Consider autoplaying videos when opened

[chammoru]

Problem

Q1View currently opens a video in a paused state, so the user must press Space before playback begins.

For a viewer that supports video playback, this may feel less natural than common media-player behavior, where explicitly opening a video is treated as a request to play it immediately.

Reference behavior

• VLC begins playback after the user opens a media file.
• mpv starts playback by default; starting paused requires an explicit pause option.
• QuickTime Player separates opening and playback more clearly, so autoplay is not universal across all viewer-style applications.

This suggests that autoplay is common in media-player-oriented applications, but Q1View should still make it a deliberate UX decision.

Proposed behavior

When a video file is explicitly opened, start playback automatically after initialization succeeds.

This should apply to user-initiated paths such as:

• double-clicking a video associated with Q1View
• File > Open
• drag-and-drop into Viewer
• activating a video from the thumbnail drawer

Space should continue to toggle play/pause normally.

Design questions

• Should autoplay be enabled by default?
• Should there be a persistent Autoplay videos when opened preference?
• Should videos opened while navigating a folder autoplay, or only those opened through an explicit activation?
• Should session restore or automatic reopening remain paused?
• Should current mute, volume, speed, and looping state be preserved?

Suggested policy

Explicit open / double-click / drag-and-drop / thumbnail activation
    -> autoplay according to user preference

Automatic session restore or background preload
    -> remain paused

Implementation notes

• Start playback only after the decoder, timing information, and first frame are ready.
• Avoid briefly flashing a paused frame before playback starts.
• Preserve existing mute, volume, playback-speed, loop, and seek behavior.
• Do not trigger autoplay during thumbnail generation or background inspection.
• Ensure playback starts only once and does not duplicate timers, decoder startup, or audio initialization.

Acceptance criteria

• Explicitly opening a supported video starts playback automatically when autoplay is enabled.
• Space continues to toggle play/pause.
• Autoplay can be disabled and remembered across sessions if configurability is adopted.
• Session restore or non-interactive preload does not unexpectedly start video or audio.
• Image-opening behavior remains unchanged.