`e9322b0`

Use CGDisplayBounds(CGMainDisplayID) for primary height

NSScreen.screens caches and only refreshes on certain notifications, so
plugging an external monitor while ers is running left primary_height
stuck at the pre-hotplug value. Every CG-to-Cocoa Y conversion was
therefore off by the difference between the old primary height and the
new one — visible as borders drawn far from their windows on the
external display.

CGDisplayBounds(CGMainDisplayID()) reflects the current state on every
call and matches what tarmac's display module already uses.

Authored by mfwolffe <wolffemf@dukes.jmu.edu> 1 week ago

SHA: e9322b044ba1b0e565984377712a96fefd238d27
Parents: 03f53bc
Tree: 23796fc

2 changed files

Status	File	+	-
M	`Cargo.toml`	1	0
M	`src/nswindow_overlay.rs`	25	27

Cargo.tomlmodified

      "CGColor",
      "CGColorSpace",
      "CGPath",
 +    "CGDirectDisplay",
  ] }

src/nswindow_overlay.rsmodified

  /// Top-left Y in CG global coordinates becomes bottom-left Y in Cocoa
  /// global coordinates by subtracting from the primary screen height.
  ///
 -/// The "primary" screen is the one whose Cocoa frame origin is (0, 0) —
 -/// by definition the bottom-left of the menu-bar screen, which is the
 -/// shared anchor between CG (top-left) and Cocoa (bottom-left) global
 -/// coordinates. `[NSScreen screens][0]` is documented as the primary
 -/// but isn't reliable on every macOS version, so we look it up by
 -/// origin instead.
 -fn primary_screen_height(mtm: MainThreadMarker) -> f64 {
 -    let screens = NSScreen::screens(mtm);
 -    let count = screens.count();
 -    for i in 0..count {
 -        let s = screens.objectAtIndex(i);
 -        let f = s.frame();
 -        if f.origin.x.abs() < 0.5 && f.origin.y.abs() < 0.5 {
 -            return f.size.height;
 -        }
 -    }
 -    if count > 0 {
 -        screens.objectAtIndex(0).frame().size.height
 -    } else {
 -        0.0
 +/// We use the main CGDisplay's bounds rather than `NSScreen.screens`
 +/// because NSScreen caches and only refreshes on certain notifications
 +/// — when a monitor is plugged or unplugged, NSScreen.screens can
 +/// return stale primary-height values, causing every cocoa Y on the
 +/// new layout to be off by the difference. CGDisplayBounds reflects
 +/// the current state immediately.
 +fn primary_screen_height() -> f64 {
 +    unsafe {
 +        let main_id = objc2_core_graphics::CGMainDisplayID();
 +        objc2_core_graphics::CGDisplayBounds(main_id).size.height
+     }
+ }
 -fn cg_to_cocoa_frame(cg: CGRect, mtm: MainThreadMarker) -> CGRect {
 -    let primary_height = primary_screen_height(mtm);
 +fn cg_to_cocoa_frame(cg: CGRect, _mtm: MainThreadMarker) -> CGRect {
 +    let primary_height = primary_screen_height();
      let cocoa_y = primary_height - cg.origin.y - cg.size.height;
      CGRect::new(
          CGPoint::new(cg.origin.x, cocoa_y),
  /// multi-monitor coordinate issues.
  pub fn log_screens(mtm: MainThreadMarker) {
      let screens = NSScreen::screens(mtm);
 -    let primary_h = primary_screen_height(mtm);
 +    let primary_h = primary_screen_height();
 +    let cg_main_bounds = unsafe {
 +        let id = objc2_core_graphics::CGMainDisplayID();
 +        objc2_core_graphics::CGDisplayBounds(id)
 +    };
      tracing::debug!(
 -        primary_height = primary_h,
 -        count = screens.count(),
 -        "NSScreen layout"
 +        cg_primary_height = primary_h,
 +        cg_main_x = cg_main_bounds.origin.x,
 +        cg_main_y = cg_main_bounds.origin.y,
 +        cg_main_w = cg_main_bounds.size.width,
 +        cg_main_h = cg_main_bounds.size.height,
 +        nsscreen_count = screens.count(),
 +        "screen layout"
      );
      for i in 0..screens.count() {
          let s = screens.objectAtIndex(i);
              cocoa_y = f.origin.y,
              w = f.size.width,
              h = f.size.height,
 -            "screen"
 +            "nsscreen"
          );
+     }
+ }