Vaadin Table: how to set maximum initial column width

Question

I have a Vaadin Table with some columns that can have widely-varying content widths. Sometimes there might be no rows with more than a few characters in them; other times, there might be rows with enough text to fill a screen.

I want to set an explicit column width to prevent the column from taking up too much space by default. This can be done with Table#setColumnWidth. However, if all values for the column are shorter than that specified width, I would like to revert to auto-sizing, so that the column is only as wide as it needs to be.

In all cases, I still want the column to be manually resizable.

Essentially, I want to say 'auto-size, up to a maximum width of x'. Is there a way to do this?

Answer 1

It is possible. You will need to jump into Javascript. SSCCE:

@com.vaadin.annotations.JavaScript("main.js")
public class QwertUI extends UI {

    @WebServlet(value = "/*", asyncSupported = true)
    @VaadinServletConfiguration(productionMode = false, ui = QwertUI.class)
    public static class Servlet extends VaadinServlet {
    }

    @Override
    protected void init(VaadinRequest request) {
        final VerticalLayout layout = new VerticalLayout();
        layout.setMargin(true);
        setContent(layout);

        final Table table = new Table("The Brightest Stars");

        table.addContainerProperty("Name", String.class, null);
        table.addContainerProperty("Mag",  Float.class, null);

        Object newItemId = table.addItem();
        Item row1 = table.getItem(newItemId);
        row1.getItemProperty("Name").setValue("Sirius");
        row1.getItemProperty("Mag").setValue(-1.46f);

        // Add a few other rows using shorthand addItem()
        table.addItem(new Object[]{"Canopus",        -0.72f}, 2);
        table.addItem(new Object[]{"Arcturus",       -0.04f}, 3);
        table.addItem(new Object[]{"Alpha Centaurissssssssssssssssssssssssssssssssssssssssssss", -0.01f}, 4);
        JavaScript.getCurrent().addFunction("YouAreWelcome", new JavaScriptFunction(){
            @Override
            public void call(JsonArray arguments)
            {
                Object o = arguments.get(0).asString();
                table.setColumnWidth("Name", new Integer(o.toString()));
            }
        });
        JavaScript.getCurrent().execute("WeChooseToGoToTheMoon()");
        table.setPageLength(table.size());
        layout.addComponent(table);
    }

}

And main.js

function WeChooseToGoToTheMoon(){
    var myMaxWidth = 200;
    var elements = document.getElementsByClassName("v-table-cell-content");
    var maxSize = -1;
    for(i=0; i<elements.length; i++){
        if(elements[i].clientWidth > maxSize){
            maxSize = elements[i].clientWidth;
        }
    }
    if(maxSize < myMaxWidth){
        YouAreWelcome(maxSize);
    }else{
        YouAreWelcome(myMaxWidth);
    }
}

You may need to adjust the javascript to suit your needs.