Add further scrollback option for longer terminal history

CommandNotch/CommandNotch.xcodeproj/project.pbxproj

@@ -15,6 +15,7 @@
 		187F4B521BFC3BD29ADA79E3 /* HotkeyManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = EEB7FE2BDE5C25B7E599F340 /* HotkeyManager.swift */; };
 		1AB4A0F1BE668D3130EFBA93 /* TerminalTheme.swift in Sources */ = {isa = PBXBuildFile; fileRef = CFE9E5BADB0C427903A0D874 /* TerminalTheme.swift */; };
 		2089566A2BBAA65EA82119B3 /* NotchOrchestratorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF6D136A0B3FC79DDE12A826 /* NotchOrchestratorTests.swift */; };
+		21373D6E9C2F34FD63CEC6A5 /* TerminalScrollCoordinatorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 40D9E323185F6D722B360C3C /* TerminalScrollCoordinatorTests.swift */; };
 		2375B9DA559A0777FE558A8B /* WorkspaceStoreTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4FA62DFE9AD003F4C5B55F14 /* WorkspaceStoreTests.swift */; };
 		23E2DDCF36D0DAB2EA72C39C /* NotchState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B352301BC9CAD7C9D8B7AA9 /* NotchState.swift */; };
 		26AE379040149CBE05B314BB /* WorkspacesSettingsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = F70A31EFACF23DD9262A040E /* WorkspacesSettingsView.swift */; };
@@ -22,6 +23,7 @@
 		2DF22798D3A7514E2A9183FC /* WorkspaceSummary.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7B2BCA543CE54DAB1DB80E43 /* WorkspaceSummary.swift */; };
 		34AF69BF7AF8DC78ADE3774A /* GeneralSettingsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 27E7EEEDFBD8D9CEB8FD86A5 /* GeneralSettingsView.swift */; };
 		3B69CB3CDEC2E5F2DCE600F9 /* NotchSettings.swift in Sources */ = {isa = PBXBuildFile; fileRef = 297BA3E5B837FBDDEED9DE66 /* NotchSettings.swift */; };
+		40183737D8C237022D0882FD /* TerminalScrollbackEstimatorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D77DC2AED643512C786AD70A /* TerminalScrollbackEstimatorTests.swift */; };
 		4CFA0C79095ACE0A327A2469 /* WorkspaceRegistry.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0E97758F68FACCFFACA895B7 /* WorkspaceRegistry.swift */; };
 		4D335F67B71F7DD977B6AEF9 /* AppSettingsStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9E6C98C406899F4B242075AF /* AppSettingsStore.swift */; };
 		4E0AD14B7427532271E485AA /* NotchWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = EFAC70814C72BAF76D90B9DF /* NotchWindow.swift */; };
@@ -56,6 +58,7 @@
 		D4CEB4B895F75D91FA892A06 /* PopoutWindowController.swift in Sources */ = {isa = PBXBuildFile; fileRef = CB593A2546BF2C0BE8E40387 /* PopoutWindowController.swift */; };
 		DAD3AB4A0DAADA32C02D959E /* SettingsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3125FD3DC55420122CF85D80 /* SettingsView.swift */; };
 		DCFD5B03E64A46783F46726B /* TerminalCommandArrowBehavior.swift in Sources */ = {isa = PBXBuildFile; fileRef = F22AA47452CF798A977A6F47 /* TerminalCommandArrowBehavior.swift */; };
+		DD116B0FCC341D66F1534EC4 /* TerminalScrollbackEstimator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 165DCCD7BB164A6470D49BBF /* TerminalScrollbackEstimator.swift */; };
 		E63FD5862C0EC54E284F6A0F /* ScreenRegistry.swift in Sources */ = {isa = PBXBuildFile; fileRef = AAF23753B5A0CAF04D7566A3 /* ScreenRegistry.swift */; };
 		E792411FA82E79E810F4B4C3 /* HotkeyRecorderView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2B81432CECBDB61D21EE4DC3 /* HotkeyRecorderView.swift */; };
 		EE72479BA5A25FF31BACCC50 /* NotchOrchestrator.swift in Sources */ = {isa = PBXBuildFile; fileRef = DC7912AF01E1600B8619AF31 /* NotchOrchestrator.swift */; };
@@ -82,6 +85,7 @@
 
