Live in the system tray instead of the taskbar, bump to 0.1.14

- A tray icon (the app icon) is there for as long as wIRC runs. Left click hides
  or shows every wIRC window; right click has Show wIRC, Hide wIRC and Exit. Exit
  disconnects every server and quits.
- No wIRC window has a taskbar button. Each window is given a hidden owner window
  through JNA, because Window.Type.UTILITY can't be set after Compose builds the
  window and would take wIRC main's minimize button away.
- Minimizing any window hides all of them to the tray. Showing them again puts
  each one back where it was. Hidden windows stay connected and keep filling their
  buffers. Closing a window with X works the same as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "com.tpuahsiew.wirc"
-version = "0.1.11"
+version = "0.1.14"
 
 // No project-level repositories{} block here: settings.gradle.kts sets
 // dependencyResolutionManagement.repositoriesMode = FAIL_ON_PROJECT_REPOS and already
@@ -22,6 +22,8 @@ dependencies {
     implementation(compose.materialIconsExtended)
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-swing:1.8.1")
     implementation("org.json:json:20240303")
+    // Native Windows calls that keep wIRC's windows off the taskbar (see AppTray.kt)
+    implementation("net.java.dev.jna:jna-platform:5.14.0")
 }
 
 kotlin {
@@ -38,7 +40,7 @@ compose.desktop {
             appResourcesRootDir.set(project.file("installerResources"))
             targetFormats(TargetFormat.Msi, TargetFormat.Exe)
             packageName = "wIRC"
-            packageVersion = "0.1.11"
+            packageVersion = "0.1.14"
             windows {
                 menuGroup = "wIRC"
                 upgradeUuid = "8f14e45f-ceea-4a5e-9c3b-5b1f0e8c2b7a"

src/main/kotlin/Main.kt

@@ -23,6 +23,7 @@ import data.storageId
 import irc.ConnectionManager
 import ui.ChannelWindow
 import ui.MainScreen
+import ui.TrayWindowBehavior
 import ui.rememberPersistentWindowState
 import java.io.File
 
@@ -51,6 +52,8 @@ fun main() = application {
     // Loaded once here (not per-window) so the alias map is truly global - every
     // ChannelWindow's command router reads from this same AliasRepository singleton.
     AliasRepository.init()
+    // Ask Windows for the desktop icon grid now, so the first window drag can already snap to it
+    ui.DesktopGrid.refreshAsync()
 
     val repo = remember { ServerRepository(appRoot) }
     val prefsRepo = remember { WindowPrefsRepository(appRoot) }
@@ -85,19 +88,39 @@ fun main() = application {
     // ("wirc-main__main"), same as every channel and PM window - see WindowPlacement.kt.
     val mainWindowState = rememberPersistentWindowState(prefsRepo, MAIN_BUFFER_KEY.storageId(), DpSize(800.dp, 700.dp))
     val mainDisplaySettings by prefsRepo.settingsFor(MAIN_BUFFER_KEY.storageId()).collectAsState()
+    // Snap to the desktop grid after a move, and to whole lines after a resize
+    val mainLineGap = ui.rememberLineGap()
+    ui.WindowSnapping(mainWindowState, mainLineGap, osFrame = true)
 
-    // There's no persistent tray/notification surface on this build, so closing the main
+    // wIRC lives in the tray: no window is on the taskbar, and minimizing any window hides
-    // server-list window quits the whole app (and every channel window with it) - the
+    // all of them (see TrayWindowBehavior). Hidden windows stay composed and connected, so
-    // same "closing the primary window ends the session" convention most desktop chat
+    // nothing is lost while they're away; showing them again puts each back where it was.
-    // apps without a tray icon follow.
+    // A window opened while hidden (e.g. a new PM) stays hidden until they're shown.
+    var windowsShown by remember { mutableStateOf(true) }
+    val hideAll: () -> Unit = { windowsShown = false }
+    val mainTitle = if (mainUnread > 0) "wIRC - Main ($mainUnread new)" else "wIRC - Main"
+
+    ui.AppTray(
+        // The unread count shows on the tray icon's tooltip too, so new server messages
+        // are visible even when the windows are hidden.
+        tooltip = if (mainUnread > 0) "wIRC ($mainUnread new)" else "wIRC",
+        onToggle = { windowsShown = !windowsShown },
+        onShow = { windowsShown = true },
+        onHide = hideAll,
+        onExit = shutdownApp
+    )
+
+    // Closing the main server-list window quits the whole app (and every channel window
+    // with it) - the tray's Exit does the same, and also disconnects first.
     Window(
         onCloseRequest = ::exitApplication,
-        // The unread count shows in the taskbar too, so new server messages are visible
+        visible = windowsShown,
-        // even when the main window is behind other windows.
+        title = mainTitle,
-        title = if (mainUnread > 0) "wIRC - Main ($mainUnread new)" else "wIRC - Main",
         icon = painterResource("icon.png"),
         state = mainWindowState
     ) {
+        TrayWindowBehavior(mainWindowState, hideAll)
+        androidx.compose.runtime.CompositionLocalProvider(ui.LocalLineGap provides mainLineGap) {
         MaterialTheme(colorScheme = neutralDarkScheme) {
             Surface {
                 MainScreen(
@@ -114,6 +137,7 @@ fun main() = application {
             }
         }
         }
+    }
 
