fullscreen command: support [on|off] argument

#153

LocalPackage/Sources/Common/cmdArgs/FullscreenCmdArgs.swift

@@ -0,0 +1,20 @@
+public struct FullscreenCmdArgs: CmdArgs, RawCmdArgs {
+    public init() {}
+    public static let parser: CmdParser<Self> = cmdParser(
+        kind: .fullscreen,
+        allowInConfig: true,
+        help: """
+              USAGE: fullscreen [-h|--help] [on|off]
+
+              OPTIONS:
+                -h, --help   Print help
+
+              ARGUMENTS:
+                [on|off]     'on' means enter fullscreen mode. 'off' means exit fullscreen mode.
+                             Toggle between the two if not specified
+              """,
+        options: [:],
+        arguments: [ArgParser(\.toggle, parseToggleEnum)]
+    )
+    public var toggle: ToggleEnum = .toggle
+}

LocalPackage/Sources/Common/cmdArgs/noCmdArgs.swift

@@ -2,10 +2,6 @@ public struct FlattenWorkspaceTreeCmdArgs: RawCmdArgs, CmdArgs {
     public init() {}
     public static let parser: CmdParser<Self> = noArgsParser(.flattenWorkspaceTree, allowInConfig: true)
 }
-public struct FullscreenCmdArgs: RawCmdArgs, CmdArgs {
-    public init() {}
-    public static let parser: CmdParser<Self> = noArgsParser(.fullscreen, allowInConfig: true)
-}
 public struct ReloadConfigCmdArgs: RawCmdArgs, CmdArgs {
     public init() {}
     public static let parser: CmdParser<Self> = noArgsParser(.reloadConfig, allowInConfig: true)

docs/aerospace-fullscreen.adoc

@@ -7,7 +7,7 @@ include::util/man-attributes.adoc[]
 
 == Synopsis
 // tag::synopsis[]
-aerospace fullscreen [-h|--help]
+aerospace fullscreen [-h|--help] [on|off]
 // end::synopsis[]
 
 == Description
@@ -16,10 +16,17 @@ aerospace fullscreen [-h|--help]
 {manpurpose}
 
 Switching to a different tiling window within the same workspace while the current focused window is in fullscreen mode results in the fullscreen window exiting fullscreen mode.
-// end::body[]
 
 include::util/conditional-options-header.adoc[]
 
 -h, --help:: Print help
 
+include::util/conditional-arguments-header.adoc[]
+
+[on|off]::
+'on' means enter fullscreen mode. 'off' means exit fullscreen mode.
+Toggle between the two if not specified
+
+// end::body[]
+
 include::util/man-footer.adoc[]

src/command/FullscreenCommand.swift

@@ -1,15 +1,32 @@
 import Common
 
 struct FullscreenCommand: Command {
-    let args = FullscreenCmdArgs()
+    let args: FullscreenCmdArgs
 
     func _run(_ state: CommandMutableState, stdin: String) -> Bool {
         check(Thread.current.isMainThread)
         guard let window = state.subject.windowOrNil else {
             state.stderr.append(noWindowIsFocused)
             return false
         }
-        window.isFullscreen = !window.isFullscreen
+        let newState: Bool
+        switch args.toggle {
+        case .on:
+            newState = true
+        case .off:
+            newState = false
+        case .toggle:
+            newState = !window.isFullscreen
+        }
+        if newState == window.isFullscreen {
+            if newState {
+                state.stderr.append("Already fullscreen")
+            } else {
+                state.stderr.append("Already not fullscreen")
+            }
+            return false
+        }
+        window.isFullscreen = newState
 
         // Focus on its own workspace
         window.markAsMostRecentChild()

src/command/other/parseCommand.swift

@@ -24,7 +24,7 @@ extension CmdArgs {
         case .focus:
             command = FocusCommand(args: self as! FocusCmdArgs)
         case .fullscreen:
-            command = FullscreenCommand()
+            command = FullscreenCommand(args: self as! FullscreenCmdArgs)
         case .joinWith:
             command = JoinWithCommand(args: self as! JoinWithCmdArgs)
         case .layout: