
+pub const FEED: f32 = 64.0;
+
 #[derive(Default)]
 pub struct Context {
     font_stuff: FontStuff,
 }
 
 pub trait Drawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()>;
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()>;
 }
 
 pub struct Command(Box<dyn Drawing + Send>);
@@ -44,12 +47,12 @@ impl HasFontStuff for Context {
 
 pub struct Drawer {
     rx: mpsc::Receiver<Command>,
-    printer: Printer,
+    printer: PersistentPrinter,
     ctx: Context,
 }
 
 impl Drawer {
-    pub fn new(rx: mpsc::Receiver<Command>, printer: Printer) -> Self {
+    pub fn new(rx: mpsc::Receiver<Command>, printer: PersistentPrinter) -> Self {
         Self {
             rx,
             printer,

showbits-thermal-printer/src/drawer/backlog.rs

@@ -0,0 +1,12 @@
+use crate::persistent_printer::PersistentPrinter;
+
+use super::{Context, Drawing};
+
+pub struct BacklogDrawing;
+
+impl Drawing for BacklogDrawing {
+    fn draw(&self, printer: &mut PersistentPrinter, _ctx: &mut Context) -> anyhow::Result<()> {
+        printer.print_backlog()?;
+        Ok(())
+    }
+}

showbits-thermal-printer/src/drawer/calendar.rs

@@ -9,9 +9,9 @@ use taffy::{
     style_helpers::{length, percent, repeat},
 };
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct CalendarDrawing {
     pub year: i16,
@@ -19,7 +19,7 @@ pub struct CalendarDrawing {
 }
 
 impl Drawing for CalendarDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut date = civil::Date::new(self.year, self.month, 1)?;
 
         let mut tree = Tree::<Context>::new(WHITE);
@@ -86,6 +86,7 @@ impl Drawing for CalendarDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -94,7 +95,6 @@ impl Drawing for CalendarDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/cells.rs

@@ -3,11 +3,11 @@ use image::{
     imageops::{self, FilterType},
 };
 use showbits_common::{Node, Tree, WidgetExt, color, widgets::Image};
-use taffy::{AlignItems, Display, FlexDirection, style_helpers::percent};
+use taffy::{AlignItems, Display, FlexDirection, prelude::length, style_helpers::percent};
 
-use crate::printer::Printer;
+use crate::{persistent_printer::PersistentPrinter, printer::Printer};
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 const BLACK: Rgba<u8> = Rgba([0, 0, 0, 255]);
 const WHITE: Rgba<u8> = Rgba([255, 255, 255, 255]);
@@ -49,8 +49,8 @@ pub struct CellsDrawing {
 }
 
 impl Drawing for CellsDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
-        let mut image = RgbaImage::new(Printer::WIDTH / self.scale, self.rows);
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
+        let mut image: image::ImageBuffer<Rgba<u8>, Vec<u8>> = RgbaImage::new(Printer::WIDTH / self.scale, self.rows);
 
         // Initialize first line randomly
         for x in 0..image.width() {
@@ -79,6 +79,7 @@ impl Drawing for CellsDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -86,7 +87,6 @@ impl Drawing for CellsDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/chat_message.rs

@@ -8,7 +8,7 @@ use taffy::{
     style_helpers::{length, percent},
 };
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
 use super::{Context, Drawing};
 
@@ -18,7 +18,7 @@ pub struct ChatMessageDrawing {
 }
 
 impl Drawing for ChatMessageDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut tree = Tree::<Context>::new(WHITE);
 
         let max_username_width_in_chars = 32.0;

showbits-thermal-printer/src/drawer/egg.rs

@@ -6,11 +6,11 @@ use showbits_common::{
     color::{self, WHITE},
     widgets::{Image, Text},
 };
-use taffy::{AlignItems, Display, FlexDirection, style_helpers::percent};
+use taffy::{prelude::length, style_helpers::percent, AlignItems, Display, FlexDirection};
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct EggDrawing;
 
@@ -21,7 +21,7 @@ fn load_image(bytes: &[u8]) -> RgbaImage {
 }
 
 impl Drawing for EggDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut rng = rand::rng();
 
