diff --git a/apps/vectorcraft/src/cursor_theme.rs b/apps/vectorcraft/src/cursor_theme.rs new file mode 100644 index 000000000..ebb8ce871 --- /dev/null +++ b/apps/vectorcraft/src/cursor_theme.rs @@ -0,0 +1,212 @@ +//! Linux Wayland: tell winit where the cursor theme is (#2450). +//! +//! Without the cursor-shape protocol (GNOME 46 and others) winit loads the pointer from an Xcursor +//! theme itself. When that lookup finds nothing, no pointer is ever set and the compositor keeps +//! showing its default one, until the canvas hides the system pointer to paint a tool glyph +//! (`CursorIcon::None`). Then the arrow never comes back over the panels and menus. The lookup +//! fails in a Flatpak sandbox (`XCURSOR_PATH` unset, no cursor theme in the runtime) and where the +//! `default` theme is a dangling symlink; the desktop's own setting names a theme that loads. +//! +//! Where no cursor theme can be found at all (KDE or sway without gsettings), the env fix does +//! nothing: [`theme_missing`] tells the canvas to keep the system pointer visible beside the tool glyph. +//! +//! This reads the desktop's cursor theme and size and sets what the user left unset, once, before +//! any thread starts and before the window opens. +#![cfg_attr(not(target_os = "linux"), allow(dead_code))] + +use std::ffi::OsString; +use std::path::{Path, PathBuf}; + +/// Where a Flatpak sandbox mounts the host's cursor themes (user and system). +const FLATPAK_HOST_ICONS: [&str; 2] = ["/run/host/user-share/icons", "/run/host/share/icons"]; + +/// The desktop's cursor settings (GNOME's `org.gnome.desktop.interface`). +#[derive(Debug, Default, PartialEq)] +pub struct DesktopCursor { + pub theme: Option, + pub size: Option, +} + +/// The variables to set, given the environment, the host icon folders that exist and the +/// desktop's cursor settings. Empty unless this is a Wayland session; variables the user set +/// stay as they are. +pub fn plan(var: impl Fn(&str) -> Option, host_icons: &[&str], desktop: DesktopCursor) -> Vec<(&'static str, OsString)> { + let set = |name: &str| var(name).is_some_and(|v| !v.is_empty()); + if !(set("WAYLAND_DISPLAY") || set("WAYLAND_SOCKET")) { + return Vec::new(); + } + let mut out = Vec::new(); + if !set("XCURSOR_PATH") && !host_icons.is_empty() { + out.push(("XCURSOR_PATH", OsString::from(host_icons.join(":")))); + } + if !set("XCURSOR_THEME") + && let Some(theme) = desktop.theme.filter(|t| !t.is_empty()) + { + out.push(("XCURSOR_THEME", OsString::from(theme))); + } + if !set("XCURSOR_SIZE") + && let Some(size) = desktop.size.filter(|s| (1..=512).contains(s)) + { + out.push(("XCURSOR_SIZE", OsString::from(size.to_string()))); + } + out +} + +/// Xcursor's default search path when `XCURSOR_PATH` is unset (relative entries are in `$HOME`). +const DEFAULT_ICON_DIRS: [&str; 5] = ["~/.local/share/icons", "~/.icons", "/usr/share/icons", "/usr/share/pixmaps", "/usr/X11R6/lib/X11/icons"]; + +/// The themes `index.theme` lists after `Inherits=`. +fn inherits(index: &str) -> Vec { + index + .lines() + .find_map(|l| l.trim().strip_prefix("Inherits=")) + .map(|v| v.split([',', ';']).map(|t| t.trim().to_owned()).filter(|t| !t.is_empty()).collect()) + .unwrap_or_default() +} + +/// Can Xcursor load a pointer for the environment's theme (`XCURSOR_THEME`, else `default`)? It does +/// when the theme, or one it inherits from, has a `default` or `left_ptr` cursor file in a folder of +/// `XCURSOR_PATH` (else Xcursor's default folders). `read` returns a file's text, `exists` tells +/// whether a file is there. +pub fn theme_usable( + var: impl Fn(&str) -> Option, + home: Option<&Path>, + read: impl Fn(&Path) -> Option, + exists: impl Fn(&Path) -> bool, +) -> bool { + let dirs: Vec = match var("XCURSOR_PATH").filter(|v| !v.is_empty()) { + Some(v) => std::env::split_paths(&v).collect(), + None => DEFAULT_ICON_DIRS + .iter() + .filter_map(|d| match