heavy refacotring, improve error handling, make `command` optional

4 files changed, 655 insertions, 633 deletions

diff --git a/README.md b/README.md
index a742256..4c18872 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ riverctl spawn i3bar-river
 
 The configuration file should be stored in `$XDG_CONFIG_HOME/i3bar-river/config.toml` or `~/.config/i3bar-river/config.toml`.
 
-Example configuration (everything except for `command` is optional):
+Example configuration (every parameter is optional):
 
 ```toml
 background = "#282828"
@@ -54,5 +54,5 @@ tag_urgent_fg = "#282828"
 tag_urgent_bg = "#cc241d"
 font = "JetBrainsMono Nerd Font 10"
 height = 20
-command = "~/i3status-rust/target/debug/i3status-rs"
+command = "i3status-rs"
 ```
diff --git a/src/bar_state.rs b/src/bar_state.rs
new file mode 100644
index 0000000..c9c43f4
--- /dev/null
+++ b/src/bar_state.rs
@@ -0,0 +1,523 @@
+use std::cell::{Cell, RefCell};
+use std::collections::{BinaryHeap, HashMap};
+use std::io;
+use std::rc::Rc;
+
+use smithay_client_toolkit::{
+    reexports::{
+        client::protocol::{wl_output::WlOutput, wl_seat::WlSeat, wl_shm, wl_surface::WlSurface},
+        client::{Attached, Main},
+        protocols::wlr::unstable::layer_shell::v1::client::{
+            zwlr_layer_shell_v1, zwlr_layer_surface_v1,
+        },
+    },
+    shm::AutoMemPool,
+};
+
+use pangocairo::cairo;
+
+use crate::button_manager::ButtonManager;
+use crate::config::Config;
+use crate::i3bar_protocol::{self, Block, MinWidth};
+use crate::ord_adaptor::DefaultLess;
+use crate::pointer_btn::PointerBtn;
+use crate::river_protocols::zriver_command_callback_v1;
+use crate::river_protocols::zriver_control_v1;
+use crate::river_protocols::zriver_output_status_v1;
+use crate::river_protocols::zriver_status_manager_v1;
+use crate::status_cmd::StatusCmd;
+use crate::tags::{compute_tag_label, TagState, TagsInfo};
+use crate::text;
+use crate::text::{ComputedText, RenderOptions};
+
+#[derive(PartialEq, Copy, Clone)]
+enum RenderEvent {
+    Configure { width: u32, height: u32 },
+    TagsUpdated,
+    Closed,
+}
+
+pub struct BarState {
+    pub status_cmd: Option<StatusCmd>,
+    config: Rc<RefCell<Config>>,
+    is_error: bool,
+    blocks: Vec<Block>,
+    blocks_updated: bool,
+    surfaces: Vec<Surface>,
+}
+
+impl BarState {
+    pub fn new() -> Self {
+        let mut error = Ok(());
+
+        let config = Config::new()
+            .map_err(|e| error = Err(e))
+            .unwrap_or_default();
+
+        let status_cmd = match &error {
+            Err(_) => None,
+            Ok(()) => config.command.as_deref().and_then(|cmd| {
+                StatusCmd::new(cmd)
+                    .map_err(|e| error = Err(anyhow!(e)))
+                    .ok()
+            }),
+        };
+
+        let mut s = Self {
+            status_cmd,
+            config: Rc::new(RefCell::new(config)),
+            is_error: false,
+            blocks: Vec::new(),
+            blocks_updated: false,
+            surfaces: Default::default(),
+        };
+
+        if let Err(e) = error {
+            s.set_error(e.to_string());
+        }
+
+        s
+    }
+
+    pub fn set_blocks(&mut self, blocks: Vec<Block>) {
+        self.blocks = blocks;
+        self.blocks_updated = true;
+    }
+
+    pub fn set_error(&mut self, error: impl Into<String>) {
+        self.is_error = true;
+        self.set_blocks(vec![Block {
+            full_text: error.into(),
+            ..Default::default()
+        }]);
+    }
+
+    pub fn remove_surface(&mut self, output_id: u32) {
+        self.surfaces.retain(|s| s.output_id != output_id);
+    }
+
+    pub fn notify_available(&mut self) -> io::Result<()> {
+        if let Some(cmd) = &mut self.status_cmd {
+            if let Some(blocks) = cmd.notify_available()? {
+                self.set_blocks(blocks);
+            }
+        }
+        Ok(())
+    }
+
+    pub fn handle_click(
+        &mut self,
+        surface: &WlSurface,
+        seat: &WlSeat,
+        x: f64,
+        y: f64,
+        btn: PointerBtn,
+    ) {
+        if let Some(s) = self.surfaces.iter().find(|s| &s.surface == surface) {
+            if let Some(event) = s.click(btn, seat, x, y) {
+                if let Some(cmd) = &mut self.status_cmd {
+                    if let Err(e) = cmd.send_click_event(&event) {
+                        self.set_error(e.to_string());
+                    }
+                }
+            }
+        }
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub fn add_surface(
+        &mut self,
+        output: &WlOutput,
+        output_id: u32,
+        surface: WlSurface,
+        layer_shell: &Attached<zwlr_layer_shell_v1::ZwlrLayerShellV1>,
+        river_status: &Attached<zriver_status_manager_v1::ZriverStatusManagerV1>,
+        river_control: Attached<zriver_control_v1::ZriverControlV1>,
+        pool: AutoMemPool,
+    ) {
+        let layer_surface = layer_shell.get_layer_surface(
+            &surface,
+            Some(output),
+            zwlr_layer_shell_v1::Layer::Top,
+            "i3bar-river".to_owned(),
+        );
+
+        // Set the height
+        layer_surface.set_size(0, self.config.borrow().height);
+        // Anchor to the top
+        layer_surface.set_anchor(
+            zwlr_layer_surface_v1::Anchor::Top
+                | zwlr_layer_surface_v1::Anchor::Left
+                | zwlr_layer_surface_v1::Anchor::Right,
+        );
+
+        let next_render_event = Rc::new(Cell::new(None));
+        let next_render_event_handle = Rc::clone(&next_render_event);
+        layer_surface.quick_assign(move |layer_surface, event, _| {
+            match (event, next_render_event_handle.get()) {
+                (zwlr_layer_surface_v1::Event::Closed, _) => {
+                    next_render_event_handle.set(Some(RenderEvent::Closed));
+                }
+                (
+                    zwlr_layer_surface_v1::Event::Configure {
+                        serial,
+                        width,
+                        height,
+                    },
+                    next,
+                ) if next != Some(RenderEvent::Closed) => {
+                    layer_surface.ack_configure(serial);
+                    next_render_event_handle.set(Some(RenderEvent::Configure { width, height }));
+                }
