CODEWITHSUNDEEP
javagwt
quarks
quarks

Reputation: 35346

How to prevent or remove duplicate value(s) in a ValueListBox

Our gwt app uses ValueListBox, 

records.setValue(model);
records.setAcceptableValues(models);

Where model is a subset of models. The problem I'm having is that the ValueListBox contains duplicated value. How do I prevent or remove it?

Upvotes: 2

Views: 571

Answers (3)

Braj
Braj

Reputation: 46871

Override setAcceptableValues methods

@Override
public void setAcceptableValues(Collection<T> newValues) {
   super.setAcceptableValues(new HashSet<T>(newValues));
}

Sample code:

ValueListBox<Integer> semester = new ValueListBox<Integer>(new Renderer<Integer>() {
    public String render(Integer object) {
        String s = "";
        if (object != null) {
            s = object.toString();
        }
        return s;
    }

    public void render(Integer object, Appendable appendable) throws IOException {
        String s = render(object);
        appendable.append(s);
    }
}) {
    @Override
    public void setAcceptableValues(Collection<Integer> newValues) {
        super.setAcceptableValues(new HashSet<Integer>(newValues));
    }
};

semester.setAcceptableValues(Arrays.asList(1, 1, 3, 3, 2, 2, 3, 4, 5, 7, 8, 9, 1, 3, 2));
semester.setValue(2);

--EDIT--

As per your last comment try this one

class MyModel {
    private String id;
    private String name;

    public MyModel(String id, String name) {
        this.id = id;
        this.name = name;
    }

    public String getName() {
        return name;
    }

    @Override
    public int hashCode() {
        return this.id.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof MyModel) {
            return this.id.equals(((MyModel) obj).id);
        }
        return false;
    }
}

ValueListBox<MyModel> semester = new ValueListBox<MyModel>(new Renderer<MyModel>() {
    public String render(MyModel object) {
        String s = "";
        if (object != null) {
            s = object.getName();
        }
        return s;
    }

    public void render(MyModel object, Appendable appendable) throws IOException {
        String s = render(object);
        appendable.append(s);
    }
}) {
    @Override
    public void setAcceptableValues(Collection<MyModel> newValues) {
        super.setAcceptableValues(new HashSet<MyModel>(newValues));
    }
};

semester.setAcceptableValues(Arrays.asList(new MyModel("1", "a"), new MyModel("1", "a"),
        new MyModel("2", "b"), new MyModel("3", "c")));
semester.setValue(new MyModel("1", "a"));

Upvotes: 2

bgth
bgth

Reputation: 460

Try using the below.

records.setAcceptableValues(new HashSet<String>(models);

If it is a user defined object other than string etc, then you have to implement hashcode and equals.

Upvotes: 4

Andrei Volgin
Andrei Volgin

Reputation: 41099

There is no method to prevent or remove duplicate options in ListBox or ValueListBox. You have to remove duplicate values before you pass them to your ValueListBox.

Upvotes: 0

Related Questions