button with icon react native ui
import FontAwesome from "react-native-vector-icons/FontAwesome";
import { Text, TouchableOpacity } from "react-native";
<TouchableOpacity
style={{ borderRadius:5, paddingVertical:10, paddingHorizontal:30, flexDirection: 'row', backgroundColor: '#3578E5' }}
onPress={() => this.signInFacebook(context.updateAuthUser)}>
<FontAwesome name='facebook' size={20} color='#fff' />
<Text style={{ marginLeft: 10, color: '#fff', fontWeight: 'bold' }}>
Login With Facebook
</Text>
</TouchableOpacity>