feat(eml): Fullscreen borderless video player with premium controls

[Dawnflare]

Fullscreen Video Capability - Extra Metadata Loader

This update adds the ability to view game videos in a borderless, maximized fullscreen window within the Extra Metadata Loader extension for Playnite.

✨ Features

• Multiple Triggers:
  • Click the new Fullscreen (⛶) button in the embedded video player's control bar.
  • Double-click anywhere on the video surface to rapidly pop it out.
• State Preservation: A completely seamless handoff. The video continues from its exact current position, volume level, and muted/unmuted state when switching between embedded and fullscreen modes.
• Animated Transport Controls:
  • A bottom-aligned control bar containing full premium features.
  • Animated Opacity: The entire control bar, as well as the exit button, rests at an unobtrusive 15% opacity so it doesn't distract from the video. Hovering immediately triggers a smooth fade-in to 90% opacity (200ms in, 400ms out).
  • Play/Pause Toggle: Features a dedicated toggle button, but can also be triggered by hitting the Spacebar or with a Single-click anywhere on the video surface.
  • Timeline Slider: A scrubbable timeline slider with live timestamp updates relative to the total duration.
  • Volume & Mute Controls: Includes a slider with a perceptually accurate (linear to quadratic) curve, a dedicated mute toggle button, and is also mapped to the M key.
• Exit Methods:
  • Press the Escape key.
  • Double-click the fullscreen video.
  • Click the ✕ overlay button in the top-right corner.
• Auto-Looping: Respects the "Repeat trailer videos" setting from the plugin configuration.

🛠️ Technical Implementation & Bug Fixes

This feature has been surgically ported to the stable emlCrashFix2025 branch, avoiding regressions in the master repository (such as the broken Steam Video downloader). It includes robust fixes to the WPF MediaElement implementation:

• Spacebar Focus Fix: Explicitly set Focusable="False" on all interactive control buttons and sliders in the fullscreen window. This prevents mouse clicks from stealing keyboard focus, ensuring the Spacebar consistently acts as a global Play/Pause toggle rather than re-triggering the last clicked button.
• Black Screen on Pause resolved: When entering fullscreen while a video is paused, WPF natively fails to render the initial frame, presenting a black screen. A robust fsPlayer.Pause() injection during initialization forces the pipeline to immediately render the initial start position frame.
• Stream Reset fixed: Prevented an aggressive WPF bug that resets a manual stream back to 00:00 the very first time Play() is called from a Paused state.
• Mute Syncing: Fixed logic where the fullscreen player would ignore the embedded player's mute state.
• Compilation & Integration: Cleanly injected the new windows into the existing ExtraMetadataLoader.csproj structure, ensuring zero compilation errors on the emlCrashFix2025 foundation while adhering to the original author's strict coding guidelines (PascalCase, camelCase with underscores, etc.).

🧪 Installation & Testing Instructions

1. Build and Import

To test these changes, you need to compile the project and manually replace the extension files in your Playnite installation.

1. Build the Project:
   Open a terminal in the project root and run:

   msbuild source\Generic\ExtraMetadataLoader\ExtraMetadataLoader.csproj /p:Configuration=Debug /t:Build

   This will produce ExtraMetadataLoader.dll in source\Generic\ExtraMetadataLoader\bin\Debug\.

2. Locate Playnite Extensions:
   Open Playnite, go to Main Menu > About Playnite > User data directory.
   Navigate to the Extensions folder (not ExtensionsData).
   Look for a folder named ExtraMetadataLoader or 705fdbca-e1fc-4004-b839-1d040b8b4429 (the Extra Metadata Loader GUID).

3. Replace Files:

   • Close Playnite completely.
   • Copy the newly built ExtraMetadataLoader.dll from your build output to the extensions folder, overwriting the existing one.
   • Ensure the Localization and Controls folders (if applicable) are also synced if you made XAML changes that aren't embedded.

2. Verification Checklist

Follow these steps to verify the feature:

1. Launch Playnite: Open a game that has a video trailer.
2. Toggle Button: Hover over the video to reveal the control bar. Click the ⛶ button. The video should pop into fullscreen.
3. Double-Click: Exit fullscreen, then double-click the video surface. It should enter fullscreen.
4. Exit Triggers: While in fullscreen, verify that Escape, Double-clicking, and the top-right X button all return you to the Playnite interface.
5. State Restore: Pause a video at 0:10, enter fullscreen. It should be paused at 0:10. Play it to 0:15, exit fullscreen. It should be playing at 0:15 in the embedded player.
6. Volume & Mute Sync: Mute the video in Playnite. Enter fullscreen. The video should be muted. Change the volume and un-mute in the fullscreen controls, hit Escape, and verify those changes persisted back to the embedded player.