Draw a cursor, handle the lid, and everything a real config needs

Groundwork for actually daily-driving this: porting the user's Hyprland
config exposed what srdwm couldn't yet express, and testing on a bare TTY
exposed something worse.

A visible mouse cursor. Nothing drew a pointer at all - on a bare TTY the
mouse was simply invisible. It hid because the nested backend runs inside
another compositor, which draws a cursor over srdwm's window; only the DRM
backend, i.e. the actual session path, was affected. A built-in arrow is now
composited above everything on the output the pointer is on. It's a
reviewable ASCII bitmap rather than an XCursor theme: a cursor that is always
present beats a prettier one that sometimes isn't, the same reasoning as
decoration.rs's font fallback. Client-set cursor surfaces and named shapes
are still not rendered, so an app asking for an I-beam gets the arrow.

Lid switch. libinput switch events are handled and surfaced to config as
srd.on("lid_closed"/"lid_open", fn), so closing the lid can lock and suspend
instead of doing nothing.

Config-driven additions, each needed by a binding in the ported config and
none of which existed: fullscreen (Window.fullscreen was a dead field --
declared, never read or written), directional window move that swaps with
the neighbour and reorders the stack so tiling follows, focus cycling,
modifier+drag to move/resize anywhere in a window rather than only by the
titlebar, modifier+scroll to change workspace, and 8 XF86 media/power
keysyms taken from the system's own XF86keysym.h. The keysym tables are
hand-maintained in both directions and a key missing from either fails
silently, so a round-trip test now covers every one the configs bind.

Verified in the QEMU VM: a bare-TTY screendump shows a recognisable arrow at
the pointer position (113 white fill + 58 black outline pixels at screen
centre, where the pointer starts).

1 files changed, 67 insertions, 0 deletions

diff --git a/crates/wayland/src/input.rs b/crates/wayland/src/input.rs
index 76607ee..6959c8f 100644
--- a/crates/wayland/src/input.rs
+++ b/crates/wayland/src/input.rs
@@ -20,6 +20,11 @@ use smithay::wayland::shell::wlr_layer::{KeyboardInteractivity, Layer};
 
 use srdwm_core::{Event as CoreEvent, Modifiers, TitlebarHit, WindowId};
 
+/// Modifier that turns a drag anywhere in a window into move/resize.
+/// Matches the `SUPER` the shipped and ported configs use for
+/// `bindm ... movewindow` / `resizewindow`.
+const DRAG_MODIFIER: Modifiers = Modifiers::SUPER;
+
 use crate::state::CompState;
 
 pub(crate) fn last_pointer_pos(state: &CompState) -> Point<f64, Logical> {
@@ -134,6 +139,7 @@ pub(crate) fn focus_window(state: &mut CompState, id: WindowId) {
 
 pub(crate) fn handle_pointer_button(state: &mut CompState, pos: Point<f64, Logical>, button: u32, pressed: bool, time: u32) {
     const BTN_LEFT: u32 = 0x110;
+    const BTN_RIGHT: u32 = 0x111;
     let serial = SERIAL_COUNTER.next_serial();
 
     // Locked: forward the click to the lock surface (it may have a button or
@@ -146,6 +152,33 @@ pub(crate) fn handle_pointer_button(state: &mut CompState, pos: Point<f64, Logic
         return;
     }
 
+    // Modifier+drag: with the modifier held, dragging *anywhere* in a window
+    // moves it (left button) or resizes it from the nearest corner (right
+    // button) - the `bindm SUPER, mouse:272/273` gesture. Without this a
+    // window can only be moved by its titlebar, which is useless for
+    // windows that have none (fullscreen, CSD apps, layer surfaces).
+    //
+    // Checked before the titlebar hit-test so the modifier wins over the
+    // decoration: holding the modifier and grabbing the titlebar should
+    // still move, not press a titlebar button.
+    if pressed && (button == BTN_LEFT || button == BTN_RIGHT) {
+        let mods = state.seat.get_keyboard().map(|k| core_modifiers_from_xkb(&k.modifier_state()));
+        if mods.is_some_and(|m| m.contains(DRAG_MODIFIER)) {
+            let target = state.wm.borrow().window_at(pos.x as i32, pos.y as i32);
+            if let Some(id) = target {
+                focus_window(state, id);
+                let mut wm = state.wm.borrow_mut();
+                if button == BTN_LEFT {
+                    wm.start_drag(id, pos.x as i32, pos.y as i32);
+                } else {
+                    let edge = wm.nearest_corner(id, pos.x as i32, pos.y as i32);
+                    wm.start_resize(id, edge, pos.x as i32, pos.y as i32);
+                }
+                return;
+            }
+        }
+    }
+
     if pressed && button == BTN_LEFT {
         let layer_hit = layer_surface_under(state, pos);
         if let Some((surface, _)) = &layer_hit {
@@ -275,3 +308,37 @@ pub(crate) fn core_modifiers_from_xkb(mods: &smithay::input::keyboard::Modifiers
     }
     m
 }
+
+/// Modifier+scroll cycles workspaces, consuming the event.
+///
+/// Returns `true` if it handled the scroll, in which case the caller must
+/// *not* also forward it to the client. Generic over the input backend for
+/// the same reason the keyboard handler is: both backends deliver scroll
+/// through smithay's `PointerAxisEvent` trait.
+pub(crate) fn handle_workspace_scroll<B, E>(state: &mut CompState, event: &E) -> bool
+where
+    B: smithay::backend::input::InputBackend,
+    E: smithay::backend::input::PointerAxisEvent<B>,
+{
+    use smithay::backend::input::Axis;
+
+    if state.lock.locked {
+        return false;
+    }
+    let mods = state.seat.get_keyboard().map(|k| core_modifiers_from_xkb(&k.modifier_state()));
+    if !mods.is_some_and(|m| m.contains(DRAG_MODIFIER)) {
+        return false;
+    }
+    let Some(v) = event.amount(Axis::Vertical).filter(|v| *v != 0.0) else { return false };
+
+    let mut wm = state.wm.borrow_mut();
+    let ids: Vec<_> = wm.workspaces().iter().map(|w| w.id).collect();
+    if ids.is_empty() {
+        return false;
+    }
+    let current = ids.iter().position(|&id| id == wm.current_workspace()).unwrap_or(0);
+    // Scrolling down (positive) advances, matching `workspace, e+1`.
+    let next = if v > 0.0 { (current + 1) % ids.len() } else { (current + ids.len() - 1) % ids.len() };
+    wm.switch_workspace(ids[next]);
+    true
+}