 /* Begin PBXFileReference section */
 		0E97758F68FACCFFACA895B7 /* WorkspaceRegistry.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceRegistry.swift; sourceTree = "<group>"; };
+		165DCCD7BB164A6470D49BBF /* TerminalScrollbackEstimator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalScrollbackEstimator.swift; sourceTree = "<group>"; };
 		27E7EEEDFBD8D9CEB8FD86A5 /* GeneralSettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GeneralSettingsView.swift; sourceTree = "<group>"; };
 		297BA3E5B837FBDDEED9DE66 /* NotchSettings.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotchSettings.swift; sourceTree = "<group>"; };
 		2B81432CECBDB61D21EE4DC3 /* HotkeyRecorderView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HotkeyRecorderView.swift; sourceTree = "<group>"; };
@@ -91,6 +95,7 @@
 		3CB1DFD6FCDF64B4DF24230A /* WorkspaceController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceController.swift; sourceTree = "<group>"; };
 		3F57837A7115DEEE11E14B40 /* NotchShape.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotchShape.swift; sourceTree = "<group>"; };
 		3F5FF5623898FA150C3B70D4 /* AppSettingsControllerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppSettingsControllerTests.swift; sourceTree = "<group>"; };
+		40D9E323185F6D722B360C3C /* TerminalScrollCoordinatorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalScrollCoordinatorTests.swift; sourceTree = "<group>"; };
 		48198AFE5473B0F7AECAB3FB /* AboutSettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AboutSettingsView.swift; sourceTree = "<group>"; };
 		496267F03E261FEC9EBD5A9D /* CommandNotchUITests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = CommandNotchUITests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		49E1791BB45E1505500ACC67 /* TerminalSession.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalSession.swift; sourceTree = "<group>"; };
@@ -124,6 +129,7 @@
 		CFE9E5BADB0C427903A0D874 /* TerminalTheme.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalTheme.swift; sourceTree = "<group>"; };
 		D03D042117E59DCA9D553844 /* HotkeySettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HotkeySettingsView.swift; sourceTree = "<group>"; };
 		D288132700770C4A625A15F6 /* WindowFrameCalculatorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WindowFrameCalculatorTests.swift; sourceTree = "<group>"; };
+		D77DC2AED643512C786AD70A /* TerminalScrollbackEstimatorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalScrollbackEstimatorTests.swift; sourceTree = "<group>"; };
 		DC7912AF01E1600B8619AF31 /* NotchOrchestrator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotchOrchestrator.swift; sourceTree = "<group>"; };
 		DF0FFBC96F2446687D6474F4 /* WorkspaceSwitcherView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceSwitcherView.swift; sourceTree = "<group>"; };
 		E37A6DCD9C5DE1FE11C4C1CD /* TerminalSettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TerminalSettingsView.swift; sourceTree = "<group>"; };
@@ -165,6 +171,7 @@
 				7181BB1F3926B457445105E5 /* ScreenContext.swift */,
 				AAF23753B5A0CAF04D7566A3 /* ScreenRegistry.swift */,
 				567E85A2ED628460CEC760DB /* TerminalManager.swift */,
+				165DCCD7BB164A6470D49BBF /* TerminalScrollbackEstimator.swift */,
 				49E1791BB45E1505500ACC67 /* TerminalSession.swift */,
 				CFE9E5BADB0C427903A0D874 /* TerminalTheme.swift */,
 				3CB1DFD6FCDF64B4DF24230A /* WorkspaceController.swift */,
@@ -218,6 +225,8 @@
 				A770A63582CF9834F4E7F058 /* ScreenContextTests.swift */,
 				EEC7F7D8D15A1BC4EE43DDDB /* ScreenRegistryTests.swift */,
 				C0D19729317029008D81F361 /* TerminalCommandArrowBehaviorTests.swift */,
+				D77DC2AED643512C786AD70A /* TerminalScrollbackEstimatorTests.swift */,
+				40D9E323185F6D722B360C3C /* TerminalScrollCoordinatorTests.swift */,
 				D288132700770C4A625A15F6 /* WindowFrameCalculatorTests.swift */,
 				591FCE91AF83A8A8E44E1625 /* WorkspaceRegistryTests.swift */,
 				4FA62DFE9AD003F4C5B55F14 /* WorkspaceStoreTests.swift */,
@@ -370,7 +379,6 @@
 				};
 			};
 			buildConfigurationList = C47A3896770C98F2A3E62B7A /* Build configuration list for PBXProject "CommandNotch" */;
-			compatibilityVersion = "Xcode 14.0";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
@@ -383,6 +391,7 @@
 				28377BE3F9997892D4929B6E /* XCRemoteSwiftPackageReference "SwiftTerm" */,
 			);
 			preferredProjectObjectVersion = 77;
+			productRefGroup = B269158E04E8E603B61448F0 /* Products */;
 			projectDirPath = "";
 			projectRoot = "";
 			targets = (
@@ -423,6 +432,8 @@
 				D2468B19D6F0A2C1DFDFE2B7 /* ScreenContextTests.swift in Sources */,
 				8A1B2A4CD61B0D9A4BAB075B /* ScreenRegistryTests.swift in Sources */,
 				CFBBE994BA6BAD4658AAB9CB /* TerminalCommandArrowBehaviorTests.swift in Sources */,
+				21373D6E9C2F34FD63CEC6A5 /* TerminalScrollCoordinatorTests.swift in Sources */,
+				40183737D8C237022D0882FD /* TerminalScrollbackEstimatorTests.swift in Sources */,
 				0F133E8A88D2E313D90C32AD /* WindowFrameCalculatorTests.swift in Sources */,
 				154F363D434A26105C5999B5 /* WorkspaceRegistryTests.swift in Sources */,
 				2375B9DA559A0777FE558A8B /* WorkspaceStoreTests.swift in Sources */,
@@ -465,6 +476,7 @@
 				88113BA9B217DA579C36BEBE /* TabBar.swift in Sources */,
 				DCFD5B03E64A46783F46726B /* TerminalCommandArrowBehavior.swift in Sources */,
 				6F249EDFA2D654457DF385F1 /* TerminalManager.swift in Sources */,
+				DD116B0FCC341D66F1534EC4 /* TerminalScrollbackEstimator.swift in Sources */,
 				7A69B5AAC686174BCA54D0F0 /* TerminalSession.swift in Sources */,
 				65C7DB7296C6C6A77598A1F4 /* TerminalSettingsView.swift in Sources */,
 				1AB4A0F1BE668D3130EFBA93 /* TerminalTheme.swift in Sources */,
@@ -499,14 +511,20 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_ENTITLEMENTS = CommandNotch/Resources/CommandNotch.entitlements;
+				CODE_SIGN_IDENTITY = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
+				DEVELOPMENT_TEAM = G698BP272N;
 				INFOPLIST_FILE = CommandNotch/Resources/Info.plist;
+				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.developer-tools";
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MARKETING_VERSION = 0.0.3;
 				PRODUCT_BUNDLE_IDENTIFIER = com.commandnotch.app;
 				PRODUCT_NAME = CommandNotch;
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = macosx;
 			};
 			name = Debug;
@@ -598,14 +616,20 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_ENTITLEMENTS = CommandNotch/Resources/CommandNotch.entitlements;
+				CODE_SIGN_IDENTITY = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
+				DEVELOPMENT_TEAM = G698BP272N;
 				INFOPLIST_FILE = CommandNotch/Resources/Info.plist;
+				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.developer-tools";
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MARKETING_VERSION = 0.0.3;
 				PRODUCT_BUNDLE_IDENTIFIER = com.commandnotch.app;
 				PRODUCT_NAME = CommandNotch;
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = macosx;
 			};
 			name = Release;

