Vaadin Multiline Field (List<String> in TextArea)

MultiLineField.groovy

import com.vaadin.ui.Component
import com.vaadin.ui.CustomField
import com.vaadin.ui.TextArea

class MultiLineField extends CustomField<List<String>> {

    private TextArea textArea = new TextArea()

    MultiLineField() {
        super()
    }

    MultiLineField(String caption) {
        this()
        setCaption(caption)
    }

    @Override
    protected Component initContent() {
        return textArea
    }

    @Override
    Class<? extends List<String>> getType() {
        return List
    }

    @Override
    protected List<String> getInternalValue() {
        return textArea.value.readLines()
    }

    protected void setInternalValue(List<String> newValue) {
        super.setInternalValue(newValue)
        if (newValue!=null) {
            textArea.value = newValue.join("\n")
        }
    }
}