Multi-Window Chat App in Compose Desktop | Kotlin Desktop #13

Build a multi-window chat app with Kotlin Compose Desktop! Learn how to use the application composable for multiple windows, create dynamic windows with for loops and key(), share state across windows with mutableStateListOf, add a system tray icon, and control window position with rememberWindowState. What You'll Learn: - application composable for managing app lifecycle with multiple windows - Window composable with rememberWindowState for position and size - Dynamic window creation using for loops over mutable state lists - key() composable for stable identity tracking of dynamic windows - Tray composable for system tray icon with dropdown menu - BufferedImage and Java 2D for programmatic tray icon creation - mutableStateListOf and mutableStateMapOf for shared cross-window state - LaunchedEffect for auto-scroll and auto-reply - onPreviewKeyEvent for Enter-to-send keyboard handling Timestamps: 0:00 - Introduction 0:15 - Preview: What We're Building 0:45 - Project Setup (Gradle, Compose Dependencies) 2:14 - Chat Data (Contact, Message, ChatState) 4:28 - Contact List (LazyColumn, ContactRow, Status Dots) 7:06 - Chat Window (Messages, Input Bar, Auto-Reply) 10:59 - Main & Compile (Tray, Window, Dynamic Windows) 14:04 - Live Demo: Multi-Window Chat in Action 15:08 - Recap & Key Takeaways 16:08 - Thanks for Watching Key Takeaways: 1. application — Manages app lifecycle, multiple Window calls create multiple windows 2. Dynamic Windows — Loop over state to create windows, key() ensures proper identity 3. Shared State — mutableStateListOf and mutableStateMapOf share data across windows 4. Tray — System tray icon with menu, persists when windows are closed 5. Window State — rememberWindowState controls position and size, stagger to prevent overlap Previous Lesson: Lesson 12: Animations https://youtube.com/... Next Lesson: Lesson 14: Navigation (coming soon) Tech Stack: Kotlin 2.1, Compose Multiplatform 1.7.3, Material3 Multi-Window API, System Tray, Shared State Gradle 8.10, JVM 17+ Source Code: https://github.com/GoCelesteAI/kotlin_desktop_multi_window Taught by CelesteAI If you found this helpful, please like and subscribe for more Kotlin Desktop tutorials! #kotlin #compose #desktop #material3 #multiwindow #tray #dynamicwindows #sharedstate #tutorial #programming Tags kotlin, compose multiplatform, compose desktop, material3, multi-window, multiple windows, system tray, tray icon, dynamic windows, key composable, shared state, mutableStateListOf, rememberWindowState, window management, chat app, jetbrains compose, kotlin tutorial, desktop app, jvm, composable