Add event-driven wallpaper rotation

config/dot/quickshell/wallpaper-service-harness.qml

@@ -7,8 +7,10 @@ import qs.services
 
 ShellRoot {
     Component.onCompleted: {
-        Wallpaper.outputNames = function() { return ["DP-2", "HDMI-A-1"]; };
+        Wallpaper.outputOverride = ["DP-2", "HDMI-A-1"];
+        Wallpaper.candidateOverride = ["/images/a.jpg", "/images/b.jpg", "/images/c.jpg"];
         Wallpaper.startupRestoreEnabled = false;
+        Wallpaper.slideshowIntervalOverrideMs = 60000;
         Wallpaper.available = ["/images/a.jpg", "/images/b.jpg", "/images/c.jpg"];
     }
 
@@ -31,6 +33,25 @@ ShellRoot {
             return Wallpaper.set(path);
         }
 
+        function seedSlideshow(paths: string, shuffle: bool): void {
+            DesktopPreferences.set("wallpaperMode", "slideshow");
+            DesktopPreferences.set("wallpaperPath", "/images/a.jpg");
+            DesktopPreferences.set("wallpaperSlideshowPaths", JSON.parse(paths));
+            DesktopPreferences.set("wallpaperShuffle", shuffle);
+            Wallpaper.slideshowPath = "/images/a.jpg";
+            Wallpaper.shuffleBag = [];
+        }
+
+        function advanceSlideshow(): bool {
+            return Wallpaper.advanceSlideshow();
+        }
+
+        function rapidOutputs(): void {
+            Wallpaper.outputOverride = ["DP-2"];
+            Wallpaper.outputOverride = ["HDMI-A-1"];
+            Wallpaper.outputOverride = ["DP-2", "HDMI-A-1"];
+        }
+
         function status(): string {
             return JSON.stringify({
                 busy: Wallpaper.busy,
@@ -39,7 +60,10 @@ ShellRoot {
                 active: Wallpaper.active,
                 mode: DesktopPreferences.get("wallpaperMode"),
                 path: DesktopPreferences.get("wallpaperPath"),
-                assignments: DesktopPreferences.get("wallpaperPerMonitor")
+                assignments: DesktopPreferences.get("wallpaperPerMonitor"),
+                slideshowPath: Wallpaper.slideshowPath,
+                shuffleBag: Wallpaper.shuffleBag,
+                slideshowTimerRunning: Wallpaper.slideshowTimerRunning
             });
         }
     }