Vaadin Charts. Click Listening: absolute value to chart axis value

Flow
1

Hello, guys! ChartClickEvent contains xAxisValue and absoluteX, but I want to click above the chart and get xAxisValue from absolute x value. if this is impossible, then other question: how to catch mouse down, mouse up events on the chart?

Thanks.

2

Hi Vitaly!

(Referring to the other question)
You could create an extension for the Chart for this purpose. This means that you would essentially need on the server side:

ChartExtension extends AbstractExtension implements ChartExtensionServerRpc{
  ...
    public ChartExtension() {
        registerRpc(this); 
    }

    public void extend(Chart chart) {
        super.extend(chart);
    }
 ...
}

On the client side, you would need a Connector and define the ServerRPC:
ChartExtensionServerRpc:

public interface ChartExtensionServerRpc extends ServerRpc { ... your methods ... }

ChartExtensionConnector:

@Connect(ChartExtension.class)   // Connect to your extension you created
public class ChartExtensionConnector extends AbstractExtensionConnector {
...
    @Override
    protected void extend(ServerConnector target) {
        final Widget extendedWidget = ((ComponentConnector) target).getWidget();
          // example with mouseDownhandler
        MouseDownHandler mdh = new MouseDownHandler() {

            @Override
            public void onMouseDown(MouseDownEvent event) {
                // This will call your method on the server side with your specified parameters
                getRpcProxy(ChartExtensionServerRpc.class).yourDefinedMethod(event.getClientX()); // For example the clientX
            }
        };
        // Store the handle to  be able to call removeHandler when needed
        mouseDownHandlerRegistration = extended.addDomHandler(mdh, MouseDownEvent.getType());
    }

And then in your app (after widgetset compilation or in dev mode) you can simply use your extension like this (for example):

    Chart c = new Chart(ChartType.PIE);
    new ChartExtension.extend(c);
    addComponent(c);