How to set different mode setting for leged in qwt ?

Hi,

I'm working on qwt library,
My moto is to add Button/Marker or anything which I can use to trigger signal on mouse click on that.

For this I have tried QPushButton but not succeeded, so I have tried with QwtLegend,

So, I have added QwtLegend, in which I have set legend defaultmode Checkable.
I have 4 QwtPlotMarker on legend, and all are Checkable, but I want only one of then Clickable to just trigger one signal.

How I can set different mode setting to same legend, or how I can achieve this.

If some one has solution on QPushButton then also appreciable.


Thanks