In my company we need to know if a task/issue is currently in progress or on hold so we would like to have the following kanban states:

1. On hold
2. In progress
3. Blocked
4. Ready for next stage

Ideally I would like to create a custom module for that purpose but, as a first step, it would be ok to find which files should be modified in order to make such an addition.

Here:

'kanban_state': fields.selection([('normal', 'Normal'),('blocked', 'Blocked'),('done', 'Ready for next stage')], 'Kanban State',

in https://github.com/odoo/odoo/blob/8.0/addons/project_issue/project_issue.py#L247
I think I found a starting point in order to create the extra option for project issues.

Then, I searched for the file that controls the related views and I found this:

<field name="kanban_state" class="oe_inline" widget="kanban_state_selection"/>

for the form view here: https://github.com/odoo/odoo/blob/master/addons/project_issue/project_issue_view.xml#L56
and for the kanban view here: https://github.com/odoo/odoo/blob/master/addons/project_issue/project_issue_view.xml#L221

I can see that a 'widget' is called but from this point some help would save me enough time. Where can I find the code for that 'widget' ?

Which files should I look in order to add an extra kanban_state?

--------------------------------------

Edit: Beware! I'm asking for the kanban_state which is something different from the project stages which you can change from configuration options.