Lazy loading listbox items in Delphi

Question

I am trying to parse a RSS feed and load its data into the listbox. The item contents are in the form as follows:

type
  TFeedItem = class
  private
    FTitle: string;
    FDescription: string;
    FLink: string;
    FImageUrl: string;
  public
    property Title: string read FTitle;
    property Description: string read FDescription;
    property Link: string read FLink;
    property ImageUrl: string read FImageUrl;
  end;

The list is custom drawn and will show all the above fields in each item. Since there are more than 100 feed items, it takes much time to download each ImageUrl and display it on corresponding list item. So I thought to fetch first 10 items first. When the user scrolls to end of the listbox, fetch the next 10 items and so on. Actually I am trying to implement the way Facebook and many other android application displays more data items on scroll to end event.

A google search gives most of the results for android implementation or for windows phones.