Disable progress editing on project task

How can i disable editing of progress only on project task type?
And is there any way to change edit properties for custom types of tasks?

you can use API events to examine task before start of editing operation and cancel operation if needed. E.g.
docs.dhtmlx.com/gantt/api__gantt … event.html

You can also use css to hide certain controls, such as slider for a task progress
docs.dhtmlx.com/gantt/api__gantt … plate.html


Thanks for the info.
At the end I set the global property: gantt.config.readonly = true;
and use the editable:true property on tasks that have editing enabled