d.strip_prefix("~/") { + Some(rest) => home.map(|h| h.join(rest)), + None => Some(PathBuf::from(d)), + }) + .collect(), + }; + let first = var("XCURSOR_THEME").and_then(|v| v.into_string().ok()).filter(|t| !t.is_empty()).unwrap_or_else(|| "default".into()); + let mut todo = vec![first]; + let mut seen: Vec = Vec::new(); + while let Some(theme) = todo.pop() { + // Bounded: themes inherit in short chains, and a cycle must end. + if seen.contains(&theme) || seen.len() >= 16 { + continue; + } + for dir in &dirs { + let base = dir.join(&theme); + if ["default", "left_ptr"].iter().any(|c| exists(&base.join("cursors").join(c))) { + return true; + } + if let Some(index) = read(&base.join("index.theme")) { + todo.extend(inherits(&index)); + } + } + seen.push(theme); + } + false +} + +/// On this machine, after [`apply`]: is there no cursor theme Xcursor can load? Then winit never +/// sets a pointer, and the canvas must not hide the system one (#2450). +pub fn theme_missing() -> bool { + let home = std::env::var_os("HOME").filter(|h| !h.is_empty()).map(PathBuf::from); + !theme_usable(|n| std::env::var_os(n), home.as_deref(), |p| std::fs::read_to_string(p).ok(), |p| p.exists()) +} + +/// The value of a `gsettings get` line: `'Adwaita'` becomes `Adwaita`, `24` stays `24`. +fn gsettings_value(output: &str) -> &str { + output.trim().trim_matches('\'') +} + +#[cfg(target_os = "linux")] +fn desktop_cursor() -> DesktopCursor { + let get = |key: &str| { + let out = std::process::Command::new("gsettings").args(["get", "org.gnome.desktop.interface", key]).output().ok()?; + out.status.success().then(|| String::from_utf8_lossy(&out.stdout).into_owned()) + }; + DesktopCursor { + theme: get("cursor-theme").map(|v| gsettings_value(&v).to_owned()), + size: get("cursor-size").and_then(|v| gsettings_value(&v).parse().ok()), + } +} + +/// Sets `XCURSOR_PATH`, `XCURSOR_THEME` and `XCURSOR_SIZE` where a Wayland session leaves them +/// unset. Call first thing in `main`, while the process is single-threaded. +#[cfg(target_os = "linux")] +#[allow(unsafe_code)] +pub fn apply() { + let host: Vec<&str> = FLATPAK_HOST_ICONS.iter().copied().filter(|p| std::path::Path::new(p).is_dir()).collect(); + for (name, value) in plan(|n| std::env::var_os(n), &host, desktop_cursor()) { + log::debug!("cursor theme: {name}={value:?}"); + // SAFETY: called at the top of `main`, before the app starts any thread. + unsafe { std::env::set_var(name, value) }; + } +} + +#[cfg(test)] +mod tests { + use super::*; + + fn env<'a>(pairs: &'a [(&'a str, &'a str)]) -> impl Fn(&str) -> Option + 'a { + move |name| pairs.iter().find(|(k, _)| *k == name).map(|(_, v)| OsString::from(v)) + } + + fn adwaita() -> DesktopCursor { + DesktopCursor { theme: Some("Adwaita".into()), size: Some(24) } + } + + #[test] + fn a_wayland_session_gets_the_desktop_theme_and_the_host_icons() { + let got = plan(env(&[("WAYLAND_DISPLAY", "wayland-0")]), &["/run/host/share/icons"], adwaita()); + assert_eq!( + got, + vec![ + ("XCURSOR_PATH", OsString::from("/run/host/share/icons")), + ("XCURSOR_THEME", OsString::from("Adwaita")), + ("XCURSOR_SIZE", OsString::from("24")), + ] + ); + } + + #[test] + fn settings_the_user_made_and_other_sessions_stay_untouched() { + let set = [("WAYLAND_DISPLAY", "wayland-0"), ("XCURSOR_PATH", "/x"), ("XCURSOR_THEME", "Bibata"), ("XCURSOR_SIZE", "32")]; + assert!(plan(env(&set), &["/run/host/share/icons"], adwaita()).is_empty()); + assert!(plan(env(&[("DISPLAY", ":0")]), &["/run/host/share/icons"], adwaita()).is_empty()); + // A theme-less desktop and an absurd size set nothing. + let odd = DesktopCursor { theme: Some(String::new()), size: Some(0) }; + assert!