wallpaper: a singleton for the chosen transition

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/desktop/modules/appearance/Transitions.qml b/desktop/modules/appearance/Transitions.qml
new file mode 100644
index 0000000..e28718c
--- /dev/null
+++ b/desktop/modules/appearance/Transitions.qml
@@ -0,0 +1,63 @@
+// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+pragma Singleton
+
+import Quickshell
+import QtQuick
+import "../.."
+import "TransitionPick.js" as TransitionPick
+
+// Which transition covers a wallpaper change. The page edits the draft, Apply
+// saves it, and each run asks next() once, so both screens play the same one.
+// See the spec, docs/superpowers/specs/2026-11-06-wallpaper-transitions-design.md.
+Singleton {
+    id: root
+
+    readonly property var all: [
+        { name: "burn", label: "Burn" },
+        { name: "ink", label: "Ink" },
+        { name: "shatter", label: "Shatter" },
+        { name: "ripple", label: "Ripple" },
+        { name: "melt", label: "Melt" },
+        { name: "blinds", label: "Blinds" },
+        { name: "crosswarp", label: "Cross-warp" },
+    ]
+    readonly property var names: all.map(t => t.name)
+    readonly property int duration: 3500
+
+    readonly property var saved: TransitionPick.clean(Prefs.wallTransition, names)
+    property string draftPick: saved.pick
+    property var draftPool: saved.pool
+    onSavedChanged: reset()
+
+    readonly property bool dirty: draftPick !== saved.pick
+        || JSON.stringify(draftPool) !== JSON.stringify(saved.pool)
+    readonly property bool valid: draftPick !== "random" || draftPool.length > 0
+
+    function toggle(name) {
+        const on = draftPool.indexOf(name) >= 0;
+        draftPool = names.filter(n => n === name ? !on : draftPool.indexOf(n) >= 0);
+    }
+    function reset() {
+        draftPick = saved.pick;
+        draftPool = saved.pool;
+    }
+    function apply() {
+        if (valid) Prefs.setWallTransition({ pick: draftPick, pool: draftPool });
+    }
+
+    property string last: ""
+    function next() {
+        last = TransitionPick.choose(saved.pick, saved.pool, last);
+        return last;
+    }
+}