style: StyleProp<ViewStyle>

return(
<TextInput style={SharedStyles.loginTextInput} 

        placeholder='Email'
        onSubmitEditing={() => { this.passInput.focus(); }}
        blurOnSubmit={false}  

        ></TextInput>

        <TextInput style={SharedStyles.loginTextInput} 

        placeholder='Password'
        ref={(input) => { this.passInput = input; }}

        ></TextInput>
);

Determines the maximum number of items rendered outside of the visible area, in units of visible lengths. So if your list fills the screen, then windowSize={21} (the default) will render the visible screen area plus up to 10 screens above and 10 below the viewport. Reducing this number will reduce memory consumption and may improve performance, but will increase the chance that fast scrolling may reveal momentary blank areas of unrendered content.