Preloads Apps to speed up ListActivity

The AppInfos are asyncronously loaded

Closes #59

app/src/main/java/com/finnmglas/launcher/Functions.kt

@@ -22,6 +22,7 @@ import android.widget.ImageView
 import android.widget.Switch
 import android.widget.Toast
 import com.finnmglas.launcher.list.ListActivity
+import com.finnmglas.launcher.list.apps.AppInfo
 import com.finnmglas.launcher.list.apps.AppsRecyclerAdapter
 import com.finnmglas.launcher.settings.SettingsActivity
 import com.finnmglas.launcher.settings.intendedSettingsPause
@@ -61,7 +62,7 @@ const val PREF_STARTED_TIME = "firstStartup"
 const val PREF_VERSION = "version"
 
 /* Objects used by multiple activities */
-lateinit var appListViewAdapter: AppsRecyclerAdapter
+val appsList: MutableList<AppInfo> = ArrayList()
 
 /* Variables containing settings */
 val displayMetrics = DisplayMetrics()
@@ -301,6 +302,29 @@ fun openAppsList(activity: Activity){
     activity.startActivity(intent)
 }
 
+/**
+ * [loadApps] is used to speed up the [AppsRecyclerAdapter] loading time,
+ * as it caches all the apps and allows for fast access to the data.
+ */
+fun loadApps(packageManager: PackageManager) {
+    val loadList = mutableListOf<AppInfo>()
+
+    val i = Intent(Intent.ACTION_MAIN, null)
+    i.addCategory(Intent.CATEGORY_LAUNCHER)
+    val allApps = packageManager.queryIntentActivities(i, 0)
+    for (ri in allApps) {
+        val app = AppInfo()
+        app.label = ri.loadLabel(packageManager)
+        app.packageName = ri.activityInfo.packageName
+        app.icon = ri.activityInfo.loadIcon(packageManager)
+        loadList.add(app)
+    }
+    loadList.sortBy { it.label.toString() }
+
+    appsList.clear()
+    appsList.addAll(loadList)
+}
+
 fun loadSettings() {
     upApp = launcherPreferences.getString(ACTION_UP, "")!!
     downApp = launcherPreferences.getString(ACTION_DOWN, "")!!

app/src/main/java/com/finnmglas/launcher/HomeActivity.kt

@@ -52,11 +52,6 @@ class HomeActivity: UIObject, AppCompatActivity(),
 
         loadSettings()
 
-        // Preload list of apps (speed up loading time)
-        AsyncTask.execute {
-            appListViewAdapter = AppsRecyclerAdapter(this)
-        }
-
         // First time opening the app: show Tutorial, else: check versions
         if (!launcherPreferences.getBoolean(PREF_STARTED, false))
             startActivity(Intent(this, TutorialActivity::class.java))
@@ -86,6 +81,9 @@ class HomeActivity: UIObject, AppCompatActivity(),
             }
         }
 
+        // Preload apps to speed up the Apps Recycler
+        AsyncTask.execute { loadApps(packageManager) }
+
         // Initialise layout
         setContentView(R.layout.home)
     }

app/src/main/java/com/finnmglas/launcher/list/apps/AppsRecyclerAdapter.kt

@@ -5,6 +5,7 @@ import android.content.Context
 import android.content.Intent
 import android.content.pm.PackageManager
 import android.net.Uri
+import android.os.AsyncTask
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -32,7 +33,6 @@ class AppsRecyclerAdapter(val activity: Activity,
                           val forApp: String? = ""):
     RecyclerView.Adapter<AppsRecyclerAdapter.ViewHolder>() {
 
-    private val appsList: MutableList<AppInfo>
     private val appsListDisplayed: MutableList<AppInfo>
 
     inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView),
@@ -140,22 +140,15 @@ class AppsRecyclerAdapter(val activity: Activity,
     }
 
     init {
-        appsList = ArrayList()
-        appsListDisplayed = ArrayList()
-
-        val pm: PackageManager = activity.packageManager
-
-        val i = Intent(Intent.ACTION_MAIN, null)
-        i.addCategory(Intent.CATEGORY_LAUNCHER)
-        val allApps = pm.queryIntentActivities(i, 0)
-        for (ri in allApps) {
-            val app = AppInfo()
-            app.label = ri.loadLabel(pm)
-            app.packageName = ri.activityInfo.packageName
-            app.icon = ri.activityInfo.loadIcon(pm)
-            appsList.add(app)
+        // Load the apps
+        if (appsList.size == 0)
+            loadApps(activity.packageManager)
+        else {
+            AsyncTask.execute { loadApps(activity.packageManager) }
+            notifyDataSetChanged()
         }
-        appsList.sortBy { it.label.toString() }
+
+        appsListDisplayed = ArrayList()
         appsListDisplayed.addAll(appsList)
     }