refactor(Notifications): further support for duplicate notification logic

- New setting to stack or suppress identical alerts (on by default)
Closes #2334

quickshell/Common/SettingsData.qml

@@ -688,6 +688,7 @@ Singleton {
     property int notificationTimeoutNormal: 5000
     property int notificationTimeoutCritical: 0
     property bool notificationCompactMode: false
+    property bool notificationDedupeEnabled: true
     property int notificationPopupPosition: SettingsData.Position.Top
     property int notificationAnimationSpeed: SettingsData.AnimationSpeed.Short
     property int notificationCustomAnimationDuration: 400

quickshell/Common/settings/SettingsSpec.js

@@ -399,6 +399,7 @@ var SPEC = {
     notificationTimeoutNormal: { def: 5000 },
     notificationTimeoutCritical: { def: 0 },
     notificationCompactMode: { def: false },
+    notificationDedupeEnabled: { def: true },
     notificationPopupPosition: { def: 0 },
     notificationAnimationSpeed: { def: 1 },
     notificationCustomAnimationDuration: { def: 400 },

quickshell/Modules/Notifications/Center/HistoryNotificationCard.qml

@@ -182,11 +182,15 @@ Rectangle {
                 Row {
                     width: parent.width
                     spacing: Theme.spacingXS
-                    readonly property real reservedTrailingWidth: historySeparator.implicitWidth + Math.max(historyTimeText.implicitWidth, 72) + spacing
+
+                    Item {
+                        width: Math.max(0, parent.width - historySeparator.implicitWidth - Math.max(historyTimeText.implicitWidth, 72) - parent.spacing * 2)
+                        height: historyTitleText.implicitHeight
+                        visible: historyTitleText.text.length > 0
 
                         StyledText {
                             id: historyTitleText
-                        width: Math.min(implicitWidth, Math.max(0, parent.width - parent.reservedTrailingWidth))
+                            anchors.fill: parent
                             text: {
                                 let title = historyItem.summary || "";
                                 const appName = historyItem.appName || "";
@@ -201,7 +205,7 @@ Rectangle {
                             font.weight: Font.Medium
                             elide: Text.ElideRight
                             maximumLineCount: 1
-                        visible: text.length > 0
+                        }
                     }
                     StyledText {
                         id: historySeparator

quickshell/Modules/Settings/NotificationsTab.qml

@@ -273,6 +273,17 @@ Item {
                     onToggled: checked => SettingsData.set("notificationCompactMode", checked)
                 }
 
+                SettingsToggleRow {
+                    settingKey: "notificationDedupeEnabled"
+                    tags: ["notification", "duplicate", "dedupe", "stack", "coalesce", "repeat"]
+                    text: I18n.tr("Suppress Duplicate Notifications")
+                    description: SettingsData.notificationDedupeEnabled
+                             ? I18n.tr("Identical alerts show as one popup instead of stacking")
+                             : I18n.tr("Identical alerts stack as separate notification cards")
+                    checked: SettingsData.notificationDedupeEnabled
+                    onToggled: checked => SettingsData.set("notificationDedupeEnabled", checked)
+                }
+
                 SettingsToggleRow {
                     settingKey: "notificationPopupShadowEnabled"
                     tags: ["notification", "popup", "shadow", "radius", "rounded"]

quickshell/Services/NotificationService.qml

@@ -35,6 +35,8 @@ Singleton {
     property int maxIngressPerSecond: 20
     property double _lastIngressSec: 0
     property int _ingressCountThisSec: 0
+    readonly property int notificationDedupBurstMs: 5000
+    property var _recentDedupKeys: []
 
     property var _dismissQueue: []
     property int _dismissBatchSize: 8
@@ -291,18 +293,58 @@ Singleton {
         return Date.now() / 1000.0;
     }
 
