Fix Swing multithreading issue, clean up slightly

src/main/kotlin/link/infra/packwiz/installer/Main.kt

@@ -18,6 +18,9 @@ import kotlin.system.exitProcess
 
 @Suppress("unused")
 class Main(args: Array<String>) {
+	// Don't attempt to start a GUI if we are headless
+	var guiEnabled = !GraphicsEnvironment.isHeadless()
+
 	private fun startup(args: Array<String>) {
 		val options = Options()
 		addNonBootstrapOptions(options)
@@ -28,19 +31,24 @@ class Main(args: Array<String>) {
 			parser.parse(options, args)
 		} catch (e: ParseException) {
 			e.printStackTrace()
-			try {
+			if (guiEnabled) {
-				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName())
+				EventQueue.invokeAndWait {
-			} catch (e1: Exception) {
+					try {
-				// Ignore the exceptions, just continue using the ugly L&F
+						UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName())
+					} catch (ignored: Exception) {
+						// Ignore the exceptions, just continue using the ugly L&F
+					}
+					JOptionPane.showMessageDialog(null, e.message, "packwiz-installer", JOptionPane.ERROR_MESSAGE)
+				}
 			}
-			JOptionPane.showMessageDialog(null, e.message, "packwiz-installer", JOptionPane.ERROR_MESSAGE)
 			exitProcess(1)
 		}
 
-		// if "headless", GUI creation will fail anyway!
+		if (guiEnabled && cmd.hasOption("no-gui")) {
-		val ui = if (cmd.hasOption("no-gui") || GraphicsEnvironment.isHeadless()) {
+			guiEnabled = false
-			CLIHandler()
+		}
-		} else InstallWindow()
+
+		val ui = if (guiEnabled) InstallWindow() else CLIHandler()
 
 		val unparsedArgs = cmd.args
 		if (unparsedArgs.size > 1) {
@@ -49,15 +57,13 @@ class Main(args: Array<String>) {
 			ui.handleExceptionAndExit(RuntimeException("URI to install from must be specified!"))
 		}
 
-		cmd.getOptionValue("title")?.also {
+		cmd.getOptionValue("title")?.also(ui::setTitle)
-			ui.setTitle(it)
-		}
 
 		val inputStateHandler = InputStateHandler()
 		ui.show(inputStateHandler)
 
 		val uOptions = UpdateManager.Options().apply {
-			side = cmd.getOptionValue("side")?.let { UpdateManager.Options.Side.from(it) } ?: side
+			side = cmd.getOptionValue("side")?.let((UpdateManager.Options.Side)::from) ?: side
 			packFolder = cmd.getOptionValue("pack-folder") ?: packFolder
 			manifestFile = cmd.getOptionValue("meta-file") ?: manifestFile
 		}
@@ -113,11 +119,13 @@ class Main(args: Array<String>) {
 			startup(args)
 		} catch (e: Exception) {
 			e.printStackTrace()
-			EventQueue.invokeLater {
+			if (guiEnabled) {
-				JOptionPane.showMessageDialog(null,
+				EventQueue.invokeLater {
+					JOptionPane.showMessageDialog(null,
 						"A fatal error occurred: \n" + e.javaClass.canonicalName + ": " + e.message,
 						"packwiz-installer", JOptionPane.ERROR_MESSAGE)
-				exitProcess(1)
+					exitProcess(1)
+				}
 			}
 			// In case the EventQueue is broken, exit after 1 minute
 			Thread.sleep(60 * 1000.toLong())

src/main/kotlin/link/infra/packwiz/installer/ui/InstallWindow.kt

@@ -10,10 +10,10 @@ import javax.swing.border.EmptyBorder
 import kotlin.system.exitProcess
 
 class InstallWindow : IUserInterface {
-	private val frmPackwizlauncher: JFrame
+	private lateinit var frmPackwizlauncher: JFrame
-	private val lblProgresslabel: JLabel
+	private lateinit var lblProgresslabel: JLabel
-	private val progressBar: JProgressBar
+	private lateinit var progressBar: JProgressBar
-	private val btnOptions: JButton
+	private lateinit var btnOptions: JButton
 
 	private var inputStateHandler: InputStateHandler? = null
 	private var title = "Updating modpack..."
@@ -23,55 +23,57 @@ class InstallWindow : IUserInterface {
 	// TODO: separate JFrame junk from IUserInterface junk?
 
 	init {
-		frmPackwizlauncher = JFrame().apply {
+		EventQueue.invokeAndWait {
-			title = this@InstallWindow.title
+			frmPackwizlauncher = JFrame().apply {
-			setBounds(100, 100, 493, 95)
+				title = this@InstallWindow.title
-			defaultCloseOperation = JFrame.EXIT_ON_CLOSE
+				setBounds(100, 100, 493, 95)
-			setLocationRelativeTo(null)
+				defaultCloseOperation = JFrame.EXIT_ON_CLOSE
+				setLocationRelativeTo(null)
 
-			// Progress bar and loading text
+				// Progress bar and loading text
-			add(JPanel().apply {
+				add(JPanel().apply {
-				border = EmptyBorder(10, 10, 10, 10)
+					border = EmptyBorder(10, 10, 10, 10)
-				layout = BorderLayout(0, 0)
+					layout = BorderLayout(0, 0)
 
-				progressBar = JProgressBar().apply {
+					progressBar = JProgressBar().apply {
-					isIndeterminate = true
+						isIndeterminate = true
-				}
-				add(progressBar, BorderLayout.CENTER)
-
-				lblProgresslabel = JLabel("Loading...")
-				add(lblProgresslabel, BorderLayout.SOUTH)
-			}, BorderLayout.CENTER)
-
-			// Buttons
-			add(JPanel().apply {
-				border = EmptyBorder(0, 5, 0, 5)
-				layout = GridBagLayout()
-
-				btnOptions = JButton("Optional mods...").apply {
-					alignmentX = Component.CENTER_ALIGNMENT
-
-					addActionListener {
-						text = "Loading..."
-						isEnabled = false
-						inputStateHandler?.pressOptionsButton()
 					}
-				}
+					add(progressBar, BorderLayout.CENTER)
-				add(btnOptions, GridBagConstraints().apply {
-					gridx = 0
-					gridy = 0
-				})
 
-				add(JButton("Cancel").apply {
+					lblProgresslabel = JLabel("Loading...")
-					addActionListener {
+					add(lblProgresslabel, BorderLayout.SOUTH)
-						isEnabled = false
+				}, BorderLayout.CENTER)
-						inputStateHandler?.pressCancelButton()
+
+				// Buttons
+				add(JPanel().apply {
+					border = EmptyBorder(0, 5, 0, 5)
+					layout = GridBagLayout()
+
+					btnOptions = JButton("Optional mods...").apply {
+						alignmentX = Component.CENTER_ALIGNMENT
+
+						addActionListener {
+							text = "Loading..."
+							isEnabled = false
+							inputStateHandler?.pressOptionsButton()
+						}
 					}
-				}, GridBagConstraints().apply {
+					add(btnOptions, GridBagConstraints().apply {
-					gridx = 0
+						gridx = 0
-					gridy = 1
+						gridy = 0
-				})
+					})
-			}, BorderLayout.EAST)
+
+					add(JButton("Cancel").apply {
+						addActionListener {
+							isEnabled = false
+							inputStateHandler?.pressCancelButton()
+						}
+					}, GridBagConstraints().apply {
+						gridx = 0
+						gridy = 1
+					})
+				}, BorderLayout.EAST)
+			}
 		}
 	}