CommandNotch/CommandNotch.xcodeproj/xcuserdata/harvmaster.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -5,33 +5,9 @@
 	<key>SchemeUserState</key>
 	<dict>
 		<key>CommandNotch.xcscheme_^#shared#^_</key>
-		<dict>
+		<dict/>
-			<key>orderHint</key>
-			<integer>0</integer>
-		</dict>
-		<key>CommandNotchTests.xcscheme_^#shared#^_</key>
-		<dict>
-			<key>orderHint</key>
-			<integer>2</integer>
-		</dict>
-		<key>CommandNotchUITests.xcscheme_^#shared#^_</key>
-		<dict>
-			<key>orderHint</key>
-			<integer>2</integer>
-		</dict>
 		<key>Release-CommandNotch.xcscheme_^#shared#^_</key>
-		<dict>
+		<dict/>
-			<key>orderHint</key>
-			<integer>1</integer>
-		</dict>
-	</dict>
-	<key>SuppressBuildableAutocreation</key>
-	<dict>
-		<key>1485207FA11756EC2DF4F08B</key>
-		<dict>
-			<key>primary</key>
-			<true/>
-		</dict>
 	</dict>
 </dict>
 </plist>

CommandNotch/CommandNotch/AppDelegate.swift

@@ -33,6 +33,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         observeSizePreferences()
         observeFontSizeChanges()
         observeTerminalThemeChanges()
+        observeTerminalScrollbackChanges()
         applyUITestLaunchBehaviorIfNeeded()
     }
 
@@ -90,6 +91,16 @@ class AppDelegate: NSObject, NSApplicationDelegate {
             .store(in: &cancellables)
     }
 
+    private func observeTerminalScrollbackChanges() {
+        settingsController.$settings
+            .map(\.terminal.scrollbackLines)
+            .removeDuplicates()
+            .sink { scrollbackLines in
+                WorkspaceRegistry.shared.updateAllWorkspacesScrollbackLines(scrollbackLines)
+            }
+            .store(in: &cancellables)
+    }
+
     private var launchArguments: [String] {
         ProcessInfo.processInfo.arguments
     }

