Fixing crash

app/src/main/java/net/pokeranalytics/android/ui/fragment/TableReportFragment.kt

@@ -4,12 +4,14 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.Toast
 import androidx.recyclerview.widget.LinearLayoutManager
 import io.realm.Realm
 import kotlinx.android.synthetic.main.fragment_stats.*
 import kotlinx.coroutines.*
 import net.pokeranalytics.android.R
 import net.pokeranalytics.android.calculus.*
+import net.pokeranalytics.android.model.realm.ComputableResult
 import net.pokeranalytics.android.ui.activity.StatisticDetailsActivity
 import net.pokeranalytics.android.ui.adapter.DisplayDescriptor
 import net.pokeranalytics.android.ui.adapter.RowRepresentableAdapter
@@ -148,6 +150,12 @@ open class TableReportFragment : SessionObserverFragment(), StaticRowRepresentab
 
 	override fun onRowSelected(position: Int, row: RowRepresentable, fromAction: Boolean) {
 
+		val cr = getRealm().where(ComputableResult::class.java).findAll()
+		if (cr.size < 2) {
+			Toast.makeText(context, R.string.less_then_2_values_for_display, Toast.LENGTH_LONG).show()
+			return
+		}
+
 		if (row is StatRow && row.stat.hasEvolutionGraph) {
 
 			// queryWith groups