+                (_, _) => (),
+            }
+        });
+
+        // Commit so that the server will send a configure event
+        surface.commit();
+
+        let river_output_status = river_status.get_river_output_status(output);
+        let tags_info = Rc::new(RefCell::new(TagsInfo::default()));
+        let tags_info_handle = Rc::clone(&tags_info);
+        let next_render_event_handle = Rc::clone(&next_render_event);
+        river_output_status.quick_assign(move |_, event, _| {
+            match event {
+                zriver_output_status_v1::Event::FocusedTags { tags } => {
+                    tags_info_handle.borrow_mut().focused = tags;
+                }
+                zriver_output_status_v1::Event::UrgentTags { tags } => {
+                    tags_info_handle.borrow_mut().urgent = tags;
+                }
+                _ => (),
+            }
+            if next_render_event_handle.get().is_none() {
+                next_render_event_handle.set(Some(RenderEvent::TagsUpdated));
+            }
+        });
+
+        self.surfaces.push(Surface {
+            output_id,
+            surface,
+            layer_surface,
+            next_render_event,
+            pool,
+            dimensions: (0, 0),
+            config: self.config.clone(),
+            river_output_status,
+            river_control,
+            tags_info,
+            tags_computed: Vec::with_capacity(9),
+            tags_btns: Default::default(),
+            blocks_btns: Default::default(),
+        });
+    }
+
+    pub fn handle_events(&mut self) {
+        // This is ugly, let's hope that some version of drain_filter() gets stabilized soon
+        // https://github.com/rust-lang/rust/issues/43244
+        let mut i = 0;
+        while i != self.surfaces.len() {
+            if self.surfaces[i].handle_events(&self.blocks, self.blocks_updated) {
+                self.surfaces.remove(i);
+            } else {
+                i += 1;
+            }
+        }
+        self.blocks_updated = false;
+    }
+}
+
+pub struct Surface {
+    output_id: u32,
+    surface: WlSurface,
+    layer_surface: Main<zwlr_layer_surface_v1::ZwlrLayerSurfaceV1>,
+    next_render_event: Rc<Cell<Option<RenderEvent>>>,
+    pool: AutoMemPool,
+    dimensions: (u32, u32),
+    config: Rc<RefCell<Config>>,
+    // river stuff
+    river_output_status: Main<zriver_output_status_v1::ZriverOutputStatusV1>,
+    river_control: Attached<zriver_control_v1::ZriverControlV1>,
+    // tags
+    tags_info: Rc<RefCell<TagsInfo>>,
+    tags_computed: Vec<ComputedText>,
+    // buttons
+    tags_btns: ButtonManager,
+    blocks_btns: ButtonManager<(Option<String>, Option<String>)>,
+}
+
+impl Surface {
+    /// Handles any events that have occurred since the last call, redrawing if needed.
+    /// Returns true if the surface should be dropped.
+    fn handle_events(&mut self, blocks: &[Block], blocks_updated: bool) -> bool {
+        match self.next_render_event.take() {
+            Some(RenderEvent::Closed) => return true,
+            Some(RenderEvent::Configure { width, height }) => {
+                if self.dimensions != (width, height) {
+                    self.dimensions = (width, height);
+                    self.layer_surface.set_exclusive_zone(height as _);
+                    self.draw(blocks);
+                    return false;
+                }
+            }
+            Some(RenderEvent::TagsUpdated) => {
+                self.draw(blocks);
+                return false;
+            }
+            _ => (),
+        }
+        if blocks_updated {
+            self.draw(blocks);
+            return false;
+        }
+        false
+    }
+
+    fn click(
+        &self,
+        button: PointerBtn,
+        seat: &WlSeat,
+        x: f64,
+        _y: f64,
+    ) -> Option<i3bar_protocol::Event> {
+        if let Some(id) = self.tags_btns.click(x) {
+            let cmd = match button {
+                PointerBtn::Left => "set-focused-tags",
+                PointerBtn::Right => "toggle-focused-tags",
+                _ => return None,
+            };
+            self.river_control.add_argument(cmd.into());
+            self.river_control.add_argument((1u32 << id).to_string());
+            let result = self.river_control.run_command(seat);
+            result.quick_assign(|_, event, _| match event {
+                zriver_command_callback_v1::Event::Success { output } => {
+                    info!("River cmd output: '{output}'");
+                }
+                zriver_command_callback_v1::Event::Failure { failure_message: f } => {
+                    error!("River error: '{f}'");
+                }
+            });
+        } else if let Some((name, instance)) = self.blocks_btns.click(x) {
+            return Some(i3bar_protocol::Event {
+                name: name.as_deref(),
+                instance: instance.as_deref(),
+                button,
+                ..Default::default()
+            });
+        }
+        None
+    }
+
+    fn draw(&mut self, blocks: &[Block]) {
+        let config = self.config.borrow();
+
+        let stride = 4 * self.dimensions.0 as i32;
+        let width = self.dimensions.0 as i32;
+        let height = self.dimensions.1 as i32;
+        let width_f = width as f64;
+        let height_f = height as f64;
+
+        let (canvas, buffer) = self
+            .pool
+            .buffer(width, height, stride, wl_shm::Format::Argb8888)
+            .unwrap();
+
+        let cairo_surf = unsafe {
+            cairo::ImageSurface::create_for_data_unsafe(
+                canvas.as_mut_ptr(),
+                cairo::Format::ARgb32,
+                width,
+                height,
+                stride,
+            )
+            .expect("cairo surface")
+        };
+
+        let cairo_ctx = cairo::Context::new(&cairo_surf).expect("cairo context");
+        let pango_layout = pangocairo::create_layout(&cairo_ctx).expect("pango layout");
+        pango_layout.set_font_description(Some(&config.font));
+        pango_layout.set_height(height);
+
+        // Background
+        config.background.apply(&cairo_ctx);
+        cairo_ctx.paint().expect("cairo paint");
+
+        // Compute tags
+        if self.tags_computed.is_empty() {
+            let mut x_offset = 0.0;