CommandNotch/CommandNotch/Models/AppSettings.swift

@@ -48,6 +48,7 @@ struct AppSettings: Equatable, Codable {
             fontSize: NotchSettings.Defaults.terminalFontSize,
             shellPath: NotchSettings.Defaults.terminalShell,
             themeRawValue: NotchSettings.Defaults.terminalTheme,
+            scrollbackLines: NotchSettings.Defaults.terminalScrollbackLines,
             sizePresetsJSON: NotchSettings.Defaults.terminalSizePresets
         ),
         hotkeys: HotkeySettings(
@@ -106,6 +107,7 @@ extension AppSettings {
         var fontSize: Double
         var shellPath: String
         var themeRawValue: String
+        var scrollbackLines: Int
         var sizePresetsJSON: String
 
         var theme: TerminalTheme {
@@ -155,6 +157,7 @@ struct TerminalSessionConfiguration: Equatable {
     var fontSize: CGFloat
     var theme: TerminalTheme
     var shellPath: String
+    var scrollbackLines: Int
 }
 
 @MainActor

CommandNotch/CommandNotch/Models/AppSettingsController.swift

@@ -46,7 +46,8 @@ final class AppSettingsController: ObservableObject, TerminalSessionConfiguratio
         TerminalSessionConfiguration(
             fontSize: CGFloat(settings.terminal.fontSize),
             theme: settings.terminal.theme,
-            shellPath: settings.terminal.shellPath
+            shellPath: settings.terminal.shellPath,
+            scrollbackLines: settings.terminal.scrollbackLines
         )
     }
 

CommandNotch/CommandNotch/Models/AppSettingsStore.swift

@@ -52,6 +52,7 @@ struct UserDefaultsAppSettingsStore: AppSettingsStoreType {
                 fontSize: double(NotchSettings.Keys.terminalFontSize, default: NotchSettings.Defaults.terminalFontSize),
                 shellPath: string(NotchSettings.Keys.terminalShell, default: NotchSettings.Defaults.terminalShell),
                 themeRawValue: string(NotchSettings.Keys.terminalTheme, default: NotchSettings.Defaults.terminalTheme),
+                scrollbackLines: integer(NotchSettings.Keys.terminalScrollbackLines, default: NotchSettings.Defaults.terminalScrollbackLines),
                 sizePresetsJSON: string(NotchSettings.Keys.terminalSizePresets, default: NotchSettings.Defaults.terminalSizePresets)
             ),
             hotkeys: .init(
@@ -101,6 +102,7 @@ struct UserDefaultsAppSettingsStore: AppSettingsStoreType {
         defaults.set(settings.terminal.fontSize, forKey: NotchSettings.Keys.terminalFontSize)
         defaults.set(settings.terminal.shellPath, forKey: NotchSettings.Keys.terminalShell)
         defaults.set(settings.terminal.themeRawValue, forKey: NotchSettings.Keys.terminalTheme)
+        defaults.set(settings.terminal.scrollbackLines, forKey: NotchSettings.Keys.terminalScrollbackLines)
         defaults.set(settings.terminal.sizePresetsJSON, forKey: NotchSettings.Keys.terminalSizePresets)
 
         defaults.set(settings.hotkeys.toggle.toJSON(), forKey: NotchSettings.Keys.hotkeyToggle)

CommandNotch/CommandNotch/Models/NotchSettings.swift

@@ -47,6 +47,7 @@ enum NotchSettings {
         static let terminalFontSize      = "terminalFontSize"
         static let terminalShell         = "terminalShell"
         static let terminalTheme         = "terminalTheme"
+        static let terminalScrollbackLines = "terminalScrollbackLines"
         static let terminalSizePresets   = "terminalSizePresets"
         static let workspaceSummaries    = "workspaceSummaries"
         static let screenAssignments     = "screenAssignments"
@@ -98,6 +99,7 @@ enum NotchSettings {
         static let terminalFontSize: Double     = 13
         static let terminalShell: String        = ""
         static let terminalTheme: String        = TerminalTheme.terminalApp.rawValue
+        static let terminalScrollbackLines: Int = 500
         static let terminalSizePresets: String  = TerminalSizePresetStore.defaultPresetsJSON()
 
         // Default hotkey bindings as JSON
@@ -148,6 +150,7 @@ enum NotchSettings {
             Keys.terminalFontSize:      Defaults.terminalFontSize,
             Keys.terminalShell:         Defaults.terminalShell,
             Keys.terminalTheme:         Defaults.terminalTheme,
+            Keys.terminalScrollbackLines: Defaults.terminalScrollbackLines,
             Keys.terminalSizePresets:   Defaults.terminalSizePresets,
 
