Marker Interfaces

PulseDesktop uses marker interfaces to enforce type safety at the generic level. None of them has members; they exist solely to constrain type parameters.

PulseState

interface PulseState

Marks a class as the UI state managed by a PulseViewModel. Implement with a data class so copy() is available for immutable updates.

data class CounterState(
    val count: Int = 0,
    val isLoading: Boolean = false,
) : PulseState

---

PulseAction

interface PulseAction

Marks a class as a user intent dispatched to a PulseViewModel. Implement with a sealed class so all possible actions can be enumerated exhaustively.

sealed class CounterAction : PulseAction {
    data object Increment : CounterAction()
    data object Decrement : CounterAction()
    data class SetValue(val value: Int) : CounterAction()
}

---

PulseEvent

interface PulseEvent

Marks a class as a one-time side effect emitted from a PulseViewModel to the UI. Implement with a sealed class.

sealed class CounterEvent : PulseEvent {
    data class ShowMessage(val message: String) : CounterEvent()
    data object NavigateBack : CounterEvent()
}

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PulseBroadcast

interface PulseBroadcast

Marks a class as a broadcast message. PulseContainer delivers it to all registered PulseViewModel instances. Implement with a sealed class.

sealed class AppBroadcast : PulseBroadcast {
    data object UserLoggedOut : AppBroadcast()
    data class ThemeChanged(val isDark: Boolean) : AppBroadcast()
}

---

PulseUnicast

interface PulseUnicast

Marks a class as a unicast message. A child PulseViewModel emits it to its parent PulseContainer. Implement with a sealed class.

sealed class AppUnicast : PulseUnicast {
    data object SaveRequested : AppUnicast()
    data class ItemSelected(val id: String) : AppUnicast()
}