(plan(env(&[("WAYLAND_DISPLAY", "wayland-0")]), &[], odd).is_empty()); + } + + #[test] + fn a_theme_is_usable_directly_or_through_inherits_and_missing_otherwise() { + let files = ["/i/Bibata/cursors/left_ptr", "/i/Breeze/index.theme", "/i/Loop/index.theme"]; + // Compared as paths, so the joins match on Windows too, where they use `\`. + let exists = |p: &Path| files.iter().any(|f| Path::new(f) == p); + let read = |p: &Path| { + if p == Path::new("/i/Breeze/index.theme") { + Some("[Icon Theme]\nInherits=Other, Bibata\n".to_owned()) + } else if p == Path::new("/i/Loop/index.theme") { + Some("Inherits=Loop\n".to_owned()) + } else { + None + } + }; + let with = |theme: &'static str| { + move |n: &str| (n == "XCURSOR_PATH").then(|| OsString::from("/i")).or((n == "XCURSOR_THEME").then(|| OsString::from(theme))) + }; + assert!(theme_usable(with("Bibata"), None, read, exists)); + assert!(theme_usable(with("Breeze"), None, read, exists)); + // No such theme, a theme without cursors, an inheritance loop: nothing to load. + assert!(!theme_usable(with("Nope"), None, read, exists)); + assert!(!theme_usable(with("Loop"), None, read, exists)); + // Unset: Xcursor's default folders and the `default` theme. + assert!(!theme_usable(|_| None, Some(Path::new("/home/u")), read, exists)); + } + + #[test] + fn gsettings_output_is_unquoted() { + assert_eq!(gsettings_value("'Adwaita'\n"), "Adwaita"); + assert_eq!(gsettings_value("24\n"), "24"); + } +} diff --git a/apps/vectorcraft/src/main.rs b/apps/vectorcraft/src/main.rs index 17bc010a3..23aaea179 100644 --- a/apps/vectorcraft/src/main.rs +++ b/apps/vectorcraft/src/main.rs @@ -27,6 +27,7 @@ mod clipboard; #[cfg(feature = "wgpu")] mod compositor_gpu; mod control_server; +mod cursor_theme; #[cfg(feature = "wgpu")] mod gpu; mod logging; @@ -525,6 +526,7 @@ fn services(parent: Parent, ui: egui::Context) -> Services { start_pick: cfg!(unix).then(|| Box::new(move |request: PickRequest| start_pick(request, &p5, &ui)) as vectorcraft_ui_egui::picks::StartPick), dialogs_are_sheets: cfg!(target_os = "macos"), wayland, + no_cursor_theme: wayland && cursor_theme::theme_missing(), read: Some(Box::new(|p: &str| std::fs::read(p).map_err(|e| e.to_string()))), write: Some(Box::new(write_file)), // Background Save and Export write from a worker thread. @@ -654,6 +656,9 @@ Without a window (converting, scripting, the MCP server), use vectorcraft-cli: "; fn main() -> std::process::ExitCode { + // Before any thread starts: the pointer must find a cursor theme on Wayland (#2450). + #[cfg(target_os = "linux")] + cursor_theme::apply(); // Validate roots before logging, font scans, preferences or the window: a missing value // must not clear an environment root and start the control channel without confinement. let mut control = automation_args::ControlArg::default(); diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs index e6b6157f8..2870d1d51 100644 --- a/crates/ui-egui/src/canvas.rs +++ b/crates/ui-egui/src/canvas.rs @@ -565,7 +565,8 @@ pub fn show(app: &mut VectorcraftApp, ui: &mut Ui) { && crate::cursors::paint_glyphs(crate::cursors::HIDES_ONLY_WHEN_KEY, ui.input(|i| i.focused)) && crate::cursors::paint(&painter, c, hp, 1.0 / ui_scale) => { - egui::CursorIcon::None + // No cursor theme (Wayland): the glyph is painted, the system pointer stays (#2450). + if crate::cursors::hide_system_pointer(app.services.no_cursor_theme) { egui::CursorIcon::None } else { cursor_icon(c) } } _ => cursor_icon(c), } diff --git a/crates/ui-egui/src/cursors.rs b/crates/ui-egui/src/cursors.rs index bdf2d127c..4f6723118 100644 --- a/crates/ui-egui/src/cursors.rs +++ b/crates/ui-egui/src/cursors.rs @@ -581,6 +581,13 @@ pub fn os_cursors(build: bool, wayland: bool) -> bool { build && !wayland } +/// Does the canvas hide the system pointer to show a painted tool glyph alone? Not when there is no +/// cursor theme on Wayland ([`crate::Services::no_cursor_theme`]): winit sets no pointer then, and a +/// hidden one would not come back over the panels (#2450). The system pointer stays beside the glyph. +pub fn hide_system_pointer(no_cursor_theme: bool) -> bool { + !no_cursor_theme +} + /// Does the window hide the pointer only while it is the key window? macOS does: winit hides it with /// a cursor rect holding a transparent cursor, and macOS applies the rect only in the key window. /// Over a window behind another app or under a sheet, the system pointer shows (#2020). @@ -927,6 +934,22 @@ mod tests { assert_eq!