How to Implement the Touch Screen Events?

Hi,
I am not sure of the details of your project. I am developing a touchscreen project now using QtEmbedded. Nothing really different compared to using a keyboard and mouse.
Make sure you install /configure Qt with the ts library you will be using.
All touchscreen events are the same as mouse events. You will have to consider the size of the input widgets (radiobuttons, checkboxes, etc). They are rather small for ts usage, you will probably have to use QStylesheets to make custom buttons.
Most of my gui is QGraphicsView/QGraphicsScene and Items. I am using widgets for data input (it's easier when using Designer). I then modify the radiobuttons, checkboxes to a suitable size. I try and put most of my input widgets in a frame, and filter mouse events for any mouse events within that frame as appose to just filtering the input field(QlineEdit or such). It makes the touch area more suitable for fingers rather than pen input.
Good luck