cleanup delegate

Sources/phbar/AppDelegate.swift

@@ -1,72 +0,0 @@
-import AppKit
-
-@MainActor
-final class AppDelegate: NSObject, NSApplicationDelegate {
-	var controllers: [BarController] = []
-	var windows: [BarWindow] = []
-	private var observers: [IPCObserver] = []
-
-	/// Create one bar controller per screen. Each screen resolves its own
-	/// theme, window and block set from the config, so refresh state and layout stay
-	/// independent across monitors.
-	init(
-		config: PHConfig,
-		screens: [NSScreen],
-		debug: Bool
-	) throws {
-		super.init()
-
-		// The merged environment (process + `[env]`) is shared by every screen:
-		// scripts see it as their process environment, and themes expand `$VAR`
-		// references in colors/fonts against it.
-		let environment = PHEnvironment.process.merging(config.env)
-
-		for screen in screens {
-			let name = screen.localizedName
-			let index = NSScreen.screens.firstIndex(of: screen)
-			let theme = try PHTheme.load(config.theme(screenName: name, screenIndex: index), environment: environment)
-			let blocks = try PHBlock.load(config.blocks(screenName: name, screenIndex: index))
-
-			controllers.append(
-				BarController(
-					config: config,
-					screen: screen,
-					theme: theme,
-					blocks: blocks,
-					environment: environment,
-					debug: debug
-				)
-			)
-		}
-	}
-
-	func applicationDidFinishLaunching(_ notification: Notification) {
-		for controller in controllers {
-			let window = BarWindow(controller: controller)
-			window.orderFront(nil)
-			windows.append(window)
-			controller.startAutoRefresh()
-		}
-
-		// Listen for refresh notifications from `phbar refresh`.
-		let token = IPC.observe(.refresh) { [weak self] _ in
-			Task { @MainActor in
-				self?.refresh()
-			}
-		}
-		observers.append(token)
-	}
-
-	func refresh() {
-		for controller in controllers {
-			controller.refresh()
-		}
-	}
-
-	func applicationWillTerminate(_ notification: Notification) {
-		for controller in controllers {
-			controller.stopAutoRefresh()
-		}
-		observers.removeAll()
-	}
-}

Sources/phbar/CLI/cli+start.swift

@@ -19,16 +19,9 @@ extension phbar {
 			dispatchPrecondition(condition: .onQueue(.main))
 
 			try MainActor.assumeIsolated {
-				// Spawn a bar on every screen; per-monitor window and block-set
+				guard !NSScreen.screens.isEmpty else { throw CleanExit.message("No monitor found") }
-				// selection is driven by the config's `[monitor]` overrides.
-				let screens = NSScreen.screens
-				guard !screens.isEmpty else { throw CleanExit.message("No monitor found") }
 
-				let delegate = try AppDelegate(
+				let delegate = PHBarDelegate(config: config, debug: debug)
-					config: config,
-					screens: screens,
-					debug: debug
-				)
 				let app = NSApplication.shared
 				app.setActivationPolicy(.accessory)
 				app.delegate = delegate

