fix(cef): prevent queued taps from stalling

commit: 4733629ab8cf5d405066b01e9ff25ead31ec6ed0
author: brice · 2mo ago · 2026-08-16 15:43 UTC
parent: 55df320
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

2 files · +44 -8

M internal/infrastructure/cef/webview.go +13 -8


@@ -2510,12 +2510,18 @@ func (wv *WebView) ensurePageScrollFlush() {
2510	2510		}
2511	2511
2512	2512		func (wv *WebView) drainPageScrollSynchronously() {
2513		-	for wv.drainPageScrollOnce() {
2514		-	}
2515	2513		q := &wv.pageScrollQueue
2516		-	q.mu.Lock()
2517		-	q.flushPending = false
2518		-	q.mu.Unlock()
	2514	+	for {
	2515	+	wv.drainPageScrollOnce()
	2516	+	q.mu.Lock()
	2517	+	hasWork := q.tapDX != 0 \|\| q.tapDY != 0 \|\| q.heldDX != 0 \|\| q.heldDY != 0
	2518	+	if !hasWork {
	2519	+	q.flushPending = false
	2520	+	q.mu.Unlock()
	2521	+	return
	2522	+	}
	2523	+	q.mu.Unlock()
	2524	+	}
2519	2525		}
2520	2526
2521	2527		func (wv *WebView) flushPageScroll() {

@@ -2531,7 +2537,7 @@ func (wv *WebView) flushPageScroll() {
2531	2537		}
2532	2538		}
2533	2539
2534		-	func (wv *WebView) drainPageScrollOnce() bool {
	2540	+	func (wv *WebView) drainPageScrollOnce() {
2535	2541		q := &wv.pageScrollQueue
2536	2542		q.mu.Lock()
2537	2543		tapDX, tapDY := q.tapDX, q.tapDY

@@ -2540,7 +2546,7 @@ func (wv *WebView) drainPageScrollOnce() bool {
2540	2546		beforeExecute := q.beforeExecute
2541	2547		if tapDX == 0 && tapDY == 0 && heldDX == 0 && heldDY == 0 {
2542	2548		q.mu.Unlock()
2543		-	return false
	2549	+	return
2544	2550		}
2545	2551		q.tapDX, q.tapDY, q.heldDX, q.heldDY = 0, 0, 0, 0
2546	2552		q.mu.Unlock()

@@ -2563,7 +2569,6 @@ func (wv *WebView) drainPageScrollOnce() bool {
2563	2569		wv.executeJavaScriptNow(webutil.BuildPageScrollByJS(dx, dy))
2564	2570		}
2565	2571		q.commitMu.Unlock()
2566		-	return true
2567	2572		}
2568	2573
2569	2574		// CancelPageScroll invalidates all accepted but unconsumed held-key deltas.

 }
 func (wv *WebView) drainPageScrollSynchronously() {
-	for wv.drainPageScrollOnce() {
-	}
 	q := &wv.pageScrollQueue
-	q.mu.Lock()
+	for {
-	q.flushPending = false
+		wv.drainPageScrollOnce()
-	q.mu.Unlock()
+		q.mu.Lock()
+		hasWork := q.tapDX != 0 || q.tapDY != 0 || q.heldDX != 0 || q.heldDY != 0
+		if !hasWork {
+			q.flushPending = false
+			q.mu.Unlock()
+			return
+		}
+		q.mu.Unlock()
+	}
 }
 func (wv *WebView) flushPageScroll() {
 	}
 }
-func (wv *WebView) drainPageScrollOnce() bool {
+func (wv *WebView) drainPageScrollOnce() {
 	q := &wv.pageScrollQueue
 	q.mu.Lock()
 	tapDX, tapDY := q.tapDX, q.tapDY
 	beforeExecute := q.beforeExecute
 	if tapDX == 0 && tapDY == 0 && heldDX == 0 && heldDY == 0 {
 		q.mu.Unlock()
-		return false
+		return
 	}
 	q.tapDX, q.tapDY, q.heldDX, q.heldDY = 0, 0, 0, 0
 	q.mu.Unlock()
 		wv.executeJavaScriptNow(webutil.BuildPageScrollByJS(dx, dy))
 	}
 	q.commitMu.Unlock()
-	return true
 }
 // CancelPageScroll invalidates all accepted but unconsumed held-key deltas.

