what is way to get the touch based scroll and its event on touchscreen using qt ?

[Qt embedded developer]

To get the touch based scroll on my mobile gallery.
Which area i need to choose to show thumbnail images ? which signals i need to catch ? which gesture i need to choose ?

I choose qt based c++ code for my app.

Initially which widgets i need to choose for my touchscreen based mobile gallery ?

i have implemented whole gallery without choosing proper widgets for touch screen. so that my implemented approach fail to feel like smart mobile gallery.

so if you know solution please let me know ?