Add cursor-shape protocol

src/cursor.rs

@@ -3,116 +3,310 @@ use std::collections::HashMap;
 use std::env;
 use std::fs::File;
 use std::io::Read;
+use std::rc::Rc;
+use std::sync::Mutex;
 
 use anyhow::{anyhow, Context};
 use smithay::backend::allocator::Fourcc;
 use smithay::backend::renderer::element::texture::TextureBuffer;
 use smithay::backend::renderer::gles::{GlesRenderer, GlesTexture};
-use smithay::utils::{Physical, Point, Transform};
+use smithay::input::pointer::{CursorIcon, CursorImageAttributes, CursorImageStatus};
+use smithay::reexports::wayland_server::protocol::wl_surface::WlSurface;
+use smithay::utils::{IsAlive, Logical, Point, Transform};
+use smithay::wayland::compositor::with_states;
 use xcursor::parser::{parse_xcursor, Image};
 use xcursor::CursorTheme;
 
+/// Some default looking `left_ptr` icon.
 static FALLBACK_CURSOR_DATA: &[u8] = include_bytes!("../resources/cursor.rgba");
 
-type CursorCache = HashMap<i32, (TextureBuffer<GlesTexture>, Point<i32, Physical>)>;
+type XCursorCache = HashMap<(CursorIcon, i32), Option<Rc<XCursor>>>;
 
-pub struct Cursor {
-    images: Vec<Image>,
-    size: i32,
-    cache: RefCell<CursorCache>,
+pub struct CursorManager {
+    theme: CursorTheme,
+    size: u8,
+    current_cursor: CursorImageStatus,
+    named_cursor_cache: RefCell<XCursorCache>,
 }
 
-impl Cursor {
-    /// Load the said theme as well as set the `XCURSOR_THEME` and `XCURSOR_SIZE`
-    /// env variables.
-    pub fn load(theme: &str, size: u8) -> Self {
+impl CursorManager {
+    pub fn new(theme: &str, size: u8) -> Self {
+        Self::ensure_env(theme, size);
+
+        let theme = CursorTheme::load(theme);
+
+        Self {
+            theme,
+            size,
+            current_cursor: CursorImageStatus::default_named(),
+            named_cursor_cache: Default::default(),
+        }
+    }
+
+    /// Reload the cursor theme.
+    pub fn reload(&mut self, theme: &str, size: u8) {
+        Self::ensure_env(theme, size);
+        self.theme = CursorTheme::load(theme);
+        self.size = size;
+        self.named_cursor_cache.get_mut().clear();
+    }
+
+    /// Checks if the cursor WlSurface is alive, and if not, cleans it up.
+    pub fn check_cursor_image_surface_alive(&mut self) {
+        if let CursorImageStatus::Surface(surface) = &self.current_cursor {
+            if !surface.alive() {
+                self.current_cursor = CursorImageStatus::default_named();
+            }
+        }
+    }
+
+    /// Get the current rendering cursor.
+    pub fn get_render_cursor(&self, scale: i32) -> RenderCursor {
+        match self.current_cursor.clone() {
+            CursorImageStatus::Hidden => RenderCursor::Hidden,
+            CursorImageStatus::Surface(surface) => {
+                let hotspot = with_states(&surface, |states| {
+                    states
+                        .data_map
+                        .get::<Mutex<CursorImageAttributes>>()
+                        .unwrap()
+                        .lock()
+                        .unwrap()
+                        .hotspot
+                });
+
+                RenderCursor::Surface { hotspot, surface }
+            }
+            CursorImageStatus::Named(icon) => self
+                .get_cursor_with_name(icon, scale)
+                .map(|cursor| RenderCursor::Named {
+                    icon,
+                    scale,
+                    cursor,
+                })
+                .unwrap_or_else(|| RenderCursor::Named {
+                    icon: Default::default(),
+                    scale,
+                    cursor: self.get_default_cursor(scale),
+                }),
+        }
+    }
+
+    pub fn is_current_cursor_animated(&self, scale: i32) -> bool {
+        match &self.current_cursor {
+            CursorImageStatus::Hidden => false,
+            CursorImageStatus::Surface(_) => false,
+            CursorImageStatus::Named(icon) => self
+                .get_cursor_with_name(*icon, scale)
+                .unwrap_or_else(|| self.get_default_cursor(scale))
+                .is_animated_cursor(),
+        }
+    }
+
+    /// Get named cursor for the given `icon` and `scale`.
+    pub fn get_cursor_with_name(&self, icon: CursorIcon, scale: i32) -> Option<Rc<XCursor>> {
+        self.named_cursor_cache
+            .borrow_mut()
+            .entry((icon, scale))
+            .or_insert_with_key(|(icon, scale)| {
+                let size = self.size as i32 * scale;
+                let mut cursor = Self::load_xcursor(&self.theme, icon.name(), size);
+                if let Err(err) = &cursor {
+                    warn!("error loading xcursor {}@{size}: {err:?}", icon.name());
+                }
+
+                // The default cursor must always have a fallback.
+                if *icon == CursorIcon::Default && cursor.is_err() {
+                    cursor = Ok(Self::fallback_cursor());
+                }
+
+                cursor.ok().map(Rc::new)
+            })
+            .clone()
+    }
+
+    /// Get default cursor.
+    pub fn get_default_cursor(&self, scale: i32) -> Rc<XCursor> {
+        // The default cursor always has a fallback.
+        self.get_cursor_with_name(CursorIcon::Default, scale)
+            .unwrap()
+    }
+
+    /// Currenly used cursor_image as a cursor provider.
+    pub fn cursor_image(&self) -> &CursorImageStatus {
+        &self.current_cursor
+    }
+
+    /// Set new cursor image provider.
+    pub fn set_cursor_image(&mut self, cursor: CursorImageStatus) {
+        self.current_cursor = cursor;
+    }
+
+    /// Load the cursor with the given `name` from the file system picking the closest
+    /// one to the given `size`.
+    fn load_xcursor(theme: &CursorTheme, name: &str, size: i32) -> anyhow::Result<XCursor> {
+        let _span = tracy_client::span!("load_xcursor");
+
+        let path = theme
+            .load_icon(name)
+            .ok_or_else(|| anyhow!("no default icon"))?;
+
+        let mut file = File::open(path).context("error opening cursor icon file")?;
+        let mut buf = vec![];
+        file.read_to_end(&mut buf)
+            .context("error reading cursor icon file")?;
+
+        let mut images = parse_xcursor(&buf).context("error parsing cursor icon file")?;
+
+        let (width, height) = images
+            .iter()
+            .min_by_key(|image| (size - image.size as i32).abs())
+            .map(|image| (image.width, image.height))
+            .unwrap();
+
+        images.retain(move |image| image.width == width && image.height == height);
+
+        let animation_duration = images.iter().fold(0, |acc, image| acc + image.delay);
+
+        Ok(XCursor {
+            images,
+            animation_duration,
+        })
+    }
+
+    /// Set the common XCURSOR env variables.
+    fn ensure_env(theme: &str, size: u8) {
         env::set_var("XCURSOR_THEME", theme);
         env::set_var("XCURSOR_SIZE", size.to_string());
+    }
 