             Keys.hotkeyToggle:          Defaults.hotkeyToggle,

CommandNotch/CommandNotch/Models/TerminalScrollbackEstimator.swift

@@ -0,0 +1,54 @@
+import AppKit
+import CoreText
+import SwiftTerm
+
+enum TerminalScrollbackEstimator {
+    private static let minimumColumns = 1
+    private static let minimumRows = 1
+    private static let defaultBytesPerLineOverhead = 256
+
+    struct Estimate: Equatable {
+        let bytes: Int
+        let columns: Int
+        let rows: Int
+
+        var formattedBytes: String {
+            ByteCountFormatter.string(fromByteCount: Int64(bytes), countStyle: .memory)
+        }
+    }
+
+    static func estimate(
+        scrollbackLines: Int,
+        fontSize: Double,
+        openWidth: Double,
+        openHeight: Double
+    ) -> Estimate {
+        let safeScrollbackLines = max(0, scrollbackLines)
+        let dimensions = terminalGridDimensions(
+            fontSize: fontSize,
+            openWidth: openWidth,
+            openHeight: openHeight
+        )
+        let totalLines = safeScrollbackLines + dimensions.rows
+        let bytesPerCell = MemoryLayout<CharData>.stride
+        let bytesPerLine = (dimensions.columns * bytesPerCell) + defaultBytesPerLineOverhead
+        let totalBytes = max(0, totalLines * bytesPerLine)
+
+        return Estimate(bytes: totalBytes, columns: dimensions.columns, rows: dimensions.rows)
+    }
+
+    private static func terminalGridDimensions(
+        fontSize: Double,
+        openWidth: Double,
+        openHeight: Double
+    ) -> (columns: Int, rows: Int) {
+        let font = NSFont.monospacedSystemFont(ofSize: CGFloat(max(1, fontSize)), weight: .regular)
+        let cellWidth = max(1, font.advancement(forGlyph: font.glyph(withName: "W")).width)
+        let cellHeight = max(1, ceil(CTFontGetAscent(font) + CTFontGetDescent(font) + CTFontGetLeading(font)))
+
+        let columns = max(minimumColumns, Int(CGFloat(max(1, openWidth)) / cellWidth))
+        let rows = max(minimumRows, Int(CGFloat(max(1, openHeight)) / cellHeight))
+
+        return (columns, rows)
+    }
+}

CommandNotch/CommandNotch/Models/TerminalSession.swift

@@ -2,6 +2,58 @@ import AppKit
 import SwiftTerm
 import Combine
 
+/// Tracks whether the terminal viewport should follow live output or preserve
+/// the user's current scrollback position.
+final class TerminalScrollCoordinator {
+    private let bottomThreshold: Double
+    private var suppressScrollTracking = false
+
+    private(set) var followsOutput = true
+    private(set) var preservedScrollPosition: Double = 1
+
+    init(bottomThreshold: Double = 0.999) {
+        self.bottomThreshold = bottomThreshold
+    }
+
+    func terminalDidScroll(to position: Double, canScroll: Bool) {
+        guard !suppressScrollTracking else { return }
+
+        guard canScroll else {
+            followsOutput = true
+            preservedScrollPosition = 1
+            return
+        }
+
+        let clampedPosition = min(max(position, 0), 1)
+        if clampedPosition >= bottomThreshold {
+            followsOutput = true
+            preservedScrollPosition = 1
+        } else {
+            followsOutput = false
+            preservedScrollPosition = clampedPosition
+        }
+    }
+
+    func outputRestorePosition(canScroll: Bool) -> Double? {
+        guard canScroll, !followsOutput else { return nil }
+        return preservedScrollPosition
+    }
+
+    @discardableResult
+    func userDidStartTyping() -> Bool {
+        let shouldJumpToBottom = !followsOutput
+        followsOutput = true
+        preservedScrollPosition = 1
+        return shouldJumpToBottom
+    }
+
+    func suppressTracking<T>(_ body: () -> T) -> T {
+        suppressScrollTracking = true
+        defer { suppressScrollTracking = false }
+        return body()
+    }
+}
+
 /// Wraps a single SwiftTerm TerminalView + LocalProcess pair.
 @MainActor
 class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @preconcurrency TerminalViewDelegate {
@@ -12,7 +64,9 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
     private var keyEventMonitor: Any?
     private let backgroundColor = NSColor.black
     private let configuredShellPath: String
+    private var scrollbackLines: Int
     private let launchDirectory: String
+    private let scrollCoordinator = TerminalScrollCoordinator()
 
     @Published var title: String = "shell"
     @Published var isRunning: Bool = true
@@ -22,11 +76,13 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String? = nil,
         startImmediately: Bool = true
     ) {
         terminalView = TerminalView(frame: NSRect(x: 0, y: 0, width: 600, height: 300))
         configuredShellPath = shellPath
+        self.scrollbackLines = max(0, scrollbackLines)
         launchDirectory = Self.resolveInitialDirectory(initialDirectory)
         currentDirectory = launchDirectory
         super.init()
@@ -36,6 +92,7 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
         let font = NSFont.monospacedSystemFont(ofSize: fontSize, weight: .regular)
         terminalView.font = font
         applyTheme(theme)
+        updateScrollbackLines(self.scrollbackLines)
         installCommandArrowMonitor()
 
         if startImmediately {
@@ -128,6 +185,12 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
         terminalView.installColors(theme.ansiColors)
     }
 
