Rust Hover Preview

Rust Hover Preview is a Windows 11 system tray app that shows instant image and video previews in File Explorer when you hover files with the mouse or navigate with the keyboard.

Inspired by QTTabBar (QuizoApps) hover preview.

Showcase.webm

Highlights

• Mouse-hover and keyboard-navigation previews in Explorer
• Static image previews plus animated GIF playback and libwebp-backed animated WebP playback
• Video previews through FFmpeg (ffplay + ffprobe)
• Tray controls for enable/disable, delay, positioning, startup, off-trigger key, and volume
• Explorer Shell view detection, folder caching, and path normalization for reliable hover matching
• Topmost, non-activating preview windows designed to avoid focus stealing

Supported Formats

Images

jpg, jpeg, png, gif, bmp, ico, tiff, tif, webp

Videos (FFmpeg required)

mp4, webm, mkv, avi, mov, wmv, flv, m4v

Installation (Recommended)

Download prebuilt assets from the repository Releases tab:

1. Open Releases
2. Download one of the latest assets:
   • .msi installer (recommended for most users)
   • .exe portable build
3. If you downloaded .msi, run the installer. It installs to %LOCALAPPDATA%\rust-hover-preview. If you downloaded .exe, place it in any folder you prefer (for example: C:\Tools\RustHoverPreview)
4. Launch Rust Hover Preview

No Rust toolchain is needed when installing from Releases.

Optional: Enable Video Preview (FFmpeg)

Video previews require ffplay and ffprobe available in PATH.

Option A: Install with winget

winget install --id Gyan.FFmpeg -e

Then reopen your terminal and verify:

ffplay -version
ffprobe -version

Option B: Manual install

1. Download a Windows FFmpeg build from https://ffmpeg.org/download.html
2. Extract it to a location such as C:\ffmpeg
3. Add C:\ffmpeg\bin to your user PATH
4. Open a new terminal and run:

ffplay -version
ffprobe -version

Usage

1. Start the app (tray icon appears)
2. Hover media files in Explorer to preview them
3. Use keyboard navigation in Explorer (arrow keys/tab) to trigger focused-item previews
4. Right-click the tray icon to configure behavior

System Tray Menu

• Enable Preview: Turn previews on or off
• Preview Delay: Instant (0 ms), Fast (200 ms), Medium (500 ms), Relaxed (750 ms), Slow (1000 ms)
• Same File Rehover Delay: delay before the same file can preview again after the preview self-dismisses
• Video Volume: Max (100%), High (80%), Medium (50%), Low (25%), Very Low (10%), Mute (0%)
• Preview Position: Follow Cursor or Best Position
• Transparent Background: Transparent, Black, White, or Checkerboard
• Enable Off Trigger Key: Temporarily suppress previews while the displayed configured key is held
• Run at Startup: Add/remove startup entry in Windows
• Edit Config.ini: Open configuration file in your default editor
• Exit: Close the application

Configuration

Settings are stored at:

%APPDATA%\rust-hover-preview\config.ini

Example:

[settings]
run_at_startup=true
hover_delay_ms=0
same_file_rehover_delay_ms=750
preview_enabled=true
enable_off_trigger_key=true
off_trigger_key=alt
follow_cursor=false
transparent_background=transparent
video_volume=0

When enable_off_trigger_key is enabled, hold the configured off_trigger_key to keep previews hidden while browsing Explorer.

Build from Source

Requirements

• Windows 11
• Rust toolchain 1.70+
• Visual Studio Build Tools (MSVC)
• Windows SDK

Build Commands

# Debug
cargo build

# Release
cargo build --release

Release binary output:

target/release/rust-hover-preview.exe

Architecture Notes

• Uses Windows accessibility APIs (MSAA + UI Automation) to resolve hovered/focused Explorer items
• Uses Shell COM APIs to identify active Explorer windows and folders
• Uses GDI for image rendering in a layered topmost preview window
• Uses Google's libwebp through webp-animation for animated WebP decoding
• Uses directories for Windows roaming configuration paths
• Uses ffprobe for video dimensions and ffplay for video playback
• Uses the registry (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) for startup control

License

MIT. See LICENSE.