fix(controller): pick up macOS presses while mpv is in front (#321)

scripts/macos-controller-watch.swift

@@ -0,0 +1,87 @@
+#!/usr/bin/env swift
+//
+//  macos-controller-watch.swift
+//  SubMiner - Report controller button presses on macOS while SubMiner is in the background
+//
+//  macOS only delivers GameController input to the frontmost app, so the overlay sees no
+//  presses while mpv is in front. This helper opts in to background events and prints one
+//  line per press so SubMiner can focus the overlay and replay the press there.
+//
+//  Usage: macos-controller-watch (long-running; exits when stdin closes)
+//  Output: "press <index> <connected pads>" per button press, using the W3C standard gamepad
+//  button indices. SubMiner only replays a press when one pad is connected: nothing identifies
+//  a pad to both GameController and Chromium, so with several it could hit the wrong one.
+//
+
+import Cocoa
+import Foundation
+import GameController
+
+private func emit(_ line: String) {
+    FileHandle.standardOutput.write(Data((line + "\n").utf8))
+}
+
+/// Standard gamepad mapping (https://w3c.github.io/gamepad/#remapping), matching the
+/// indices Chromium reports for the same pad.
+private func standardButtons(_ pad: GCExtendedGamepad) -> [(Int, GCControllerButtonInput?)] {
+    return [
+        (0, pad.buttonA),
+        (1, pad.buttonB),
+        (2, pad.buttonX),
+        (3, pad.buttonY),
+        (4, pad.leftShoulder),
+        (5, pad.rightShoulder),
+        (6, pad.leftTrigger),
+        (7, pad.rightTrigger),
+        (8, pad.buttonOptions),
+        (9, pad.buttonMenu),
+        (10, pad.leftThumbstickButton),
+        (11, pad.rightThumbstickButton),
+        (12, pad.dpad.up),
+        (13, pad.dpad.down),
+        (14, pad.dpad.left),
+        (15, pad.dpad.right),
+        (16, pad.buttonHome),
+    ]
+}
+
+private func connectedPadCount() -> Int {
+    return GCController.controllers().filter { $0.extendedGamepad != nil }.count
+}
+
+private func watch(_ controller: GCController) {
+    guard let pad = controller.extendedGamepad else { return }
+    for (index, button) in standardButtons(pad) {
+        button?.pressedChangedHandler = { _, _, pressed in
+            if pressed {
+                emit("press \(index) \(connectedPadCount())")
+            }
+        }
+    }
+}
+
+// Exit with SubMiner: it holds our stdin open for as long as it runs.
+private func exitWhenStdinCloses() {
+    Thread.detachNewThread {
+        while !FileHandle.standardInput.availableData.isEmpty {}
+        exit(0)
+    }
+}
+
+let app = NSApplication.shared
+app.setActivationPolicy(.prohibited)
+GCController.shouldMonitorBackgroundEvents = true
+
+NotificationCenter.default.addObserver(
+    forName: .GCControllerDidConnect,
+    object: nil,
+    queue: .main
+) { notification in
+    if let controller = notification.object as? GCController {
+        watch(controller)
+    }
+}
+GCController.controllers().forEach(watch)
+
+exitWhenStdinCloses()
+app.run()