+    func updateScrollbackLines(_ scrollbackLines: Int) {
+        let sanitizedScrollbackLines = max(0, scrollbackLines)
+        self.scrollbackLines = sanitizedScrollbackLines
+        terminalView.getTerminal().changeHistorySize(sanitizedScrollbackLines)
+    }
+
     func terminate() {
         process?.terminate()
         process = nil
@@ -142,7 +205,16 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
 
     nonisolated func dataReceived(slice: ArraySlice<UInt8>) {
         let data = slice
-        Task { @MainActor in self.terminalView.feed(byteArray: data) }
+        Task { @MainActor in
+            if let restorePosition = self.scrollCoordinator.outputRestorePosition(canScroll: self.terminalView.canScroll) {
+                self.scrollCoordinator.suppressTracking {
+                    self.terminalView.feed(byteArray: data)
+                    self.terminalView.scroll(toPosition: restorePosition)
+                }
+            } else {
+                self.terminalView.feed(byteArray: data)
+            }
+        }
     }
 
     nonisolated func getWindowSize() -> winsize {
@@ -155,6 +227,9 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
     // MARK: - TerminalViewDelegate
 
     func send(source: TerminalView, data: ArraySlice<UInt8>) {
+        if scrollCoordinator.userDidStartTyping() {
+            terminalView.scroll(toPosition: 1)
+        }
         process?.send(data: data)
     }
 
@@ -179,7 +254,9 @@ class TerminalSession: NSObject, ObservableObject, LocalProcessDelegate, @precon
         currentDirectory = normalizedDirectory
     }
 
-    func scrolled(source: TerminalView, position: Double) {}
+    func scrolled(source: TerminalView, position: Double) {
+        scrollCoordinator.terminalDidScroll(to: position, canScroll: source.canScroll)
+    }
     func rangeChanged(source: TerminalView, startY: Int, endY: Int) {}
 
     func clipboardCopy(source: TerminalView, content: Data) {

CommandNotch/CommandNotch/Models/WorkspaceController.swift

@@ -7,6 +7,7 @@ protocol TerminalSessionFactoryType {
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String?
     ) -> TerminalSession
 }
@@ -16,12 +17,14 @@ struct LiveTerminalSessionFactory: TerminalSessionFactoryType {
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String?
     ) -> TerminalSession {
         TerminalSession(
             fontSize: fontSize,
             theme: theme,
             shellPath: shellPath,
+            scrollbackLines: scrollbackLines,
             initialDirectory: initialDirectory
         )
     }
@@ -106,6 +109,7 @@ final class WorkspaceController: ObservableObject {
             fontSize: config.fontSize,
             theme: config.theme,
             shellPath: config.shellPath,
+            scrollbackLines: config.scrollbackLines,
             initialDirectory: activeTab?.currentDirectory
         )
 
@@ -187,4 +191,10 @@ final class WorkspaceController: ObservableObject {
             tab.applyTheme(theme)
         }
     }
+
+    func updateAllScrollbackLines(_ scrollbackLines: Int) {
+        for tab in tabs {
+            tab.updateScrollbackLines(scrollbackLines)
+        }
+    }
 }

CommandNotch/CommandNotch/Models/WorkspaceRegistry.swift

@@ -157,6 +157,12 @@ final class WorkspaceRegistry: ObservableObject {
         }
     }
 
+    func updateAllWorkspacesScrollbackLines(_ scrollbackLines: Int) {
+        for controller in controllers.values {
+            controller.updateAllScrollbackLines(scrollbackLines)
+        }
+    }
+
     private func resolvedWorkspaceName(from proposedName: String?) -> String {
         let trimmed = proposedName?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
         if !trimmed.isEmpty {

CommandNotch/CommandNotch/Views/TerminalSettingsView.swift

@@ -1,6 +1,8 @@
 import SwiftUI
 
 struct TerminalSettingsView: View {
+    private static let scrollbackRange = 0...1_000_000
+
     @ObservedObject private var settingsController = AppSettingsController.shared
     @State private var sizePresets: [TerminalSizePreset] = []
 
@@ -40,6 +42,34 @@ struct TerminalSettingsView: View {
                     .foregroundStyle(.secondary)
             }
 