         // Choose which set of egg images to use
@@ -84,6 +84,7 @@ impl Drawing for EggDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -92,7 +93,6 @@ impl Drawing for EggDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/image.rs

@@ -5,11 +5,11 @@ use showbits_common::{
     color::{self, BLACK, WHITE},
     widgets::{DitherAlgorithm, Image},
 };
-use taffy::{AlignItems, Display, FlexDirection, style_helpers::percent};
+use taffy::{AlignItems, Display, FlexDirection, prelude::length, style_helpers::percent};
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct ImageDrawing {
     pub image: RgbaImage,
@@ -19,7 +19,7 @@ pub struct ImageDrawing {
 }
 
 impl Drawing for ImageDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut image = self.image.clone();
         if self.bright {
             for pixel in image.pixels_mut() {
@@ -40,6 +40,7 @@ impl Drawing for ImageDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -47,7 +48,6 @@ impl Drawing for ImageDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/photo.rs

@@ -9,9 +9,9 @@ use taffy::{
     style_helpers::{length, percent},
 };
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct PhotoDrawing {
     pub image: RgbaImage,
@@ -19,7 +19,7 @@ pub struct PhotoDrawing {
 }
 
 impl Drawing for PhotoDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut tree = Tree::<Context>::new(WHITE);
 
         let mut image = self.image.clone();
@@ -45,6 +45,7 @@ impl Drawing for PhotoDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -54,7 +55,6 @@ impl Drawing for PhotoDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/text.rs

@@ -1,14 +1,14 @@
 use showbits_common::{Node, Tree, WidgetExt, color::WHITE, widgets::Text};
 use taffy::style_helpers::percent;
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
 use super::{Context, Drawing};
 
 pub struct TextDrawing(pub String);
 
 impl Drawing for TextDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut tree = Tree::<Context>::new(WHITE);
 
         let text = Text::new()

showbits-thermal-printer/src/drawer/tictactoe.rs

@@ -8,14 +8,14 @@ use taffy::{
     style_helpers::{length, percent, repeat},
 };
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct TicTacToeDrawing;
 
 impl Drawing for TicTacToeDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let block_size = length(128.0);
         let width = length(2.0);
 
@@ -57,6 +57,7 @@ impl Drawing for TicTacToeDrawing {
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .with_display(Display::Flex)
             .with_flex_direction(FlexDirection::Column)
             .with_align_items(Some(AlignItems::Center))
@@ -66,7 +67,6 @@ impl Drawing for TicTacToeDrawing {
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/drawer/typst.rs

@@ -1,25 +1,25 @@
 use showbits_common::{Node, Tree, WidgetExt, color::WHITE, widgets::Typst};
-use taffy::style_helpers::percent;
+use taffy::{prelude::length, style_helpers::percent};
 
-use crate::printer::Printer;
+use crate::persistent_printer::PersistentPrinter;
 
-use super::{Context, Drawing};
+use super::{Context, Drawing, FEED};
 
 pub struct TypstDrawing(pub String);
 
 impl Drawing for TypstDrawing {
-    fn draw(&self, printer: &mut Printer, ctx: &mut Context) -> anyhow::Result<()> {
+    fn draw(&self, printer: &mut PersistentPrinter, ctx: &mut Context) -> anyhow::Result<()> {
         let mut tree = Tree::<Context>::new(WHITE);
 
         let typst = Typst::new(self.0.clone()).node().register(&mut tree)?;
 
         let root = Node::empty()
             .with_size_width(percent(1.0))
+            .with_padding_bottom(length(FEED))
             .and_child(typst)
             .register(&mut tree)?;
 
         printer.print_tree(&mut tree, ctx, root)?;
-        printer.feed()?;
         Ok(())
     }
 }

showbits-thermal-printer/src/main.rs

@@ -1,19 +1,24 @@
 mod drawer;
+mod persistent_printer;
 mod printer;
 mod server;
 