+            //  TODO make configurable
+            for (id, text) in ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
+                .iter()
+                .enumerate()
+            {
+                let tag = compute_tag_label(text.to_string(), config.font.clone(), &cairo_ctx);
+                self.tags_btns.push(x_offset, tag.width, id);
+                x_offset += tag.width;
+                self.tags_computed.push(tag);
+            }
+        }
+
+        // Display tags
+        let mut offset_left = 0.0;
+        let tags_info = self.tags_info.borrow();
+        for (i, label) in self.tags_computed.iter().enumerate() {
+            let (bg, fg) = match tags_info.get_state(i) {
+                TagState::Focused => (config.tag_focused_bg, config.tag_focused_fg),
+                TagState::Inactive => (config.tag_bg, config.tag_fg),
+                TagState::Urgent => (config.tag_urgent_bg, config.tag_urgent_fg),
+            };
+            label.render(
+                &cairo_ctx,
+                RenderOptions {
+                    x_offset: offset_left,
+                    bar_height: height_f,
+                    fg_color: fg,
+                    bg_color: Some(bg),
+                },
+            );
+            offset_left += label.width;
+        }
+
+        // Display the blocks
+        render_blocks(
+            &cairo_ctx,
+            &*config,
+            blocks,
+            &mut self.blocks_btns,
+            offset_left,
+            width_f,
+            height_f,
+        );
+
+        // Attach the buffer to the surface and mark the entire surface as damaged
+        self.surface.attach(Some(&buffer), 0, 0);
+        self.surface
+            .damage_buffer(0, 0, width as i32, height as i32);
+
+        // Finally, commit the surface
+        self.surface.commit();
+    }
+}
+
+impl Drop for Surface {
+    fn drop(&mut self) {
+        self.layer_surface.destroy();
+        self.surface.destroy();
+        self.river_output_status.destroy();
+    }
+}
+
+fn render_blocks(
+    context: &cairo::Context,
+    config: &Config,
+    blocks: &[Block],
+    buttons: &mut ButtonManager<(Option<String>, Option<String>)>,
+    offset_left: f64,
+    full_width: f64,
+    full_height: f64,
+) {
+    let mut blocks_computed = Vec::with_capacity(blocks.len());
+    let mut blocks_width = 0.0;
+    let mut deltas = HashMap::<&str, f64>::new();
+    for (i, block) in blocks.iter().enumerate() {
+        let markup = block.markup.as_deref() == Some("pango");
+        let min_width = match &block.min_width {
+            Some(MinWidth::Pixels(p)) => Some(*p as f64),
+            Some(MinWidth::Text(t)) => Some(text::width_of(t, context, markup, &config.font.0)),
+            None => None,
+        };
+        let full_text = text::Text {
+            text: block.full_text.clone(),
+            attr: text::Attributes {
+                font: config.font.clone(),
+                padding_left: 0.0,
+                padding_right: 0.0,
+                min_width,
+                align: block.align.unwrap_or_default(),
+                markup,
+            },
+        }
+        .compute(context);
+        let short_text = block.short_text.clone().map(|short_text| {
+            text::Text {
+                text: short_text,
+                attr: text::Attributes {
+                    font: config.font.clone(),
+                    padding_left: 0.0,
+                    padding_right: 0.0,
+                    min_width,
+                    align: block.align.unwrap_or_default(),
+                    markup,
+                },
+            }
+            .compute(context)
+        });
+        blocks_width += full_text.width;
+        if i + 1 != blocks.len() {
+            blocks_width += block.separator_block_width as f64;
+        }
+        if let Some(short) = &short_text {
+            if let Some(name) = &block.name {
+                *deltas.entry(name).or_insert(0.0) += full_text.width - short.width;
+            }
+        }
+        blocks_computed.push((block.name.as_deref(), full_text, short_text));
+    }
+
+    // Progressively switch to short mode
+    if offset_left + blocks_width > full_width {
+        let mut heap = BinaryHeap::new();
+        for (name, delta) in deltas {
+            if delta > 0.0 {
+                heap.push((DefaultLess(delta), name));
+            }
+        }
+        while let Some((DefaultLess(delta), to_switch)) = heap.pop() {
+            for (name, full, short) in &mut blocks_computed {
+                if *name == Some(to_switch) {
+                    if let Some(short) = short {
+                        std::mem::swap(full, short);
+                    }
+                }
+            }
+            blocks_width -= delta;
+            if offset_left + blocks_width <= full_width {
+                break;
+            }
+        }
+    }
+
+    buttons.clear();
+    for (i, (block, computed)) in blocks
+        .iter()
+        .zip(blocks_computed.iter().map(|(_, full, _)| full))
+        .enumerate()
+    {
+        computed.render(
+            context,
+            RenderOptions {
+                x_offset: full_width - blocks_width,
+                bar_height: full_height,
+                fg_color: block.color.unwrap_or(config.color),
+                bg_color: block.background,
+            },
+        );
+        buttons.push(
+            full_width - blocks_width,
+            computed.width,
+            (block.name.clone(), block.instance.clone()),
+        );
+        blocks_width -= computed.width;
+        if i + 1 != blocks.len() && block.separator_block_width > 0 {
+            let w = block.separator_block_width as f64;
+            if block.separator {
+                config.separator.apply(context);
+                context.set_line_width(2.0);
+                context.move_to(full_width - blocks_width + w * 0.5, full_height * 0.1);
+                context.line_to(full_width - blocks_width + w * 0.5, full_height * 0.9);
+                context.stroke().unwrap();
+            }
+            blocks_width -= w;
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 48542d9..09795d0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,7 @@
 #[macro_use]
 extern crate log;
+#[macro_use]
+extern crate anyhow;
 