+            Section("Scrollback") {
+                HStack {
+                    Text("Lines")
+                    Spacer()
+                    TextField(
+                        "Scrollback lines",
+                        value: scrollbackBinding,
+                        format: .number.grouping(.automatic)
+                    )
+                    .textFieldStyle(.roundedBorder)
+                    .frame(width: 140)
+                }
+
+                Stepper(
+                    value: scrollbackBinding,
+                    in: Self.scrollbackRange,
+                    step: scrollbackStepSize
+                ) {
+                    Text("\(settingsController.settings.terminal.scrollbackLines.formatted()) lines")
+                        .monospacedDigit()
+                }
+
+                let estimate = scrollbackEstimate
+                Text("Based on the current terminal size, this may use ~\(estimate.formattedBytes) of RAM (\(estimate.columns) columns x \(estimate.rows) rows visible).")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+
             Section("Size Presets") {
                 ForEach($sizePresets) { $preset in
                     TerminalSizePresetEditor(
@@ -94,6 +124,39 @@ struct TerminalSettingsView: View {
         sizePresets.removeAll { $0.id == id }
     }
 
+    private var scrollbackBinding: Binding<Int> {
+        Binding(
+            get: { settingsController.settings.terminal.scrollbackLines },
+            set: { newValue in
+                let clampedValue = min(max(Self.scrollbackRange.lowerBound, newValue), Self.scrollbackRange.upperBound)
+                settingsController.update {
+                    $0.terminal.scrollbackLines = clampedValue
+                }
+            }
+        )
+    }
+
+    private var scrollbackEstimate: TerminalScrollbackEstimator.Estimate {
+        TerminalScrollbackEstimator.estimate(
+            scrollbackLines: settingsController.settings.terminal.scrollbackLines,
+            fontSize: settingsController.settings.terminal.fontSize,
+            openWidth: settingsController.settings.display.openWidth,
+            openHeight: settingsController.settings.display.openHeight
+        )
+    }
+
+    private var scrollbackStepSize: Int {
+        let lines = settingsController.settings.terminal.scrollbackLines
+        switch lines {
+        case ..<10_000:
+            return 500
+        case ..<100_000:
+            return 5_000
+        default:
+            return 10_000
+        }
+    }
+
     private func applyPreset(_ preset: TerminalSizePreset) {
         settingsController.update {
             $0.display.openWidth = preset.width

CommandNotch/CommandNotchTests/AppSettingsControllerTests.swift

@@ -7,11 +7,13 @@ final class AppSettingsControllerTests: XCTestCase {
         let store = InMemoryAppSettingsStore()
         var settings = AppSettings.default
         settings.terminal.shellPath = "/opt/homebrew/bin/fish"
+        settings.terminal.scrollbackLines = 12_000
         store.storedSettings = settings
 
         let controller = AppSettingsController(store: store)
 
         XCTAssertEqual(controller.terminalSessionConfiguration.shellPath, "/opt/homebrew/bin/fish")
+        XCTAssertEqual(controller.terminalSessionConfiguration.scrollbackLines, 12_000)
     }
 
     func testTerminalSizePresetsDecodeFromTypedSettings() {

CommandNotch/CommandNotchTests/AppSettingsStoreTests.swift

@@ -26,6 +26,7 @@ final class AppSettingsStoreTests: XCTestCase {
         settings.appearance.blurRadius = 4.5
         settings.terminal.fontSize = 16
         settings.terminal.themeRawValue = TerminalTheme.dracula.rawValue
+        settings.terminal.scrollbackLines = 25_000
         settings.terminal.sizePresetsJSON = TerminalSizePresetStore.encodePresets([
             TerminalSizePreset(name: "Wide", width: 960, height: 420, hotkey: .cmdShiftDigit(4))
         ])

CommandNotch/CommandNotchTests/ScreenRegistryTests.swift

@@ -306,7 +306,7 @@ private final class TestAppSettingsStore: AppSettingsStoreType {
 }
 
 private final class ScreenRegistryTestSettingsProvider: TerminalSessionConfigurationProviding {
-    let terminalSessionConfiguration = TerminalSessionConfiguration(fontSize: 13, theme: .terminalApp, shellPath: "")
+    let terminalSessionConfiguration = TerminalSessionConfiguration(fontSize: 13, theme: .terminalApp, shellPath: "", scrollbackLines: 500)
     let hotkeySettings = AppSettings.default.hotkeys
     let terminalSizePresets = TerminalSizePresetStore.loadDefaults()
 }
@@ -317,6 +317,7 @@ private struct ScreenRegistryUnusedTerminalSessionFactory: TerminalSessionFactor
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String?
     ) -> TerminalSession {
         fatalError("ScreenRegistryTests should not create live terminal sessions.")

