@node Part III Deprecated Objects
@chapter Deprecated Objects

In this chapter describes object types that have been replaced by
newer ones. They may be in use in older applications and also still
can be used in new programs (though this isn't recommended). There
probably will be no more support for these objects in terms of bug
fixes etc.


@ifnottex
@menu
* Choice Object:  Choice Object
* Menu Object:    Menu Object
* XPopup:         XPopup
@end menu

@end ifnottex


@node Choice Object
@section Choice Object

A choice object is an object that allows the user the choose among a
number of choices. The current choice is shown in the box of the
choice object. The user can either cycle through the list of choices
using the middle or right mouse button or get the list as a menu using
the left mouse button.

@ifnottex

@menu
* Adding Choice Objects:   Adding Choice Objects
* Choice Types:            Choice Types
* Choice Interaction:      Choice Interaction
* Other Choice Routines:   Other Choice Routines
* Choice Attributes:       Choice Attributes
* Remarks:                 Choice Remarks
@end menu

@end ifnottex


@node Adding Choice Objects
@subsection Adding Choice Objects

To add a choice object to a form use the routine
@findex fl_add_choice()
@anchor{fl_add_choice()}
@example
FL_OBJECT *fl_add_choice(int type, FL_Coord x, FL_Coord y,
                         FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
It shows a box on the screen with the label to the left of it and the
current choice (empty in the beginning), centered in the box.

@node Choice Types
@subsection Choice Types

The following types are available:
@table @code
@tindex FL_NORMAL_CHOICE
@anchor{FL_NORMAL_CHOICE}
@item FL_NORMAL_CHOICE
Middle/right mouse button shortcut.

@tindex FL_NORMAL_CHOICE2
@anchor{FL_NORMAL_CHOICE2}
@item FL_NORMAL_CHOICE2
Same as @code{FL_NORMAL_CHOICE} except drawn differently.

@tindex FL_DROPLIST_CHOICE
@anchor{FL_DROPLIST_CHOICE}
@item FL_DROPLIST_CHOICE
Menu is activated only by pressing and releasing the mouse on the arrow.
@end table

@node Choice Interaction
@subsection Choice Interaction

There are two ways in which the user can pick a new choice. One way is
using the right or middle mouse button. Pressing and releasing the
right mouse button on the choice object selects the next choice in the
list. When pressing the middle mouse button the previous choice is
taken. Keeping the mouse pressed slowly cycles through the list. The
other way is to use the left mouse button. In this case a menu appears
from which the user can select the proper choice. Normally in both cases,
whenever a choice is selected (even when it is the original one) the
object is returned to the application program.

You can control the condition under which the choice object gets
returned to the application by using the function
@example
int fl_set_object_return(FL_OBJECT *obj, unsigned int when)
@end example
where @code{when} can have the following values
@table @code
@item @ref{FL_RETURN_NONE}
Never return or invoke callback.

@item @ref{FL_RETURN_END_CHANGED}
Return or invoke callback if end of interaction and selection of an
item coincide.

@item @ref{FL_RETURN_CHANGED}
Return or invoke callback whenever an item is selected (this is the
default).

@item @ref{FL_RETURN_END}
Return or invoke callback on end of an interaction.

@item @ref{FL_RETURN_ALWAYS}
Return (or invoke callback) whenever the interaction ends and/or
an item is selected.
@end table


@node Other Choice Routines
@subsection Other Choice Routines

There are a number of routines to change the list of possible choices.
To add a line to a choice object use
@findex fl_addto_choice()
@anchor{fl_addto_choice()}
@example
int fl_addto_choice(FL_OBJECT *obj, const char *text);
@end example
@noindent
The function returns the number of the new item. The items in the list
are numbered in the order in which they were inserted. The first item
has number 1, etc.

