fix(macos): clamp context-menu popup so it fits on-screen

.changes/macos-popup-clamp.md

@@ -0,0 +1,5 @@
+---
+"muda": patch
+---
+
+On macOS, fix context-menu popups overflowing off the bottom or right edge of the screen with scroll arrows by switching `show_context_menu_for_nsview` to `popUpContextMenu:withEvent:forView:`. AppKit clamps and auto-flips the menu against the active screen's visible frame for free, including menu bar / Dock margins and multi-monitor setups.

Cargo.toml

@@ -57,6 +57,7 @@ objc2-foundation = { version = "0.3.0", default-features = false, features = [
   "std",
   "NSAttributedString",
   "NSData",
+  "NSDate",
   "NSDictionary",
   "NSGeometry",
   "NSString",
@@ -68,6 +69,7 @@ objc2-app-kit = { version = "0.3.0", default-features = false, features = [
   "NSApplication",
   "NSCell",
   "NSEvent",
+  "NSGraphicsContext",
   "NSImage",
   "NSMenu",
   "NSMenuItem",

src/platform_impl/macos/mod.rs

@@ -26,17 +26,18 @@ use objc2_app_kit::{
     NSAboutPanelOptionApplicationIcon, NSAboutPanelOptionApplicationName,
     NSAboutPanelOptionApplicationVersion, NSAboutPanelOptionCredits, NSAboutPanelOptionVersion,
     NSApplication, NSControlStateValueOff, NSControlStateValueOn, NSEvent, NSEventModifierFlags,
-    NSImage, NSImageName, NSMenu, NSMenuDelegate, NSMenuItem, NSRunningApplication, NSView,
+    NSEventType, NSImage, NSImageName, NSMenu, NSMenuDelegate, NSMenuItem, NSRunningApplication,
+    NSView,
 };
 use objc2_foundation::{
-    ns_string, MainThreadMarker, NSAttributedString, NSDictionary, NSInteger, NSObject, NSPoint,
-    NSSize, NSString,
+    ns_string, MainThreadMarker, NSAttributedString, NSDate, NSDictionary, NSInteger, NSObject,
+    NSPoint, NSSize, NSString,
 };
 
 use self::util::strip_mnemonic;
 use crate::{
     accelerator::KeyAccelerator,
-    dpi::{LogicalPosition, Position},
+    dpi::Position,
     icon::{Icon, NativeIcon},
     items::*,
     util::{AddOp, Counter},
@@ -1197,21 +1198,61 @@ unsafe fn show_context_menu(
 
     let window = view.window().expect("view must be installed in a window");
     let scale_factor = window.backingScaleFactor();
-    let (location, in_view) = if let Some(pos) = position.map(|p| p.to_logical(scale_factor)) {
-        let view_rect = view.frame();
-        let location = NSPoint::new(pos.x, view_rect.size.height - pos.y);
-        (location, Some(view))
-    } else {
-        let mouse_location = unsafe { NSEvent::mouseLocation() };
-        let pos = LogicalPosition {
-            x: mouse_location.x,
-            y: mouse_location.y,
+
+    // Compute the popup location in `window`'s coordinate space (bottom-left
+    // origin). The synthesized event below carries this location, and AppKit
+    // interprets it relative to the event's window — which must be the same
+    // window the target view belongs to.
+    let location_in_window: NSPoint =
+        if let Some(pos) = position.map(|p| p.to_logical(scale_factor)) {
+            // `pos` is in the view's logical coordinate system with top-left
+            // origin (the rest of muda's API). Flip Y to AppKit's view coords
+            // (bottom-left), then convert to window coords.
+            let view_rect = view.frame();
+            let view_point = NSPoint::new(pos.x, view_rect.size.height - pos.y);
+            unsafe { view.convertPoint_toView(view_point, None) }
+        } else {
+            // No explicit position → use the current mouse location. It is
+            // in screen coords; convert into the view's window's coords.
+            let mouse = unsafe { NSEvent::mouseLocation() };
+            window.convertPointFromScreen(mouse)
+        };
+
+    // Synthesize a right-mouse-down event so we can call
+    // `popUpContextMenu:withEvent:forView:`, which (unlike
+    // `popUpMenuPositioningItem:atLocation:inView:`) auto-flips and clamps
+    // the menu against the screen's visible frame for free.
+    let timestamp = NSDate::timeIntervalSinceReferenceDate_class();
+    let event = unsafe {
+        NSEvent::mouseEventWithType_location_modifierFlags_timestamp_windowNumber_context_eventNumber_clickCount_pressure(
+            NSEventType::RightMouseDown,
+            location_in_window,
+            NSEventModifierFlags(0),
+            timestamp,
+            window.windowNumber(),
+            None,
+            0,
+            1,
+            1.0,
+        )
+    };
+
+    let Some(event) = event else {
+        // Synthesizing an event can fail in pathological situations; fall
+        // back to the legacy positioning call so we still pop up something.
+        return unsafe {
+            ns_menu.popUpMenuPositioningItem_atLocation_inView(None, location_in_window, Some(view))
         };
-        let location = NSPoint::new(pos.x, pos.y);
-        (location, None)
     };
 
-    unsafe { ns_menu.popUpMenuPositioningItem_atLocation_inView(None, location, in_view) }
+    // `popUpContextMenu:withEvent:forView:` lets macOS append contextual-menu
+    // plug-in items (AutoFill, Services, third-party plug-ins) to the menu.
+    // The legacy positioning call never did that, so opt out to keep the
+    // menu's contents exactly what the consumer built.
+    ns_menu.setAllowsContextMenuPlugIns(false);
+
+    unsafe { NSMenu::popUpContextMenu_withEvent_forView(ns_menu, &event, view) };
+    true
 }
 
 impl NativeIcon {