M internal/infrastructure/cef/webview_scroll_test.go +31 -0


@@ -326,6 +326,37 @@ func TestCancelPageScroll_DropsHeldDeltaButPreservesTap(t *testing.T) {
326	326		}
327	327		}
328	328
	329	+	func TestDrainPageScrollSynchronously_DrainsTapEnqueuedDuringExecution(t *testing.T) {
	330	+	browser := cefmocks.NewMockBrowser(t)
	331	+	frame := cefmocks.NewMockFrame(t)
	332	+	browser.EXPECT().GetMainFrame().Return(frame).Twice()
	333	+
	334	+	wv := &WebView{browser: browser}
	335	+	calls := 0
	336	+	frame.EXPECT().ExecuteJavaScript(mock.Anything, "", int32(0)).Run(func(_, _ string, _ int32) {
	337	+	calls++
	338	+	if calls == 1 {
	339	+	if err := wv.ScrollPage(context.Background(), port.PageScrollRequest{FallbackDY: 80}); err != nil {
	340	+	t.Errorf("enqueue tap during execution: %v", err)
	341	+	}
	342	+	}
	343	+	}).Twice()
	344	+
	345	+	if err := wv.ScrollPage(context.Background(), port.PageScrollRequest{FallbackDY: 80}); err != nil {
	346	+	t.Fatal(err)
	347	+	}
	348	+	if calls != 2 {
	349	+	t.Fatalf("ExecuteJavaScript calls=%d, want 2", calls)
	350	+	}
	351	+
	352	+	q := &wv.pageScrollQueue
	353	+	q.mu.Lock()
	354	+	defer q.mu.Unlock()
	355	+	if q.flushPending \|\| q.tapDX != 0 \|\| q.tapDY != 0 \|\| q.heldDX != 0 \|\| q.heldDY != 0 {
	356	+	t.Fatalf("queue not drained: pending=%t tap=(%d,%d) held=(%d,%d)", q.flushPending, q.tapDX, q.tapDY, q.heldDX, q.heldDY)
	357	+	}
	358	+	}
	359	+
329	360		func TestCancelPageScroll_AfterDrainDropsOldHeldAndPreservesTapAndNextGesture(t *testing.T) {
330	361		oldNewTask, oldPostTask := cefNewTask, cefPostTask
331	362		defer func() { cefNewTask, cefPostTask = oldNewTask, oldPostTask }()


@@ -326,6 +326,37 @@ func TestCancelPageScroll_DropsHeldDeltaButPreservesTap(t *testing.T) {
326	}	326		}
327	}	327		}
328		328
		329	+	func TestDrainPageScrollSynchronously_DrainsTapEnqueuedDuringExecution(t *testing.T) {
		330	+	browser := cefmocks.NewMockBrowser(t)
		331	+	frame := cefmocks.NewMockFrame(t)
		332	+	browser.EXPECT().GetMainFrame().Return(frame).Twice()
		333	+
		334	+	wv := &WebView{browser: browser}
		335	+	calls := 0
		336	+	frame.EXPECT().ExecuteJavaScript(mock.Anything, "", int32(0)).Run(func(_, _ string, _ int32) {
		337	+	calls++
		338	+	if calls == 1 {
		339	+	if err := wv.ScrollPage(context.Background(), port.PageScrollRequest{FallbackDY: 80}); err != nil {
		340	+	t.Errorf("enqueue tap during execution: %v", err)
		341	+	}
		342	+	}
		343	+	}).Twice()
		344	+
		345	+	if err := wv.ScrollPage(context.Background(), port.PageScrollRequest{FallbackDY: 80}); err != nil {
		346	+	t.Fatal(err)
		347	+	}
		348	+	if calls != 2 {
		349	+	t.Fatalf("ExecuteJavaScript calls=%d, want 2", calls)
		350	+	}
		351	+
		352	+	q := &wv.pageScrollQueue
		353	+	q.mu.Lock()
		354	+	defer q.mu.Unlock()
		355	+	if q.flushPending \|\| q.tapDX != 0 \|\| q.tapDY != 0 \|\| q.heldDX != 0 \|\| q.heldDY != 0 {
		356	+	t.Fatalf("queue not drained: pending=%t tap=(%d,%d) held=(%d,%d)", q.flushPending, q.tapDX, q.tapDY, q.heldDX, q.heldDY)
		357	+	}
		358	+	}
		359	+
329	func TestCancelPageScroll_AfterDrainDropsOldHeldAndPreservesTapAndNextGesture(t *testing.T) {	360		func TestCancelPageScroll_AfterDrainDropsOldHeldAndPreservesTapAndNextGesture(t *testing.T) {
330	oldNewTask, oldPostTask := cefNewTask, cefPostTask	361		oldNewTask, oldPostTask := cefNewTask, cefPostTask
331	defer func() { cefNewTask, cefPostTask = oldNewTask, oldPostTask }()	362		defer func() { cefNewTask, cefPostTask = oldNewTask, oldPostTask }()