diff --git a/app-unpriv/src/main/java/im/angry/openeuicc/ui/UnprivilegedEuiccManagementFragment.kt b/app-unpriv/src/main/java/im/angry/openeuicc/ui/UnprivilegedEuiccManagementFragment.kt
index 22e3933..95eb8b4 100644
--- a/app-unpriv/src/main/java/im/angry/openeuicc/ui/UnprivilegedEuiccManagementFragment.kt
+++ b/app-unpriv/src/main/java/im/angry/openeuicc/ui/UnprivilegedEuiccManagementFragment.kt
@@ -24,8 +24,10 @@ class UnprivilegedEuiccManagementFragment : EuiccManagementFragment() {
         super.onCreateOptionsMenu(menu, inflater)
         inflater.inflate(R.menu.fragment_sim_toolkit, menu)
         menu.findItem(R.id.open_sim_toolkit).apply {
-            isVisible = stk.isAvailable(slotId)
-            setOnMenuItemClickListener { stk.launch(slotId) }
+            val slot = stk[slotId]
+            if (slot == null) return@apply
+            isVisible = true
+            setOnMenuItemClickListener { slot.launch() }
         }
     }
 }
\ No newline at end of file
diff --git a/app-unpriv/src/main/java/im/angry/openeuicc/util/SIMToolkit.kt b/app-unpriv/src/main/java/im/angry/openeuicc/util/SIMToolkit.kt
index fe65023..ca3c0ad 100644
--- a/app-unpriv/src/main/java/im/angry/openeuicc/util/SIMToolkit.kt
+++ b/app-unpriv/src/main/java/im/angry/openeuicc/util/SIMToolkit.kt
@@ -3,7 +3,6 @@ package im.angry.openeuicc.util
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
-import android.content.pm.ActivityInfo
 import android.content.pm.PackageManager
 import android.net.Uri
 import android.provider.Settings
@@ -21,36 +20,37 @@ class SIMToolkit(private val context: Context) {
         put(1, getComponentNames(R.array.sim_toolkit_slot_2))
     }
 
-    private val packageNames: Iterable<String>
-        get() = slots.values.flatten().map { it.packageName }.toSet()
-
-    private val activities: Iterable<ComponentName>
-        get() = packageNames.flatMap(context.packageManager::getActivities)
-            .filter { it.exported }
-            .map { ComponentName(it.packageName, it.name) }
-
-    private val launchIntent: Intent?
-        get() = packageNames.firstNotNullOfOrNull(context.packageManager::getLaunchIntent)
-
-    private fun getComponentsBySlotId(slotId: Int) = buildSet {
-        addAll(slots.getOrDefault(slotId, emptySet()))
-        addAll(slots.getOrDefault(-1, emptySet()))
+    operator fun get(slotId: Int): Slot? = when (slotId) {
+        -1, EuiccChannelManager.USB_CHANNEL_ID -> null
+        else -> Slot(context, buildSet {
+            addAll(slots.getOrDefault(slotId, emptySet()))
+            addAll(slots.getOrDefault(-1, emptySet()))
+        })
     }
 
-    private fun intentActivity(slotId: Int): Intent? {
-        val component = getComponentsBySlotId(slotId).find(activities::contains)
-            ?: return launchIntent
-        val disabled = try {
-            isDisabledState(context.packageManager.getComponentEnabledSetting(component))
-        } catch (e: IllegalArgumentException) {
-            true
+    data class Slot(private val context: Context, private val components: Set<ComponentName>) {
+        private val packageNames: Iterable<String>
+            get() = components.map { it.packageName }.toSet()
+
+        private val launchIntent: Intent?
+            get() = packageNames.firstNotNullOfOrNull(context.packageManager::getLaunchIntent)
+
+        private val activities: Iterable<ComponentName>
+            get() = packageNames.flatMap(context.packageManager::getActivities)
+                .filter { it.exported }.map { ComponentName(it.packageName, it.name) }
+
+        private fun getIntent(): Intent? {
+            try {
+                val component = components.find(activities::contains) ?: return launchIntent
+                if (isDisabledState(context.packageManager.getComponentEnabledSetting(component)))
+                    return null
+                return Intent.makeMainActivity(component)
+            } catch (e: IllegalArgumentException) {
+                return null
+            }
         }
-        if (disabled) return null
-        return Intent.makeMainActivity(component)
-    }
 
-    private fun getDisabledPackageName(slotId: Int) =
-        getComponentsBySlotId(slotId).map { it.packageName }.toSet().find {
+        private fun getDisabledPackageName() = packageNames.find {
             try {
                 isDisabledState(context.packageManager.getApplicationEnabledSetting(it))
             } catch (e: IllegalArgumentException) {
@@ -58,28 +58,23 @@ class SIMToolkit(private val context: Context) {
             }
         }
 
-    fun isAvailable(slotId: Int) = when (slotId) {
-        -1 -> false
-        EuiccChannelManager.USB_CHANNEL_ID -> false
-        else -> intentActivity(slotId) != null || getDisabledPackageName(slotId) != null
-    }
-
-    fun launch(slotId: Int): Boolean {
-        var intent = intentActivity(slotId)
-        if (intent == null) {
-            val pkgName = getDisabledPackageName(slotId) ?: return false
-            val message = context.getString(
-                R.string.toast_prompt_to_enable_sim_toolkit,
-                context.packageManager.getApplicationLabel(pkgName)
-            )
-            intent = Intent(
-                Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
-                Uri.fromParts("package", pkgName, null)
-            )
-            Toast.makeText(context, message, Toast.LENGTH_LONG).show()
+        fun launch(): Boolean {
+            var intent = getIntent()
+            if (intent == null) {
+                val pkgName = getDisabledPackageName() ?: return false
+                val message = context.getString(
+                    R.string.toast_prompt_to_enable_sim_toolkit,
+                    context.packageManager.getApplicationLabel(pkgName)
+                )
+                intent = Intent(
+                    Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
+                    Uri.fromParts("package", pkgName, null)
+                )
+                Toast.makeText(context, message, Toast.LENGTH_LONG).show()
+            }
+            context.startActivity(intent)
+            return true
         }
-        context.startActivity(intent)
-        return true
     }
 }
 
@@ -102,5 +97,5 @@ private fun PackageManager.getActivities(packageName: String) = try {
     getPackageInfo(packageName, PackageManager.GET_ACTIVITIES)
         .activities?.toList() ?: emptyList()
 } catch (_: PackageManager.NameNotFoundException) {
-    emptyList<ActivityInfo>()
+    emptyList()
 }