     openBuffers.forEach { bufferKey ->
         key(bufferKey) {
@@ -121,6 +145,8 @@ fun main() = application {
                 bufferKey = bufferKey,
                 prefsRepo = prefsRepo,
                 colorScheme = neutralDarkScheme,
+                visible = windowsShown,
+                onHideAll = hideAll,
                 onOpenBuffer = { newKey -> openBuffers = openBuffers + newKey },
                 onCloseSelf = { openBuffers = openBuffers - bufferKey },
                 // openBuffers is read when /quit runs, so every window open at that moment

src/main/kotlin/data/WindowPrefsRepository.kt

@@ -10,6 +10,13 @@ import java.nio.file.Files
 import java.nio.file.StandardCopyOption
 import java.util.concurrent.ConcurrentHashMap
 
+// Font sizes offered in the settings dialog (whole sizes only, same range as QuickClaude)
+const val MIN_FONT_SIZE = 10
+const val MAX_FONT_SIZE = 18
+
+private fun pickerFontSize(size: Float): Float =
+    Math.round(size).coerceIn(MIN_FONT_SIZE, MAX_FONT_SIZE).toFloat()
+
 data class WindowDisplaySettings(
     val backgroundAlpha: Float = 0.85f,   // 0f = fully transparent, 1f = fully opaque
     val textColorMircIndex: Int = 0,   // index into the standard mIRC palette; 0 = white
@@ -63,7 +70,7 @@ class WindowPrefsRepository(rootDir: File) {
 
     fun setTextColorMircIndex(bufferKeyId: String, index: Int) = update(bufferKeyId) { it.copy(textColorMircIndex = index) }
 
-    fun setFontSize(bufferKeyId: String, fontSize: Float) = update(bufferKeyId) { it.copy(fontSize = fontSize) }
+    fun setFontSize(bufferKeyId: String, fontSize: Float) = update(bufferKeyId) { it.copy(fontSize = pickerFontSize(fontSize)) }
 
     fun setFontId(bufferKeyId: String, fontId: String) = update(bufferKeyId) { it.copy(fontId = fontId) }
 
@@ -109,7 +116,8 @@ class WindowPrefsRepository(rootDir: File) {
                 stored[key] = WindowDisplaySettings(
                     backgroundAlpha = o.optDouble("backgroundAlpha", 0.85).toFloat(),
                     textColorMircIndex = o.optInt("textColorMircIndex", 0),
-                    fontSize = o.optDouble("fontSize", 14.0).toFloat(),
+                    // Sizes saved by the old slider (any value from 10 to 24) round to the nearest picker size
+                    fontSize = pickerFontSize(o.optDouble("fontSize", 14.0).toFloat()),
                     fontId = o.optString("fontId", "monospace"),
                     showUserList = o.optBoolean("showUserList", true),
                     mentionHighlightColorArgb = o.optLong("mentionHighlightColorArgb", 0x40FFA500L).toInt(),

