You can create a type='object' button in the tree view. The button method should return an action to open the selected line. You have to click on the button, not anywhere in the line.

class mymodule_model(osv.osv):
    _name = 'my_module.model'
    ...
    ...
    def open_line(self, cr, uid, id, context=None):
        return {
            'type': 'ir.actions.act_window',
            'name': 'Model Title', 
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': self._name,
            'res_id': id[0],
            'target': 'current',
        }

In the Tree view we can put editable="bottom", now we can edit in the same form,

                          <field name="One2many_field_name" >
                                    <tree editable="bottom">
                                        <field name="name"/>                                       
                                    </tree>
                                </field>