To delete a line use:
@findex fl_delete_choice()
@anchor{fl_delete_choice()}
@example
void fl_delete_choice(FL_OBJECT *obj, int line);
@end example

Whenever the application program wants to clear the complete list of
choices it should use the routine
@findex fl_clear_choice()
@anchor{fl_clear_choice()}
@example
void fl_clear_choice(FL_OBJECT *obj) 
@end example

One can also replace a line using
@findex fl_replace_choice()
@anchor{fl_replace_choice()}
@example
void fl_replace_choice(FL_OBJECT *obj, int line, const char *text);
@end example

To obtain the currently selected item in the choice object use the call
@findex fl_get_choice()
@anchor{fl_get_choice()}
@example
int fl_get_choice(FL_OBJECT *obj);
@end example
@noindent
The function returns the number of the current choice (0 if there is
no choice).

You can also obtain the text of the currently selected choice item
using the call
@findex fl_get_choice_text()
@anchor{fl_get_choice_text()}
@example
const char *fl_get_choice_text(FL_OBJECT *obj);
@end example
@@noindent
@code{NULL} is returned when there is no current choice.

To obtain the text of an arbitrary choice item, use the following routine
@findex fl_get_choice_item_text()
@anchor{fl_get_choice_item_text()}
@example
const char *fl_get_choice_item_text(FL_OBJECT *obj, int n);
@end example

To obtain the total number of choice items, use the following function
@findex fl_get_choice_maxitems()
@anchor{fl_get_choice_maxitems()}
@example
int fl_get_choice_maxitems(FL_OBJECT *obj);
@end example

One can set various attributes of an item using the following routine
@findex fl_set_choice_item_mode()
@anchor{fl_set_choice_item_mode()}
@example
void fl_set_choice_item_mode(FL_OBJECT *obj, int numb, unsigned mode);
@end example
@noindent
Here @code{mode} is the same as that used for menu objects (see
above). See also @ref{XPopup}, for details.

You can use the follow routine to populate a choice object at once,
including mode and shortcut, by using
@findex fl_set_choice_entries()
@anchor{fl_set_choice_entries()}
@example
int fl_set_choice_entries(FL_OBJECT *obj, FL_PUP_ENTRY *entries);
@end example
@noindent
where @code{entries} is a pointer to a @code{FL_PUP_ENTRY} structure
(terminated by a @code{NULL} text field) as already described above
for the function @code{@ref{fl_set_menu_entries()}}. Also see
@ref{XPopup}, for more details. Please note that for choice objects no
nested entries are permitted and the item callback functions are
ignored. The function returns the number of items added to the choice
object.

Finally, the application program can set the currently selected entry
of the choice using a call of
@findex fl_set_choice()
@anchor{fl_set_choice()}
@findex fl_set_choice_text()
@anchor{fl_set_choice_text()}
@example
void fl_set_choice(FL_OBJECT *obj, int line);
void fl_set_choice_text(FL_OBJECT *obj, const char *txt)
@end example
@noindent
where @code{txt} must must be the text of exactly one of the choice
items. For example, after the following choice is created
@example
fl_addto_choice(obj," item1 | item2 | item3 ");
@end example
@noindent
You can select the second item by either using
@example
fl_set_choice(obj, 2);
@end example
@noindent
or
@example
fl_set_choice_text(obj, " item2 ");
@end example
@noindent
Note the spaces in the text.


@node Choice Attributes
@subsection Choice Attributes

Don't use @code{FL_NO_BOX} as the boxtype for a choice object.

The first color argument (@code{col1} to
@code{@ref{fl_set_object_color()}} controls the color of the box and
the second (@code{col2}) the color of the text in the box.

The current choice by default is shown centered in the box. To change
the alignment of the choice text in the box, use the following routine
@findex fl_set_choice_align()
@anchor{fl_set_choice_align()}
@example
void fl_set_choice_align(FL_OBJECT *obj, int align);
@end example

To set the font size used inside the choice object use
@findex fl_set_choice_fontsize()
@anchor{fl_set_choice_fontsize()}
@example
void fl_set_choice_fontsize(FL_OBJECT *obj, int size);
@end example

To set the font style used inside the choice object use
@findex fl_set_choice_fontstyle()
@anchor{fl_set_choice_fontstyle()}
@example
void fl_set_choice_fontstyle(FL_OBJECT *obj, int style);
@end example

Note that the above functions only change the font inside the choice
object, not the font used in the popup. To change the font used in the
popup, use the XPopup functions
@code{@ref{fl_setpup_default_fontsize()}} and
@code{@ref{fl_setpup_default_fontstyle()}}. Note that these functions
influence the font settings of all popups! @xref{Label Attributes and
Fonts}, for details on font sizes and styles.


