FastTheme 0.1.6 [ALPHA-2026-09-27] — High-Performance Native Window Styling & Dynamic Theming for Java

⚡ High-performance native Windows window styling, zero-allocation dynamic theming, and OS bridge for Java.

FastTheme brings native Windows 10/11 styling and schema-free dynamic theming to Java Swing, AWT, OpenGL, and CLI applications. It enables native dark mode title bars, Mica/Acrylic effects, and custom window decorations by bridging Java with the Desktop Window Manager (DWM) API, paired with an open, dynamically-allocated theme engine.

Watch Styling Demo (YouTube) | Watch Overlay Demo (YouTube) | Watch JMH Benchmark (YouTube)

Quick Start

1. Dynamic Schema-Free Theme Loading & Access

import fasttheme.FastTheme;
import fasttheme.ThemeKeys;
import fasttheme.ThemeParser;
import java.awt.Color;

public class Demo {
    public static void main(String[] args) {
        // 1. Load schema-free theme directly from .theme text, .themebin binary, or file
        FastTheme.load("""
                THEME = Modern Dark
                window.background = #13141F
                window.text = #C3CDF7
                titlebar.background = #0C0E10
                accent.cyan = #00E0FF
                button.hover = @accent.cyan
                """);

        // 2. Direct String Key Access (32-bit packed ARGB int)
        int bg = FastTheme.get("window.background");

        // 3. Fast cached slot access for hot loops (zero-allocation primitive array read)
        int bgSlot = ThemeKeys.slot("window.background");
        int fastBg = FastTheme.get(bgSlot);

        // 4. AWT/Swing Color Object
        Color awtBg = FastTheme.getColor("window.background");
    }
}

2. Native Windows 10/11 DWM Window Synchronization

import fasttheme.FastTheme;
import javax.swing.JFrame;
import java.awt.Color;

public class NativeDemo {
    public static void main(String[] args) {
        JFrame frame = new JFrame("FastTheme Window");
        frame.setSize(600, 400);
        frame.setLocationRelativeTo(null);
        frame.addNotify(); // Realizes native Win32 peer before showing to prevent flicker

        long hwnd = FastTheme.getWindowHandle(frame);
        if (hwnd != 0) {
            // Automatically synchronizes DWM title bar and background from active theme
            FastTheme.applyToWindow(hwnd);
        }
        frame.setVisible(true);
    }
}

3. Premium Borderless Window with Native Drop Shadow (Raycast-Style)

import fasttheme.FastTheme;
import javax.swing.JFrame;
import java.awt.Color;

public class BorderlessDemo {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setSize(500, 320);
        frame.setLocationRelativeTo(null);
        frame.getContentPane().setBackground(new Color(20, 20, 24));
        frame.addNotify(); // Realize native HWND peer

        long hwnd = FastTheme.getWindowHandle(frame);
        if (hwnd != 0) {
            FastTheme.setBorderlessShadow(hwnd, true);     // Removes titlebar, retains OS drop shadow
            FastTheme.setOverlayDragHeight(hwnd, 48);      // Top 48px act as invisible drag area
            FastTheme.setCornerStyle(hwnd, 2);            // Windows 11 Rounded Corners (2 = Rounded)
        }
        frame.setVisible(true);
    }
}

Why FastTheme?

Traditional Java Look & Feels (like FlatLaf, Radiance, or Nimbus) style internal Swing components, but leave the OS window frame untouched or resort to flickering, undecorated window simulations. FastTheme bridges the gap between Java and the native OS compositor while delivering zero-allocation theme execution:

Real Native Windows Chrome (Beyond Swing Simulation)
Controls the actual Windows 10/11 Desktop Window Manager (DWM) directly via JNI. Get real OS dark mode title bars, native caption colors, Mica/Acrylic glass materials, Windows 11 rounded corners, and native borderless drop shadows without custom decoration lag or resize jitter.
Zero-Allocation Memory Architecture
Built like a game engine rather than a bloated UI framework. Themes are stored in flat, contiguous int[] primitive ARGB arrays delivering sub-nanosecond $O(1)$ slot reads with 0 bytes GC allocation in hot rendering loops.
100% Schema-Free & Dynamic Registry
No rigid enum constraints or hardcoded schemas. Applications and plugins allocate custom theme tokens dynamically on demand (ThemeKeys.slot("custom.token")).
Dual Formats (.theme & .themebin)
Support for both human-readable .theme text definitions (with @KEY alias resolution) and sub-microsecond binary .themebin payloads for instant CLI and desktop startup.
Unified Design Matrix (GUI, TUI, and OS)
A single theme definition simultaneously synchronizes Swing/AWT window chrome, borderless overlay geometries, and terminal CLI interfaces.

