From c8eb510bc6e1445905039c19802ae69380483100 Mon Sep 17 00:00:00 2001
From: Andrew Hutchings <andrew@wolfssl.com>
Date: Thu, 23 Jul 2026 10:09:15 +0100
Subject: [PATCH 1/2] web: suppress the browser default on held-key
 auto-repeats

The keydown handler bailed out on e.repeat before reaching
preventDefault, so while the initial press of a captured key was
consumed, every auto-repeat fell through to the browser and its default
action fired - holding a cursor key scrolled the page under the game.

Skipping repeats is still right for the emulator side (the Amiga
keyboard sends one down code per press; the guest OS does its own key
repeat), so track which codes the first keydown consumed and call
preventDefault on their repeats without re-forwarding them. The keyup
handler clears the entry, which also covers a hold that survives a
focus loss.
---
 crates/copperline-web/www/try.js | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/crates/copperline-web/www/try.js b/crates/copperline-web/www/try.js
index 1b5cac3..bed6198 100644
--- a/crates/copperline-web/www/try.js
+++ b/crates/copperline-web/www/try.js
@@ -996,13 +996,26 @@ function updatePadStatus(releasedPort1) {
 
 // --- keyboard ------------------------------------------------------------
 
+// Auto-repeat keydowns must not reach the emulator (the Amiga keyboard
+// sends one down code; the guest OS does its own repeat), but the browser
+// default still has to be suppressed on every repeat or holding a cursor
+// key scrolls the page. Track which codes the first keydown consumed.
+const consumedKeys = new Set();
 window.addEventListener('keydown', (e) => {
-  if (!emu || !running || e.repeat) return;
-  if (joystickKey(e.code, true) || emu.key_event(e.code, true)) e.preventDefault();
+  if (!emu || !running) return;
+  if (e.repeat) {
+    if (consumedKeys.has(e.code)) e.preventDefault();
+    return;
+  }
+  if (joystickKey(e.code, true) || emu.key_event(e.code, true)) {
+    consumedKeys.add(e.code);
+    e.preventDefault();
+  }
 });
 window.addEventListener('keyup', (e) => {
   if (!emu || !running) return;
-  if (joystickKey(e.code, false) || emu.key_event(e.code, false)) e.preventDefault();
+  const consumed = joystickKey(e.code, false) || emu.key_event(e.code, false);
+  if (consumedKeys.delete(e.code) || consumed) e.preventDefault();
 });
 
 // --- mouse ---------------------------------------------------------------

From ed8183b726088ecf184f99c365b45085aea68889 Mon Sep 17 00:00:00 2001
From: Andrew Hutchings <andrew@wolfssl.com>
Date: Thu, 23 Jul 2026 10:21:22 +0100
Subject: [PATCH 2/2] web: keep the consumed-key set from going stale across
 stop or blur

A hold that spans an emulator stop skipped the keyup delete behind the
running check, and a hold broken by a focus loss gets no keyup at all.
Delete before the running check on keyup, and let a non-repeat keydown
that consumes nothing clear any leftover entry for its code, so the set
corrects itself no matter how a hold ends.
---
 crates/copperline-web/www/try.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/crates/copperline-web/www/try.js b/crates/copperline-web/www/try.js
index bed6198..ea6c602 100644
--- a/crates/copperline-web/www/try.js
+++ b/crates/copperline-web/www/try.js
@@ -1010,12 +1010,18 @@ window.addEventListener('keydown', (e) => {
   if (joystickKey(e.code, true) || emu.key_event(e.code, true)) {
     consumedKeys.add(e.code);
     e.preventDefault();
+  } else {
+    consumedKeys.delete(e.code);
   }
 });
 window.addEventListener('keyup', (e) => {
+  // Delete before the running check: a hold that spans an emulator stop
+  // or a focus loss must not leave a stale entry behind.
+  const consumed = consumedKeys.delete(e.code);
   if (!emu || !running) return;
-  const consumed = joystickKey(e.code, false) || emu.key_event(e.code, false);
-  if (consumedKeys.delete(e.code) || consumed) e.preventDefault();
+  if (joystickKey(e.code, false) || emu.key_event(e.code, false) || consumed) {
+    e.preventDefault();
+  }
 });
 
 // --- mouse ---------------------------------------------------------------