The Ruffle Flash Player emulator on iOS

Work in progress.

See ruffle.rs for a general introduction.

Design choices

A normal person might have wrapped the Rust in some extern "C" fns, and then used SwiftUI, or at least Objective-C for the UI shell. I would probably recommend that for most use-cases.

I'm developing objc2 though, and I want to improve the user-interface of that, so I decided to be a bit unortodox, and do everything in Rust.

Testing

Run the core player on Mac Catalyst with:

cargo bundle --target=aarch64-apple-ios-macabi --bin run_swf && ./target/aarch64-apple-ios-macabi/debug/bundle/ios/Ruffle.app/run_swf

UI

Similar to https://getutm.app/, we should have:

• A library of "installed" SWFs/bundles/saved links, editable.
• When selecting an SWF, the navigation bar at the top shows various options
  • Opening keyboard (maybe?)
  • Context menu "play, rewind, forward, back, etc."?
  • Allow changing between scale
  • Back button to go back to library
• "Add" and "edit" are two different flows, and should show two different UIs
  • "Add" doesn't have to show all the extra settings; it is only about getting the file. The user can edit it later.

Library item settings

Settings are stored per Ruffle Bundle.

• PlayerOptions
  • https://github.com/ruffle-rs/ruffle/blob/master/frontend-utils/src/bundle/README.md#player
• Inputs:
  • Configurable
  • Swipe for arrow keys?
  • https://openemu.org/ does it pretty well, equivalent for iOS?
• Custom name?
• Custom image?

Storage ideas

Goals:

• Store a Ruffle bundle.
• Store user settings.
• Store data the SWF itself may have stored (the key-value store).
• Sync to iCloud.
• Be backwards and forwards compatible with new versions of the Ruffle app.
  • Upheld for Ruffle Bundles.

So, we want to support several modes of launching:

• Import bundle permanently.
• Open a Ruffle Bundle without importing.
• What happens when a bundle has moved relative to the user settings?

Bundles, when imported, are unpackaged from zip, renamed to bundle.ruf and moved to library/$random_uuid/, to not conflict with other bundles with the same name. Imported SWFs are converted to a Ruffle bundle with name = "file_stem", url = "file:///file_stem.swf". The files are stored on disk in the application's directory. User settings are stored in settings.toml next to bundle.ruf. Application data in app_data/.

Rule for syncing is "newest wins". This should be fine if e.g. the user has modified their settings on two different devices, though might require different logic for application data.

Note that we could have used a Core Data model, but that's difficult and won't really help us when our settings is mostly defined by the Ruffle Bundle.

Terminology

What do we call an swf? "Game"? "Movie"? "SWF"? "Flash Animation"?

Plan

1. Get the Ruffle UI running in a UIView
2. Wire up some way to start it using an SWF on the local device

TODO

• Set idleTimerDisabled at the appropriate time
• Use white for labels, orange for buttons
• Add settings button in library item

Choices

• Intentionally use public.app-category.games to get better performance ("Game Mode" on macOS).
  • This is not necessarily the correct choice for Ruffle, but it's the closest.
• It doesn't make sense to have root settings like in the desktop version
• No tab bar, not really desired, since we generally want the SWF's UI to fill most of the screen
  • Though if we decide to add an easy way to download from "trusted" sources, we could add a tab bar for that
• A navigation bar is useful though
  • To display some settings for the current swf
  • To go back to library
  • Hide when entering full screen?