Sources/phbar/Models/PHBarDelegate.swift

@@ -0,0 +1,69 @@
+import AppKit
+
+@MainActor
+final class PHBarDelegate: NSObject, NSApplicationDelegate {
+	/// One window per attached screen — the single source of truth. The matching
+	/// controllers are reached through `windows[i].barController`.
+	var windows: [BarWindow] = []
+
+	/// Convenience accessor over `windows`.
+	var controllers: [BarController] { windows.map(\.barController) }
+
+	/// Resolves a controller for any screen from the current config. Swapped by
+	/// `reloadAll()` so a live reload re-reads theme/blocks from disk.
+	var factory: PHBarFactory
+
+	private var observers: [IPCObserver] = []
+	private var screenObserver: NSObjectProtocol?
+
+	/// `config` is captured here (not re-read per screen) so all bars share one
+	/// resolved config + environment for their lifetime. Live reload swaps the
+	/// whole factory via `reloadAll()`.
+	init(config: PHConfig, debug: Bool) {
+		let environment = PHEnvironment.process.merging(config.env)
+		self.factory = PHBarFactory(config: config, environment: environment, debug: debug)
+		super.init()
+	}
+
+	func applicationDidFinishLaunching(_ notification: Notification) {
+		syncScreens()
+
+		// React to monitor connect/disconnect and resolution changes. macOS
+		// delivers a single app-level notification for any of these; `syncScreens`
+		// diffs so unchanged bars are left untouched.
+		screenObserver = NotificationCenter.default.addObserver(
+			forName: NSApplication.didChangeScreenParametersNotification,
+			object: nil,
+			queue: .main
+		) { [weak self] _ in
+			Task { @MainActor in self?.syncScreens() }
+		}
+
+		// Listen for refresh notifications from `phbar refresh`.
+		let token = IPC.observe(.refresh) { [weak self] _ in
+			Task { @MainActor in self?.refresh() }
+		}
+		observers.append(token)
+	}
+
+	func refresh() {
+		for controller in controllers {
+			controller.refresh()
+		}
+	}
+
+	func applicationWillTerminate(_ notification: Notification) {
+		for controller in controllers {
+			controller.stopAutoRefresh()
+		}
+		observers.removeAll()
+		if let screenObserver {
+			NotificationCenter.default.removeObserver(screenObserver)
+			self.screenObserver = nil
+		}
+	}
+
+	func stderr(_ message: String) {
+		FileHandle.standardError.write(Data("phbar: \(message)\n".utf8))
+	}
+}

Sources/phbar/Models/PHBarDelegate/PHBarDelegate+Lifecycle.swift

@@ -0,0 +1,43 @@
+import AppKit
+
+extension PHBarDelegate {
+	/// Build, show, and start a bar for `screen`. Returns `false` (and prints to
+	/// stderr) if the screen's theme or blocks fail to load, so one bad screen
+	/// can't take down the others.
+	@discardableResult
+	func addBar(for screen: NSScreen) -> Bool {
+		let controller: BarController
+		do {
+			controller = try factory.make(for: screen)
+		} catch {
+			stderr("skipping screen \(screen.localizedName): \(error)")
+			return false
+		}
+		let window = BarWindow(controller: controller)
+		window.orderFront(nil)
+		windows.append(window)
+		controller.startAutoRefresh()
+		return true
+	}
+
+	/// Stop refresh, hide, and drop the bar running on `screen` (if any).
+	func removeBar(for screen: NSScreen) {
+		guard let index = windows.firstIndex(where: { $0.barController.screen === screen }) else {
+			return
+		}
+		windows[index].barController.stopAutoRefresh()
+		windows[index].orderOut(nil)
+		windows.remove(at: index)
+	}
+
+	/// The window currently running on `screen`, if any.
+	func window(for screen: NSScreen) -> BarWindow? {
+		windows.first { $0.barController.screen === screen }
+	}
+
+	/// The window currently running on the monitor named `name`, if any.
+	func window(named name: String) -> BarWindow? {
+		windows.first { $0.barController.screen.localizedName == name }
+	}
+
+}

Sources/phbar/Models/PHBarDelegate/PHBarDelegate+Reload.swift

@@ -0,0 +1,44 @@
+extension PHBarDelegate {
+	// MARK: - Reload (entry points for a future `phbar reload`)
+
+	/// Re-read config from disk and rebuild every bar against it. Screens are
+	/// kept; only theme/blocks/window are re-resolved. This is the global path
+	/// for picking up config edits at runtime.
+	func reloadAll() {
+		let config: PHConfig
+		do {
+			config = try PHConfig.load()
+		} catch {
+			stderr("reload failed, could not read config: \(error)")
+			return
+		}
+		factory = PHBarFactory(
+			config: config,
+			environment: PHEnvironment.process.merging(config.env),
+			debug: factory.debug
+		)
+		rebuildAllBars()
+	}
+
+	/// Rebuild a single monitor's bar against the current factory. Per-monitor
+	/// path for picking up config edits at runtime. Returns `false` if no bar
+	/// currently runs on `name` (or its reload failed to load).
+	@discardableResult
+	func reload(screenNamed name: String) -> Bool {
+		guard let screen = window(named: name)?.barController.screen else { return false }
+		removeBar(for: screen)
+		return addBar(for: screen)
+	}
+
+	/// Tear down every bar and rebuild against the current factory, preserving
+	/// the set of screens.
+	private func rebuildAllBars() {
+		let screens = controllers.map(\.screen)
+		for screen in screens {
+			removeBar(for: screen)
+		}
+		for screen in screens {
+			addBar(for: screen)
+		}
+	}
+}