@node Choice Remarks
@subsection Remarks

See @file{choice.c} for an example of the use of choice objects.


@node Menu Object
@section Menu Object

Also menus can be added to forms. These menus can be used to let the
user choose from many different possibilities. Each menu object has a
box with a label in it in the form. Whenever the user presses the
mouse inside the box (or moves the mouse on top of the box) a pop-up
menu appears. The user can then make a selection from the menu.

@ifnottex

@menu
* Adding Menu Objects:   Adding Menu Objects
* Menu Types:            Menu Types
* Menu Interaction:      Menu Interaction
* Other Menu Routines:   Other Menu Routines
* Menu Attributes:       Menu Attributes
* Remarks:               Menu Remarks
@end menu

@end ifnottex


@node Adding Menu Objects
@subsection Adding Menu Objects

To add a menu to a form use the routine
@findex fl_add_menu()
@anchor{fl_add_menu()}
@example
FL_OBJECT *fl_add_menu(int type, FL_Coord x, FL_Coord y,
                       FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
It shows a box on the screen with the label centered in it.


@node Menu Types
@subsection Menu Types

The following types are available:
@table @code
@tindex FL_PUSH_MENU
@anchor{FL_PUSH_MENU}
@item FL_PUSH_MENU
The menu appears when the user presses a mouse button on it.

@tindex FL_PULLDOWN_MENU
@anchor{FL_PULLDOWN_MENU}
@item FL_PULLDOWN_MENU
The menu appears when the user presses a mouse button on it.

@tindex FL_TOUCH_MENU
@anchor{FL_TOUCH_MENU}
@item FL_TOUCH_MENU
The menu appears when the user move the mouse inside it.
@end table

@code{FL_PUSH_MENU} and @code{FL_PULLDOWN_MENU} behave rather similar.
When you click on a @code{FL_PUSH_MENU} per default a pop-up window
gets opened on top of the @code{FL_PUSH_MENU} menu's box that has a
label at the top, indicating the currently selected menu item. The
pop-up window stays open until you either select an item or press a
mouse button somewhere outside the pop-up window.

When you click on @code{FL_PULLDOWN_MENU} also a pop-up window is
shown, but directly below the menu's box. This pop-up window has
no label and it only stays open until you release the mouse button.

@code{FL_PUSH_MENU} and @code{FL_PULLDOWN_MENU} can be made even more
similar by using the @code{@ref{fl_set_menu_notitle()}} function (see
below). This changes it's properties so that the pop-up window also
appears below the menu's box and that no label is shown in the pop-up
window. The only remaining difference then is that a
@code{FL_PUSH_MENU} only gets closed when a menu item is selected or
the user presses the mouse outside of the pop-up window while a
@code{FL_PULLDOWN_MENU} also gets closed when the mouse button is
released.


@node Menu Interaction
@subsection Menu Interaction

When the menu appears the user can make a selection using the left
mouse button or make no selection by clicking outside the menu (or by
simply releasing the mouse button in case of a @code{FL_PULLDOWN_MENU}
type menu. Normally when he makes a selection the menu object is
returned by the interaction routines.

You can control the condition under which the menu object gets
returned to the application by using the function
@example
int fl_set_object_return(FL_OBJECT *obj, unsigned int when)
@end example
where @code{when} can have the following values
@table @code
@item @ref{FL_RETURN_NONE}
Never return the object or invoke its callback.

@item @ref{FL_RETURN_END_CHANGED}
Return or invoke callback if end of interaction and selection of an
item coincide (this is the default for all menu objects except those
of type @code{FL_TOUCH_MENU}).

