hi,
I want to create a simple mainwindow which is consisted of a menubar for openfile and a plotting area (qwt). So far I had created a custom widget consisted of the plot area and a button "Plot it". They were both in the same class so I could connect the button signal to an internal function (getData(Qstring)) that would read some data .txt file and plot it to the plotting area.

Now I am trying to have a menubar with openFile so I can choose which data file I want my application to plot. I have managed to create the widgets (mainwindow,menubar, plotarea) but I haven't understood well how to connect the menubar (i.e. the data file i choose from open file menu) with the slot "getData(Qstring)" of the plotArea. I am definitely missing out the hierarchy of these widgets: mainwindow,menubar, plotarea
Any ideas?