src/main/kotlin/ui/AppTray.kt

@@ -0,0 +1,126 @@
+package ui
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.ui.awt.ComposeWindow
+import androidx.compose.ui.window.FrameWindowScope
+import androidx.compose.ui.window.WindowState
+import com.sun.jna.Native
+import com.sun.jna.Pointer
+import com.sun.jna.platform.win32.User32
+import com.sun.jna.platform.win32.WinDef
+import com.sun.jna.platform.win32.WinUser
+import java.awt.Frame
+import java.awt.MenuItem
+import java.awt.PopupMenu
+import java.awt.SystemTray
+import java.awt.TrayIcon
+import java.awt.event.MouseAdapter
+import java.awt.event.MouseEvent
+import javax.imageio.ImageIO
+
+/**
+ * wIRC's icon in the Windows notification area, there for as long as the app runs. wIRC
+ * windows never show on the taskbar (see [hideFromTaskbar]), so this is how they come back
+ * after being hidden. Left click toggles all windows; right click opens Show / Hide / Exit.
+ * Plain AWT instead of Compose's Tray, because Compose's Tray only reports a double click.
+ */
+@Composable
+fun AppTray(
+    tooltip: String,
+    onToggle: () -> Unit,
+    onShow: () -> Unit,
+    onHide: () -> Unit,
+    onExit: () -> Unit
+) {
+    val currentToggle by rememberUpdatedState(onToggle)
+    val currentShow by rememberUpdatedState(onShow)
+    val currentHide by rememberUpdatedState(onHide)
+    val currentExit by rememberUpdatedState(onExit)
+
+    val trayIcon = remember {
+        if (!SystemTray.isSupported()) return@remember null
+        val image = Thread.currentThread().contextClassLoader.getResourceAsStream("icon.png")?.use { ImageIO.read(it) }
+            ?: return@remember null
+        val menu = PopupMenu().apply {
+            add(MenuItem("Show wIRC").apply { addActionListener { currentShow() } })
+            add(MenuItem("Hide wIRC").apply { addActionListener { currentHide() } })
+            addSeparator()
+            add(MenuItem("Exit").apply { addActionListener { currentExit() } })
+        }
+        TrayIcon(image, tooltip, menu).apply {
+            isImageAutoSize = true
+            addMouseListener(object : MouseAdapter() {
+                override fun mouseClicked(e: MouseEvent) {
+                    if (e.button == MouseEvent.BUTTON1) currentToggle()
+                }
+            })
+        }
+    }
+
+    DisposableEffect(trayIcon) {
+        trayIcon?.let { runCatching { SystemTray.getSystemTray().add(it) } }
+        onDispose { trayIcon?.let { SystemTray.getSystemTray().remove(it) } }
+    }
+    LaunchedEffect(trayIcon, tooltip) { trayIcon?.toolTip = tooltip }
+}
+
+/**
+ * Called first thing inside every wIRC Window's content:
+ *  - Keeps the window off the taskbar (see [hideFromTaskbar]).
+ *  - Turns a minimize (the title-bar button, Win+D, etc.) into hiding every wIRC window to
+ *    the tray: with no taskbar button, a minimized window would have no way back.
+ */
+@Composable
+fun FrameWindowScope.TrayWindowBehavior(state: WindowState, onHideAll: () -> Unit) {
+    remember(window) { hideFromTaskbar(window) }
+    val currentHideAll by rememberUpdatedState(onHideAll)
+    LaunchedEffect(state) {
+        snapshotFlow { state.isMinimized }.collect { minimized ->
+            if (minimized) {
+                currentHideAll()
+                // Hidden before it's un-minimized, so it doesn't flash back up on the way
+                window.isVisible = false
+                state.isMinimized = false
+            }
+        }
+    }
+}
+
+/**
+ * Windows gives a taskbar button only to windows that have no owner, so every wIRC window is
+ * given one: a window that's never shown. Done natively because Window.Type.UTILITY (AWT's
+ * own way off the taskbar) can only be set before Compose has built the window, and on a
+ * framed window like wIRC main it also swaps in a small tool-window title bar with no
+ * minimize button. Runs while the window is built but not yet shown, which is when the
+ * taskbar decides whether it gets a button.
+ */
+fun hideFromTaskbar(window: ComposeWindow) {
+    try {
+        val hwnd = WinDef.HWND(Pointer(window.windowHandle))
+        val user32 = User32.INSTANCE
+        user32.SetWindowLongPtr(hwnd, GWLP_HWNDPARENT, TaskbarOwner.hwnd.pointer)
+        val exStyle = user32.GetWindowLong(hwnd, WinUser.GWL_EXSTYLE)
+        if (exStyle and WS_EX_APPWINDOW != 0) {
+            user32.SetWindowLong(hwnd, WinUser.GWL_EXSTYLE, exStyle and WS_EX_APPWINDOW.inv())
+        }
+    } catch (e: Throwable) {
+        // Not on Windows, or no native access: the window just keeps its taskbar button
+    }
+}
+
+private const val GWLP_HWNDPARENT = -8
+private const val WS_EX_APPWINDOW = 0x00040000
+
+private object TaskbarOwner {
+    val hwnd: WinDef.HWND by lazy {
+        // Made displayable (so it has a native window) but never shown
+        val frame = Frame().apply { addNotify() }
+        WinDef.HWND(Native.getComponentPointer(frame))
+    }
+}