@item @ref{FL_RETURN_CHANGED}
Return or invoke callback whenever an item is selected (this is the
default for all menu objects of type @code{FL_TOUCH_MENU}).

@item @ref{FL_RETURN_END}
Return or invoke callback on end of an interaction.

@item @ref{FL_RETURN_ALWAYS}
Return (or invoke callback) whenever the interaction ends and/or
an item is selected.
@end table


@node Other Menu Routines
@subsection Other Menu Routines

There are two ways to populate a menu, i.e.@: add items. The first one
is a bit more complex but allows for more flexibility, e.g.@: later
adding and removing items, associating callbacks with individual items
etc. For the more simple (and in many cases sufficient) method see the
function @code{@ref{fl_set_menu_entries()}}.

To set the actual menu for a menu object, use the routine
@findex fl_set_menu()
@anchor{fl_set_menu()}
@example
void fl_set_menu(FL_OBJECT *obj, const char *menustr, ...);
@end example
@noindent
@code{menustr} describes the menu in the form used by XPopups
(@pxref{XPopup}). In the simplest case, it just contains the texts fr
the menu items, separated by a bar (@code{'|'}), e.g.@:
@code{"First|Second|Third"}. But it's also possible to employ special
tags (@pxref{Creating XPopups}) that can be used to indicate special
attributes (radio, toggle and greyed-out, for example). Whenever the
user selects a menu item, a pointer to the menu object it belongs to
is returned to the application program.

Please note that if you call @code{@ref{fl_set_menu()}} on a menu that
already contains items those items are removed. The function calls
@code{@ref{fl_clear_menu()}} internally before the new items are
added.

If you explicitely assign a menu item ID to a menu using the special
tag @code{%x} it is your responsibility to make sure that this ID
isn't already used by a different menu item in the same menu. Failure
to do so may make it impossible to use the menu properly. All
functions working on items expect the menu item ID as one of their
arguments.

In case you don't set menu item IDs they are assigned automatically
with the first item obtaining the menu item ID 1, the next 2 etc.,
i.e.@: it directly reflects the position of the item in the menu.

It is also possible to add menu items to an existing menu using a call
of
@findex fl_addto_menu()
@anchor{fl_addto_menu()}
@example
int fl_addto_menu(FL_OBJECT *obj, const char *menustr, ...);
@end example
@noindent
where @code{menustr} is a string of the same form as used in
@code{@ref{fl_set_menu()}} (you can add one or more new menu items
this way).

Also routines exist to delete a particular menu item or change it:
@findex fl_delete_menu_item()
@anchor{fl_delete_menu_item()}
@findex fl_replace_menu_item()
@anchor{fl_replace_menu_item()}
@example
void fl_delete_menu_item(FL_OBJECT *obj, int miid);
void fl_replace_menu_item(FL_OBJECT *obj, int miid,
                           const char *menustr, ...);
@end example
@code{miid} is the menu item ID. @code{menustr} must be a string as
used in @code{@ref{fl_set_menu()}} with the only difference that only
a single menu item can be specified.

Please note: when deleting a menu item all other items keep their
menu item IDs. The menu item ID of the deleted menu item isn't
re-used when new items are added later. Instead for each menu an
internal counter exists that gets incremented for each menu item
added and which value is used for the menu item ID unless one is
explicitely assigned to the menu item. The counter oly gets reset to 1
when the menu is cleared used @code{@ref{fl_clear_menu()}}.

The menu item ID of a menu item changed by using
@code{@ref{fl_replace_menu_item()}} does not change unless the library
is explicitely asked to via @code{%x} in @code{menustr}.

For most applications, the following routine may be easier to use at
the expense of somewhat restrictive value a menu item can have as
well as a loss of the ability to delete menu items or associate
callbacks with menu items. 
@findex fl_set_menu_entries()
@anchor{fl_set_menu_entries()}
@example
int fl_set_menu_entries(FL_OBJECT *obj, FL_PUP_ENTRY *ent);
@end example
@noindent
where @code{ent} is a pointer to an array of structure of the
following type, terminated by an element, where at least the
@code{text} member is a @code{NULL} pointer:
@tindex FL_PUP_ENTRY
@example
typedef struct @{
    const char *text;
    FL_PUP_CB callback;
    const char *shortcut;
    int mode;
@} FL_PUP_ENTRY;
@end example
The meaning of each member is explained in Section 21.3. For menus,
item callback function can be @code{NULL} if the menu callback handles
the interaction results. See demo program @file{popup.c} for an
example use of @code{@ref{fl_set_menu_entries()}}.

