xfa/fwl is a Widget Library for XFA Forms.

CFWL_Widget is the base class that widget classes extend. The derived widget classes are both controllers and renderers for each widget. The hierarchy is:

  • CFWL_Widget
    • CFWL_Form
    • CFWL_Caret
    • CFWL_CheckBox
    • CFWL_ComboBox
    • CFWL_DateTimePicker
    • CFWL_Edit
      • CFWL_Barcode
      • CFWL_ComboEdit
      • CFWL_DateTimeEdit
    • CFWL_ListBox
      • CFWL_ComboList
    • CFWL_MonthCalendar
    • CFWL_PictureBox
    • CFWL_PushButton
    • CFWL_ScrollBar
    • CFWL_SpinButton

These CFWL widgets are instantiated by and closely related to the CXFA classes in the xfa/fxfa directory. See xfa/fxfa/README.md.

CFWL_Widget implements IFWL_WidgetDelegate through which it receives messages, events and draw calls.

Messages consist of user input for a widget to handle. Each type of message is identified by an enum value in Message::Type and has its own class derived from the base CFWL_Message.

  • CFWL_Message
    • CFWL_MessageKey
    • CFWL_MessageKillFocus
    • CFWL_MessageMouse
    • CFWL_MessageMouseWheel
    • CFWL_MessageSetFocus

Events are originated in the widgets and are then handled by other CFWL_Widget and CXFA classes.

  • CFWL_Event
    • CFWL_EventCheckWord
    • CFWL_EventMouse
    • CFWL_EventScroll
    • CFWL_EventSelectChanged
    • CFWL_EventTextWillChange
    • CFWL_EventValidate

The widgets use IFWL_ThemeProvider for rendering everything, calling DrawBackground() and DrawText() and passing many options in their parameters, respectively of types CFWL_ThemeBackground and CFWL_ThemeText. See xfa/fwl/theme/README.md.