I am using CheckBoxSelectionModel in Grid. When there is no data in Grid, the checkbox in header always get selected by default while refreshing. Is there any way of unchecking the checkbox depending on data is available in Grid or not ?

I am using below lines of code for refreshing the grid:
Button redrawButton = new Button("Redraw");
redrawButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {