Slide 9.8: Line-by-line anatomy of Menu.c (cont.)

Line-by-line Anatomy of Menu.c (Cont.)


  case  keyDownEvent:

This event keyDownEvent is sent by the system when the user enters a Graffiti or Graffiti 2 character, presses one of the buttons below the display, or taps one of the icons in the icon area; for example, the Find icon. For this event, the data field contains the structure defined below. Access the information stored in the data field in this way:

   wchar32_t = eventP->data.keyDown.chr;

   struct  _KeyDownEventType {
      WChar   chr;
      UInt16  keyCode;
      UInt16  modifiers;
   };

chr: The character code
keyCode: Unused
modifiers: 0, or one or more of the values from Graffiti


  FormObjectKind  objType;

The enum FormObjectKind specifies values for the objectType field of the FormObjListType. It specifies how to interpret the object field.

frmFieldObj: Text field
frmControlObj: Control
frmListObj: List
frmTableObj: Table
frmBitmapObj: Form bitmap
frmLineObj: Line

frmFrameObj: Frame
frmRectangleObj: Rectangle
frmLabelObj: Label
frmTitleObj: Form title
frmPopupObj: Popup list
frmGraffitiStateObj: Graffiti


  focus = FrmGetFocus( frm );

This function UInt16 FrmGetFocus( const FormType *formP ) returns the item (index) number of the object that has the focus.

formP

FormType