Feature	FlatLaf / Swing Look&Feel	JNA DWM Hacks	FastTheme
Window Frame Styling	Swing custom decoration	Manual JNA calls	Native DWM (`DwmSetWindowAttribute`)
Windows 11 Rounded Corners	Emulated in Java graphics	Manual pointer struct	Native OS DWM Corner Preference
Runtime Color Query	`Map<String, Object>` / UIDefaults	Object wrappers	Sub-nanosecond `int[]` Slot Lookup
Garbage Collection Churn	High (`java.awt.Color` objects)	Native handle churn	0 Bytes GC (Packed 32-bit ARGB `int`)
Format & Startup	XML / Properties parsing	Hardcoded C bindings	Dual Text (`.theme`) & Binary (`.themebin`)
Dependencies	External Look&Feel JAR	JNA Runtime (~15 MB)	Pure Java 17+ backed by FastCore

Key Features

🌙 Native Windows 10/11 Styling — Immersive Dark Mode, custom title bar captions, Mica materials, and borderless drop shadows.
⚡ Open Dynamic Key Registry — Unlimited dynamic keys registered on demand (ThemeKeys.slot("KEY")) with $O(1)$ primitive array reads.
📄 Dual File Formats — Human-readable .theme text (supporting @KEY variable aliasing) and sub-microsecond binary .themebin.
🧮 WCAG 2.1 Contrast Safety — Relative luminance calculation, auto-readable text foreground selection, and tint/shade math.
🔄 Live Observer State — Global JVM state management with dynamic ThemeListener change notifications.
📦 Zero Dependency Bloat — Purely decoupled and standalone, requiring only FastCore for native library extraction.

Real-World Scenarios

⚡ Live Reactive Theming — Real-time theme reloading and user-customizable color palettes without window rebuilding or UI flicker.
🪟 Windows 11 Immersive Chrome — Seamless Mica backdrops, dark mode title bars, and custom accent styling for enterprise desktop suites.
🚀 Raycast & Spotlight Overlays — Draggable borderless launcher windows with native drop shadows, rounded corners, and subtle alpha glass.
♿ High-Contrast Accessible Tooling — Automated WCAG 2.1 compliance guaranteeing text readability on dynamic user palettes.

Performance Benchmarks

FastTheme is rigorously profiled using JMH to guarantee zero-allocation sub-nanosecond execution.

Benchmark Operation	Score (ops/ms)	Ops per Second	Memory Allocation
Cached Slot Array Read (`FastTheme.get(slot)`)	~245,000 ops/ms	> 245 Million	0 bytes / op (Zero GC)
String Key Lookup (`FastTheme.get(key)`)	~68,000 ops/ms	> 68 Million	0 bytes / op (Zero GC)
WCAG Contrast Foreground Calculation	~85,000 ops/ms	> 85 Million	0 bytes / op (Zero GC)
Binary `.themebin` Deserialization	~1,200 ops/ms	> 1.2 Million	Sub-microsecond

Run the benchmarks locally: .\run-benchmark.bat

API Quick Reference

Dynamic Theme State Management (`FastTheme`)

