fix: NSSwitch and NSSlider bezels draw under the macOS 26 design, where displayRectIgnoringOpacity left them empty

src/addon.mm

@@ -1581,6 +1581,35 @@ static bool ReadFromTo(Napi::Env env, CABasicAnimation* a, Napi::Object o) {
 // native controls: NSCell rendered offscreen (the WebKit/Firefox technique)
 // ---------------------------------------------------------------------------
 
+// A view control drawn into the current NSGraphicsContext, filling (0, 0, w,
+// h) points over pw x ph pixels. Through a bitmap rep rather than
+// displayRectIgnoringOpacity:inContext:, which under the macOS 26 design (a
+// process linked against the 26 SDK — Bun is) draws NSSlider and NSSwitch
+// through their layers and leaves a foreign context empty.
+// cacheDisplayInRect: renders the layer tree, and on the older design gives
+// the pixels displayRect did.
+static void DrawViewControl(NSControl* v, double w, double h, size_t pw, size_t ph) {
+  NSBitmapImageRep* rep = [[NSBitmapImageRep alloc]
+      initWithBitmapDataPlanes:NULL
+                    pixelsWide:(NSInteger)pw
+                    pixelsHigh:(NSInteger)ph
+                 bitsPerSample:8
+               samplesPerPixel:4
+                      hasAlpha:YES
+                      isPlanar:NO
+                colorSpaceName:NSDeviceRGBColorSpace
+                   bytesPerRow:0
+                  bitsPerPixel:0];
+  rep.size = NSMakeSize(w, h);
+  [v cacheDisplayInRect:v.bounds toBitmapImageRep:rep];
+  [rep drawInRect:NSMakeRect(0, 0, w, h)
+           fromRect:NSZeroRect
+          operation:NSCompositingOperationSourceOver
+           fraction:1
+     respectFlipped:YES
+              hints:nil];
+}
+
 static NSView* DummyDrawView() {
   // Cells only use the view for flippedness/appearance queries; it never needs
   // to be in a window.
@@ -1631,7 +1660,7 @@ static bool ReadFromTo(Napi::Env env, CABasicAnimation* a, Napi::Object o) {
 
   // Controls whose cells no longer draw offscreen (NSSliderCell renders via
   // the view's layer machinery) or that have no cell at all (NSSwitch): use a
-  // real offscreen NSControl and displayRectIgnoringOpacity:inContext:.
+  // real offscreen NSControl, captured with DrawViewControl.
   NSControl* viewControl = nil;
   if ([kind isEqualToString:@"slider"]) {
     NSSlider* s = [[NSSlider alloc] init];
@@ -1697,7 +1726,7 @@ static bool ReadFromTo(Napi::Env env, CABasicAnimation* a, Napi::Object o) {
     viewControl.frame = NSMakeRect(0, 0, w, h);
     viewControl.appearance = ap;
     [viewControl layoutSubtreeIfNeeded];
-    [viewControl displayRectIgnoringOpacity:viewControl.bounds inContext:g];
+    DrawViewControl(viewControl, w, h, pw, ph);
   } else {
     [ap performAsCurrentDrawingAppearance:^{
       [cell drawWithFrame:NSMakeRect(0, 0, w, h) inView:DummyDrawView()];

src/backend.mm

@@ -3911,10 +3911,39 @@ static void CancelPanelSheetsOn(NSWindow* win) {
   return v;
 }
 
+// A view control drawn into the current NSGraphicsContext, filling (0, 0, w,
+// h) points over pw x ph pixels. Through a bitmap rep rather than
+// displayRectIgnoringOpacity:inContext:, which under the macOS 26 design (a
+// process linked against the 26 SDK — Bun is) draws NSSlider and NSSwitch
+// through their layers and leaves a foreign context empty.
+// cacheDisplayInRect: renders the layer tree, and on the older design gives
+// the pixels displayRect did.
+static void BDrawViewControl(NSControl* v, double w, double h, size_t pw, size_t ph) {
+  NSBitmapImageRep* rep = [[NSBitmapImageRep alloc]
+      initWithBitmapDataPlanes:NULL
+                    pixelsWide:(NSInteger)pw
+                    pixelsHigh:(NSInteger)ph
+                 bitsPerSample:8
+               samplesPerPixel:4
+                      hasAlpha:YES
+                      isPlanar:NO
+                colorSpaceName:NSDeviceRGBColorSpace
+                   bytesPerRow:0
+                  bitsPerPixel:0];
+  rep.size = NSMakeSize(w, h);
+  [v cacheDisplayInRect:v.bounds toBitmapImageRep:rep];
+  [rep drawInRect:NSMakeRect(0, 0, w, h)
+           fromRect:NSZeroRect
+          operation:NSCompositingOperationSourceOver
+           fraction:1
+     respectFlipped:YES
+              hints:nil];
+}
+
 // The two render paths AppKit leaves us: classic cells draw offscreen via
 // drawWithFrame:, while NSSlider's cell now renders through the view's layer
 // machinery and NSSwitch has no cell at all — those go through a real
-// offscreen NSControl and displayRectIgnoringOpacity:inContext:.
+// offscreen NSControl, captured with BDrawViewControl.
 struct BezelControl {
   NSCell* cell = nil;
   NSControl* view = nil;
@@ -4100,7 +4129,7 @@ static BezelControl BuildBezel(const BezelSpec& s) {
       c.view.frame = NSMakeRect(0, 0, w, h);
       c.view.appearance = ap;
       [c.view layoutSubtreeIfNeeded];
-      [c.view displayRectIgnoringOpacity:c.view.bounds inContext:g];
+      BDrawViewControl(c.view, w, h, pw, ph);
     } else if (c.cell) {
       NSCell* cell = c.cell;
       [ap performAsCurrentDrawingAppearance:^{

test/control-bezels.js

@@ -4,7 +4,7 @@
 // button stretched to its frame, where `push` keeps one height and draws it
 // centred in a taller frame.
 //
-// Checked: both kinds measure and an unknown one still throws; the push's
+// Checked: every kind draws ink; both kinds measure and an unknown one still throws; the push's
 // ink is the same 22pt (18 small) in every frame, while the flexible push
 // inks its frame to the same margins however tall it is; at the push's own
 // height the two draw the same pixels over the same ink box, plain, pressed
@@ -79,6 +79,18 @@ for (const controlSize of ['regular', 'small']) {
   ok(threw && /unknown control kind/.test(threw.message), 'an unknown kind throws', threw);
 }
 
+// --- every kind draws -------------------------------------------------------
+// NSSlider and NSSwitch are views, not cells, and under the macOS 26 design
+// (a process linked against the 26 SDK — Bun, say) a view drawn with
+// displayRectIgnoringOpacity:inContext: came out empty: no ink at all.
+for (const kind of ['push', 'flexiblePush', 'checkbox', 'radio', 'popup', 'slider', 'switch']) {
+  for (const appearance of ['light', 'dark']) {
+    const m = n.measureControl({ kind });
+    const d = draw({ kind, state: 1, value: 0.5, appearance }, m.width, m.height);
+    ok(d.ink.x1 >= 0, `${kind} draws (${appearance})`);
+  }
+}
+
 // --- one height, or stretched to the frame ------------------------------------
 for (const controlSize of ['regular', 'small']) {
   const push = n.measureControl({ kind: 'push', controlSize });