-use std::path::PathBuf;
+use std::{path::PathBuf, time::Duration};
 
 use clap::Parser;
-use drawer::Drawer;
-use printer::Printer;
+use drawer::{BacklogDrawing, Command};
 use tokio::{runtime::Runtime, sync::mpsc};
 
+use self::{drawer::Drawer, persistent_printer::PersistentPrinter};
+
 #[derive(Parser)]
 struct Args {
     /// Address the web server will listen at.
     addr: String,
 
+    /// Path to the queue directory.
+    queue: PathBuf,
+
     /// Path to the printer's USB device file.
     ///
     /// Usually, this is located at `/dev/usb/lp0` or a similar location.
@@ -30,11 +35,17 @@ fn main() -> anyhow::Result<()> {
 
     let (tx, rx) = mpsc::channel(3);
 
-    let printer = Printer::new(args.printer, args.export)?;
+    let printer = PersistentPrinter::new(args.printer, args.export, args.queue);
     let mut drawer = Drawer::new(rx, printer);
 
     let runtime = Runtime::new()?;
-    runtime.spawn(server::run(tx, args.addr));
+    runtime.spawn(server::run(tx.clone(), args.addr));
+    runtime.spawn(async move {
+        loop {
+            let _ = tx.send(Command::draw(BacklogDrawing)).await;
+            tokio::time::sleep(Duration::from_secs(1)).await;
+        }
+    });
 
     println!("Running");
     drawer.run()?;

showbits-thermal-printer/src/persistent_printer.rs

@@ -0,0 +1,135 @@
+use std::{fs, io::ErrorKind, path::PathBuf};
+
+use anyhow::{Context, bail};
+use image::RgbaImage;
+use jiff::Timestamp;
+use showbits_common::Tree;
+use taffy::{AvailableSpace, NodeId, Size};
+
+use crate::printer::Printer;
+
+pub struct PersistentPrinter {
+    printer_file: Option<PathBuf>,
+    export_file: Option<PathBuf>,
+    queue_dir: PathBuf,
+
+    printer: Option<Printer>,
+}
+
+impl PersistentPrinter {
+    pub fn new(
+        printer_file: Option<PathBuf>,
+        export_file: Option<PathBuf>,
+        queue_dir: PathBuf,
+    ) -> Self {
+        Self {
+            printer_file,
+            export_file,
+            queue_dir,
+            printer: None,
+        }
+    }
+
+    fn render_tree_to_image<C>(
+        tree: &mut Tree<C>,
+        ctx: &mut C,
+        root: NodeId,
+    ) -> anyhow::Result<RgbaImage> {
+        let available = Size {
+            width: AvailableSpace::Definite(Printer::WIDTH as f32),
+            // TODO Maybe MinContent? If not, why not?
+            height: AvailableSpace::MaxContent,
+        };
+
+        tree.render(ctx, root, available)
+    }
+
+    fn print_image(&mut self, image: &RgbaImage) -> anyhow::Result<()> {
+        let Some(printer) = &mut self.printer else {
+            bail!("no printer found");
+        };
+        printer.print_image(image)?;
+        Ok(())
+    }
+
+    fn reconnect_printer(&mut self) -> anyhow::Result<()> {
+        let printer = Printer::new(self.printer_file.clone(), self.export_file.clone())?;
+        self.printer = Some(printer);
+        Ok(())
+    }
+
+    fn print_image_robustly(&mut self, image: &RgbaImage) -> anyhow::Result<()> {
+        println!("Printing image");
+        if self.print_image(image).is_ok() {
+            return Ok(());
+        }
+        println!("First attempt failed, reconnecting and retrying");
+        self.reconnect_printer()?;
+        self.print_image(image)?;
+        Ok(())
+    }
+
+    fn enqueue_image(&mut self, image: &RgbaImage) -> anyhow::Result<()> {
+        let now = Timestamp::now();
+        let path = self.queue_dir.join(format!("{now}.png"));
+        println!("Enqueuing image {}", path.display());
+
+        fs::create_dir_all(&self.queue_dir)
+            .with_context(|| format!("At {}", self.queue_dir.display()))
+            .context("Failed to create queue directory")?;
+
+        image
+            .save(&path)
+            .with_context(|| format!("At {}", path.display()))
+            .context("Failed to save image to queue")?;
+
+        Ok(())
+    }
+
+    pub fn print_tree<C>(
+        &mut self,
+        tree: &mut Tree<C>,
+        ctx: &mut C,
+        root: NodeId,
+    ) -> anyhow::Result<()> {
+        let image = Self::render_tree_to_image(tree, ctx, root)?;
+        if self.print_image_robustly(&image).is_err() {
+            self.enqueue_image(&image)?;
+        }
+        Ok(())
+    }
+
+    pub fn print_backlog(&mut self) -> anyhow::Result<()> {
+        let mut files = vec![];
+
+        match self.queue_dir.read_dir() {
+            Err(err) if err.kind() == ErrorKind::NotFound => {}
+
+            Err(err) => Err(err)
+                .with_context(|| format!("At {}", self.queue_dir.display()))
+                .context("Failed to open queue dir")?,
+
+            Ok(dir) => {
+                for entry in dir {
+                    let entry = entry?;
+                    if entry.file_type()?.is_file() {
+                        files.push(entry.path());
+                    }
+                }
+            }
+        }
+
+        files.sort_unstable();
+
+        for file in files {
+            println!("Dequeuing image {}", file.display());
+            let image: RgbaImage = image::open(&file)?.into_rgba8();
+            if self.print_image_robustly(&image).is_err() {
+                return Ok(());
+            }
+            fs::remove_file(&file)?;
+        }
+
+        Ok(())
+    }
+}

