Question

I have a page using StackLayoutPanel.

In that 3 stacks requires separate CellTables.

Currently events I need to use are RangeChangeEvent, SelectionChangeEvent.

Now question is how to differentiate OnRangeChangeEvent from one another.

Answer 1

The source table is referenced by the event that you are catching. “event.getSource()”
always gives a reference to the object that caused the event.

For example, if you have three tables, and you attach the same handler as below:

RangeChangeEvent.Handler handler = new RangeChangeEvent.Handler() { 
  @Override             
  public void onRangeChange(RangeChangeEvent event) {
    if(table1 == event.getSource()){
      // first table
    } else if (table2 == event.getSource()){
      // second table
    } else if (table3 == event.getSource()){
      // third table
    }           
 };

table1.addRangeChangeHandler(handler);
table2.addRangeChangeHandler(handler);
table3.addRangeChangeHandler(handler);

The above example assumes that there is no selection model specified on the tables. If there is, the selection model will be the source of the events.

Alternatively, you can just attach a table-specific handler to each table:

RangeChangeEvent.Handler handler1 = new RangeChangeEvent.Handler() { 
  @Override             
  public void onRangeChange(RangeChangeEvent event) {
      // Handle stuff happening to table 1
  }
};

RangeChangeEvent.Handler handler2 = new RangeChangeEvent.Handler() { 
  @Override             
  public void onRangeChange(RangeChangeEvent event) {
      // Handle stuff happening to table 2
  }
};

table1.addRangeChangeHandler(handler1);
table2.addRangeChangeHandler(handler2);
// And so on for any more tables

With this approach you won’t need to worry about the event source, as you already know which handler corresponds to which table.