src/main/kotlin/ui/ChannelScreen.kt

@@ -61,6 +61,7 @@ import androidx.compose.ui.input.pointer.pointerHoverIcon
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.layout.LayoutCoordinates
+import androidx.compose.ui.layout.layout
 import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.AnnotatedString
@@ -78,11 +79,12 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.window.DialogWindow
 import androidx.compose.ui.window.WindowScope
-import androidx.compose.ui.window.WindowState
 import androidx.compose.ui.window.rememberDialogState
 import data.ChannelBuffer
 import data.ChannelUser
 import data.IrcMessage
+import data.MAX_FONT_SIZE
+import data.MIN_FONT_SIZE
 import data.MessageKind
 import data.WindowDisplaySettings
 import irc.extractImageUrls
@@ -102,6 +104,7 @@ import java.net.URL
 import java.text.SimpleDateFormat
 import java.util.*
 import kotlin.math.floor
+import kotlin.math.roundToInt
 
 // Title-bar button fade (nicklist / settings / minimize / close). The buttons sit at
 // TITLE_BAR_BUTTON_REST_ALPHA until hovered, then animate to TITLE_BAR_BUTTON_HOVER_ALPHA
@@ -180,7 +183,7 @@ private fun copyToClipboardSafely(scope: CoroutineScope, text: String) {
 @OptIn(ExperimentalMaterial3Api::class, androidx.compose.foundation.ExperimentalFoundationApi::class)
 @Composable
 fun WindowScope.ChannelScreen(
-    windowState: WindowState,
+    onMinimize: () -> Unit,
     onCloseWindow: () -> Unit,
     channelName: String,
     buffer: ChannelBuffer?,
@@ -379,7 +382,7 @@ fun WindowScope.ChannelScreen(
                         FadingTitleBarButton(onClick = { showSettings = !showSettings }) {
                             Icon(Icons.Default.Settings, contentDescription = "Window settings", tint = textColor, modifier = Modifier.size(16.dp))
                         }
-                        FadingTitleBarButton(onClick = { windowState.isMinimized = true }) {
+                        FadingTitleBarButton(onClick = onMinimize) {
                             Box(
                                 modifier = Modifier
                                     .size(width = 10.dp, height = 2.dp)
@@ -417,7 +420,9 @@ fun WindowScope.ChannelScreen(
                         Surface {
                             WindowSettingsPanel(
                                 displaySettings = displaySettings,
-                                textColor = textColor,
+                                // Always white: the dialog is black, so the window's own text
+                                // color (black, say) would make every label invisible here
+                                textColor = Color.White,
                                 onAlphaChange = onAlphaChange,
                                 onTextColorChange = onTextColorChange,
                                 onFontSizeChange = onFontSizeChange,
@@ -859,10 +864,14 @@ fun MessageScrollback(
         // real cause was a race between the scroll effect and the LazyColumn's
         // own layout catching up to new items - see the scroll effects below.
         val snappedHeight = if (lineHeightDp > 0.dp) {
-            lineHeightDp * floor(maxHeight / lineHeightDp).toInt()
+            minOf(maxHeight, lineHeightDp * wholeLines(maxHeight, lineHeightDp))
         } else {
             maxHeight
         }
+        // Tells the window how much space is left under the last whole line, so a resize can
+        // trim the window itself to fit (see WindowSnapping.kt)
+        val lineGap = LocalLineGap.current
+        SideEffect { lineGap?.gap = maxHeight - snappedHeight }
 
         // NOTE: this used to also re-snap the scroll *offset* to the first
         // visible item on every resize/font-size change, to fix a partial line
@@ -1050,7 +1059,10 @@ fun MessageScrollback(
                 }
             }
 
