Here are the latest widgets and its following classes usable in odoo js to include or extend also use syntax widget="any_widget_name" with odoo views,
'char' : 'instance.web.form.FieldChar',
'id' : 'instance.web.form.FieldID',
'email' : 'instance.web.form.FieldEmail',
'url' : 'instance.web.form.FieldUrl',
'text' : 'instance.web.form.FieldText',
'html' : 'instance.web.form.FieldTextHtml',
'char_domain': 'instance.web.form.FieldCharDomain',
'date' : 'instance.web.form.FieldDate',
'datetime' : 'instance.web.form.FieldDatetime',
'selection' : 'instance.web.form.FieldSelection',
'radio' : 'instance.web.form.FieldRadio',
'many2one' : 'instance.web.form.FieldMany2One',
'many2onebutton' : 'instance.web.form.Many2OneButton',
'many2many' : 'instance.web.form.FieldMany2Many',
'many2many_tags' : 'instance.web.form.FieldMany2ManyTags',
'many2many_kanban' : 'instance.web.form.FieldMany2ManyKanban',
'one2many' : 'instance.web.form.FieldOne2Many',
'one2many_list' : 'instance.web.form.FieldOne2Many',
'reference' : 'instance.web.form.FieldReference',
'boolean' : 'instance.web.form.FieldBoolean',
'float' : 'instance.web.form.FieldFloat',
'percentpie': 'instance.web.form.FieldPercentPie',
'barchart': 'instance.web.form.FieldBarChart',
'integer': 'instance.web.form.FieldFloat',
'float_time': 'instance.web.form.FieldFloat',
'progressbar': 'instance.web.form.FieldProgressBar',
'image': 'instance.web.form.FieldBinaryImage',
'binary': 'instance.web.form.FieldBinaryFile',
'many2many_binary': 'instance.web.form.FieldMany2ManyBinaryMultiFiles',
'statusbar': 'instance.web.form.FieldStatus',
'monetary': 'instance.web.form.FieldMonetary',
'many2many_checkboxes': 'instance.web.form.FieldMany2ManyCheckBoxes',
'x2many_counter': 'instance.web.form.X2ManyCounter',
'priority':'instance.web.form.Priority',
'kanban_state_selection':'instance.web.form.KanbanSelection',
'statinfo': 'instance.web.form.StatInfo',
