reduce redundancy codes
prevent suffix be changed
fix bug : update new file name when reload
move heavy task to another thread
change tab name
add icons
use icon to replace the function of open folder
add remove all function
able to add files
fix bug--can not select files
add file name
change file name
able to delete selected files
append file name
forbit user to move the toolbar; make icon become easier to read
make codes easier to read
add new files without remove the old files