GWT Data grid does not show data

Question

i have been trying to implement datagrid in my project , the problem is that the data grid does not show data , the data is there but is not visible , i tried to inspect the html page and with adding some height and width to the inner divs inside the datagrid parent div the data is displayed perfectly , i can do this using css and its done , but if there is another solution or in other words anyone knows whats wrong with datagrid?

public class DataGridTest implements EntryPoint, ClickHandler {

private ListDataProvider<TestObject> listProvider;


public void onModuleLoad() {
    List<TestObject> list = new ArrayList<TestObject>();
    list.add(new TestObject("Amer",22));
    list.add(new TestObject("Essa",25));
    list.add(new TestObject("Asem",29));


    DataGrid<TestObject> dataGrid = new DataGrid<TestObject>();
    dataGrid.setStyleName("dataGridTest");
    TextColumn<TestObject> nameColumn = new TextColumn<TestObject>(){

        @Override
        public String getValue(TestObject object) {
            return object.getName();
        }

    };

    dataGrid.addColumn(nameColumn,"Name");

    TextColumn<TestObject> ageColumn = new TextColumn<TestObject>(){

        @Override
        public String getValue(TestObject object) {
            return object.getAge()+"";
        }

    };

    dataGrid.addColumn(ageColumn,"Age");

    listProvider = new ListDataProvider<TestObject>();
    listProvider.addDataDisplay(dataGrid);
    listProvider.setList(list);
    LayoutPanel layoutPanel = new LayoutPanel();
    layoutPanel.add(dataGrid);
    RootPanel.get().add(layoutPanel);
    layoutPanel.forceLayout();
    Button btn = new Button("lala");
    btn.getElement().getStyle().setPosition(Position.ABSOLUTE);
    RootPanel.get().add(btn);
    btn.addClickHandler(this);

}


public class TestObject {

    private String name;

    private int age;

    public TestObject(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return this.name;
    }

    public int getAge() {
        return this.age;
    }

}


@Override
public void onClick(ClickEvent event) {
    listProvider.getList().add(new TestObject("lala", 10));

}

}

Ümit Ümit · Accepted Answer · 2014-06-29T10:39:27

You are mixing RootPanel and LayoutPanel, which doesn't work.
You must use RootLayoutPanel instead.
The DataGrid has to be put in a LayoutPanel and there must an unbroken chain up to the RootLayoutPanel.

Alternatively you have to specify explicit dimensions (height, width) on the parent container of your DataGrid or use a CellTable instead.

RootLayoutPanel.get().add(layoutPanel) should fix your issue.

GWT Data grid does not show data

1 Answers