You can set readonly
attribute inside of beforeShowForm
on the field (see here) or alternatively you can set/remove readonly: 'readonly'
property (see here) of the editoptions
for the column inside of beforeInitData
which will be called before the edit form will be created. You can use setColProp
for example to change editoptions
(see here an example).
To implement the changes depends on the cell value from some column you need just get the id of selected row with respect of getGridParam
and then get the cell value using getCell
(see here).
In any cases I recommend you to use recreateForm: true
option of form editing. It should be default options in my opinion.