-            Column(modifier = Modifier.fillMaxWidth()) {
+            // Every row is kept a whole number of lines tall (nearest whole line, to absorb
+            // the pixel or two a wrapped message can be off by), so the line snapping above
+            // stays lined up all the way to the top of the window instead of drifting.
+            Column(modifier = Modifier.fillMaxWidth().snapHeightToLines(lineHeightPx, roundUp = false)) {
             // Timestamp + nick are one text and the body another, both BasicText with
             // the same explicit style - BasicText never merges the ambient LocalTextStyle,
             // so neither picks up MaterialTheme's bodyLarge 24sp lineHeight (which once
@@ -1076,6 +1088,10 @@ fun MessageScrollback(
             }
             if (displaySettings.showImagePreviews) {
                 extractImageUrls(msg.rawText).forEach { url ->
+                    // A thumbnail can be any height, so its slot is rounded UP to whole lines
+                    // (never cropping the picture); otherwise every line above it in the
+                    // window would sit a fraction of a line off and show cut in half at the top.
+                    Box(modifier = Modifier.snapHeightToLines(lineHeightPx, roundUp = true)) {
                         UrlImagePreview(
                             url = url,
                             modifier = Modifier
@@ -1092,11 +1108,26 @@ fun MessageScrollback(
     }
     }
     }
+    }
     Spacer(modifier = Modifier.weight(1f))
     }
     }
 }
 
+// Reports this element's height as a whole number of text lines ([linePx] each): rounded up
+// for image slots (the picture is never cut), to the nearest line for text rows (a wrapped
+// message can measure a pixel or two off an exact multiple). Content is drawn from the top.
+private fun Modifier.snapHeightToLines(linePx: Int, roundUp: Boolean): Modifier = layout { measurable, constraints ->
+    val placeable = measurable.measure(constraints.copy(minHeight = 0))
+    val h = placeable.height
+    val snapped = when {
+        linePx <= 0 || h == 0 -> h
+        roundUp -> ((h + linePx - 1) / linePx) * linePx
+        else -> (((h + linePx / 2) / linePx).coerceAtLeast(1)) * linePx
+    }.coerceIn(constraints.minHeight, constraints.maxHeight.coerceAtLeast(constraints.minHeight))
+    layout(placeable.width, snapped) { placeable.place(0, 0) }
+}
+
 // Which of a row's two texts a TextPos is in: the timestamp/nick prefix, or the body.
 private const val PART_PREFIX = 0
 private const val PART_BODY = 1
@@ -1441,13 +1472,24 @@ private fun WindowSettingsPanel(
             colors = sliderColors
         )
         Spacer(Modifier.height(4.dp))
-        Text("Font size", color = textColor, style = MaterialTheme.typography.bodySmall)
+        Text("Font size:", color = textColor, style = MaterialTheme.typography.bodySmall)
-        Slider(
+        // Fixed sizes 10 to 18 (same as QuickClaude's Font size menu), square boxes in a row
-            value = displaySettings.fontSize,
+        val currentSize = displaySettings.fontSize.roundToInt()
-            onValueChange = onFontSizeChange,
+        Row(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
-            valueRange = 10f..24f,
+            for (size in MIN_FONT_SIZE..MAX_FONT_SIZE) {
-            colors = sliderColors
+                val selected = size == currentSize
-        )
+                Box(
+                    modifier = Modifier
+                        .size(28.dp)
+                        .background(if (selected) Color.White.copy(alpha = 0.25f) else Color.Transparent)
+                        .border(1.dp, if (selected) Color.White else Color.White.copy(alpha = 0.35f))
+                        .clickableNoRipple { onFontSizeChange(size.toFloat()) },
+                    contentAlignment = Alignment.Center
+                ) {
+                    Text(size.toString(), color = textColor, fontSize = 12.sp)
+                }
+            }
+        }
         Spacer(Modifier.height(4.dp))
         Text("Font:", color = textColor, style = MaterialTheme.typography.bodySmall)
         FontPickerList(displaySettings.fontId, textColor, onFontChange)

src/main/kotlin/ui/ChannelWindow.kt

@@ -3,6 +3,7 @@ package ui
 import androidx.compose.material3.ColorScheme
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.derivedStateOf
@@ -45,6 +46,8 @@ fun ChannelWindow(
     bufferKey: BufferKey,
     prefsRepo: WindowPrefsRepository,
     colorScheme: ColorScheme,
+    visible: Boolean,
+    onHideAll: () -> Unit,
     onOpenBuffer: (BufferKey) -> Unit,
     onCloseSelf: () -> Unit,
     onDisconnectServer: () -> Unit
@@ -74,14 +77,20 @@ fun ChannelWindow(
     // Restored from window_prefs.json (or cascaded if there's no usable saved position)
     // and saved back on move/resize/close - see WindowPlacement.kt.
     val windowState = rememberPersistentWindowState(prefsRepo, bufferKey.storageId(), DpSize(800.dp, 600.dp))
+    // Snap to the desktop grid after a move, and to whole lines after a resize
+    val lineGap = rememberLineGap()
+    WindowSnapping(windowState, lineGap)
 
     // undecorated + transparent trade the native OS title bar for real per-pixel window
     // transparency (Windows only honors transparency on undecorated windows) - ChannelScreen
     // supplies its own title bar with minimize/close/drag/resize to make up for what the
     // OS chrome would otherwise provide. No Surface wrapper here (M3 Surface paints an
     // opaque background) - ChannelScreen already paints its own alpha-aware background.
+    // Hidden to the tray along with every other wIRC window when [visible] is false - the
+    // window and its composition stay alive, so its buffer keeps filling while hidden.
     Window(
         onCloseRequest = onCloseSelf,
+        visible = visible,
         title = windowTitle,
         icon = painterResource("icon.png"),
         state = windowState,
@@ -89,9 +98,11 @@ fun ChannelWindow(
         transparent = true,
         resizable = true
     ) {
+        TrayWindowBehavior(windowState, onHideAll)
+        CompositionLocalProvider(LocalLineGap provides lineGap) {
         MaterialTheme(colorScheme = colorScheme) {
                 ChannelScreen(
-                    windowState = windowState,
+                    onMinimize = onHideAll,
                     onCloseWindow = onCloseSelf,
                     channelName = windowTitle,
                     buffer = buffer,
@@ -199,4 +210,5 @@ fun ChannelWindow(
                 )
         }
         }
+    }
 }

src/main/kotlin/ui/MainScreen.kt

@@ -205,9 +205,9 @@ fun MainScreen(
             MaterialTheme(colorScheme = colorScheme) {
                 Surface {
                     Column(modifier = Modifier.fillMaxSize().padding(8.dp).verticalScroll(rememberScrollState())) {
-                        Text("Server messages font:", color = textColor, style = MaterialTheme.typography.bodySmall)
+                        Text("Server messages font:", color = Color.White, style = MaterialTheme.typography.bodySmall)
                         Spacer(Modifier.height(4.dp))
-                        FontPickerList(displaySettings.fontId, textColor, onFontChange)
+                        FontPickerList(displaySettings.fontId, Color.White, onFontChange)
                     }
                 }
             }

