feat(app): follow a live window's app through a relaunch

.lane/memory/apps/desktop/native/live.m/01M5YZZPH2ADYVC2F2ACMCP7B2-a-closed-window-s-scstream-s.md

@@ -4,8 +4,9 @@ anchor: '@file'
 created: 2026-10-27T15:34:41Z
 norm: '1'
 sig: f5f542a9730901ae
-body_hash: 0d3d7801d2eeec11
-raw_hash: b7c0ca684f0d3c15
+body_hash: 9d55ad18b75658fb
+raw_hash: 31da00fc4410d54a
+vouched: 2026-10-27T15:52:56Z
 lines: 1-249
 ---
 

.lane/memory/apps/desktop/native/live.m/01M5Z10R62MZBHB2W46VYCP5ND-a-relaunch-must-be-followed.md

@@ -0,0 +1,12 @@
+---
+id: 01M5Z10R62MZBHB2W46VYCP5ND
+anchor: '@file'
+created: 2026-10-27T15:52:44Z
+norm: '1'
+sig: f5f542a9730901ae
+body_hash: 9d55ad18b75658fb
+raw_hash: 31da00fc4410d54a
+lines: 1-266
+---
+
+a relaunch must be followed without a click, since make run restarts the app on every change

apps/app/src/panels/live.tsx

@@ -21,13 +21,21 @@ export function Live(
 ) {
 	const ref = useRef<HTMLElement>(null);
 	const relink = useRef<{ app?: string }>(undefined);
+	// After Ace restarts, only the tab knows the app, so a lost window tries it once on its own.
+	const tried = useRef(false);
 	const [lost, setLost] = useState(false);
 
 	const report = useEffectEvent((status: LiveStatus | null) => {
 		if (!status) return;
+		if (status.state === "lost" && app && !tried.current) {
+			tried.current = true;
+			relink.current = { app };
+			return;
+		}
 		setLost(status.state === "lost");
 		// A relink moves the tab to the app's new window, and the app is kept for the next one.
 		if (status.state !== "live") return;
+		tried.current = false;
 		if (status.window !== window || status.app !== app) {
 			update({ window: status.window, app: status.app });
 		}

apps/desktop/native/live.m

@@ -17,6 +17,8 @@ @interface AceLiveView : NSView <SCStreamOutput, SCStreamDelegate>
 @property(nonatomic, strong) NSTimer *watch;
 @property(nonatomic) BOOL stopped;
 @property(nonatomic) BOOL lost;
+/** Until when a closed window's app is followed to its next window, as after a rebuild. */
+@property(nonatomic, strong) NSDate *deadline;
 /** Bumped by each start or relink, so a slow lookup can't attach a superseded window. */
 @property(nonatomic) NSUInteger generation;
 @end
@@ -58,6 +60,8 @@ - (void)start:(CGWindowID)target {
 	[self stop];
 	self.target = target;
 	self.bundle = nil;
+	self.deadline = nil;
+	self.layer.contents = nil;
 	[self attach:nil];
 }
 
@@ -72,7 +76,6 @@ - (void)relink:(NSString *)app {
 - (void)attach:(NSString *)app {
 	self.stopped = NO;
 	self.lost = NO;
-	self.layer.contents = nil;
 	NSUInteger generation = ++self.generation;
 	CGWindowID target = self.target;
 	[SCShareableContent getShareableContentExcludingDesktopWindows:YES
@@ -101,6 +104,7 @@ - (void)attach:(NSString *)app {
 - (void)capture:(SCWindow *)window {
 	self.bundle = window.owningApplication.bundleIdentifier;
 	self.current = window.windowID;
+	self.deadline = nil;
 	SCContentFilter *filter = [[SCContentFilter alloc] initWithDesktopIndependentWindow:window];
 	SCStreamConfiguration *config = [SCStreamConfiguration new];
 	CGFloat scale = filter.pointPixelScale;
@@ -137,9 +141,22 @@ - (void)lost:(SCStream *)stream {
 	});
 }
 
-// Shows the page's relink prompt underneath; the app may have quit or relaunched.
+// A rebuilt app relaunches with a new window ID, so its app is followed for a while, keeping the
+// last frame, before the page's relink prompt shows underneath.
 - (void)lose {
 	[self stop];
+	if (!self.bundle) return [self give];
+	if (!self.deadline) self.deadline = [NSDate dateWithTimeIntervalSinceNow:10];
+	if (self.deadline.timeIntervalSinceNow <= 0) return [self give];
+	self.stopped = NO;
+	NSUInteger generation = self.generation;
+	dispatch_after(dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC / 2), dispatch_get_main_queue(), ^{
+		if (!self.stopped && self.generation == generation) [self attach:self.bundle];
+	});
+}
+
+- (void)give {
+	self.deadline = nil;
 	self.lost = YES;
 	self.layer.contents = nil;
 }