settings highlight optimized

Modules/Settings/NavPane/NavLocations.qml

@@ -249,7 +249,7 @@ VerticalFadeFlickable {
 									elide: Text.ElideRight
 									font.pointSize: Appearance.font.size.medium
 									text: SettingsSearcher.highlight(result.modelData.title, root.search, DynamicColors.palette.m3primary)
-									textFormat: Text.StyledText
+									textFormat: text.includes("<font") ? Text.StyledText : Text.PlainText
 								}
 
 								CustomText {
@@ -258,7 +258,7 @@ VerticalFadeFlickable {
 									elide: Text.ElideRight
 									font.pointSize: Appearance.font.size.small
 									text: SettingsSearcher.highlight(result.modelData.subtext, root.search, DynamicColors.palette.m3primary)
-									textFormat: Text.StyledText
+									textFormat: text.includes("<font") ? Text.StyledText : Text.PlainText
 									visible: result.modelData.subtext.length > 0
 								}
 							}

Modules/Settings/SettingsSearcher.qml

@@ -10,16 +10,39 @@ Singleton {
 	id: root
 
 	property var fzfFinder: null
+	readonly property var highlightCache: ({
+			"search": "",
+			"pattern": null
+		})
 	property var inverted: ({})
 	property var ranking: ({})
 
 	function highlight(text: string, search: string, colour: color): string {
 		const escaped = text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
-		const tokens = tokenize(search);
-		if (tokens.length === 0)
+		if (search.length === 0)
 			return escaped;
-		const escapedTokens = tokens.map(t => t.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"));
-		const pattern = new RegExp("\\b(" + escapedTokens.join("|") + ")", "gi");
+
+		const cache = root.highlightCache;
+		if (search !== cache.search) {
+			const tokens = tokenize(search);
+			cache.search = search;
+			if (tokens.length === 0)
+				cache.pattern = null;
+			else {
+				const escapedTokens = tokens.map(t => t.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"));
+				cache.pattern = new RegExp("\\b(" + escapedTokens.join("|") + ")", "gi");
+			}
+		}
+
+		const pattern = cache.pattern;
+		if (!pattern)
+			return escaped;
+
+		pattern.lastIndex = 0;
+		if (!pattern.test(escaped))
+			return escaped;
+
+		pattern.lastIndex = 0;
 		return escaped.replace(pattern, `<font color="${colour}">$1</font>`);
 	}