Customizing Sharepoint DRag and drop control for file upload

how can i upload documents with meta data information? currently in documents webpart in sharepoint 2013 when i drag and drop files it will immediately uploading but i need just drag and drop feature , once i add the meta data information to the each document i will upload by clicking submit button. how can i achieve this? currently in our old application we are using SAXfile Upload object for drag and drop but it will not support on 64bit. please let me know is there any other solutions available? or how can i customize the current built in drag and drop web part code