(out.platform_output.cursor_icon, egui::CursorIcon::None); } + /// Without a cursor theme the canvas keeps the system pointer visible (#2450). + #[test] + fn no_cursor_theme_keeps_the_system_pointer() { + assert!(!hide_system_pointer(true)); + assert!(hide_system_pointer(false)); + let mut app = VectorcraftApp::new(Session::new(), crate::Services { wayland: true, no_cursor_theme: true, ..Default::default() }); + app.run("file.new", json!({"width": 400, "height": 300})).unwrap(); + let ctx = egui::Context::default(); + for _ in 0..3 { + frame(&mut app, &ctx, vec![]); + } + let over = app.canvas_rect.unwrap().center(); + let out = frame(&mut app, &ctx, vec![egui::Event::PointerMoved(over)]); + assert_ne!(out.platform_output.cursor_icon, egui::CursorIcon::None); + } + /// On macOS a window without the focus shows the system pointer over the canvas, and the glyph /// is not painted next to it (#2020). With the focus back, the canvas sets `CursorIcon::None` again /// on the next frame, without a pointer move. diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs index bc1fe3d8a..64998ed24 100644 --- a/crates/ui-egui/src/lib.rs +++ b/crates/ui-egui/src/lib.rs @@ -275,6 +275,10 @@ pub struct Services { /// The window is on Wayland: the tool cursors are painted into it instead of handed to the /// compositor as bitmaps ([`cursors::os_cursors`]). pub wayland: bool, + /// On Wayland, no cursor theme can be loaded, so winit sets no pointer and the compositor's + /// default one would never come back once the canvas hid it: the canvas keeps the system + /// pointer visible next to the tool glyph ([`cursors::hide_system_pointer`], #2450). + pub no_cursor_theme: bool, } /// Cached canvas raster. diff --git a/packaging/linux/flatpak/ai.storyteller.vectorcraft.bundle.yml b/packaging/linux/flatpak/ai.storyteller.vectorcraft.bundle.yml index b245e0b31..687445a55 100644 --- a/packaging/linux/flatpak/ai.storyteller.vectorcraft.bundle.yml +++ b/packaging/linux/flatpak/ai.storyteller.vectorcraft.bundle.yml @@ -24,6 +24,10 @@ finish-args: - --socket=fallback-x11 # GPU access for the wgpu renderer (Vulkan, or GL as a fallback). - --device=dri + # Cursor theme: without the cursor-shape protocol (e.g. GNOME 46) winit loads the theme itself. + # The sandbox sets no XCURSOR_PATH and ships no cursor themes, so the pointer would turn invisible + # over the window. The host's themes are mounted under /run/host (#2450). + - --env=XCURSOR_PATH=/run/host/user-share/icons:/run/host/share/icons # Open/Save dialogs use the file-chooser portal (rfd), and drag-and-drop uses the document # portal, so broad filesystem access isn't needed. Pictures is granted for opening files by # path from the command line. diff --git a/packaging/linux/flatpak/ai.storyteller.vectorcraft.yml b/packaging/linux/flatpak/ai.storyteller.vectorcraft.yml index 865609509..cbee5b720 100644 --- a/packaging/linux/flatpak/ai.storyteller.vectorcraft.yml +++ b/packaging/linux/flatpak/ai.storyteller.vectorcraft.yml @@ -22,6 +22,10 @@ finish-args: - --socket=wayland - --socket=fallback-x11 - --device=dri + # Cursor theme: without the cursor-shape protocol (e.g. GNOME 46) winit loads the theme itself. + # The sandbox sets no XCURSOR_PATH and ships no cursor themes, so the pointer would turn invisible + # over the window. The host's themes are mounted under /run/host (#2450). + - --env=XCURSOR_PATH=/run/host/user-share/icons:/run/host/share/icons # Open/Save dialogs use the file-chooser portal (rfd), and drag-and-drop uses the document # portal, so broad filesystem access isn't needed. Pictures is granted for opening files by # path from the command line.