Improve app result ranking

app/ui/src/main/java/de/mm20/launcher2/ui/launcher/search/SearchVM.kt

@@ -472,20 +472,15 @@ class SearchVM : ViewModel(), KoinComponent {
     private suspend fun <T : SavableSearchable> List<T>.applyRanking(order: SearchResultOrder): List<T> {
         if (size <= 1) return this
         val sequence = asSequence()
-        val sorted = if (order == SearchResultOrder.Weighted) {
-            val sortedKeys = searchableRepository.sortByWeight(map { it.key }).first()
-            sequence.sortedWith { a, b ->
-                val aRank = sortedKeys.indexOf(a.key)
-                val bRank = sortedKeys.indexOf(b.key)
-                when {
-                    aRank != -1 && bRank != -1 -> aRank.compareTo(bRank)
-                    aRank == -1 && bRank != -1 -> 1
-                    aRank != -1 && bRank == -1 -> -1
-                    else -> a.compareTo(b)
-                }
-            }
-        } else {
-            sequence.sorted()
+        val weights = searchableRepository.getWeights(map { it.key }).first()
+        val sorted = sequence.sortedWith { a, b ->
+            val aWeight = weights[a.key] ?: 0.0
+            val bWeight = weights[b.key] ?: 0.0
+
+            val aScore = a.score.score * 0.7f + aWeight.toFloat() * 0.3f
+            val bScore = b.score.score * 0.7f + bWeight.toFloat() * 0.3f
+
+            bScore.compareTo(aScore)
         }
         return sorted.distinctBy { it.key }.toList()
     }

core/base/build.gradle.kts

@@ -52,6 +52,8 @@ dependencies {
     runtimeOnly(libs.androidx.compose.runtime)
     implementation(libs.androidx.compose.materialicons)
 
+    implementation(libs.stringsimilarity)
+
     implementation(project(":core:ktx"))
     implementation(project(":core:i18n"))
     implementation(project(":libs:material-color-utilities"))

core/base/src/main/java/de/mm20/launcher2/licenses/OpenSourceLicenses.kt

@@ -220,4 +220,12 @@ val OpenSourceLicenses = arrayOf(
         url = "https://github.com/woheller69/AndroidAddressFormatter",
         copyrightNote = "Copyright (c) 2022 woheller69",
     ),
+    OpenSourceLibrary(
+        name = "String Similarity for Kotlin",
+        description = "A library that implements various measures of string similarity and distance.",
+        licenseName = R.string.mit_license_name,
+        licenseText = R.raw.license_mit,
+        url = "https://github.com/aallam/string-similarity-kotlin",
+        copyrightNote = "Copyright (c) 2023 Mouaad Aallam",
+    ),
 )