Method / Signature	Return Type	Description	Docs
`FastTheme.load(String text)`	`void`	Parses and globally activates a `.theme` formatted text definition.	Wiki
`FastTheme.load(byte[] binaryData)`	`void`	Deserializes and globally activates a `.themebin` binary payload.	Wiki
`FastTheme.loadFile(String path)` / `(File file)`	`void`	Loads and activates `.theme` or `.themebin` directly from a file path.	Wiki
`FastTheme.addListener(ThemeListener)`	`void`	Registers functional observers for live theme change events.	Wiki
`FastTheme.removeListener(ThemeListener)`	`void`	Unregisters functional observers for live theme change events.	Wiki
`FastTheme.current()`	`ThemeData`	Returns the currently active `ThemeData` instance.	Wiki
`FastTheme.get(String key)` / `get(int slot)`	`int`	Retrieves packed 32-bit ARGB color integer ($O(1)$ zero-allocation array read for slot).	Wiki
`FastTheme.getColor(String key)` / `(int slot)`	`Color`	Converts the resolved color to a standard Java AWT/Swing `Color` object.	Wiki
`FastTheme.set(ThemeData theme)`	`void`	Activates a `ThemeData` instance globally and notifies all registered listeners.	Wiki

Native Win32 DWM Window Styling (`FastTheme`)

Method / Signature	Return Type	Description	Docs
`FastTheme.applyToWindow(long hwnd)` / `(Component comp)`	`void`	Automatically applies title bar background, text, and window colors from active theme.	Wiki
`FastTheme.applyToWindow(hwnd, bgKey, fgKey, winKey)`	`void`	Applies specific user-defined theme keys to the native window DWM chrome.	Wiki
`FastTheme.enableMica(long hwnd, boolean enabled)`	`boolean`	Enables Windows 11 native Mica backdrop material effect (with legacy fallback).	Wiki
`FastTheme.getWindowHandle(Component comp)`	`long`	Extracts the native 64-bit `HWND` handle from an AWT/Swing component.	Wiki
`FastTheme.getConsoleWindowHandle()`	`long`	Queries the native Win32 `HWND` of the active Windows console window (`cmd.exe`/ConHost).	Wiki
`FastTheme.isNativeAvailable()`	`boolean`	Checks whether the native Windows styling DLL is loaded and functional.	Wiki
`FastTheme.isSystemDarkMode()`	`boolean`	Detects global Windows system dark mode setting.	Wiki
`FastTheme.setTitleBarDarkMode(long hwnd, boolean dark)`	`boolean`	Toggles Windows 10/11 immersive dark mode for the native title bar.	Wiki
`FastTheme.setTitleBarColor(long hwnd, int r, int g, int b)`	`boolean`	Sets the native caption background color on Windows 11.	Wiki
`FastTheme.setTitleBarTextColor(long hwnd, int r, int g, int b)`	`boolean`	Sets the native title bar text/foreground color on Windows 11.	Wiki
`FastTheme.setWindowBackgroundColor(long hwnd, int r, int g, int b)`	`boolean`	Sets the Win32 window background fill color.	Wiki
`FastTheme.setWindowTransparency(long hwnd, int alpha)`	`boolean`	Sets window alpha blending from `0` (transparent) to `255` (fully opaque).	Wiki
`FastTheme.setSystemBackdropType(long hwnd, int type)`	`boolean`	Sets native Windows 11 backdrop material (`BACKDROP_MICA`, `BACKDROP_ACRYLIC`, `BACKDROP_MICA_ALT`).	Wiki
`FastTheme.setCornerStyle(long hwnd, int style)`	`boolean`	Sets window corner preference on Windows 11 (`0`=Default, `1`=Square, `2`=Rounded, `3`=Small Rounded).	Wiki
`FastTheme.setBorderlessShadow(long hwnd, boolean enabled)`	`boolean`	Removes native title bar while preserving native OS drop shadow (Raycast-style).	Wiki
`FastTheme.setOverlayDragHeight(long hwnd, int height)`	`boolean`	Defines top invisible grab area (in pixels) for draggable borderless windows.	Wiki
`FastTheme.setWindowButtonsVisible(long hwnd, boolean min, boolean max)`	`boolean`	Toggles native minimize and maximize buttons in the window title bar.	Wiki
`FastTheme.setAlwaysOnTop(long hwnd, boolean alwaysOnTop)`	`boolean`	Toggles native Win32 window topmost z-order.	Wiki

Supporting Utilities (`ThemeKeys`, `ThemeParser`, `ThemeColorUtil`)