 use smithay_client_toolkit::{
     self as sctk, default_environment,
@@ -8,22 +10,16 @@ use smithay_client_toolkit::{
     output::{with_output_info, OutputInfo},
     reexports::{
         calloop,
-        client::protocol::{wl_output, wl_pointer, wl_seat, wl_shm, wl_surface},
-        client::{Attached, Main},
-        protocols::wlr::unstable::layer_shell::v1::client::{
-            zwlr_layer_shell_v1, zwlr_layer_surface_v1,
-        },
+        client::protocol::{wl_output, wl_pointer},
+        protocols::wlr::unstable::layer_shell::v1::client::zwlr_layer_shell_v1,
     },
-    shm::AutoMemPool,
     WaylandSource,
 };
 
-use pangocairo::cairo;
-
-use std::cell::{Cell, RefCell};
-use std::collections::{BinaryHeap, HashMap};
+use std::cell::RefCell;
 use std::rc::Rc;
 
+mod bar_state;
 mod button_manager;
 mod color;
 mod config;
@@ -36,18 +32,10 @@ mod tags;
 mod text;
 mod utils;
 
-use button_manager::ButtonManager;
-use config::Config;
-use i3bar_protocol::{Block, MinWidth};
-use ord_adaptor::DefaultLess;
+use bar_state::BarState;
 use pointer_btn::PointerBtn;
-use river_protocols::zriver_command_callback_v1;
 use river_protocols::zriver_control_v1;
-use river_protocols::zriver_output_status_v1;
 use river_protocols::zriver_status_manager_v1;
-use status_cmd::StatusCmd;
-use tags::{compute_tag_label, TagState, TagsInfo};
-use text::{ComputedText, RenderOptions};
 
 default_environment!(Env,
     fields = [
@@ -75,29 +63,18 @@ fn main() {
     )
     .expect("Initial roundtrip failed!");
 
-    let config = Rc::new(RefCell::new(Config::new().unwrap()));
-    let surfaces = Rc::new(RefCell::new(Vec::<Surface>::new()));
-    let blocks = Rc::new(RefCell::new(Vec::<Block>::new()));
-
-    let cmd = config.borrow_mut().command.take().unwrap();
-    let status_cmd = StatusCmd::new(&cmd, Rc::clone(&blocks), Rc::clone(&surfaces))
-        .expect("failed run status command");
+    let bar_state = Rc::new(RefCell::new(BarState::new()));
 
     let layer_shell = env.require_global::<zwlr_layer_shell_v1::ZwlrLayerShellV1>();
     let river_status = env.require_global::<zriver_status_manager_v1::ZriverStatusManagerV1>();
     let river_control = env.require_global::<zriver_control_v1::ZriverControlV1>();
 
     let env_handle = env.clone();
-    let surfaces_handle = Rc::clone(&surfaces);
-    let config_handle = Rc::clone(&config);
-    let blocks_handle = Rc::clone(&blocks);
-    let status_cmd_handle = status_cmd.clone();
+    let bar_state_handle = Rc::clone(&bar_state);
     let output_handler = move |output: wl_output::WlOutput, info: &OutputInfo| {
         if info.obsolete {
             info!("Output removed");
-            surfaces_handle
-                .borrow_mut()
-                .retain(|s| s.output_id != info.id);
+            bar_state_handle.borrow_mut().remove_surface(info.id);
             output.release();
         } else {
             info!("Output detected");
@@ -105,7 +82,7 @@ fn main() {
             let pool = env_handle
                 .create_auto_pool()
                 .expect("Failed to create a memory pool!");
-            (*surfaces_handle.borrow_mut()).push(Surface::new(
+            bar_state_handle.borrow_mut().add_surface(
                 &output,
                 info.id,
                 surface,
@@ -113,10 +90,7 @@ fn main() {
                 &river_status,
                 river_control.clone(),
                 pool,
-                config_handle.clone(),
-                blocks_handle.clone(),
-                status_cmd_handle.clone(),
-            ));
+            );
         }
     };
 
@@ -133,97 +107,73 @@ fn main() {
         env.listen_for_outputs(move |output, info, _| output_handler(output, info));
 
