From 0a48c5c75dd2f7a5033f48ba685ca499fc6e4b2d Mon Sep 17 00:00:00 2001
From: Steven Hugg <hugg@fasterlight.com>
Date: Tue, 15 Sep 2026 10:41:34 +0200
Subject: [PATCH] ui: in tab mode, pause/resume emulator when show/hide
 emulator tab

---
 README.md         | 21 ++++++++++++---------
 src/ide/layout.ts |  6 ++++++
 src/ide/ui.ts     | 15 +++++++++++++++
 3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index db01165d..d0a61e84 100644
--- a/README.md
+++ b/README.md
@@ -37,8 +37,6 @@ Bleeding edge (built from HEAD):
 * Export ROMs, save screenshots/videos, share playable links, and sync
   projects to GitHub
 
-Read the [IDE documentation](src/docs/index.md) for a guided tour.
-
 ## Install Locally
 
 Requirements:
@@ -68,6 +66,14 @@ TypeScript and lezer grammars, and runs esbuild.
 To use GitHub integration locally, download the Firebase config file,
 e.g. https://8bitworkshop.com/v[version]/config.js
 
+### Develop with VSCode
+
+To fix TypeScript errors in VSCode:
+* Open any TypeScript file
+* Open the command palette (Cmd+Shift+P)
+* Select "TypeScript: Select TypeScript Version"
+* Select "Use Workspace Version"
+
 ### Start Local Web Server
 
 Start a web server on http://localhost:8000/ while TypeScript compiles
@@ -241,21 +247,18 @@ distributable replacement images are included — see
 licenses.
 
 To use your own firmware, add it to the project as a binary file named
-`<platform-id>.rom` (for example `c64.rom`); the IDE loads it as the
+`<platform-id>.rom` (for example `apple2.rom`); the IDE loads it as the
 BIOS at startup. Only freely distributable firmware should be shared.
 
-* http://www.virtualdub.org/altirra.html
+* http://www.virtualdub.org/altirra.html (GPL-2)
 * https://github.com/MEGA65/open-roms (LGPL-3.0)
-* https://sourceforge.net/projects/cbios/
-* https://www.pledgebank.com/opense
+* https://sourceforge.net/projects/cbios/ (BSD)
 
 ### Related Projects
 
-* https://github.com/sehugg/8bitworkshop-compilers
 * https://github.com/sehugg/8bit-tools (CC0-1.0)
 * https://github.com/sehugg/awesome-8bitgamedev (Public Domain)
-* https://github.com/sehugg?tab=repositories (CC0-1.0)
-
+* https://github.com/sehugg/8bitworkshop-compilers
 
 ## Tool Server (experimental)
 
diff --git a/src/ide/layout.ts b/src/ide/layout.ts
index 3c04c9a8..d039c13b 100644
--- a/src/ide/layout.ts
+++ b/src/ide/layout.ts
@@ -26,6 +26,8 @@ export interface LayoutHooks {
   hasLocalStorage: boolean;
   resizePlatform(): void;
   resizeWindows(): void;
+  // tab mode only: the visible pane changed (e.g. 'sidebar', 'editor', 'emulator')
+  onTabChanged?(tab: string): void;
 }
 
 var hooks: LayoutHooks = null;
@@ -77,6 +79,8 @@ function setActiveTabClass(tab: string) {
   $("#sidebar,#workspace,#emulator").removeClass("active");
   var sel = activeTab === 'sidebar' ? '#sidebar' : activeTab === 'emulator' ? '#emulator' : '#workspace';
   $(sel).addClass("active");
+  // only meaningful in tab mode; on desktop all panes stay visible
+  if (tabMode && hooks && hooks.onTabChanged) hooks.onTabChanged(activeTab);
 }
 
 function setTabMode(on: boolean) {
@@ -109,6 +113,8 @@ function updateSplitLayout() {
     // leaving tab mode: restore the side-by-side panes and their sizes
     setTabMode(false);
     $("#sidebar,#workspace,#emulator").removeClass("active");
+    // all panes are visible again; let the emulator resume if a tab hid it
+    if (hooks && hooks.onTabChanged) hooks.onTabChanged('emulator');
     createSplit(desktopSizes || [12, 44, 44]);
     hooks.resizePlatform();
     hooks.resizeWindows();
diff --git a/src/ide/ui.ts b/src/ide/ui.ts
index 27179b75..4140fe11 100644
--- a/src/ide/ui.ts
+++ b/src/ide/ui.ts
@@ -86,6 +86,7 @@ var toolbar = $("#controls_top");
 var uitoolbar: Toolbar;
 var stateRecorder: StateRecorderImpl;
 var userPaused: boolean;		// did user explicitly pause?
+var tabPausedEmulator = false;	// did a tab switch (mobile tab mode) pause the emulator?
 var debugSessionActive: boolean;	// has the user entered a debug session? (drives debug shortcut chips)
 var current_output: any;     // current ROM (or other object)
 var current_preset: Preset;	// current preset object (if selected)
@@ -2475,6 +2476,20 @@ export async function startUI() {
     hasLocalStorage: hasLocalStorage,
     resizePlatform: () => { if (platform && platform.resize) platform.resize(); },
     resizeWindows: () => { if (projectWindows) projectWindows.resize(); },
+    // in tab mode only one pane is visible; pause the emulator when the
+    // emulator tab isn't on screen, and resume it when it comes back
+    onTabChanged: (tab) => {
+      if (!isPlatformReady()) return;
+      if (tab !== 'emulator') {
+        if (platform.isRunning()) {
+          _pause();
+          tabPausedEmulator = true; // remember it was us, not the user
+        }
+      } else if (tabPausedEmulator) {
+        tabPausedEmulator = false;
+        if (!platform.isRunning()) _resume();
+      }
+    },
   });
   // get store ID, repo id or platform id
   store_id = repo_id || getBasePlatform(platform_id);