# MainMenu.swf — Multiplayer button patch guide

Reference export: [`scripts/MainMenu.as`](scripts/MainMenu.as)  
Edit the script **inside FFDec** on the SWF (or paste changes back into FFDec after editing the export). Saving only the `.as` file does not update `MainMenu.swf`.

## Why texts/sprites only showed CONTINUE

The main menu is a **dynamic list** (`MainPanel_mc.List_mc`). Items like `$NEW`, `$LOAD`, `$SETTINGS` are pushed in **`InitList()`**, not stored as static text tags.

## Three edits in `MainMenu` class

### 1. Add index constant (~line 214)

After `INSTALLED_CONTENT_INDEX`:

```actionscript
private const MULTIPLAYER_INDEX:Number = 15;
```

Index `15` is unused in vanilla (highest defined is `INSTALLED_CONTENT_INDEX = 14`).

### 2. Add list entry in `InitList()` (~line 589)

Insert **after** the `$LOAD` push and **before** the PS5 transfer / DLC block — only on the title screen (`!PauseMode`):

```actionscript
         this.MainPanel_mc.List_mc.entryList.push({
            "text":"$LOAD",
            "disabled":!this.HasRecentSave || !param6,
            "index":this.LOAD_INDEX
         });
         // --- ADD BELOW ---
         if(!this.PauseMode)
         {
            this.MainPanel_mc.List_mc.entryList.push({
               "text":"Multiplayer",
               "index":this.MULTIPLAYER_INDEX
            });
         }
         // --- ADD ABOVE ---
         if(param8 == true)
```

Using literal `"MULTIPLAYER"` avoids needing a `.strings` entry for the PoC. Later switch to `"$COSYNC_MULTIPLAYER"` + `Interface/Translate_en.txt` if you want localization.

**Label text:** For the PoC use a **literal** label (no `$` prefix):

```actionscript
"text":"Multiplayer",
```

Strings starting with `$` are looked up in `Interface/Translate_en.txt` (from `Fallout4 - Interface.ba2`). A lone `Interface/Translations/MainMenu_en.txt` is **not** how vanilla resolves main-menu keys, so `$MULTIPLAYER` shows as-is until you merge the key into `Translate_en.txt` (extract from BA2, append `$MULTIPLAYER	Multiplayer`, redeploy loose file).

Regenerate optional translation stub: `python tools/write_mainmenu_translation.py` (for future i18n / Translate_en merge only).

### Fallout 4 must load loose Interface files

Loose `Data/Interface/*.swf` overrides are **ignored** unless archive invalidation is on. Add to `%USERPROFILE%/Documents/My Games/Fallout4/Fallout4Custom.ini`:

```ini
[Archive]
bInvalidateOlderFiles=1
```

(MO2 enables this automatically; manual `Data/` copies need it.)

Without invalidation, the game keeps using `Fallout4 - Interface.ba2` — your patched SWF never loads even though the file is on disk.

Suggested placement: between **Load** and **Add-ons** so it reads naturally on the main menu.

### 3. Handle selection in `onMainListItemPress()` switch (~line 864)

Add **before** `case this.HELP_INDEX:` (or anywhere in the switch):

```actionscript
               case this.MULTIPLAYER_INDEX:
                  this.BGSCodeObj.PlayOKSound();
                  if(root.f4se != null && root.f4se.plugins != null && root.f4se.plugins.commonwealthOnline != null)
                  {
                     root.f4se.plugins.commonwealthOnline.openManager();
                  }
                  break;
```

Requires the C++ plugin to register `commonwealthOnline.openManager()` via F4SE Scaleform (not done yet). Until then, the button will play the OK sound and do nothing else — safe for SWF-only testing.

## FFDec workflow

1. Open `Interface/MainMenu.swf` in FFDec.
2. **scripts → MainMenu** → right-click → **Replace / Edit** (or open script, paste from [`scripts/MainMenu.as`](scripts/MainMenu.as)).
3. **File → Save** (overwrites SWF).
4. Deploy to `Fallout 4/Data/Interface/MainMenu.swf` or your mod folder.
5. Launch via F4SE and test.

**Re-import from edited export:** In FFDec, select the **MainMenu** script under **scripts**, use **Edit ActionScript** and paste the full contents of `Interface/exported/scripts/MainMenu.as`, then save the SWF. FFDec may also offer **Import script** / **Replace script** from file depending on version.

Keep `MainMenu.swf.vanilla.bak` unchanged.

## Related functions (no edit needed for PoC)

| Function | Role |
|----------|------|
| `InitList()` | Builds `entryList` with `$CONTINUE`, `$NEW`, `$LOAD`, … |
| `onMainListItemPress()` | `switch` on `selectedEntry.index` |
| `onListItemPress()` | Routes list press events to `onMainListItemPress()` |
| Index constants (~184–212) | `CONTINUE_INDEX` … `INSTALLED_CONTENT_INDEX` |

## Next step (code)

Implement `commonwealthOnline.openManager()` in `CommonwealthOnline.dll` and `CoSyncServerBrowser.swf` per [docs/custom-swf-ui.md](../../docs/custom-swf-ui.md).