     // Right now river only supports one seat: default
-    let pointer_output_id = Rc::new(Cell::new(None));
     for seat in env.get_all_seats() {
         sctk::seat::with_seat_data(&seat, |seat_data| {
             if seat_data.has_pointer && !seat_data.defunct && seat_data.name == "default" {
                 let pointer = seat.get_pointer();
-                let surfaces_handle = Rc::clone(&surfaces);
-                let pointer_output_id_handle = Rc::clone(&pointer_output_id);
+                let bar_state_handle = bar_state.clone();
                 let seat = seat.clone();
-                pointer.quick_assign(move |_, event, _| {
-                    info!("pointer event");
-                    match event {
-                        wl_pointer::Event::Enter {
-                            serial: _,
-                            surface,
-                            surface_x: y,
-                            surface_y: x,
-                        } => {
-                            if let Some(surf) = surfaces_handle
-                                .borrow_mut()
-                                .iter_mut()
-                                .find(|s| s.surface == surface)
-                            {
-                                surf.pointer = Some((x, y));
-                                pointer_output_id_handle.set(Some(surf.output_id));
-                            }
-                        }
-                        wl_pointer::Event::Leave { serial: _, surface } => {
-                            if let Some(surf) = surfaces_handle
-                                .borrow_mut()
-                                .iter_mut()
-                                .find(|s| s.surface == surface)
-                            {
-                                surf.pointer = None;
-                                pointer_output_id_handle.set(None);
-                            }
-                        }
-                        wl_pointer::Event::Motion {
-                            time: _,
-                            surface_x: x,
-                            surface_y: y,
-                        } => {
-                            if let Some(output_id) = pointer_output_id_handle.get() {
-                                if let Some(surf) = surfaces_handle
-                                    .borrow_mut()
-                                    .iter_mut()
-                                    .find(|s| s.output_id == output_id)
-                                {
-                                    surf.pointer = Some((x, y));
-                                }
-                            }
-                        }
-                        wl_pointer::Event::Button {
-                            serial: _,
-                            time: _,
-                            button,
-                            state,
-                        } if state == wl_pointer::ButtonState::Pressed => {
-                            if let Some(output_id) = pointer_output_id_handle.get() {
-                                if let Some(surf) = surfaces_handle
-                                    .borrow_mut()
-                                    .iter_mut()
-                                    .find(|s| s.output_id == output_id)
-                                {
-                                    surf.click(button.into(), &seat);
-                                }
-                            }
+                let mut pos = (0.0, 0.0);
+                let mut cur_surface = None;
+                pointer.quick_assign(move |_, event, _| match event {
+                    wl_pointer::Event::Enter {
+                        serial: _,
+                        surface,
+                        surface_x: y,
+                        surface_y: x,
+                    } => {
+                        cur_surface = Some(surface);
+                        pos = (x, y);
+                    }
+                    wl_pointer::Event::Leave {
+                        serial: _,
+                        surface: _,
+                    } => {
+                        cur_surface = None;
+                    }
+                    wl_pointer::Event::Motion {
+                        time: _,
+                        surface_x: x,
+                        surface_y: y,
+                    } => {
+                        pos = (x, y);
+                    }
+                    wl_pointer::Event::Button {
+                        serial: _,
+                        time: _,
+                        button,
+                        state,
+                    } if state == wl_pointer::ButtonState::Pressed => {
+                        if let Some(cur_surface) = &cur_surface {
+                            bar_state_handle.borrow_mut().handle_click(
+                                cur_surface,
+                                &seat,
+                                pos.0,
+                                pos.1,
+                                button.into(),
+                            );
                         }
-                        wl_pointer::Event::Axis {
-                            time: _,
-                            axis,
-                            value,
-                        } if axis == wl_pointer::Axis::VerticalScroll => {
-                            if let Some(output_id) = pointer_output_id_handle.get() {
-                                if let Some(surf) = surfaces_handle
-                                    .borrow_mut()
-                                    .iter_mut()
-                                    .find(|s| s.output_id == output_id)
-                                {
-                                    surf.click(
-                                        if value > 0.0 {
-                                            PointerBtn::WheelDown
-                                        } else {
-                                            PointerBtn::WheelUp
-                                        },
-                                        &seat,
-                                    );
-                                }
-                            }
+                    }
+                    wl_pointer::Event::Axis {
+                        time: _,
+                        axis,
+                        value,
+                    } if axis == wl_pointer::Axis::VerticalScroll => {
+                        if let Some(cur_surface) = &cur_surface {
+                            bar_state_handle.borrow_mut().handle_click(
+                                cur_surface,
+                                &seat,
+                                pos.0,
+                                pos.1,
+                                if value > 0.0 {
+                                    PointerBtn::WheelDown
+                                } else {
+                                    PointerBtn::WheelUp
+                                },
+                            );
                         }
-                        _ => (),
                     }
+                    _ => (),
                 });
             }
         });
@@ -235,452 +185,20 @@ fn main() {
         .quick_insert(event_loop.handle())
         .unwrap();
 
-    // Run command
-    let blocks_handle = Rc::clone(&blocks);
-    let surfaces_handle = Rc::clone(&surfaces);
-    event_loop
-        .handle()
-        .insert_source(
-            calloop::generic::Generic::new(
-                status_cmd,
-                calloop::Interest {
-                    readable: true,
-                    writable: false,
-                },
-                calloop::Mode::Level,
-            ),
-            move |ready, cmd, _| {
-                info!("status command update");
-                if ready.readable {
-                    cmd.notify_available()?;
-                    Ok(calloop::PostAction::Continue)
-                } else {
-                    *blocks_handle.borrow_mut() = vec![Block {
-                        full_text: "[error reading from status command]".into(),
-                        ..Default::default()
-                    }];
-                    for s in &mut *surfaces_handle.borrow_mut() {
-                        s.blocks_need_update = true;
-                    }
-                    Ok(calloop::PostAction::Remove)
-                }
-            },
-        )
-        .expect("failed to inser calloop source");
+    if let Some(cmd) = &bar_state.borrow().status_cmd {
+        let bar_state_handle = Rc::clone(&bar_state);
+        cmd.quick_insert(event_loop.handle(), bar_state_handle);
+    }
 