The function @code{@ref{fl_set_menu_entries()}} works by creating and
associating a popup menu with the menu object. The popup ID is
returned by the function. Whenever the function is called, the old
popup associated with the object (if one exists) is freed and a new
one is created. Although you can manipulate the menu either through
the menu API (but adding and removing menu items is not supported for
menus created this way ) or popup API, the application should not free
the popup directly and use @code{@ref{fl_clear_menu()}} instead.


To clear the whole menu use
@findex fl_clear_menu()
@anchor{fl_clear_menu()}
@example
void fl_clear_menu(FL_OBJECT *obj);
@end example

To find the menu item selected by the user use
@findex fl_get_menu()
@anchor{fl_get_menu()}
@example
int fl_get_menu(FL_OBJECT *obj);
@end example
@noindent
The the function returns the menu item ID. In the simplest possible
case this is just the position of the menu item (starting at 1). This
stops to be true when either IDs have been explicitely assigned to
items or items have been deleted. In that case the following rules
apply:
@enumerate
@item
A menu item ID may have been assigned to a menu item using @code{%xn}
in the string for the text of the menu item.
@item
Menu items can get associated with a callback function that is
executed when the menu item is selected. The callback function is of
type @code{FL_PUP_CB} and receives the menu item ID of the selected
menu. If such a callback is set for a menu item the return value of
@code{@ref{fl_get_menu()}} is the return value of this function
instead of the menu item ID that would have been returned otherwise.
@end enumerate

To obtain the text of the item selected
@findex fl_get_menu_text()
@anchor{fl_get_menu_text()}
@example
const char *fl_get_menu_text(FL_OBJECT *obj);
@end example

To obtain the text of any item, use the following routine
@findex fl_get_menu_item_text()
@anchor{fl_get_menu_item_text()}
@example
const char *fl_get_menu_item_text(FL_OBJECT *obj, int miid);
@end example
@noindent
where @code{miid} is the menu item ID. If @code{n} isn't a valid menu
iem ID item @code{NULL} is returned.

To obtain the total number of menu items, use the function
@findex fl_get_menu_maxitems()
@anchor{fl_get_menu_maxitems()}
@example
int fl_get_menu_maxitems(FL_OBJECT *obj);
@end example

One can change the appearance of different menu items. In particular,
it is sometimes desirable to make grey-out menu items and make them
unselectable or to put boxes with and without checkmarks in front of
them. This can be done using the routine:
@findex fl_set_menu_item_mode()
@anchor{fl_set_menu_item_mode()}
@example
void fl_set_menu_item_mode(FL_OBJECT *obj, int miid, unsigned mode);
@end example
@noindent
@code{miid} is the menu index ID of the memu item you want to change.
@code{mode} represents the special properties you want to apply to the
chosen item. You can specify more than one at a time by adding or
bitwise OR-ing these values together. For this parameter, the
following symbolic constants exist:
@table @code
@tindex FL_PUP_NONE
@anchor{FL_PUP_NONE}
@item FL_PUP_NONE
No special display characteristic, the default.

@tindex FL_PUP_BOX
@anchor{FL_PUP_BOX}
@item FL_PUP_BOX
"Binary" entry, i.e.@: an entry that stands for a choice that can
be switched on and off. Displayed with an unchecked box to the
left.

@tindex FL_PUP_RADIO
@anchor{FL_PUP_RADIO}
@item FL_PUP_RADIO
"Radio" item belonging to a group, so that gets automatically
switched off when another item of the group is selected. Displayed
with a diamoned-shaped box at the left.

