Add slideshow support to mpvpaper plugin and the new mpvpaper auto-pause flags

mpvpaper/README.md

@@ -8,6 +8,10 @@ Noctalia does not decode video itself. This plugin runs `mpvpaper`, which draws
 outputs you assign a video to — so the video shows through, with the bar and dock still
 drawn above it.
 
+In addition to single-file wallpapers, the plugin can run **directory slideshows**:
+when you set a slideshow interval from the picker, mpvpaper loops over all supported
+videos in the selected file’s directory, starting at the one you clicked.
+
 ## Plugin
 
 | Field | Value |
@@ -20,6 +24,11 @@ drawn above it.
 Install `mpvpaper` and `mpv` on `PATH`. `mpvpaper` renders the wallpaper
 surface, and `mpv` renders picker thumbnails.
 
+For slideshow state tracking (so the picker highlights the correct tile and static
+wallpaper frames follow the current slideshow file), the service talks to mpv over
+JSON IPC using the `socat` command; if `socat` is missing, slideshows still play, but
+tile highlighting and static-frame extraction may not reflect the current file.
+
 The plugin works on `wlr-layer-shell` compositors (Niri, Hyprland, Sway, Mango).
 
 ## Usage
@@ -34,27 +43,34 @@ The plugin works on `wlr-layer-shell` compositors (Niri, Hyprland, Sway, Mango).
 3. Choose a target output (or **All outputs**), then click a video to apply it.
    Use **Stop** to restore Noctalia's own wallpaper on that output.
 
-Assignments persist across restarts. Supported files: `mp4`, `webm`, `mkv`, `mov`, `gif`.
+4. To enable a **slideshow**, click the **Slideshow** button in the picker’s
+   header to expand the interval slider. Drag the slider to choose an interval
+   (in minutes) and release to commit; the service converts this to seconds and
+   passes `--slideshow <seconds>` to mpvpaper, building a playlist from all
+   supported videos in that directory, starting at the file you selected.
+
+Assignments (including the last slideshow interval) persist across restarts. Supported
+files: `mp4`, `webm`, `mkv`, `mov`, `gif`.
 
 ## IPC Commands
 
 You can control the video wallpaper externally via Noctalia's IPC mechanism. Replace `[connector]` with your display name (e.g. `DP-1`), or omit it to target all monitors:
 
-- `noctalia msg plugin noctalia/mpvpaper:service all pause [connector]` - Pauses playback via cgroups freezer.
+- `noctalia msg plugin noctalia/mpvpaper:service all pause [connector]` - Pauses playback via cgroups freezer (or SIGSTOP when systemd is disabled).
 - `noctalia msg plugin noctalia/mpvpaper:service all resume [connector]` - Resumes playback.
 - `noctalia msg plugin noctalia/mpvpaper:service all toggle [connector]` - Toggles playback between paused and resumed state.
-- `noctalia msg plugin noctalia/mpvpaper:service all clear <connector>` - Stops the wallpaper on the specified monitor and extracts a frame as a static wallpaper.
+- `noctalia msg plugin noctalia/mpvpaper:service all clear <connector>` - Stops the wallpaper on the specified monitor and extracts a frame as a static wallpaper (when enabled).
 - `noctalia msg plugin noctalia/mpvpaper:service all clear-all` - Stops all active video wallpapers.
-
+- `noctalia msg plugin noctalia/mpvpaper:service all slideshow <minutes>` - Changes the slideshow interval to the value in minutes
 ## Settings
 
 | Setting | Type | Default | Description |
 | --- | --- | --- | --- |
 | `video_directory` | `folder` | *(empty)* | Folder scanned for wallpaper videos; defaults to `~/Videos` when empty. |
 | `mute` | `bool` | `true` | Starts video wallpapers muted. |
 | `hardware_decode` | `bool` | `true` | Uses `mpv` hardware decoding. |
-| `auto_pause` | `bool` | `true` | Pauses playback while a fullscreen window covers the wallpaper. |
-| `mpv_options` | `string` | *(empty)* | Additional space-separated `mpv` options. |
+| `auto_pause` | `select` | `"full"` | Automatically pauses or stops playback while a window covers the wallpaper (`off`, `maximized`, or `fullscreen`). |
+| `mpv_options` | `string` | *(empty)* | Additional space-separated `mpv` options (forwarded via `-o`), e.g. `panscan=1.0 video-zoom=0.1`. |
 | `run_as_systemd` | `bool` | `false` | Runs instances inside systemd transient scopes (`systemd-run`) for resource control. |
 | `extract_last_frame` | `bool` | `true` | Extracts a static frame to use as a wallpaper when video playback is stopped or paused. |
 | `cpu_quota` | `number` | `0` | Systemd `CPUQuota=` limit in percentage. Requires `run_as_systemd`. |
@@ -66,4 +82,13 @@ You can control the video wallpaper externally via Noctalia's IPC mechanism. Rep
 
 ## How it works
 
-A headless service natively supervises `mpvpaper` instances (one per output), either launching them directly or wrapping them in systemd transient scopes (`systemd-run`) for strict CPU and memory resource limits. The picker panel and bar widget are thin clients that drive the service through the plugin's shared state. When the plugin is disabled or Noctalia exits, the service's `onExit` hook terminates every running `mpvpaper` instance — including frozen or paused ones — so no orphan processes remain.
+A headless service natively supervises `mpvpaper` instances (one per output), either launching them directly or wrapping them in systemd transient scopes (`systemd-run`) for strict CPU and memory resource limits. The picker panel and bar widget are thin clients that drive the service through the plugin's shared state.
+
+When you set a slideshow interval, the service builds an `.m3u` playlist from all
+supported videos in the selected file’s directory and starts mpvpaper with that
+playlist and `--slideshow` enabled; the service then polls mpv over JSON IPC to
+track which file is currently shown, updating assignments and static wallpaper
+frames so the picker highlights the right tile and stop operations extract the
+correct frame.
+
+When the plugin is disabled or Noctalia exits, the service's `onExit` hook terminates every running `mpvpaper` instance — including frozen or paused ones — so no orphan processes remain.