src/main/kotlin/ui/WindowSnapping.kt

@@ -0,0 +1,204 @@
+package ui
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.snapshotFlow
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.DpSize
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.isSpecified
+import androidx.compose.ui.window.WindowPlacement
+import androidx.compose.ui.window.WindowPosition
+import androidx.compose.ui.window.WindowState
+import java.awt.AWTEvent
+import java.awt.GraphicsEnvironment
+import java.awt.Rectangle
+import java.awt.Toolkit
+import java.awt.event.AWTEventListener
+import java.awt.event.MouseEvent
+import java.util.Base64
+import java.util.concurrent.TimeUnit
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.collectLatest
+import kotlin.math.floor
+import kotlin.math.roundToInt
+
+/**
+ * Space left over under the last whole line of a window's scrollback, reported by
+ * MessageScrollback (which already sizes the scrollback itself to whole lines). When a
+ * resize ends, the window is trimmed by this much so the window itself fits whole lines too.
+ */
+class LineGap {
+    @Volatile var gap: Dp = 0.dp
+}
+
+val LocalLineGap = staticCompositionLocalOf<LineGap?> { null }
+
+@Composable
+fun rememberLineGap(): LineGap = remember { LineGap() }
+
+/**
+ * After the mouse is let go at the end of a drag or resize:
+ *  - a move snaps the window's top-left corner to the desktop icon grid
+ *  - a resize trims the window to whole lines of scrollback text (keeping whichever edge
+ *    didn't move in place)
+ * Channel windows are undecorated, so their moves and resizes happen inside the app (the
+ * title-bar drag area and Compose's own edge resizer) and the mouse release reaches wIRC.
+ * wIRC main has a normal Windows frame, whose drags Windows handles itself without telling
+ * the app when the button comes up, so for it ([osFrame] = true) the snap happens once the
+ * window has sat still for a moment instead.
+ */
+@Composable
+fun WindowSnapping(state: WindowState, lineGap: LineGap, osFrame: Boolean = false) {
+    if (osFrame) {
+        LaunchedEffect(state, lineGap) {
+            var settledPos: WindowPosition = state.position
+            var settledSize: DpSize = state.size
+            snapshotFlow { state.position to state.size }.collectLatest {
+                delay(OS_FRAME_SETTLE_MS)
+                afterMoveOrResize(state, lineGap, settledPos, settledSize)
+                settledPos = state.position
+                settledSize = state.size
+            }
+        }
+        return
+    }
+    DisposableEffect(state, lineGap) {
+        var startPos: WindowPosition? = null
+        var startSize: DpSize? = null
+        val listener = AWTEventListener { event ->
+            val e = event as? MouseEvent ?: return@AWTEventListener
+            if (e.button != MouseEvent.BUTTON1) return@AWTEventListener
+            when (e.id) {
+                MouseEvent.MOUSE_PRESSED -> {
+                    startPos = state.position
+                    startSize = state.size
+                }
+                MouseEvent.MOUSE_RELEASED -> {
+                    val p0 = startPos
+                    val s0 = startSize
+                    startPos = null
+                    startSize = null
+                    if (p0 != null && s0 != null) afterMoveOrResize(state, lineGap, p0, s0)
+                }
+            }
+        }
+        Toolkit.getDefaultToolkit().addAWTEventListener(listener, AWTEvent.MOUSE_EVENT_MASK)
+        onDispose { Toolkit.getDefaultToolkit().removeAWTEventListener(listener) }
+    }
+}
+
+// How long wIRC main has to sit still after a move/resize before it snaps
+private const val OS_FRAME_SETTLE_MS = 400L
+
+private fun afterMoveOrResize(state: WindowState, lineGap: LineGap, p0: WindowPosition, s0: DpSize) {
+    if (state.isMinimized || state.placement != WindowPlacement.Floating) return
+    val pos = state.position as? WindowPosition.Absolute ?: return
+    val size = state.size
+    if (!size.isSpecified || !s0.isSpecified) return
+    val start = p0 as? WindowPosition.Absolute
+
+    val resized = (size.width - s0.width).value.let { it > 0.5f || it < -0.5f } ||
+        (size.height - s0.height).value.let { it > 0.5f || it < -0.5f }
+
+    if (resized) {
+        val gap = lineGap.gap
+        if (gap > 0.5.dp && size.height - gap >= 120.dp) {
+            // Dragged the top edge (top moved, bottom stayed): keep the bottom where it is
+            val fromTop = start != null && (pos.y - start.y).value.let { it > 0.5f || it < -0.5f } &&
+                ((pos.y + size.height) - (start.y + s0.height)).value.let { it < 0.5f && it > -0.5f }
+            state.size = DpSize(size.width, size.height - gap)
+            if (fromTop) state.position = WindowPosition.Absolute(pos.x, pos.y + gap)
+        }
+        return
+    }
+
+    if (start == null || (start.x == pos.x && start.y == pos.y)) return
+    val (sx, sy) = DesktopGrid.spacing() ?: return
