# DI_RADIOBUTTON

The DI_RADIOBUTTON dialog item describes a Radio Button control. It is also known as the "button with dependent fixation". It acts like a Check Box, except that if the first radio button item in a group of several consequent radio button items have the DIF_GROUP flag set, they become mutually exclusive — if one of them has been switched on all others will be switched off.

    struct FarDialogItem
    {
      int Type          = DI_RADIOBUTTON
      int X1            = X
      int Y1            = Y
      int X2            = 0 (not used in Dialog API 1.0)
      int Y2            = Y (equals to Y1)
      int Focus         = Focus
      int Selected      = Selected
      DWORD Flags       = Flags
      int DefaultButton = DefaultButton
      char Data[512]    = Radio button caption
    };

Attention!

- This is an exemplary structure; read full description here.

### Focus

Keyboard focus flag.

### Selected

The field reflects current state of the radio button control: is it switched on or off.

### Flags

There are several flags applicable to the DI_RADIOBUTTON control:

Flag | Description
--- | ---
DIF_SETCOLOR | The low byte of Flags will be used as the item's color.
DIF_GROUP | This flag should be set for the first radio button item in a group.
DIF_MOVESELECT | Change selection in a radio button group when focus is moved. Radio buttons with this flag set are also drawn without parentheses around the selection mark (example: FAR color selection dialog).
DIF_CENTERGROUP | Sequential items with this flag set and equal vertical coordinates will be horizontally centered in the dialog. Their X1 and X2 coordinates are ignored.
DIF_DISABLE | Disables user access to the control.
DIF_NOFOCUS | The dialog item cannot receive keyboard focus, but can handle other user events.
DIF_SHOWAMPERSAND | Show ampersand symbol in caption instead of using it for defining hotkeys.

### Events

Event | Description
--- | ---
DN_DRAWDLGITEM | This event is sent to the dialog callback function before the control is drawn.
DN_CTLCOLORDLGITEM | Plugin should pass the color attributes of the control when this event comes. Param2 parameter (foreground+background):
    LoWord LoByte - color of the caption
                    (COL_WARNDIALOGBUTTON or
                     COL_DIALOGTEXT)
    LoWord HiByte - color of highlighted text
                    (COL_WARNDIALOGHIGHLIGHTTEXT or
                     COL_DIALOGHIGHLIGHTTEXT)
    HiWord LoByte - 0
    HiWord HiByte - 0
If a special attribute is used (DIF_SETCOLOR flag), the caption (LoWord LoByte) will be drawn according to the parameters.
DN_HOTKEY | Hotkey was pressed (Alt-<letter>).
DN_BTNCLICK | State of the radiobutton was changed.
DN_KEY | This event comes after the user has pressed a key in the dialog.
DN_MOUSECLICK | This event comes after the user has clicked one of the dialog items or outside the dialog with the mouse button.
DN_KILLFOCUS | This event is sent just before the button loses focus, if the flag DIF_NOFOCUS was not used.
DN_GOTFOCUS | This event is sent after the button has received keyboard focus, if the flag DIF_NOFOCUS was not used.

### Remarks

It is strongly recommended to set correct values for X2 and Y2 fields, although they aren't used in Dialog API 1.0.
See also:
DI_CHECKBOX, DI_BUTTON, FarDialogItem