     loop {
-        // This is ugly, let's hope that some version of drain_filter() gets stabilized soon
-        // https://github.com/rust-lang/rust/issues/43244
         {
-            let mut surfaces = surfaces.borrow_mut();
-            let mut i = 0;
-            while i != surfaces.len() {
-                if surfaces[i].handle_events() {
-                    surfaces.remove(i);
-                } else {
-                    i += 1;
-                }
-            }
+            // Using a new scope in order to be sure that `bar_state` will not be borrowed while
+            // dispatching the events
+            bar_state.borrow_mut().handle_events();
         }
-
         display.flush().unwrap();
-        event_loop.dispatch(None, &mut ()).unwrap();
-    }
-}
-
-#[derive(PartialEq, Copy, Clone)]
-enum RenderEvent {
-    Configure { width: u32, height: u32 },
-    TagsUpdated,
-    Closed,
-}
-
-pub struct Surface {
-    output_id: u32,
-    surface: wl_surface::WlSurface,
-    layer_surface: Main<zwlr_layer_surface_v1::ZwlrLayerSurfaceV1>,
-    next_render_event: Rc<Cell<Option<RenderEvent>>>,
-    pool: AutoMemPool,
-    dimensions: (u32, u32),
-    config: Rc<RefCell<Config>>,
-    // river stuff
-    river_output_status: Main<zriver_output_status_v1::ZriverOutputStatusV1>,
-    river_control: Attached<zriver_control_v1::ZriverControlV1>,
-    // blocks
-    blocks: Rc<RefCell<Vec<Block>>>,
-    blocks_need_update: bool,
-    status_cmd: StatusCmd,
-    // tags
-    tags_info: Rc<RefCell<TagsInfo>>,
-    tags_computed: Vec<ComputedText>,
-    // Clicking stuff
-    pointer: Option<(f64, f64)>,
-    tags_btns: ButtonManager,
-    blocks_btns: ButtonManager<(Option<String>, Option<String>)>,
-}
-
-impl Surface {
-    #[allow(clippy::too_many_arguments)]
-    fn new(
-        output: &wl_output::WlOutput,
-        output_id: u32,
-        surface: wl_surface::WlSurface,
-        layer_shell: &Attached<zwlr_layer_shell_v1::ZwlrLayerShellV1>,
-        river_status: &Attached<zriver_status_manager_v1::ZriverStatusManagerV1>,
-        river_control: Attached<zriver_control_v1::ZriverControlV1>,
-        pool: AutoMemPool,
-        config: Rc<RefCell<Config>>,
-        blocks: Rc<RefCell<Vec<Block>>>,
-        status_cmd: StatusCmd,
-    ) -> Self {
-        let layer_surface = layer_shell.get_layer_surface(
-            &surface,
-            Some(output),
-            zwlr_layer_shell_v1::Layer::Top,
-            "i3bar-river".to_owned(),
-        );
-
-        // Set the height
-        layer_surface.set_size(0, config.borrow().height);
-        // Anchor to the top
-        layer_surface.set_anchor(
-            zwlr_layer_surface_v1::Anchor::Top
-                | zwlr_layer_surface_v1::Anchor::Left
-                | zwlr_layer_surface_v1::Anchor::Right,
-        );
-
-        let next_render_event = Rc::new(Cell::new(None));
-        let next_render_event_handle = Rc::clone(&next_render_event);
-        layer_surface.quick_assign(move |layer_surface, event, _| {
-            info!("layer_surface event");
-            match (event, next_render_event_handle.get()) {
-                (zwlr_layer_surface_v1::Event::Closed, _) => {
-                    next_render_event_handle.set(Some(RenderEvent::Closed));
-                }
-                (
-                    zwlr_layer_surface_v1::Event::Configure {
-                        serial,
-                        width,
-                        height,
-                    },
-                    next,
-                ) if next != Some(RenderEvent::Closed) => {
-                    layer_surface.ack_configure(serial);
-                    next_render_event_handle.set(Some(RenderEvent::Configure { width, height }));
-                }
-                (_, _) => (),
-            }
-        });
-
-        // Commit so that the server will send a configure event
-        surface.commit();
-
-        let river_output_status = river_status.get_river_output_status(output);
-        let tags_info = Rc::new(RefCell::new(TagsInfo::default()));
-        let tags_info_handle = Rc::clone(&tags_info);
-        let next_render_event_handle = Rc::clone(&next_render_event);
-        river_output_status.quick_assign(move |_, event, _| {
-            match event {
-                zriver_output_status_v1::Event::FocusedTags { tags } => {
-                    info!("Focused tags updated: {tags}");
-                    tags_info_handle.borrow_mut().focused = tags;
-                }
-                zriver_output_status_v1::Event::UrgentTags { tags } => {
-                    info!("Urgent tags updated: {tags}");
-                    tags_info_handle.borrow_mut().urgent = tags;
-                }
-                _ => (),
-            }
-            if next_render_event_handle.get().is_none() {
-                next_render_event_handle.set(Some(RenderEvent::TagsUpdated));
-            }
-        });
-
-        Self {
-            output_id,
-            surface,
-            layer_surface,
-            next_render_event,
-            pool,
-            dimensions: (0, 0),
-            config,
-            river_output_status,
-            river_control,
-            blocks,
-            blocks_need_update: false,
-            status_cmd,
-            tags_info,
-            tags_computed: Vec::with_capacity(9),
-            pointer: None,
-            tags_btns: Default::default(),
-            blocks_btns: Default::default(),
-        }
-    }
-
-    /// Handles any events that have occurred since the last call, redrawing if needed.
-    /// Returns true if the surface should be dropped.
-    fn handle_events(&mut self) -> bool {
-        match self.next_render_event.take() {
-            Some(RenderEvent::Closed) => return true,
-            Some(RenderEvent::Configure { width, height }) => {
-                if self.dimensions != (width, height) {
-                    self.dimensions = (width, height);
-                    self.layer_surface.set_exclusive_zone(height as _);
-                    self.draw();
-                    return false;
-                }
-            }
-            Some(RenderEvent::TagsUpdated) => {
-                self.draw();
-                return false;
-            }
-            _ => (),
-        }
-        if self.blocks_need_update {
-            self.draw();
-            return false;
-        }
-        false
-    }
-
-    fn click(&mut self, button: PointerBtn, seat: &wl_seat::WlSeat) {
-        if let Some((x, _)) = self.pointer {
-            if let Some(id) = self.tags_btns.click(x) {
-                let cmd = match button {
-                    PointerBtn::Left => "set-focused-tags",
-                    PointerBtn::Right => "toggle-focused-tags",
-                    _ => return,
-                };
-                self.river_control.add_argument(cmd.into());
-                self.river_control.add_argument((1 << id).to_string());
-                let result = self.river_control.run_command(seat);
-                result.quick_assign(|_, event, _| match event {
-                    zriver_command_callback_v1::Event::Success { output } => {
-                        info!("River cmd output: '{output}'");
-                    }
-                    zriver_command_callback_v1::Event::Failure { failure_message: f } => {
-                        error!("River error: '{f}'");
-                    }
-                });
-            } else if let Some((name, instance)) = self.blocks_btns.click(x) {
-                let _ =
-                    self.status_cmd
-                        .send_click_event(button, name.as_deref(), instance.as_deref());
-            }
-        }
-    }
-
-    fn draw(&mut self) {
-        let config = self.config.borrow();
-
-        let stride = 4 * self.dimensions.0 as i32;
-        let width = self.dimensions.0 as i32;
-        let height = self.dimensions.1 as i32;