Sources/phbar/Models/PHBarDelegate/PHBarDelegate+ScreenSync.swift

@@ -0,0 +1,28 @@
+import AppKit
+
+extension PHBarDelegate {
+	/// Reconcile live bars against `screens`: tear down bars whose screen is
+	/// gone, recompute frames for screens whose geometry may have changed, and
+	/// add bars for newly attached screens.
+	///
+	/// A screen whose theme or blocks fail to load is skipped (with a stderr
+	/// message) rather than aborting the rest.
+	///
+	/// - Parameter screens: Defaults to `NSScreen.screens`; injected for tests.
+	func syncScreens(screens: [NSScreen] = NSScreen.screens) {
+		let plan = PHScreenSync.diff(
+			current: screens,
+			occupied: controllers.map(\.screen)
+		)
+
+		for screen in plan.removed {
+			removeBar(for: screen)
+		}
+		for screen in plan.kept {
+			window(for: screen)?.recomputeFrame()
+		}
+		for screen in plan.added {
+			addBar(for: screen)
+		}
+	}
+}

Sources/phbar/Models/PHBarFactory.swift

@@ -0,0 +1,39 @@
+import AppKit
+
+/// Builds a `BarController` for a screen by resolving its theme, blocks, and
+/// window from the config.
+///
+/// Extracted from `AppDelegate` so the exact same resolution drives initial
+/// launch, hot-plugged monitors (`syncScreens`), and live reload
+/// (`reloadAll` / `reload(screenNamed:)`). Each screen's theme/blocks are
+/// resolved independently, so a failure on one screen can be skipped without
+/// taking down the others.
+@MainActor
+struct PHBarFactory {
+	let config: PHConfig
+	let environment: PHEnvironment
+	let debug: Bool
+
+	/// Resolve theme + blocks for `screen` and build its controller.
+	///
+	/// - Parameter screen: The screen to build a bar for. Its localized name
+	///   and index in `NSScreen.screens` select any per-monitor config override.
+	/// - Throws: `PHTheme.load` / `PHBlock.load` errors for the resolved names.
+	func make(for screen: NSScreen) throws -> BarController {
+		let name = screen.localizedName
+		let index = NSScreen.screens.firstIndex(of: screen)
+		let theme = try PHTheme.load(
+			config.theme(screenName: name, screenIndex: index),
+			environment: environment
+		)
+		let blocks = try PHBlock.load(config.blocks(screenName: name, screenIndex: index))
+		return BarController(
+			config: config,
+			screen: screen,
+			theme: theme,
+			blocks: blocks,
+			environment: environment,
+			debug: debug
+		)
+	}
+}

Sources/phbar/Models/PHScreenSync.swift

@@ -0,0 +1,31 @@
+import AppKit
+
+/// Which screens to keep, remove, or add when reconciling live bars against the
+/// current `NSScreen.screens`.
+///
+/// Pure and identity-based (it never reads `NSScreen` properties), so it can be
+/// unit-tested with any `[NSScreen]` without driving real window lifecycle.
+enum PHScreenSync {
+	struct Diff: Equatable {
+		/// Screens that already have a bar and are still attached. Their window
+		/// frame is recomputed since geometry may have changed.
+		let kept: [NSScreen]
+		/// Screens whose bar must be torn down (monitor disconnected).
+		let removed: [NSScreen]
+		/// Screens with no bar yet that need one (monitor connected).
+		let added: [NSScreen]
+	}
+
+	/// Compare the screens now attached (`current`) against the screens currently
+	/// occupied by bars (`occupied`). A disconnected monitor reappears as a new
+	/// `NSScreen` instance, so it is reported as remove + add, never a keep.
+	static func diff(current: [NSScreen], occupied: [NSScreen]) -> Diff {
+		let currentIDs = Set(current.map(ObjectIdentifier.init))
+		let occupiedIDs = Set(occupied.map(ObjectIdentifier.init))
+		return Diff(
+			kept: occupied.filter { currentIDs.contains(ObjectIdentifier($0)) },
+			removed: occupied.filter { !currentIDs.contains(ObjectIdentifier($0)) },
+			added: current.filter { !occupiedIDs.contains(ObjectIdentifier($0)) }
+		)
+	}
+}

