Fl_Choice

## class Fl_Choice

### Class Hierarchy

    Fl_Menu_
       |
       +----Fl_Choice

### Include Files

    #include <FL/Fl_Choice.H>

### Description

This is a button that when pushed pops up a menu (or hierarchy of menus) defined by an array of `Fl_Menu_Item` objects. Motif calls this an OptionButton.

The only difference between this and a `Fl_Menu_Button` is that the name of the most recent chosen menu item is displayed inside the box, while the label is displayed outside the box. However, since the use of this is most often to control a single variable rather than do individual callbacks, some of the `Fl_Menu_Button` methods are redescribed here in those terms.

When the user picks an item off the menu the `value()` is set to that item and then the item's callback is done with the menu_button as the `Fl_Widget*` argument. If the item does not have a callback the menu_button's callback is done instead.

All three mouse buttons pop up the menu. The Forms behavior of the first two buttons to increment/decrement the choice is not implemented. This could be added with a subclass, however.

The menu will also pop up in response to shortcuts indicated by putting a '&' character in the `label()`. See `Fl_Button` for a description of this.

Typing the `shortcut()` of any of the items will do exactly the same as when you pick the item with the mouse. The '&' character in item names are only looked at when the menu is popped up, however.

### Methods

- Fl_Choice
- ~Fl_Choice
- clear_changed
- changed
- down_box
- set_changed
- value

#### Fl_Choice::Fl_Choice(int x, int y, int w, int h, const char *label = 0)

Creates a new `Fl_Choice` widget using the given position, size, and label string. The default boxtype is `FL_UP_BOX`.

The constructor sets `menu()` to `NULL`. See `Fl_Menu_` for the methods to set or change the menu.

#### virtual Fl_Choice::~Fl_Choice()

The destructor removes the `Fl_Choice` widget and all of its menu items.

#### int Fl_Choice::value() const
int Fl_Choice::value(int)
int Fl_Choice::value(const Fl_Menu *)

The value is the index into the `Fl_Menu` array of the last item chosen by the user. It is zero initially. You can set it as an integer, or set it with a pointer to a menu item. The set routines return non-zero if the new value is different than the old one. Changing it causes a `redraw()`.

#### int Fl_Widget::changed() const

This value is true if the user picks a different value. It is turned off by `value()` and just before doing a callback (the callback can turn it back on if desired).

#### void Fl_Widget::set_changed()

This method sets the `changed()` flag.

#### void Fl_Widget::clear_changed()

This method clears the `changed()` flag.

#### Fl_Boxtype Fl_Choice::down_box() const
void Fl_Choice::down_box(Fl_Boxtype b)

The first form gets the current down box, which is used when the menu is popped up. The default down box type is `FL_DOWN_BOX` The second form sets the current down box type to `b`.