-        let width_f = width as f64;
-        let height_f = height as f64;
-
-        let (canvas, buffer) = self
-            .pool
-            .buffer(width, height, stride, wl_shm::Format::Argb8888)
-            .unwrap();
-
-        let cairo_surf = unsafe {
-            cairo::ImageSurface::create_for_data_unsafe(
-                canvas.as_mut_ptr(),
-                cairo::Format::ARgb32,
-                width,
-                height,
-                stride,
-            )
-            .expect("cairo surface")
-        };
-
-        let cairo_ctx = cairo::Context::new(&cairo_surf).expect("cairo context");
-        let pango_layout = pangocairo::create_layout(&cairo_ctx).expect("pango layout");
-        pango_layout.set_font_description(Some(&config.font));
-        pango_layout.set_height(height);
-
-        // Background
-        config.background.apply(&cairo_ctx);
-        cairo_ctx.paint().expect("cairo paint");
-
-        // Compute tags
-        if self.tags_computed.is_empty() {
-            let mut x_offset = 0.0;
-            //  TODO make configurable
-            for (id, text) in ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
-                .iter()
-                .enumerate()
-            {
-                let tag = compute_tag_label(text.to_string(), config.font.clone(), &cairo_ctx);
-                self.tags_btns.push(x_offset, tag.width, id);
-                x_offset += tag.width;
-                self.tags_computed.push(tag);
-            }
-        }
-
-        // Display tags
-        let mut offset_left = 0.0;
-        let tags_info = self.tags_info.borrow();
-        for (i, label) in self.tags_computed.iter().enumerate() {
-            let (bg, fg) = match tags_info.get_state(i) {
-                TagState::Focused => (config.tag_focused_bg, config.tag_focused_fg),
-                TagState::Inactive => (config.tag_bg, config.tag_fg),
-                TagState::Urgent => (config.tag_urgent_bg, config.tag_urgent_fg),
-            };
-            label.render(
-                &cairo_ctx,
-                RenderOptions {
-                    x_offset: offset_left,
-                    bar_height: height_f,
-                    fg_color: fg,
-                    bg_color: Some(bg),
-                },
-            );
-            offset_left += label.width;
-        }
-
-        // Display the blocks
-        render_blocks(
-            &cairo_ctx,
-            &*config,
-            &*self.blocks.borrow(),
-            &mut self.blocks_btns,
-            offset_left,
-            width_f,
-            height_f,
-        );
-        self.blocks_need_update = false;
-
-        // Attach the buffer to the surface and mark the entire surface as damaged
-        self.surface.attach(Some(&buffer), 0, 0);
-        self.surface
-            .damage_buffer(0, 0, width as i32, height as i32);
-
-        // Finally, commit the surface
-        self.surface.commit();
-    }
-}
-
-impl Drop for Surface {
-    fn drop(&mut self) {
-        self.layer_surface.destroy();
-        self.surface.destroy();
-        self.river_output_status.destroy();
-    }
-}
-
-fn render_blocks(
-    context: &cairo::Context,
-    config: &Config,
-    blocks: &[Block],
-    buttons: &mut ButtonManager<(Option<String>, Option<String>)>,
-    offset_left: f64,
-    full_width: f64,
-    full_height: f64,
-) {
-    let mut blocks_computed = Vec::with_capacity(blocks.len());
-    let mut blocks_width = 0.0;
-    let mut deltas = HashMap::<&str, f64>::new();
-    for (i, block) in blocks.iter().enumerate() {
-        let markup = block.markup.as_deref() == Some("pango");
-        let min_width = match &block.min_width {
-            Some(MinWidth::Pixels(p)) => Some(*p as f64),
-            Some(MinWidth::Text(t)) => Some(text::width_of(t, context, markup, &config.font.0)),
-            None => None,
-        };
-        let full_text = text::Text {
-            text: block.full_text.clone(),
-            attr: text::Attributes {
-                font: config.font.clone(),
-                padding_left: 0.0,
-                padding_right: 0.0,
-                min_width,
-                align: block.align.unwrap_or_default(),
-                markup,
-            },
-        }
-        .compute(context);
-        let short_text = block.short_text.clone().map(|short_text| {
-            text::Text {
-                text: short_text,
-                attr: text::Attributes {
-                    font: config.font.clone(),
-                    padding_left: 0.0,
-                    padding_right: 0.0,
-                    min_width,
-                    align: block.align.unwrap_or_default(),
-                    markup,
-                },
-            }
-            .compute(context)
-        });
-        blocks_width += full_text.width;
-        if i + 1 != blocks.len() {
-            blocks_width += block.separator_block_width as f64;
-        }
-        if let Some(short) = &short_text {
-            if let Some(name) = &block.name {
-                *deltas.entry(name).or_insert(0.0) += full_text.width - short.width;
-            }
-        }
-        blocks_computed.push((block.name.as_deref(), full_text, short_text));
-    }
-
-    // Progressively switch to short mode
-    if offset_left + blocks_width > full_width {
-        let mut heap = BinaryHeap::new();
-        for (name, delta) in deltas {
-            if delta > 0.0 {
-                heap.push((DefaultLess(delta), name));
-            }
-        }
-        while let Some((DefaultLess(delta), to_switch)) = heap.pop() {
-            for (name, full, short) in &mut blocks_computed {
-                if *name == Some(to_switch) {
-                    if let Some(short) = short {
-                        std::mem::swap(full, short);
-                    }
-                }
-            }
-            blocks_width -= delta;
-            if offset_left + blocks_width <= full_width {
-                break;
-            }
-        }
-    }
-
-    buttons.clear();
-    for (i, (block, computed)) in blocks
-        .iter()
-        .zip(blocks_computed.iter().map(|(_, full, _)| full))
-        .enumerate()
-    {
-        computed.render(
-            context,
-            RenderOptions {
-                x_offset: full_width - blocks_width,
-                bar_height: full_height,
-                fg_color: block.color.unwrap_or(config.color),
-                bg_color: block.background,
-            },
-        );
-        buttons.push(
-            full_width - blocks_width,
-            computed.width,
-            (block.name.clone(), block.instance.clone()),
-        );
-        blocks_width -= computed.width;
-        if i + 1 != blocks.len() && block.separator_block_width > 0 {
-            let w = block.separator_block_width as f64;
-            if block.separator {
-                config.separator.apply(context);
-                context.set_line_width(2.0);
-                context.move_to(full_width - blocks_width + w * 0.5, full_height * 0.1);
-                context.line_to(full_width - blocks_width + w * 0.5, full_height * 0.9);
-                context.stroke().unwrap();
-            }
-            blocks_width -= w;
+        if let Err(e) = event_loop.dispatch(None, &mut ()) {
+            bar_state.borrow_mut().set_error(e.to_string());
         }
     }
 }
diff --git a/src/status_cmd.rs b/src/status_cmd.rs
index e77e4b2..9824be4 100644
--- a/src/status_cmd.rs
+++ b/src/status_cmd.rs
@@ -1,97 +1,78 @@
-use crate::Surface;
 use std::cell::RefCell;
-use std::io::Result;
-use std::io::{BufRead, BufReader, Write};
-use std::os::unix::prelude::{AsRawFd, RawFd};
-use std::process::{ChildStdin, ChildStdout, Command, Stdio};
+use std::io::{BufRead, BufReader, Result, Write};
+use std::os::unix::prelude::AsRawFd;
+use std::process::{Child, ChildStdin, ChildStdout, Command, Stdio};
 use std::rc::Rc;
 
