Simplify filtering apps

Just do what is necessary for the chosen search strategy instead of
filling three lists when only one is ever used.

Also use better names to improve readabilty.

app/src/main/java/de/markusfisch/android/pielauncher/content/AppMenu.java

@@ -157,51 +157,45 @@ public List<AppIcon> filterAppsBy(Context context, String query) {
 				? ""
 				: query.trim().toLowerCase(defaultLocale);
 
+		Preferences prefs = PieLauncherApp.getPrefs(context);
+		int strategy = prefs.getSearchStrictness();
 		ArrayList<AppIcon> list = new ArrayList<>();
-		ArrayList<AppIcon> contain = new ArrayList<>();
 		ArrayList<AppIcon> hamming = new ArrayList<>();
 		if (query.isEmpty()) {
 			list.addAll(apps.values());
 		} else {
-			int searchParameterPref = PieLauncherApp
-					.getPrefs(context).getSearchParameter();
-			for (Map.Entry<LauncherItemKey, AppIcon> entry :
-					apps.entrySet()) {
-				String searchParameter;
+			int item = prefs.getSearchParameter();
+			for (Map.Entry<LauncherItemKey, AppIcon> entry : apps.entrySet()) {
 				AppIcon appIcon = entry.getValue();
-				if (searchParameterPref ==
-						Preferences.SEARCH_PARAMETER_PACKAGE_NAME) {
-					searchParameter = appIcon.componentName
-							.getPackageName().toLowerCase(defaultLocale);
-				} else {
-					searchParameter = appIcon.label.toLowerCase(defaultLocale);
+				String subject = getSubject(item, appIcon, defaultLocale);
+				boolean add = false;
+				switch (strategy) {
+					case Preferences.SEARCH_STRICTNESS_STARTS_WITH:
+						add = subject.startsWith(query);
+						break;
+					case Preferences.SEARCH_STRICTNESS_HAMMING:
+						if (hammingDistance(subject, query) < 2) {
+							hamming.add(appIcon);
+						}
+						// Fall through because HAMMING includes CONTAINS
+						// for historical reasons.
+					case Preferences.SEARCH_STRICTNESS_CONTAINS:
+						add = subject.contains(query);
+						break;
 				}
-				if (searchParameter.startsWith(query)) {
+				if (add) {
 					list.add(appIcon);
-				} else if (searchParameter.contains(query)) {
-					contain.add(appIcon);
-				} else if (hammingDistance(searchParameter, query) < 2) {
-					hamming.add(appIcon);
 				}
 			}
 		}
-		Collections.sort(list, appLabelComparator);
-
-		int searchStrictness =
-				PieLauncherApp.getPrefs(context).getSearchStrictness();
-		if (searchStrictness == Preferences.SEARCH_STRICTNESS_STARTS_WITH) {
-			return list;
-		}
 
-		Collections.sort(contain, appLabelComparator);
-		list.addAll(contain);
-		if (searchStrictness == Preferences.SEARCH_STRICTNESS_CONTAINS) {
-			return list;
+		Collections.sort(list, appLabelComparator);
+		if (strategy == Preferences.SEARCH_STRICTNESS_HAMMING) {
+			// Only append hamming matches as they're less likely
+			// as good as exact matches.
+			Collections.sort(hamming, appLabelComparator);
+			list.addAll(hamming);
 		}
-
-		Collections.sort(hamming, appLabelComparator);
-		list.addAll(hamming);
-
 		return list;
 	}
 
@@ -522,6 +516,15 @@ private LauncherApps getLauncherApps(Context context) {
 		return launcherApps;
 	}
 
+	private static String getSubject(int item, AppIcon appIcon,
+			Locale defaultLocale) {
+		if (item == Preferences.SEARCH_PARAMETER_PACKAGE_NAME) {
+			return appIcon.componentName.getPackageName()
+					.toLowerCase(defaultLocale);
+		}
+		return appIcon.label.toLowerCase(defaultLocale);
+	}
+
 	private static int hammingDistance(String a, String b) {
 		int count = 0;
 		for (int i = 0, l = Math.min(a.length(), b.length()); i < l; ++i) {