disable button

i have a requirement in which when user clicks on “re run validation” the button should get disable when the backend process starts and after the process got completed,it should automatically get enable..So for this i created a process report having status,process id column and using a!queryprocesanalytics functio to fetch the active ones.(local!disablevalidation) and using disabled parameter in buttonwidget to disable it..But how we can enable it once the process got completed?