+use smithay_client_toolkit::reexports::calloop::{self, LoopHandle};
+
 use crate::i3bar_protocol::{Block, Event, Protocol};
-use crate::pointer_btn::PointerBtn;
+use crate::BarState;
 
-#[derive(Clone)]
 pub struct StatusCmd {
-    inner: Rc<RefCell<Inner>>,
-}
-
-struct Inner {
+    child: Child,
     output: BufReader<ChildStdout>,
     input: ChildStdin,
     protocol: Protocol,
-    blocks: Rc<RefCell<Vec<Block>>>,
-    surfaces: Rc<RefCell<Vec<Surface>>>,
-}
-
-impl AsRawFd for StatusCmd {
-    fn as_raw_fd(&self) -> RawFd {
-        self.inner.borrow().output.get_ref().as_raw_fd()
-    }
-}
-
-impl Inner {
-    pub fn notify_available(&mut self) -> Result<()> {
-        let buf = self.output.fill_buf()?;
-        self.protocol.process_new_bytes(buf)?;
-        let consumed = buf.len();
-        self.output.consume(consumed);
-        if let Some(new_blocks) = self.protocol.get_blocks() {
-            *self.blocks.borrow_mut() = new_blocks;
-            for s in &mut *self.surfaces.borrow_mut() {
-                s.blocks_need_update = true;
-            }
-        }
-        Ok(())
-    }
 }
 
 impl StatusCmd {
-    pub fn new(
-        cmd: &str,
-        blocks: Rc<RefCell<Vec<Block>>>,
-        surfaces: Rc<RefCell<Vec<Surface>>>,
-    ) -> Result<Self> {
+    pub fn new(cmd: &str) -> Result<Self> {
         let mut child = Command::new("sh")
             .args(["-c", &format!("exec {cmd}")])
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .spawn()?;
-        let output = BufReader::new(child.stdout.take().unwrap());
+        let output = child.stdout.take().unwrap();
         let input = child.stdin.take().unwrap();
         Ok(Self {
-            inner: Rc::new(RefCell::new(Inner {
-                output,
-                input,
-                protocol: Protocol::Unknown,
-                blocks,
-                surfaces,
-            })),
+            child,
+            output: BufReader::new(output),
+            input,
+            protocol: Protocol::Unknown,
         })
     }
 
-    pub fn notify_available(&mut self) -> Result<()> {
-        self.inner.borrow_mut().notify_available()
+    pub fn notify_available(&mut self) -> Result<Option<Vec<Block>>> {
+        let buf = self.output.fill_buf()?;
+        self.protocol.process_new_bytes(buf)?;
+        let consumed = buf.len();
+        self.output.consume(consumed);
+        Ok(self.protocol.get_blocks())
     }
 
-    pub fn send_click_event(
-        &mut self,
-        button: PointerBtn,
-        name: Option<&str>,
-        instance: Option<&str>,
-    ) -> Result<()> {
-        let mut inner = self.inner.borrow_mut();
-        if inner.protocol.supports_clicks() {
-            writeln!(
-                inner.input,
-                "{}",
-                serde_json::to_string(&Event {
-                    name,
-                    instance,
-                    button,
-                    ..Default::default()
-                })
-                .unwrap()
-            )?;
+    pub fn send_click_event(&mut self, event: &Event) -> Result<()> {
+        if self.protocol.supports_clicks() {
+            writeln!(self.input, "{}", serde_json::to_string(event).unwrap(),)?;
         }
         Ok(())
     }
+
+    pub fn quick_insert(&self, handle: LoopHandle<()>, bar_state: Rc<RefCell<BarState>>) {
+        handle
+            .insert_source(
+                calloop::generic::Generic::new(
+                    self.output.get_ref().as_raw_fd(),
+                    calloop::Interest {
+                        readable: true,
+                        writable: false,
+                    },
+                    calloop::Mode::Level,
+                ),
+                move |ready, _, _| {
+                    if ready.readable {
+                        bar_state.borrow_mut().notify_available()?;
+                        Ok(calloop::PostAction::Continue)
+                    } else {
+                        let mut bar_state = bar_state.borrow_mut();
+                        bar_state.set_error("error reading from status command");
+                        if let Some(mut child) = bar_state.status_cmd.take() {
+                            let _ = child.child.kill();
+                        }
+                        Ok(calloop::PostAction::Remove)
+                    }
+                },
+            )
+            .expect("failed to inser calloop source");
+    }
 }