-        let images = match load_xcursor(theme) {
-            Ok(images) => images,
-            Err(err) => {
-                warn!("error loading xcursor default cursor: {err:?}");
-
-                vec![Image {
-                    size: 32,
-                    width: 64,
-                    height: 64,
-                    xhot: 1,
-                    yhot: 1,
-                    delay: 1,
-                    pixels_rgba: Vec::from(FALLBACK_CURSOR_DATA),
-                    pixels_argb: vec![],
-                }]
-            }
-        };
+    fn fallback_cursor() -> XCursor {
+        let images = vec![Image {
+            size: 32,
+            width: 64,
+            height: 64,
+            xhot: 1,
+            yhot: 1,
+            delay: 0,
+            pixels_rgba: Vec::from(FALLBACK_CURSOR_DATA),
+            pixels_argb: vec![],
+        }];
 
-        Self {
+        XCursor {
             images,
-            size: size as i32,
-            cache: Default::default(),
+            animation_duration: 0,
         }
     }
+}
+
+/// The cursor prepared for renderer.
+pub enum RenderCursor {
+    Hidden,
+    Surface {
+        hotspot: Point<i32, Logical>,
+        surface: WlSurface,
+    },
+    Named {
+        icon: CursorIcon,
+        scale: i32,
+        cursor: Rc<XCursor>,
+    },
+}
+
+type TextureCache = HashMap<(CursorIcon, i32), Vec<TextureBuffer<GlesTexture>>>;
+
+#[derive(Default)]
+pub struct CursorTextureCache {
+    cache: RefCell<TextureCache>,
+}
+
+impl CursorTextureCache {
+    pub fn clear(&mut self) {
+        self.cache.get_mut().clear();
+    }
 