Sources/phbar/Views/BarWindow.swift

@@ -46,6 +46,13 @@ final class BarWindow: NSPanel {
 }
 
 extension BarWindow {
+	/// Recompute and apply the frame from the controller's screen and theme.
+	/// Used when a screen's geometry changes (resolution, layout) so the bar
+	/// stays correctly anchored without rebuilding the whole window.
+	func recomputeFrame() {
+		setFrame(Self.computeFrame(from: barController), display: true)
+	}
+
 	/// Calculate window frame and position from the theme window definition,
 	/// resolved against the controller's screen.
 	static func computeFrame(from controller: BarController) -> NSRect {

Tests/phbarTests/AppDelegateTests.swift

@@ -0,0 +1,78 @@
+import AppKit
+import Foundation
+import Testing
+
+@testable import phbar
+
+@MainActor
+struct AppDelegateTests {
+
+	// MARK: - ScreenSync.diff
+
+	@Test func diffReportsAddedWhenNothingOccupied() throws {
+		let screen = try #require(NSScreen.main)
+		let plan = PHScreenSync.diff(current: [screen], occupied: [])
+		#expect(plan.added == [screen])
+		#expect(plan.removed.isEmpty)
+		#expect(plan.kept.isEmpty)
+	}
+
+	@Test func diffReportsRemovedWhenScreenGone() throws {
+		let screen = try #require(NSScreen.main)
+		let plan = PHScreenSync.diff(current: [], occupied: [screen])
+		#expect(plan.removed == [screen])
+		#expect(plan.added.isEmpty)
+		#expect(plan.kept.isEmpty)
+	}
+
+	@Test func diffKeepsScreenStillAttached() throws {
+		let screen = try #require(NSScreen.main)
+		let plan = PHScreenSync.diff(current: [screen], occupied: [screen])
+		#expect(plan.kept == [screen])
+		#expect(plan.added.isEmpty)
+		#expect(plan.removed.isEmpty)
+	}
+
+	/// A disconnected monitor reappears as a *new* `NSScreen` instance, so the
+	/// same physical display must be reported as remove + add, never a keep.
+	@Test func diffTreatsDistinctInstancesAsRemoveThenAdd() throws {
+		let main = try #require(NSScreen.main)
+		guard let other = NSScreen.screens.first(where: { $0 !== main }) else {
+			// Single-monitor environment: nothing to contrast against. Verify
+			// identity semantics hold for the same object re-presented instead.
+			let kept = PHScreenSync.diff(current: [main], occupied: [main])
+			#expect(kept.kept == [main])
+			return
+		}
+
+		let plan = PHScreenSync.diff(current: [other], occupied: [main])
+		#expect(plan.removed == [main])
+		#expect(plan.added == [other])
+		#expect(plan.kept.isEmpty)
+	}
+
+	@Test func diffIgnoresOrdering() throws {
+		let main = try #require(NSScreen.main)
+		guard let other = NSScreen.screens.first(where: { $0 !== main }) else {
+			// Single-monitor environment: ordering is trivially stable.
+			return
+		}
+		let plan = PHScreenSync.diff(current: [other, main], occupied: [main, other])
+		#expect(Set(plan.kept.map(ObjectIdentifier.init)) == Set([main, other].map(ObjectIdentifier.init)))
+		#expect(plan.added.isEmpty)
+		#expect(plan.removed.isEmpty)
+	}
+
+	// MARK: - BarControllerFactory
+
+	@Test func factoryBuildsControllerForScreen() throws {
+		let screen = try #require(NSScreen.main)
+		let config = try PHConfig.load()
+		let factory = PHBarFactory(config: config, environment: .process, debug: false)
+
+		let controller = try factory.make(for: screen)
+
+		#expect(controller.screen === screen)
+		#expect(controller.blocks.isEmpty == false)
+	}
+}