adding some initial Room database related code

app/build.gradle

@@ -44,4 +44,8 @@ android {
 
 dependencies {
     implementation 'com.github.SimpleMobileTools:Simple-Commons:a0121a8d50'
+
+    kapt "androidx.room:room-compiler:2.4.3"
+    implementation "androidx.room:room-runtime:2.4.3"
+    annotationProcessor "androidx.room:room-compiler:2.4.3"
 }

app/src/main/kotlin/com/simplemobiletools/launcher/databases/AppsDatabase.kt

@@ -0,0 +1,27 @@
+package com.simplemobiletools.launcher.databases
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+import com.simplemobiletools.launcher.models.AppLauncher
+
+@Database(entities = [AppLauncher::class], version = 1)
+abstract class AppsDatabase : RoomDatabase() {
+
+    companion object {
+        private var db: AppsDatabase? = null
+
+        fun getInstance(context: Context): AppsDatabase {
+            if (db == null) {
+                synchronized(AppsDatabase::class) {
+                    if (db == null) {
+                        db = Room.databaseBuilder(context.applicationContext, AppsDatabase::class.java, "apps.db")
+                            .build()
+                    }
+                }
+            }
+            return db!!
+        }
+    }
+}

app/src/main/kotlin/com/simplemobiletools/launcher/models/AppLauncher.kt

@@ -1,16 +1,30 @@
 package com.simplemobiletools.launcher.models
 
 import android.graphics.drawable.Drawable
+import androidx.room.*
 import com.simplemobiletools.commons.helpers.SORT_BY_TITLE
 import com.simplemobiletools.commons.helpers.SORT_DESCENDING
 
-data class AppLauncher(val id: Int, var title: String, val packageName: String, var order: Int, val drawable: Drawable? = null) : Comparable<AppLauncher> {
+@Entity(tableName = "apps", indices = [(Index(value = ["package_name"], unique = true))])
+data class AppLauncher(
+    @PrimaryKey(autoGenerate = true) var id: Long?,
+    @ColumnInfo(name = "title") var title: String,
+    @ColumnInfo(name = "package_name") var packageName: String,
+    @ColumnInfo(name = "order") var order: Int,
+
+    @Ignore var drawable: Drawable?
+) : Comparable<AppLauncher> {
+
+    constructor() : this(null, "", "", 0, null)
+
     companion object {
         var sorting = 0
     }
 
     override fun equals(other: Any?) = packageName.equals((other as AppLauncher).packageName, true)
 
+    override fun hashCode() = super.hashCode()
+
     fun getBubbleText() = title
 
     override fun compareTo(other: AppLauncher): Int {