core/base/src/main/java/de/mm20/launcher2/search/ResultScore.kt

@@ -0,0 +1,94 @@
+package de.mm20.launcher2.search
+
+import com.aallam.similarity.JaroWinkler
+import de.mm20.launcher2.ktx.normalize
+
+@JvmInline
+value class ResultScore private constructor(private val packed: Long) : Comparable<ResultScore> {
+    constructor(
+        isPrefix: Boolean,
+        isSubstring: Boolean,
+        isPrimary: Boolean,
+        similarity: Float,
+    ) : this(
+        (similarity.toRawBits().toLong()) or
+                (if (isPrefix) (1L shl 32) else 0) or
+                (if (isSubstring) (1L shl 33) else 0) or
+                (if (isPrimary) (1L shl 34) else 0)
+    )
+
+    /**
+     * Whether the query is a literal prefix of the result.
+     */
+    val isPrefix: Boolean
+        get() = (packed and (1L shl 32)) != 0L
+
+    /**
+     * Whether the query is a substring of the result.
+     */
+    val isSubstring: Boolean
+        get() = (packed and (1L shl 33)) != 0L
+
+    /**
+     * Whether the query was matched against a primary field.
+     */
+    val isPrimary: Boolean
+        get() = (packed and (1L shl 34)) != 0L
+
+    /**
+     * The Jaro-Winkler similarity between the query and the result.
+     */
+    val similarity: Float
+        get() = Float.fromBits((packed and 0xffffffffL).toInt())
+
+    /**
+     * A total score for the result, combining the similarity with additional factors.
+     */
+    val score: Float
+        get() = (similarity + (if (isPrefix) 0.8f else 0f) + (if (isSubstring) 0.8f else 0f)) * (if (isPrimary) 1f else 0.5f)
+
+    override fun compareTo(other: ResultScore): Int {
+        return score.compareTo(other.score)
+    }
+
+    companion object {
+        operator fun invoke(
+            query: String,
+            primaryFields: Iterable<String> = emptyList(),
+            secondaryFields: Iterable<String> = emptyList(),
+        ): ResultScore {
+            val normalizedQuery = query.normalize()
+            val jaroWinkler = JaroWinkler()
+            val bestPrimaryScore = primaryFields.maxOfOrNull {
+                val normalizedTerm = it.normalize()
+                val sim = jaroWinkler.similarity(normalizedQuery, normalizedTerm).toFloat()
+                ResultScore(
+                    isPrefix = normalizedTerm.startsWith(normalizedQuery),
+                    isSubstring = normalizedQuery in normalizedTerm,
+                    isPrimary = true,
+                    similarity = sim
+                )
+            } ?: Zero
+            val bestSecondaryScore = secondaryFields.maxOfOrNull {
+                val normalizedTerm = it.normalize()
+                val sim = jaroWinkler.similarity(normalizedQuery, normalizedTerm).toFloat()
+                ResultScore(
+                    isPrefix = normalizedTerm.startsWith(normalizedQuery),
+                    isSubstring = normalizedQuery in normalizedTerm,
+                    isPrimary = false,
+                    similarity = sim
+                )
+            } ?: Zero
+
+            return maxOf(bestPrimaryScore, bestSecondaryScore)
+        }
+
+        val Zero = ResultScore(
+            isPrefix = false,
+            isSubstring = false,
+            isPrimary = false,
+            similarity = 0f
+        )
+    }
+
+}

core/base/src/main/java/de/mm20/launcher2/search/Searchable.kt

@@ -2,4 +2,7 @@ package de.mm20.launcher2.search
 
 import kotlinx.coroutines.Deferred
 
-interface Searchable
+interface Searchable {
+    val score: ResultScore
+        get() = ResultScore.Zero
+}

data/applications/src/main/java/de/mm20/launcher2/applications/AppRepository.kt

@@ -14,6 +14,7 @@ import de.mm20.launcher2.ktx.normalize
 import de.mm20.launcher2.profiles.Profile
 import de.mm20.launcher2.profiles.ProfileManager
 import de.mm20.launcher2.search.Application
+import de.mm20.launcher2.search.ResultScore
 import de.mm20.launcher2.search.SearchableRepository
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.toImmutableList
@@ -37,6 +38,7 @@ interface AppRepository : SearchableRepository<Application> {
         packageName: String,
         user: UserHandle,
     ): Flow<Application?>
+
     fun findMany(): Flow<ImmutableList<Application>>
 }
 
@@ -244,8 +246,13 @@ internal class AppRepositoryImpl(
                 if (query.isEmpty()) {
                     appResults.addAll(apps)
                 } else {
-                    appResults.addAll(apps.filter {
-                        matches(it.label, query)
+                    appResults.addAll(apps.mapNotNull {
+                        it.copy(
+                            score = ResultScore(
+                                query = query,
+                                primaryFields = listOf(it.label),
+                            )
+                        ).takeIf { it.score.score >= 0.8f }
                     })
 
                     val componentName = ComponentName.unflattenFromString(query)

data/applications/src/main/java/de/mm20/launcher2/applications/LauncherApp.kt

@@ -28,6 +28,7 @@ import de.mm20.launcher2.icons.TransparentLayer
 import de.mm20.launcher2.ktx.getSerialNumber
 import de.mm20.launcher2.ktx.isAtLeastApiLevel
 import de.mm20.launcher2.search.Application
+import de.mm20.launcher2.search.ResultScore
 import de.mm20.launcher2.search.SearchableSerializer
 import de.mm20.launcher2.search.StoreLink
 import kotlinx.coroutines.Dispatchers
@@ -40,6 +41,7 @@ internal data class LauncherApp(
     override val isSuspended: Boolean = false,
     internal val userSerialNumber: Long,
     override val labelOverride: String? = null,
+    override val score: ResultScore = ResultScore.Zero,
 ) : Application {
 
     override val componentName: ComponentName
@@ -48,11 +50,12 @@ internal data class LauncherApp(
     override val label: String = launcherActivityInfo.label.toString()
 
