Initial release

Sources/KnotchyCore/Stream/InputEvent.swift

@@ -0,0 +1,78 @@
+import Foundation
+
+public struct Modifiers: OptionSet, Hashable, Sendable {
+    public let rawValue: UInt8
+
+    public init(rawValue: UInt8) {
+        self.rawValue = rawValue
+    }
+
+    public static let shift = Modifiers(rawValue: 1 << 0)
+    public static let control = Modifiers(rawValue: 1 << 1)
+    public static let alt = Modifiers(rawValue: 1 << 2)
+    public static let meta = Modifiers(rawValue: 1 << 3)
+    public static let leftButton = Modifiers(rawValue: 1 << 4)
+    public static let rightButton = Modifiers(rawValue: 1 << 5)
+    public static let middleButton = Modifiers(rawValue: 1 << 6)
+}
+
+public enum PointerButton: UInt8, Sendable {
+    case left = 1
+    case right = 2
+    case middle = 3
+}
+
+/// A viewer → agent message. Coordinates are render pixels from the top left; negative scroll is down/right.
+public enum InputEvent: Equatable, Sendable {
+    case pointerMove(x: UInt16, y: UInt16, mods: Modifiers)
+    case pointerButton(PointerButton, pressed: Bool, x: UInt16, y: UInt16, mods: Modifiers)
+    case scroll(ticksX: Int16, ticksY: Int16, x: UInt16, y: UInt16)
+    case key(pressed: Bool, mods: Modifiers, name: String)
+    case navigate(String)
+    case script(String)
+    case keyframe
+
+    /// Nil if the agent can't use it: a payload over 64 KiB, an empty KEY name, or a NUL in a string.
+    public func encoded() -> Data? {
+        var payload = Data()
+        let type: UInt8
+        switch self {
+        case .pointerMove(let x, let y, let mods):
+            type = MessageType.pointerMove
+            payload.appendBE16(x)
+            payload.appendBE16(y)
+            payload.append(mods.rawValue)
+        case .pointerButton(let button, let pressed, let x, let y, let mods):
+            type = MessageType.pointerButton
+            payload.append(button.rawValue)
+            payload.append(pressed ? 1 : 0)
+            payload.appendBE16(x)
+            payload.appendBE16(y)
+            payload.append(mods.rawValue)
+        case .scroll(let ticksX, let ticksY, let x, let y):
+            type = MessageType.scroll
+            payload.appendBE16(UInt16(bitPattern: ticksX))
+            payload.appendBE16(UInt16(bitPattern: ticksY))
+            payload.appendBE16(x)
+            payload.appendBE16(y)
+        case .key(let pressed, let mods, let name):
+            guard !name.isEmpty, !name.utf8.contains(0) else { return nil }
+            type = MessageType.key
+            payload.append(pressed ? 1 : 0)
+            payload.append(mods.rawValue)
+            payload.append(contentsOf: Array(name.utf8))
+        case .navigate(let url):
+            guard !url.utf8.contains(0) else { return nil }
+            type = MessageType.navigate
+            payload.append(contentsOf: Array(url.utf8))
+        case .script(let javaScript):
+            guard !javaScript.utf8.contains(0) else { return nil }
+            type = MessageType.script
+            payload.append(contentsOf: Array(javaScript.utf8))
+        case .keyframe:
+            type = MessageType.keyframe
+        }
+        guard payload.count <= WireProtocol.maxOtherPayload else { return nil }
+        return framed(type, payload)
+    }
+}