A library for creating Stream Deck plugins in Swift.
Your plugin should conform to PluginDelegate, which handles event routing to you actions and lets you interact with the Stream Deck application.
@main
class CounterPlugin: PluginDelegate {
static var name: String = "Counter"
static var description: String = "Count things. On your Stream Deck!"
static var author: String = "Emory Dunn"
static var icon: String = "Icons/pluginIcon"
static var version: String = "0.4"
static var actions: [any Action.Type] = [
IncrementAction.self,
DecrementAction.self
]
required init() { }
}By using the @main attribute your plugin will be automatically initialized.
A plugin both defines the code used to interact with the Stream Deck and the manifest for the plugin. When declaring your plugin there are a number of static properties which are defined to tell the Stream Deck application about what your plugin is and what it can do. Not all properties are required, for instance your plugin doesn't need to add a custom category. Optional properties have default overloads to help reduce boilerplate.
Many of the properties are shown to users, such as the name and description. Others are used internally by the Stream Deck application. The most important property is actions which is where you define the actions your plugin provides.
static var actions: [any Action.Type] = [
IncrementAction.self,
DecrementAction.self
]Actions are provided as a type because the plugin will initialize a new instance per visible key.
There are two ways to share a global state amongst actions:
- The Environment
- Global Settings
In use they're very similar, only differing by a couple of protocols. The important difference is that environmental values aren't persisted whereas global settings are stored and will be consistent across launches of the Stream Deck app.
There are two ways to declare environmental values and global settings.
Start with a struct that conforms to EnvironmentKey or GlobalSettingKey. This defines the default value and how the value will be accessed:
struct Count: EnvironmentKey {
static let defaultValue: Int = 0
}Next add an extension to either EnvironmentValues or GlobalSettings:
extension EnvironmentValues {
var count: Int {
get { self[Count.self] }
set { self[Count.self] = newValue }
}
}To use the value in your actions use the corresponding property wrapper:
@Environment(\.count) var count // For an environment key
@GlobalSetting(\.count) var count // For a global settings keyThe value can be read and updated from inside an action callback.
Starting in Swift 5.9 two new macros will be available to make declaring environmental values and global settings easier. The macro handles generating both the struct and variable for the key path.
extension EnvironmentValues {
#environmentKey("count", defaultValue: 0, ofType: Int.self)
}
extension GlobalSettings {
#globalSetting("count", defaultValue: 0, ofType: Int.self)
}Each action in your plugin is defined as a separate struct conforming to Action. There are several helper protocols available for specific action types.
| Protocol | Description |
|---|---|
KeyAction |
A key action which has multiple states |
StatelessKeyAction |
A key action which has a single state |
EncoderAction |
A rotary encoder action on the Stream Deck + |
Using one of the above protocols simply provides default values on top of Action, and you can provide your own values as needed. For instance KeyAction sets the controllers property to [.keypad] by default, and EncoderAction sets it to [.encoder]. To create an action that provides both key and encoder actions set controllers to [.keypad, .encoder] no matter which convenience protocol you're using.
For all action there are several common static properties which need to be defined.
struct IncrementAction: KeyAction {
typealias Settings = NoSettings
static var name: String = "Increment"
static var uuid: String = "counter.increment"
static var icon: String = "Icons/actionIcon"
static var states: [PluginActionState]? = [
PluginActionState(image: "Icons/actionDefaultImage", titleAlignment: .middle)
]
var context: String
var coordinates: StreamDeck.Coordinates?
@GlobalSetting(\.count) var count
required init(context: String, coordinates: StreamDeck.Coordinates?) {
self.context = context
self.coordinates = coordinates
}
}If your action uses a property inspector for configuration you can use a Codable struct as the Settings. The current settings will be sent in the payload in events.
struct ChooseAction: KeyAction {
enum Settings: String, Codable {
case optionOne
case optionTwo
case optionThree
}
}Your action can both receive events from the app and send events to the app. Most of the events will be from user interaction, key presses and dial rotation, but also from system events such as the action appearing on a Stream Deck or the property inspector appearing.
To receive events simply implement the corresponding method in your action, for instance to be notified when a key is released use keyUp. If your action displays settings to the user, use willAppear to update the title to reflect the current value.
struct IncrementAction: KeyAction {
func willAppear(device: String, payload: AppearEvent<NoSettings>) {
setTitle(to: "\(count)", target: nil, state: nil)
}
func didReceiveGlobalSettings() {
log.log("Global settings changed, updating title with \(self.count)")
setTitle(to: "\(count)", target: nil, state: nil)
}
func keyUp(device: String, payload: KeyEvent<Settings>) {
count += 1
}
}In the above example, setTitle is an event that an action can send. In this case it sets the title of the action. It's called in two places: when the action appears to set the initial title and when the global settings are changed so it can keep the visible counter in sync.
Your plugin executable ships with an automatic way to generate the plugin's manifest.json file in a type-safe manor. Use the provided export command on your plugin binary to export the manifest and copy the binary itself. You will still need to use Elgato's DistributionTool for final packaging.
OVERVIEW: Conveniently export the plugin.
Automatically generate the manifest and copy the executable to the Plugins folder.
USAGE: plugin-command export <uri> [--output <output>] [--generate-manifest] [--preview-manifest] [--manifest-name <manifest-name>] [--copy-executable] [--executable-name <executable-name>]
ARGUMENTS:
<uri> The URI for your plugin
OPTIONS:
-o, --output <output> The folder in which to create the plugin's directory. (default: ~/Library/Application Support/com.elgato.StreamDeck/Plugins)
--generate-manifest/--preview-manifest
Encode the manifest for the plugin and either save or preview it.
-m, --manifest-name <manifest-name>
The name of the manifest file. (default: manifest.json)
-c, --copy-executable Copy the executable file.
-e, --executable-name <executable-name>
The name of the executable file.
--version Show the version.
-h, --help Show help information.To use the StreamDeck library in a SwiftPM project,
add the following line to the dependencies in your Package.swift file:
.package(name: "StreamDeck", url: "https://github.com/emorydunn/StreamDeckPlugin.git", .branch("main"))Finally, include "StreamDeck" as a dependency for your executable target:
let package = Package(
// name, products, etc.
platforms: [.macOS(.v11)],
dependencies: [
.package(name: "StreamDeck", url: "https://github.com/emorydunn/StreamDeckPlugin.git", .branch("main")),
// other dependencies
],
targets: [
.executableTarget(name: "<command-line-tool>", dependencies: [
"StreamDeck"
]),
// other targets
]
)