Fix positioning of windows on secondary displays

CGDisplayBounds returns data in "global display coordinates" (which are
the same as Zed's coordinates), different from the NS APIs which use
"screen coordinates" (which have the Y axis inverted)

Also remove some transmutes while we're at it

crates/gpui/src/platform/mac/display.rs

@@ -3,13 +3,10 @@ use anyhow::Result;
 use cocoa::{
     appkit::NSScreen,
     base::{id, nil},
-    foundation::{NSDictionary, NSString},
+    foundation::{NSDictionary, NSPoint, NSRect, NSSize, NSString},
 };
 use core_foundation::uuid::{CFUUIDGetUUIDBytes, CFUUIDRef};
-use core_graphics::{
-    display::{CGDirectDisplayID, CGDisplayBounds, CGGetActiveDisplayList},
-    geometry::{CGPoint, CGRect, CGSize},
-};
+use core_graphics::display::{CGDirectDisplayID, CGDisplayBounds, CGGetActiveDisplayList};
 use objc::{msg_send, sel, sel_impl};
 use uuid::Uuid;
 
@@ -77,14 +74,14 @@ extern "C" {
     fn CGDisplayCreateUUIDFromDisplayID(display: CGDirectDisplayID) -> CFUUIDRef;
 }
 
-/// Convert the given rectangle from CoreGraphics' native coordinate space to GPUI's coordinate space.
+/// Convert the given rectangle from Cocoa's coordinate space to GPUI's coordinate space.
 ///
-/// CoreGraphics' coordinate space has its origin at the bottom left of the primary screen,
+/// Cocoa's coordinate space has its origin at the bottom left of the primary screen,
 /// with the Y axis pointing upwards.
 ///
 /// Conversely, in GPUI's coordinate system, the origin is placed at the top left of the primary
-/// screen, with the Y axis pointing downwards.
-pub(crate) fn display_bounds_from_native(rect: CGRect) -> Bounds<GlobalPixels> {
+/// screen, with the Y axis pointing downwards (matching CoreGraphics)
+pub(crate) fn global_bounds_from_ns_rect(rect: NSRect) -> Bounds<GlobalPixels> {
     let primary_screen_size = unsafe { CGDisplayBounds(MacDisplay::primary().id().0) }.size;
 
     Bounds {
@@ -101,22 +98,22 @@ pub(crate) fn display_bounds_from_native(rect: CGRect) -> Bounds<GlobalPixels> {
     }
 }
 
-/// Convert the given rectangle from GPUI's coordinate system to CoreGraphics' native coordinate space.
+/// Convert the given rectangle from GPUI's coordinate system to Cocoa's native coordinate space.
 ///
-/// CoreGraphics' coordinate space has its origin at the bottom left of the primary screen,
+/// Cocoa's coordinate space has its origin at the bottom left of the primary screen,
 /// with the Y axis pointing upwards.
 ///
 /// Conversely, in GPUI's coordinate system, the origin is placed at the top left of the primary
-/// screen, with the Y axis pointing downwards.
-pub(crate) fn display_bounds_to_native(bounds: Bounds<GlobalPixels>) -> CGRect {
+/// screen, with the Y axis pointing downwards (matching CoreGraphics)
+pub(crate) fn global_bounds_to_ns_rect(bounds: Bounds<GlobalPixels>) -> NSRect {
     let primary_screen_height = MacDisplay::primary().bounds().size.height;
 
-    CGRect::new(
-        &CGPoint::new(
+    NSRect::new(
+        NSPoint::new(
             bounds.origin.x.into(),
             (primary_screen_height - bounds.origin.y - bounds.size.height).into(),
         ),
-        &CGSize::new(bounds.size.width.into(), bounds.size.height.into()),
+        NSSize::new(bounds.size.width.into(), bounds.size.height.into()),
     )
 }
 
@@ -155,8 +152,20 @@ impl PlatformDisplay for MacDisplay {
 
     fn bounds(&self) -> Bounds<GlobalPixels> {
         unsafe {
-            let native_bounds = CGDisplayBounds(self.0);
-            display_bounds_from_native(native_bounds)
+            // CGDisplayBounds is in "global display" coordinates, where 0 is
+            // the top left of the primary display.
+            let bounds = CGDisplayBounds(self.0);
+
+            Bounds {
+                origin: point(
+                    GlobalPixels(bounds.origin.x as f32),
+                    GlobalPixels(bounds.origin.y as f32),
+                ),
+                size: size(
+                    GlobalPixels(bounds.size.width as f32),
+                    GlobalPixels(bounds.size.height as f32),
+                ),
+            }
         }
     }
 }

crates/gpui/src/platform/mac/window.rs

@@ -1,6 +1,6 @@
-use super::{display_bounds_from_native, ns_string, MacDisplay, MetalRenderer, NSRange};
+use super::{global_bounds_from_ns_rect, ns_string, MacDisplay, MetalRenderer, NSRange};
 use crate::{
-    display_bounds_to_native, point, px, size, AnyWindowHandle, Bounds, ExternalPaths,
+    global_bounds_to_ns_rect, point, px, size, AnyWindowHandle, Bounds, ExternalPaths,
     FileDropEvent, ForegroundExecutor, GlobalPixels, KeyDownEvent, Keystroke, Modifiers,
     ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Pixels,
     PlatformAtlas, PlatformDisplay, PlatformInput, PlatformInputHandler, PlatformWindow, Point,
@@ -411,10 +411,8 @@ impl MacWindowState {
     }
 
     fn frame(&self) -> Bounds<GlobalPixels> {
-        unsafe {
-            let frame = NSWindow::frame(self.native_window);
-            display_bounds_from_native(mem::transmute::<NSRect, CGRect>(frame))
-        }
+        let frame = unsafe { NSWindow::frame(self.native_window) };
+        global_bounds_from_ns_rect(frame)
     }
 
     fn content_size(&self) -> Size<Pixels> {
@@ -527,11 +525,11 @@ impl MacWindow {
                 WindowBounds::Fixed(bounds) => {
                     let display_bounds = display.bounds();
                     let frame = if bounds.intersects(&display_bounds) {
-                        display_bounds_to_native(bounds)
+                        global_bounds_to_ns_rect(bounds)
                     } else {
-                        display_bounds_to_native(display_bounds)
+                        global_bounds_to_ns_rect(display_bounds)
                     };
-                    native_window.setFrame_display_(mem::transmute::<CGRect, NSRect>(frame), YES);
+                    native_window.setFrame_display_(frame, YES);
                 }
             }