CommandNotch/CommandNotchTests/TerminalScrollCoordinatorTests.swift

@@ -0,0 +1,46 @@
+import XCTest
+@testable import CommandNotch
+
+final class TerminalScrollCoordinatorTests: XCTestCase {
+    func testScrollAwayFromBottomDisablesOutputFollow() {
+        let coordinator = TerminalScrollCoordinator()
+
+        coordinator.terminalDidScroll(to: 0.42, canScroll: true)
+
+        XCTAssertFalse(coordinator.followsOutput)
+        XCTAssertEqual(coordinator.outputRestorePosition(canScroll: true) ?? .nan, 0.42, accuracy: 0.0001)
+    }
+
+    func testTypingReEnablesFollowAndRequestsJumpToBottom() {
+        let coordinator = TerminalScrollCoordinator()
+        coordinator.terminalDidScroll(to: 0.42, canScroll: true)
+
+        let shouldJump = coordinator.userDidStartTyping()
+
+        XCTAssertTrue(shouldJump)
+        XCTAssertTrue(coordinator.followsOutput)
+        XCTAssertNil(coordinator.outputRestorePosition(canScroll: true))
+    }
+
+    func testScrollingBackToBottomReEnablesOutputFollow() {
+        let coordinator = TerminalScrollCoordinator()
+        coordinator.terminalDidScroll(to: 0.42, canScroll: true)
+
+        coordinator.terminalDidScroll(to: 1, canScroll: true)
+
+        XCTAssertTrue(coordinator.followsOutput)
+        XCTAssertNil(coordinator.outputRestorePosition(canScroll: true))
+    }
+
+    func testSuppressedTrackingIgnoresProgrammaticScrollUpdates() {
+        let coordinator = TerminalScrollCoordinator()
+        coordinator.terminalDidScroll(to: 0.42, canScroll: true)
+
+        coordinator.suppressTracking {
+            coordinator.terminalDidScroll(to: 1, canScroll: true)
+        }
+
+        XCTAssertFalse(coordinator.followsOutput)
+        XCTAssertEqual(coordinator.outputRestorePosition(canScroll: true) ?? .nan, 0.42, accuracy: 0.0001)
+    }
+}

CommandNotch/CommandNotchTests/TerminalScrollbackEstimatorTests.swift

@@ -0,0 +1,34 @@
+import XCTest
+@testable import CommandNotch
+
+final class TerminalScrollbackEstimatorTests: XCTestCase {
+    func testEstimateIncreasesAsScrollbackGrows() {
+        let small = TerminalScrollbackEstimator.estimate(
+            scrollbackLines: 5_000,
+            fontSize: 13,
+            openWidth: 640,
+            openHeight: 350
+        )
+        let large = TerminalScrollbackEstimator.estimate(
+            scrollbackLines: 100_000,
+            fontSize: 13,
+            openWidth: 640,
+            openHeight: 350
+        )
+
+        XCTAssertGreaterThan(large.bytes, small.bytes)
+        XCTAssertGreaterThan(large.columns, 0)
+        XCTAssertGreaterThan(large.rows, 0)
+    }
+
+    func testEstimateClampsNegativeScrollbackToZero() {
+        let estimate = TerminalScrollbackEstimator.estimate(
+            scrollbackLines: -1_000,
+            fontSize: 13,
+            openWidth: 640,
+            openHeight: 350
+        )
+
+        XCTAssertGreaterThan(estimate.bytes, 0)
+    }
+}

CommandNotch/CommandNotchTests/WorkspaceRegistryTests.swift

@@ -191,7 +191,7 @@ private final class InMemoryWorkspaceStore: WorkspaceStoreType {
 }
 
 private final class TestSettingsProvider: TerminalSessionConfigurationProviding {
-    let terminalSessionConfiguration = TerminalSessionConfiguration(fontSize: 13, theme: .terminalApp, shellPath: "")
+    let terminalSessionConfiguration = TerminalSessionConfiguration(fontSize: 13, theme: .terminalApp, shellPath: "", scrollbackLines: 500)
     let hotkeySettings = AppSettings.default.hotkeys
     let terminalSizePresets = TerminalSizePresetStore.loadDefaults()
 }
@@ -204,6 +204,7 @@ private final class RecordingTerminalSessionFactory: TerminalSessionFactoryType
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String?
     ) -> TerminalSession {
         requestedDirectories.append(initialDirectory)
@@ -211,6 +212,7 @@ private final class RecordingTerminalSessionFactory: TerminalSessionFactoryType
             fontSize: fontSize,
             theme: theme,
             shellPath: shellPath,
+            scrollbackLines: scrollbackLines,
             initialDirectory: initialDirectory,
             startImmediately: false
         )
@@ -223,6 +225,7 @@ private struct UnusedTerminalSessionFactory: TerminalSessionFactoryType {
         fontSize: CGFloat,
         theme: TerminalTheme,
         shellPath: String,
+        scrollbackLines: Int,
         initialDirectory: String?
     ) -> TerminalSession {
         fatalError("WorkspaceRegistryTests should not create live terminal sessions.")