showbits-thermal-printer/src/printer.rs

@@ -1,5 +1,6 @@
 use std::path::PathBuf;
 
+use anyhow::Context;
 use escpos::{
     driver::FileDriver,
     printer::Printer as EPrinter,
@@ -7,8 +8,7 @@ use escpos::{
     utils::{GS, PageCode, Protocol},
 };
 use image::{Rgba, RgbaImage};
-use showbits_common::{Tree, color};
-use taffy::{AvailableSpace, NodeId, Size};
+use showbits_common::color;
 
 pub struct Printer {
     printer: Option<EPrinter<FileDriver>>,
@@ -44,7 +44,9 @@ impl Printer {
         export_path: Option<PathBuf>,
     ) -> anyhow::Result<Self> {
         let printer = if let Some(path) = printer_path {
-            let driver = FileDriver::open(&path)?;
+            let driver = FileDriver::open(&path)
+                .with_context(|| format!("At {}", path.display()))
+                .context("Failed to open printer driver")?;
             let protocol = Protocol::default();
             let mut options = PrinterOptions::default();
             options.page_code(Some(Self::PAGE_CODE));
@@ -59,34 +61,16 @@ impl Printer {
         })
     }
 
-    pub fn feed(&mut self) -> anyhow::Result<()> {
-        if let Some(printer) = &mut self.printer {
-            printer.init()?.feeds(3)?.print()?;
-        }
-
-        Ok(())
-    }
-
-    pub fn print_tree<C>(
-        &mut self,
-        tree: &mut Tree<C>,
-        ctx: &mut C,
-        root: NodeId,
-    ) -> anyhow::Result<()> {
-        let available = Size {
-            width: AvailableSpace::Definite(Self::WIDTH as f32),
-            // TODO Maybe MinContent? If not, why not?
-            height: AvailableSpace::MaxContent,
-        };
-
-        let image = tree.render(ctx, root, available)?;
-
+    pub fn print_image(&mut self, image: &RgbaImage) -> anyhow::Result<()> {
         if let Some(path) = &self.export_path {
-            image.save(path)?;
+            image
+                .save(path)
+                .with_context(|| format!("At {}", path.display()))
+                .context("Failed to export to-be-printed image")?;
         }
 
         if let Some(printer) = &mut self.printer {
-            Self::print_image_to_printer(printer, &image)?;
+            Self::print_image_to_printer(printer, image).context("Failed to print image")?;
         }
 
         Ok(())