Function ui_text_input_with_value 

pub fn ui_text_input_with_value(
    id: u32,
    x: f32,
    y: f32,
    w: f32,
    placeholder: &str,
    initial: &str,
) -> String

Like ui_text_input, but seeds the field with initial the first time this id is seen. Subsequent frames use the user-edited value.