 
-    constructor(context: Context, launcherActivityInfo: LauncherActivityInfo) : this(
+    constructor(context: Context, launcherActivityInfo: LauncherActivityInfo, score: ResultScore = ResultScore.Zero) : this(
         launcherActivityInfo,
         versionName = getPackageVersionName(context, launcherActivityInfo.applicationInfo.packageName),
         isSuspended = launcherActivityInfo.applicationInfo.flags and ApplicationInfo.FLAG_SUSPENDED != 0,
-        userSerialNumber = launcherActivityInfo.user.getSerialNumber(context)
+        userSerialNumber = launcherActivityInfo.user.getSerialNumber(context),
+        score = score,
     )
 
     override val user: UserHandle

data/database/src/main/java/de/mm20/launcher2/database/SearchableDao.kt

@@ -1,8 +1,8 @@
 package de.mm20.launcher2.database
 
-import android.util.Log
 import androidx.room.Dao
 import androidx.room.Insert
+import androidx.room.MapColumn
 import androidx.room.OnConflictStrategy
 import androidx.room.Query
 import androidx.room.Transaction
@@ -201,6 +201,9 @@ interface SearchableDao {
     @Query("SELECT `key` FROM Searchable WHERE `key` IN (:keys) ORDER BY `weight` DESC, pinPosition DESC")
     fun sortByWeight(keys: List<String>): Flow<List<String>>
 
+    @Query("SELECT `key`, `weight` FROM Searchable WHERE `key` IN (:keys)")
+    fun getWeights(keys: List<String>): Flow<Map<@MapColumn(columnName = "key") String, @MapColumn(columnName = "weight") Double>>
+
     @Query("SELECT hidden FROM Searchable WHERE `key` = :key UNION SELECT 0 as hidden ORDER BY hidden DESC LIMIT 1")
     fun getVisibility(key: String): Flow<Int>
 

data/searchable/src/main/java/de/mm20/launcher2/searchable/SavableSearchableRepository.kt

@@ -103,6 +103,8 @@ interface SavableSearchableRepository : Backupable {
 
     fun sortByWeight(keys: List<String>): Flow<List<String>>
 
+    fun getWeights(keys: List<String>): Flow<Map<String, Double>>
+
     /**
      * Remove this item from the Searchable database
      */
@@ -370,6 +372,11 @@ internal class SavableSearchableRepositoryImpl(
         return database.searchableDao().sortByWeight(keys)
     }
 
+    override fun getWeights(keys: List<String>): Flow<Map<String, Double>> {
+        if (keys.size > 999) return flowOf(emptyMap())
+        return database.searchableDao().getWeights(keys)
+    }
+
     private suspend fun fromDatabaseEntity(entity: SavedSearchableEntity): SavedSearchable {
         val deserializer: SearchableDeserializer? = try {
             get(named(entity.type))

gradle/libs.versions.toml

@@ -118,6 +118,7 @@ leakcanary = { group = "com.squareup.leakcanary", name = "leakcanary", version =
 suncalc = { group = "org.shredzone.commons", name = "commons-suncalc", version = "3.7" }
 jsoup = { group = "org.jsoup", name = "jsoup", version = "1.16.1" }
 commons-text = { group = "org.apache.commons", name = "commons-text", version = "1.10.0" }
+stringsimilarity = { group = "com.aallam.similarity", name = "string-similarity-kotlin", version = "0.1.0" }
 
 # 4.4.2 is the last GPL compatible version, don't update to 5.x
 mathparser = { group = "org.mariuszgromada.math", name = "MathParser.org-mXparser", version = "4.4.2" }