+    function _normalizeDedupText(text) {
+        if (!text)
+            return "";
+        let normalized = text.toString();
+        normalized = normalized.replace(/<img\b[^>]*>/gi, "");
+        normalized = normalized.replace(/<[^>]+>/g, "");
+        normalized = normalized.replace(/\s+/g, " ").trim();
+        return normalized.toLowerCase();
+    }
+
+    function _dedupAppId(source) {
+        if (!source)
+            return "";
+        const desktopEntry = (source.desktopEntry || "").toString().trim().toLowerCase();
+        if (desktopEntry)
+            return desktopEntry;
+        return (source.appName || "").toString().trim().toLowerCase();
+    }
+
     function _notificationDedupKey(source) {
         if (!source)
             return "";
-        const app = (source.appName || source.desktopEntry || "").toString();
+        const app = _dedupAppId(source);
-        const summary = (source.summary || "").toString();
+        const summary = _normalizeDedupText(source.summary);
-        const body = (source.body || "").toString();
+        const body = _normalizeDedupText(source.body);
         const urgency = typeof source.urgency === "number" ? source.urgency : NotificationUrgency.Normal;
-        const icon = (source.appIcon || "").toString();
         if (!app && !summary && !body)
             return "";
         const sep = "
";
-        return app + sep + summary + sep + body + sep + urgency + sep + icon;
+        return app + sep + summary + sep + body + sep + urgency;
+    }
+
+    function _pruneRecentDedupKeys() {
+        const cutoff = Date.now() - notificationDedupBurstMs;
+        _recentDedupKeys = _recentDedupKeys.filter(entry => entry && entry.atMs >= cutoff);
+    }
+
+    function _hasRecentDuplicate(key) {
+        if (!key)
+            return false;
+        _pruneRecentDedupKeys();
+        return _recentDedupKeys.some(entry => entry && entry.key === key);
+    }
+
+    function _recordDedupKey(key) {
+        if (!key)
+            return;
+        _pruneRecentDedupKeys();
+        _recentDedupKeys.push({
+            "key": key,
+            "atMs": Date.now()
+        });
     }
 
     function _findActiveDuplicate(notif) {
@@ -310,17 +352,14 @@ Singleton {
         if (!key)
             return null;
 
-        for (const w of visibleNotifications) {
+        for (const w of allWrappers) {
             if (!w || !w.notification || !w.popup)
                 continue;
-            if (_notificationDedupKey(w.notification) === key)
+            if (_notificationDedupKey(w.notification) !== key)
-                return w;
-        }
-
-        for (const w of notificationQueue) {
-            if (!w || !w.notification)
                 continue;
-            if (_notificationDedupKey(w.notification) === key)
+            if (visibleNotifications.indexOf(w) !== -1 || notificationQueue.indexOf(w) !== -1)
+                return w;
+            if (w.timer && w.timer.running)
                 return w;
         }
 
@@ -637,15 +676,18 @@ Singleton {
                 return;
             }
 
+            if (SettingsData.notificationDedupeEnabled) {
+                const dedupKey = _notificationDedupKey(notif);
                 const duplicate = _findActiveDuplicate(notif);
-            if (duplicate) {
+                if (duplicate || _hasRecentDuplicate(dedupKey)) {
-                if (duplicate.timer && duplicate.timer.running)
+                    if (duplicate && duplicate.timer && duplicate.timer.running)
                         duplicate.timer.restart();
                     try {
                         notif.dismiss();
                     } catch (e) {}
                     return;
                 }
+            }
 
             if (!_ingressAllowed(policy.urgency)) {
                 if (policy.urgency !== NotificationUrgency.Critical) {
@@ -686,6 +728,9 @@ Singleton {
             });
 
             if (wrapper) {
+                if (SettingsData.notificationDedupeEnabled)
+                    _recordDedupKey(_notificationDedupKey(notif));
+
                 root.allWrappers.push(wrapper);
                 if (shouldKeepInCenter) {
                     root.notifications.push(wrapper);

quickshell/translations/settings_search_index.json

@@ -5807,6 +5807,28 @@
     ],
     "description": "Use smaller notification cards"
   },
+  {
+    "section": "notificationDedupeEnabled",
+    "label": "Suppress Duplicate Notifications",
+    "tabIndex": 17,
+    "category": "Notifications",
+    "keywords": [
+      "alert",
+      "alerts",
+      "coalesce",
+      "dedupe",
+      "duplicate",
+      "duplicates",
+      "messages",
+      "notif",
+      "notification",
+      "notifications",
+      "repeat",
+      "stack",
+      "toast"
+    ],
+    "description": "Control whether identical alerts stack or show as a single popup"
+  },
   {
     "section": "notificationHistorySaveCritical",
     "label": "Critical Priority",