Method / Signature	Return Type	Description	Docs
`ThemeKeys.slot(String key)`	`int`	Retrieves existing slot ID or registers a dynamic slot index on demand.	Wiki
`ThemeKeys.indexOf(String key)` / `nameOf(int slot)`	`int` / `String`	Bidirectional translation between dynamic string key names and slot indices.	Wiki
`ThemeParser.parseText(String text)`	`ThemeData`	Deserializes human-readable `.theme` content with `@KEY` alias resolution.	Wiki
`ThemeParser.parseBinary(byte[] bytes)`	`ThemeData`	Deserializes ultra-fast binary `.themebin` payload.	Wiki
`ThemeColorUtil.getContrastForeground(int bg)`	`int`	Calculates optimal high-contrast foreground color based on WCAG 2.1 relative luminance.	Wiki
`ThemeColorUtil.lighten(argb, amt)` / `darken(argb, amt)`	`int`	Pure mathematical tinting and shading for hover/pressed UI states.	Wiki
`ThemeColorUtil.blend(c1, c2, float t)`	`int`	Linear color interpolation and channel alpha blending.	Wiki

Technical Demos & Benchmarks

Case	Java Example	Launcher	Description
Window Styling & Transitions (YouTube)	Demo.java	`run-demo.bat`	Native DWM title bar styling, dark mode detection, and live theme updates.
Premium Borderless Overlay (YouTube)	Demo2.java	`run-demo2.bat`	Borderless Raycast-style overlay with native drop shadow, invisible drag area, and window transparency.
Windows 11 Mica Material	MicaDemo.java	`run-demo-mica.bat`	Standard Windows 11 Mica backdrop (`BACKDROP_MICA`) with transparent Swing viewport.
Windows 11 Acrylic Blur	AcrylicDemo.java	`run-demo-acrylic.bat`	Windows 11 Acrylic translucid blur backdrop (`BACKDROP_ACRYLIC`).
Windows 11 Mica Alt Material	MicaAltDemo.java	`run-demo-mica-alt.bat`	Windows 11 high-contrast Mica Alt tabbed container backdrop (`BACKDROP_MICA_ALT`).
JMH Microbenchmark Suite	Benchmark.java	`run-benchmark.bat`	Formal OpenJDK JMH zero-allocation slot array access, dynamic lookups, and parser throughput benchmarks.

Installation

FastJava modules are published via JitPack and can be installed with standard build tools or direct download.

Option 1: Maven (Recommended)

Add the JitPack repository and dependencies to your pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

<dependencies>
    <!-- Core FastTheme Engine -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>FastTheme</artifactId>
        <version>0.1.6</version>
    </dependency>
    <!-- Required Native JNI loader -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>fastcore</artifactId>
        <version>0.1.0</version>
    </dependency>
    <!-- FastFileFormat - Dual-Format (.theme/.themebin) Parser & Serializer -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>FastFileFormat</artifactId>
        <version>0.1.1</version>
    </dependency>
    <!-- FastBinary - High-Performance Binary Bit-Packing & VarInt Engine -->
    <dependency>
        <groupId>com.github.andrestubbe</groupId>
        <artifactId>FastBinary</artifactId>
        <version>0.1.1</version>
    </dependency>
</dependencies>

Option 2: Gradle (via JitPack)

repositories {
    maven { url 'https://jitpack.io' }
}

dependencies {
    implementation 'com.github.andrestubbe:FastTheme:0.1.6'
    implementation 'com.github.andrestubbe:fastcore:0.1.0'
    implementation 'com.github.andrestubbe:FastFileFormat:0.1.1'
    implementation 'com.github.andrestubbe:FastBinary:0.1.1'
}

Option 3: Direct Download (No Build Tool)

Download the pre-built JARs directly to add them to your classpath:

📦 FastTheme-0.1.6.jar (Core Library & Native DLL)
📦 FastCore-0.1.0.jar (Required Native JNI loader)
📦 FastFileFormat-0.1.1.jar (Serialization & File Format Engine)
📦 FastBinary-0.1.1.jar (Binary Bit-Packing Engine)

Documentation

COMPILE.md: Full compilation guide (Maven & Native C++ Build Setup).
REFERENCE.md: Exhaustive catalog of API contracts, data structures, and JNI methods.
PHILOSOPHY.md: Dynamic slot architecture, Win32 DWM bridge, and design principles.
ROADMAP.md: Planned milestone features and performance extensions.
CHANGELOG.md: Version history and release notes.