+    val area = workAreaAt(pos.x.value, pos.y.value)
+    val x = area.x + ((pos.x.value - area.x) / sx).roundToInt() * sx
+    val y = area.y + ((pos.y.value - area.y) / sy).roundToInt() * sy
+    if (x != pos.x.value || y != pos.y.value) state.position = WindowPosition.Absolute(x.dp, y.dp)
+}
+
+// The usable area (taskbar excluded) of the screen the window's corner is on, in the same
+// logical units as WindowState positions.
+private fun workAreaAt(x: Float, y: Float): Rectangle = try {
+    val ge = GraphicsEnvironment.getLocalGraphicsEnvironment()
+    val config = ge.screenDevices.map { it.defaultConfiguration }
+        .firstOrNull { it.bounds.contains(x.toInt(), y.toInt()) } ?: ge.defaultScreenDevice.defaultConfiguration
+    val b = config.bounds
+    val i = Toolkit.getDefaultToolkit().getScreenInsets(config)
+    Rectangle(b.x + i.left, b.y + i.top, b.width - i.left - i.right, b.height - i.top - i.bottom)
+} catch (e: Exception) {
+    Rectangle(0, 0, 1280, 720)
+}
+
+/**
+ * The desktop icon grid's spacing, read from the desktop's own icon view (so it follows the
+ * icon size and spacing Windows is really using), falling back to the system icon spacing.
+ * Java can't call Windows directly without extra libraries, so a hidden PowerShell asks once
+ * at startup, in the background; snapping just skips until the answer is in.
+ */
+object DesktopGrid {
+    @Volatile private var cached: Pair<Float, Float>? = null
+    @Volatile private var started = false
+
+    fun spacing(): Pair<Float, Float>? {
+        if (!started) refreshAsync()
+        return cached
+    }
+
+    @Synchronized
+    fun refreshAsync() {
+        if (started) return
+        started = true
+        Thread {
+            try {
+                val script = """
+                    Add-Type -TypeDefinition @'
+                    using System; using System.Runtime.InteropServices;
+                    public static class WircGrid {
+                      [DllImport("user32.dll", CharSet=CharSet.Unicode)] static extern IntPtr FindWindow(string c, string n);
+                      [DllImport("user32.dll", CharSet=CharSet.Unicode)] static extern IntPtr FindWindowEx(IntPtr p, IntPtr a, string c, string n);
+                      [DllImport("user32.dll")] static extern IntPtr SendMessage(IntPtr h, int m, IntPtr w, IntPtr l);
+                      [DllImport("user32.dll")] static extern bool SystemParametersInfo(uint a, uint p, out int v, uint i);
+                      public static string Get() {
+                        IntPtr dv = FindWindowEx(FindWindow("Progman", null), IntPtr.Zero, "SHELLDLL_DefView", null);
+                        IntPtr w = IntPtr.Zero;
+                        while (dv == IntPtr.Zero) { w = FindWindowEx(IntPtr.Zero, w, "WorkerW", null); if (w == IntPtr.Zero) break; dv = FindWindowEx(w, IntPtr.Zero, "SHELLDLL_DefView", null); }
+                        IntPtr lv = dv == IntPtr.Zero ? IntPtr.Zero : FindWindowEx(dv, IntPtr.Zero, "SysListView32", null);
+                        if (lv != IntPtr.Zero) { long r = SendMessage(lv, 0x1033, IntPtr.Zero, IntPtr.Zero).ToInt64(); long cx = r & 0xFFFF, cy = (r >> 16) & 0xFFFF; if (cx > 0 && cy > 0) return cx + "," + cy; }
+                        int sx, sy; SystemParametersInfo(0x000D, 0, out sx, 0); SystemParametersInfo(0x0018, 0, out sy, 0);
+                        return sx + "," + sy;
+                      }
+                    }
+                    '@
+                    [WircGrid]::Get()
+                """.trimIndent()
+                val encoded = Base64.getEncoder().encodeToString(script.toByteArray(Charsets.UTF_16LE))
+                val proc = ProcessBuilder("powershell.exe", "-NoProfile", "-NonInteractive", "-EncodedCommand", encoded)
+                    .redirectErrorStream(true).start()
+                val out = proc.inputStream.bufferedReader().readText()
+                proc.waitFor(30, TimeUnit.SECONDS)
+                val m = Regex("""(\d+),(\d+)""").findAll(out).lastOrNull() ?: return@Thread
+                val px = m.groupValues[1].toFloat()
+                val py = m.groupValues[2].toFloat()
+                // Physical pixels at the primary screen's scaling -> the logical units windows use
+                val scale = try {
+                    GraphicsEnvironment.getLocalGraphicsEnvironment().defaultScreenDevice.defaultConfiguration.defaultTransform.scaleX.toFloat()
+                } catch (e: Exception) { 1f }.coerceAtLeast(0.5f)
+                if (px > 8 && py > 8) cached = (px / scale) to (py / scale)
+            } catch (e: Exception) {
+                // No grid info: windows just don't snap to it
+            }
+        }.apply { isDaemon = true; name = "wIRC desktop grid" }.start()
+    }
+}
+
+/** Whole lines that fit in [height] at [lineHeight], with a little slack for rounding. */
+internal fun wholeLines(height: Dp, lineHeight: Dp): Int =
+    floor((height.value + 0.5f) / lineHeight.value).toInt().coerceAtLeast(1)