rewrite randomwallpaper in rust

justfile

@@ -8,13 +8,16 @@ yaml-language-server
 "
 
 install-scripts target=(`echo $HOME` + "/.local/bin"):
+    cargo build --release --manifest-path scripts/randomwallpaper/Cargo.toml
+    cp scripts/randomwallpaper/target/release/randomwallpaper {{target}}/randomwallpaper
+
     opam install --yes clap
     cd scripts/playtwitch && dune build
     chmod -R +w scripts/playtwitch
     cp scripts/playtwitch/_build/default/playtwitch.exe {{target}}/playtwitch
 
     ln -sf \
-        `pwd`/scripts/{start-joshuto,withjava,randomwallpaper} \
+        `pwd`/scripts/{start-joshuto,withjava} \
         {{target}}
 
 install-lsps-paru:

scripts/randomwallpaper

@@ -1,8 +0,0 @@
-#!/bin/sh
-mons=$(xrandr --listactivemonitors | wc -l)
-mons=$((mons-1))
-
-feh --bg-fill $(
-    fd -L '\.(png|jpg)' /usr/share/backgrounds/ ~/.local/share/backgrounds/ \
-    | shuf | head -n 2
-)

scripts/randomwallpaper/.gitignore

@@ -0,0 +1,2 @@
+target/
+Cargo.lock

scripts/randomwallpaper/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "randomwallpaper"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1.0.53"
+rand = "0.8.5"
+walkdir = "2.3.2"
+x11 = { version = "2.19.1", features = ["xinerama", "xlib"] }

scripts/randomwallpaper/src/main.rs

@@ -0,0 +1,48 @@
+use anyhow::Context;
+use rand::prelude::{IteratorRandom, SliceRandom};
+use std::{
+    path::{Path, PathBuf},
+    process::Command,
+};
+use walkdir::{DirEntry, WalkDir};
+use xinerama::head_count;
+
+mod xinerama;
+
+fn main() -> anyhow::Result<()> {
+    let paths = [
+        PathBuf::from("/usr/share/backgrounds"),
+        Path::new(&std::env::var("HOME").context("couldn't get home directory")?)
+            .join(".local/share/backgrounds"),
+    ];
+
+    let wallpapers = paths
+        .into_iter()
+        .flat_map(dir_iter)
+        .flatten()
+        .filter(|d| {
+            d.path()
+                .extension()
+                .map(|e| ["png", "jpg"].contains(&&*e.to_string_lossy()))
+                .unwrap_or(false)
+        })
+        .map(DirEntry::into_path);
+
+    let mut wallpapers = wallpapers.choose_multiple(
+        &mut rand::thread_rng(),
+        head_count().context("Failed to get head count")? as usize,
+    );
+
+    wallpapers.shuffle(&mut rand::thread_rng());
+
+    Command::new("feh")
+        .arg("--bg-fill")
+        .args(&wallpapers)
+        .status()?;
+
+    Ok(())
+}
+
+fn dir_iter(p: impl AsRef<Path>) -> impl Iterator<Item = walkdir::Result<DirEntry>> {
+    WalkDir::new(p).follow_links(true).into_iter()
+}

scripts/randomwallpaper/src/xinerama.rs

@@ -0,0 +1,36 @@
+use std::mem::MaybeUninit;
+
+use anyhow::bail;
+use x11::{
+    xinerama::{XineramaIsActive, XineramaQueryScreens},
+    xlib::{XCloseDisplay, XFree, XOpenDisplay},
+};
+
+pub fn head_count() -> anyhow::Result<i32> {
+    unsafe {
+        let display = XOpenDisplay(b":0\0".as_ptr() as _);
+        if display.is_null() {
+            bail!("Couldn't open display");
+        }
+
+        if XineramaIsActive(display) != 1 {
+            XCloseDisplay(display);
+            bail!("Xinerama is inactive");
+        }
+
+        let mut screens = MaybeUninit::uninit();
+
+        let info = XineramaQueryScreens(display, screens.as_mut_ptr());
+        if info.is_null() {
+            XCloseDisplay(display);
+            bail!("Failed to query screens");
+        }
+
+        let count = screens.assume_init();
+
+        XFree(info as _);
+        XCloseDisplay(display);
+
+        Ok(count)
+    }
+}