diff --git a/apps/photocraft/src/window_frame.rs b/apps/photocraft/src/window_frame.rs index e418049d07..56c9be1b6a 100644 --- a/apps/photocraft/src/window_frame.rs +++ b/apps/photocraft/src/window_frame.rs @@ -20,6 +20,11 @@ //! the work area plus its own frame, clear of the taskbar. winit pins the client area to the work //! area either way (`WM_NCCALCSIZE`), so the app's pixels do not move. //! +//! An auto-hidden taskbar reserves no work area, so that trim leaves the maximize covering the +//! whole monitor, and the shell, taking it for a full-screen app, no longer reveals the taskbar +//! when the pointer reaches its edge (#4845). On each edge with an auto-hidden taskbar the guard +//! instead stops the window one pixel short of the monitor, as other custom-frame apps do. +//! //! The Windows calls go through safe `winsafe` wrappers; the workspace forbids `unsafe`, and //! winsafe can't wrap a raw handle without it, so the window is found by its handle instead. @@ -29,7 +34,20 @@ pub use platform::service; mod platform { use eframe::wgpu::rwh::{HasWindowHandle, RawWindowHandle}; use photocraft_ui_egui::WindowFrameFn; - use winsafe::{HWND, HwndPlace, POINT, SIZE, co}; + use winsafe::prelude::Handle; + use winsafe::{AtomStr, HWND, HwndPlace, POINT, SIZE, co}; + + /// A rect in desktop coordinates: `(left, top, right, bottom)`, right and bottom exclusive. + type Rect = (i32, i32, i32, i32); + + /// A monitor edge. + #[derive(Clone, Copy, Debug, PartialEq, Eq)] + enum Edge { + Left, + Top, + Right, + Bottom, + } /// A guard that keeps the window borderless each frame, or `None` when the app uses the /// system title bar (the window is decorated) or its handle can't be found. @@ -99,8 +117,11 @@ mod platform { return; }; let (m, w) = (mi.rcMonitor, mi.rcWork); - let Some((left, top, right, bottom)) = - clamped_rect((r.left, r.top, r.right, r.bottom), (m.left, m.top, m.right, m.bottom), (w.left, w.top, w.right, w.bottom)) + let (rect, monitor, work) = ((r.left, r.top, r.right, r.bottom), (m.left, m.top, m.right, m.bottom), (w.left, w.top, w.right, w.bottom)); + // The taskbars (a couple of `FindWindowEx` calls) are only looked up while the window + // covers the whole monitor, which a trimmed maximize no longer does. + let Some((left, top, right, bottom)) = clamped_rect(rect, monitor, work) + .or_else(|| covers(rect, monitor).then(|| short_of_autohide_taskbars(rect, monitor, work, &taskbar_edges(monitor))).flatten()) else { return; }; @@ -153,6 +174,69 @@ mod platform { (corrected != rect).then_some(corrected) } + /// Whether `rect` reaches every edge of `monitor`: what the shell takes for a full-screen app. + fn covers(rect: Rect, monitor: Rect) -> bool { + rect.0 <= monitor.0 && rect.1 <= monitor.1 && rect.2 >= monitor.2 && rect.3 >= monitor.3 + } + + /// The edges of `monitor` that have a taskbar (the primary `Shell_TrayWnd` or a secondary + /// monitor's `Shell_SecondaryTrayWnd`), shown or hidden. + fn taskbar_edges(monitor: Rect) -> Vec { + let mut edges = Vec::new(); + for class in ["Shell_TrayWnd", "Shell_SecondaryTrayWnd"] { + let mut after: Option = None; + // One taskbar per monitor; the bound only guards against a misbehaving shell. + for _ in 0..64 { + let Ok(Some(tray)) = HWND::NULL.FindWindowEx(after.as_ref(), AtomStr::from_str(class), None) else { + break; + }; + if let Ok(r) = tray.GetWindowRect() { + edges.extend(taskbar_edge((r.left, r.top, r.right, r.bottom), monitor)); + } + after = Some(tray); + } + } + edges + } + + /// The edge of `monitor` a taskbar with rect `taskbar` sits on: the one nearest its centre, + /// or `None` when it is on another monitor. An auto-hidden taskbar is parked mostly past its + /// edge with a sliver left on screen, so its centre may lie outside the monitor. + fn taskbar_edge(taskbar: Rect, monitor: Rect) -> Option { + let (tl, tt, tr, tb) = (i64::from(taskbar.0), i64::from(taskbar.1), i64::from(taskbar.2), i64::from(taskbar.3)); + let (ml, mt, mr, mb) = (i64::from(monitor.0), i64::from(monitor.1), i64::from(monitor.2), i64::from(monitor.3)); + if tl >= tr || tt >= tb || ml >= mr || mt >= mb || tr <= ml || tl >= mr || tb <= mt || tt >= mb { + return None; + } + // Doubled centre and distances, so nothing rounds. + let (cx, cy) = (tl + tr, tt + tb); + [(Edge::Left, cx - 2 * ml), (Edge::Top, cy - 2 * mt), (Edge::Right, 2 * mr - cx), (Edge::Bottom, 2 * mb - cy)] + .into_iter() + .min_by_key(|&(_, distance)| distance) + .map(|(edge, _)| edge) + } + + /// A maximize covering its monitor, trimmed to stop one pixel short of each edge where a + /// taskbar reserves no work area (it auto-hides), so the shell still reveals it there. + /// `None` when there is nothing to trim. + fn short_of_autohide_taskbars(rect: Rect, monitor: Rect, work: Rect, taskbars: &[Edge]) -> Option { + if !covers(rect, monitor) { + return None; + } + let (mut l, mut t, mut r, mut b) = rect; + for edge in taskbars { + match edge { + Edge::Left if work.0 == monitor.0 => l = monitor.0.checked_add(1)?, + Edge::Top if work.1 == monitor.1 => t = monitor.1.checked_add(1)?, + Edge::Right if work.2 == monitor.2 => r = monitor.2.checked_sub(1)?, + Edge::Bottom if work.3 == monitor.3 => b = monitor.3.checked_sub(1)?, + _ => {} + } + } + let trimmed = (l, t, r, b); + (l < r && t < b && trimmed != rect).then_some(trimmed) + } + /// `style` without the OS title bar and frame (`WS_CAPTION`, which already includes /// `WS_BORDER`). The sizing border (`WS_THICKFRAME`) stays, so edge resizing and Aero snap /// keep working, as they did with winit 0.27's undecorated windows. @@ -162,7 +246,7 @@ mod platform { #[cfg(test)] mod tests { - use super::{borderless, clamped_rect}; + use super::{Edge, borderless, clamped_rect, short_of_autohide_taskbars, taskbar_edge}; use winsafe::co; #[test] @@ -221,6 +305,35 @@ mod platform { assert_eq!(clamped_rect((-500, -8, 1428, 1088), monitor, work), None, "dragged"); assert_eq!(clamped_rect((0, 48, 960, 1080), monitor, work), None, "half-screen"); } + + #[test] + fn a_maximize_leaves_a_pixel_strip_on_an_auto_hidden_taskbar_edge() { + // #4845: an auto-hidden taskbar reserves no work area. + let monitor = (0, 0, 1920, 1080); + let rect = (-8, -8, 1928, 1088); + for (edge, expected) in + [(Edge::Bottom, (-8, -8, 1928, 1079)), (Edge::Top, (-8, 1, 1928, 1088)), (Edge::Left, (1, -8, 1928, 1088)), (Edge::Right, (-8, -8, 1919, 1088))] + { + assert_eq!(short_of_autohide_taskbars(rect, monitor, monitor, &[edge]), Some(expected)); + assert_eq!(short_of_autohide_taskbars(expected, monitor, monitor, &[edge]), None, "already trimmed"); + } + assert_eq!(short_of_autohide_taskbars(rect, monitor, monitor, &[]), None, "no taskbar"); + // A taskbar that reserves its work area is the clamp's job. + assert_eq!(short_of_autohide_taskbars(rect, monitor, (0, 0, 1920, 1032), &[Edge::Bottom]), None); + assert_eq!(short_of_autohide_taskbars((0, 0, 960, 1080), monitor, monitor, &[Edge::Bottom]), None, "half-screen"); + } + + #[test] + fn a_taskbar_sits_on_the_monitor_edge_nearest_its_centre() { + let monitor = (0, 0, 1920, 1080); + assert_eq!(taskbar_edge((0, 1032, 1920, 1080), monitor), Some(Edge::Bottom), "shown"); + assert_eq!(taskbar_edge((0, 1078, 1920, 1126), monitor), Some(Edge::Bottom), "auto-hidden"); + assert_eq!(taskbar_edge((0, -46, 1920, 2), monitor), Some(Edge::Top)); + assert_eq!(taskbar_edge((-60, 0, 2, 1080), monitor), Some(Edge::Left)); + assert_eq!(taskbar_edge((1918, 0, 1980, 1080), monitor), Some(Edge::Right)); + assert_eq!(taskbar_edge((1920, 1032, 3840, 1080), monitor), None, "other monitor"); + assert!(taskbar_edge((i32::MIN, i32::MIN, i32::MAX, i32::MAX), monitor).is_some(), "no overflow"); + } } }