     pub fn get(
         &self,
         renderer: &mut GlesRenderer,
+        icon: CursorIcon,
         scale: i32,
-    ) -> (TextureBuffer<GlesTexture>, Point<i32, Physical>) {
+        cursor: &XCursor,
+        idx: usize,
+    ) -> TextureBuffer<GlesTexture> {
         self.cache
             .borrow_mut()
-            .entry(scale)
-            .or_insert_with_key(|scale| {
-                let _span = tracy_client::span!("create cursor texture");
-
-                let size = self.size * scale;
-
-                let nearest_image = self
-                    .images
-                    .iter()
-                    .min_by_key(|image| (size - image.size as i32).abs())
-                    .unwrap();
-                let frame = self
-                    .images
+            .entry((icon, scale))
+            .or_insert_with(|| {
+                cursor
+                    .frames()
                     .iter()
-                    .find(move |image| {
-                        image.width == nearest_image.width && image.height == nearest_image.height
+                    .map(|frame| {
+                        let _span = tracy_client::span!("create TextureBuffer");
+
+                        TextureBuffer::from_memory(
+                            renderer,
+                            &frame.pixels_rgba,
+                            Fourcc::Abgr8888,
+                            (frame.width as i32, frame.height as i32),
+                            false,
+                            scale,
+                            Transform::Normal,
+                            None,
+                        )
+                        .unwrap()
                     })
-                    .unwrap();
-
-                let texture = TextureBuffer::from_memory(
-                    renderer,
-                    &frame.pixels_rgba,
-                    Fourcc::Abgr8888,
-                    (frame.width as i32, frame.height as i32),
-                    false,
-                    *scale,
-                    Transform::Normal,
-                    None,
-                )
-                .unwrap();
-                (texture, (frame.xhot as i32, frame.yhot as i32).into())
-            })
+                    .collect()
+            })[idx]
             .clone()
     }
+}
 
-    pub fn get_cached_hotspot(&self, scale: i32) -> Option<Point<i32, Physical>> {
-        self.cache.borrow().get(&scale).map(|(_, hotspot)| *hotspot)
-    }
+// The XCursorBuffer implementation is inspired by `wayland-rs`, thus provided under MIT license.
+
+/// The state of the `NamedCursor`.
+pub struct XCursor {
+    /// The image for the underlying named cursor.
+    images: Vec<Image>,
+    /// The total duration of the animation.
+    animation_duration: u32,
 }
 
-fn load_xcursor(theme: &str) -> anyhow::Result<Vec<Image>> {
-    let _span = tracy_client::span!();
+impl XCursor {
+    /// Given a time, calculate which frame to show, and how much time remains until the next frame.
+    ///
+    /// Time will wrap, so if for instance the cursor has an animation lasting 100ms,
+    /// then calling this function with 5ms and 105ms as input gives the same output.
+    pub fn frame(&self, mut millis: u32) -> (usize, &Image) {
+        if self.animation_duration == 0 {
+            return (0, &self.images[0]);
+        }
 
-    let theme = CursorTheme::load(theme);
-    let path = theme
-        .load_icon("default")
-        .ok_or_else(|| anyhow!("no default icon"))?;
-    let mut file = File::open(path).context("error opening cursor icon file")?;
-    let mut buf = vec![];
-    file.read_to_end(&mut buf)
-        .context("error reading cursor icon file")?;
-    let images = parse_xcursor(&buf).context("error parsing cursor icon file")?;
+        millis %= self.animation_duration;
 
-    Ok(images)
+        let mut res = 0;
+        for (i, img) in self.images.iter().enumerate() {
+            if millis < img.delay {
+                res = i;
+                break;
+            }
+            millis -= img.delay;
+        }
+
+        (res, &self.images[res])
+    }
+
+    /// Get the frames for the given `XCursor`.
+    pub fn frames(&self) -> &[Image] {
+        &self.images
+    }
+
+    /// Check whether the cursor is animated.
+    pub fn is_animated_cursor(&self) -> bool {
+        self.images.len() > 1
+    }
+
+    /// Get hotspot for the given `image`.
+    pub fn hotspot(image: &Image) -> Point<i32, Logical> {
+        (image.xhot as i32, image.yhot as i32).into()
+    }
 }

src/handlers/compositor.rs

@@ -161,7 +161,8 @@ impl CompositorHandler for State {
         self.layer_shell_handle_commit(surface);
 
         // This might be a cursor surface.
-        if matches!(&self.niri.cursor_image, CursorImageStatus::Surface(s) if s == surface) {
+        if matches!(&self.niri.cursor_manager.cursor_image(), CursorImageStatus::Surface(s) if s == surface)
+        {
             // FIXME: granular redraws for cursors.
             self.niri.queue_redraw_all();
         }