Thank you for contacting us about this. In order to best help you with your needs. Could you please let us know what sort of features you are looking for in your GUI application? By “pdftron tool button” are you referring to annotation support?
If this is what you are looking for, note that our WebViewer product offers annotation support and can be run on the desktop using Electron. Please refer to the guide here for more information.
Thanks for reply. Yes. I am referring to annotations tool box icons where I can insert signature and other editing. We are using java swt UI libraries for GUI.