This class is key adapter which tracks the chat area on each key pressed and key
released event.The main objective is to focus for ALT+s key combination.
Asks the user wheather to stop the file transfer, If true then
> set download status flag to false
> show download cancelled label to user
> hide progress bar,cancel and accept button.
connects client to remote computer, can throw bind exception while
sending muliple files, in such case it will wait for 300 ms and then
again try to connect