Platform Support

Platform	Architecture	Status	Notes
Windows 10/11	x64	✅ Fully Supported	Native Win32 / DWM (Mica, Acrylic, Dark Mode, HWND bridge)
Linux	x64, ARM64	🟡 Partial	Dynamic Theming, FastBinary, Color Math & WCAG (Pure Java fallback)
macOS	Apple Silicon, x64	🟡 Partial	Dynamic Theming, FastBinary, Color Math & WCAG (Pure Java fallback)

License

MIT License — See LICENSE for details.

Related Projects

FastCore — Native JNI Loader and Utilities
FastFileFormat — Dual text/binary serialization and parser engine
FastAnimation — Zero overhead timeline orchestration
FastTween — Zero overhead pool-based tweening
FastDWM — Native Desktop Window Manager API
FastDisplay — Native display telemetry and multi-monitor DPI scaling API
FastANSI — High-performance terminal ANSI compositor
FastUI — High-Performance GUI Framework
FastTUI — Terminal User Interface Toolkit

Part of the FastJava Ecosystem — Making the JVM faster. Small package. Maximum speed. Zero bloat. 🚀📋

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
docs		docs
examples		examples
native		native
src		src
.gitattributes		.gitattributes
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
Repo		Repo
compile.bat		compile.bat
jitpack.yml		jitpack.yml
pom.xml		pom.xml
run-benchmark.bat		run-benchmark.bat
run-demo-acrylic.bat		run-demo-acrylic.bat
run-demo-mica-alt.bat		run-demo-mica-alt.bat
run-demo-mica.bat		run-demo-mica.bat
run-demo.bat		run-demo.bat
run-demo2.bat		run-demo2.bat

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FastTheme 0.1.6 [ALPHA-2026-09-27] — High-Performance Native Window Styling & Dynamic Theming for Java

Quick Start

1. Dynamic Schema-Free Theme Loading & Access

2. Native Windows 10/11 DWM Window Synchronization

3. Premium Borderless Window with Native Drop Shadow (Raycast-Style)

Table of Contents

Why FastTheme?

Key Features

Real-World Scenarios

Performance Benchmarks

API Quick Reference

Dynamic Theme State Management (`FastTheme`)

Native Win32 DWM Window Styling (`FastTheme`)

Supporting Utilities (`ThemeKeys`, `ThemeParser`, `ThemeColorUtil`)

Technical Demos & Benchmarks

Installation

Option 1: Maven (Recommended)

Option 2: Gradle (via JitPack)

Option 3: Direct Download (No Build Tool)

Documentation

Platform Support

License

Related Projects

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FastTheme 0.1.6 [ALPHA-2026-09-27] — High-Performance Native Window Styling & Dynamic Theming for Java

Quick Start

1. Dynamic Schema-Free Theme Loading & Access

2. Native Windows 10/11 DWM Window Synchronization

3. Premium Borderless Window with Native Drop Shadow (Raycast-Style)

Table of Contents

Why FastTheme?

Key Features

Real-World Scenarios

Performance Benchmarks

API Quick Reference

Dynamic Theme State Management (FastTheme)

Native Win32 DWM Window Styling (FastTheme)

Supporting Utilities (ThemeKeys, ThemeParser, ThemeColorUtil)

Technical Demos & Benchmarks

Installation

Option 1: Maven (Recommended)

Option 2: Gradle (via JitPack)

Option 3: Direct Download (No Build Tool)

Documentation

Platform Support

License

Related Projects

About

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Dynamic Theme State Management (`FastTheme`)

Native Win32 DWM Window Styling (`FastTheme`)

Supporting Utilities (`ThemeKeys`, `ThemeParser`, `ThemeColorUtil`)