@tindex FL_PUP_GREY
@anchor{FL_PUP_GREY}
@item FL_PUP_GREY
To be OR-ed with one of the above to make that item appear
greyed-out and disable it (i.e.@: not selectable anymore).

@tindex FL_PUP_CHECK
@anchor{FL_PUP_CHECK}
@item FL_PUP_CHECK
To be OR-ed with one of @code{FL_PUP_BOX} and @code{FL_PUP_RADIO}
to make the box to the left appear checked or pushed.
@end table

There is also a routine that can be used to obtain the current mode of
an item after interaction, mostly useful for toggle or radio items:
@findex fl_get_menu_item_mode()
@anchor{fl_get_menu_item_mode()}
@example
unsigned int fl_get_menu_item_mode(FL_OBJECT *obj, int miid);
@end example

It is often useful to define keyboard shortcuts for particular menu
items. For example, it would be nice to have @code{<Alt>s} behave like
selecting "Save" from a menu. This can be done using the following
routine:
@findex fl_set_menu_item_shortcut()
@anchor{fl_set_menu_item_shortcut()}
@example
void fl_set_menu_item_shortcut(FL_OBJECT *obj, int miid,
                               const char *str);
@end example
@noindent
@code{miid} is the menu item ID of the menu item under consideration.
@code{str} contains the shortcut for the item. (Actually, it can
contain more shortcuts for the same item.) @xref{Shortcuts}, for more
information about shortcuts.

Finally there is the routine:
@findex fl_show_menu_symbol()
@anchor{fl_show_menu_symbol()}
@example
void fl_show_menu_symbol(FL_OBJECT *obj, int yes_no);
@end example
@noindent
With this routine you can indicate whether to show a menu symbol at
the right of the menu label. By default no symbol is shown.


@node Menu Attributes
@subsection Menu Attributes
Any boxtype can be used for a menu except for those of type
@code{FL_PULLDOWN_MENU}, for which @code{FL_NO_BOX} should not be
used.

The first color argument (@code{col1}) to
@code{@ref{fl_set_object_color()}} controls the color of the menu's
box when not open and the second (@code{col2}) is the color when the
menu is shown.

To change the font style and size used in the popup menus (not the menu
label), use the following routines
@findex fl_setpup_default_fontstyle()
@findex fl_setpup_default_fontsize()
@example
void fl_setpup_default_fontstyle(int style);
void fl_setpup_default_fontsize(int size);
@end example
@noindent
These settings apply to all menus at once.

If desired, you can attach an external popup to a menu object via the
following routine
@findex fl_set_menu_popup()
@anchor{fl_set_menu_popup()}
@example
void fl_set_menu_popup(FL_OBJECT *obj, int pupID);
@end example
@noindent
where @code{pupID} is the ID returned by @code{@ref{fl_newpup()}} or
@code{@ref{fl_defpup()}}. @xref{XPopup}, for more details on popup
creation.

For a menu created this way only @code{@ref{fl_get_menu()}} and
@code{@ref{fl_get_menu_text()}} work as expected. Other services such as
mode setting and query etc. should be done via the popup routines.

To obtain the popup ID associated with a menu, use the following routine
@findex fl_get_menu_popup()
@anchor{fl_get_menu_popup()}
@example
int fl_get_menu_popup(FL_OBJECT *obj);
@end example
@noindent
The function return the popup ID if the menu was created using
@code{@ref{fl_set_menu_popup()}} or
@code{@ref{fl_set_menu_entries()}}, otherwise it returns -1.

Normally in the popup opened for a menu a title is shown. This can be
switched off (and back on again by using the function
@findex fl_set_menu_notitle()
@anchor{fl_set_menu_notitle()}
@example
fl_set_menu_notitle(FL_OBJECT *obj, int off);
@end example

@node Menu Remarks
@subsection Remarks

See @file{menu.c} for an example of the use of menus. You can also use
@code{FL_MENU_BUTTON} to initiate a callback and use an XPopup
directly within the callback. See @file{pup.c} for an example of this
approach.


@node XPopup
@section XPopup

XPopup is not really an object class, but because it is used by menu
and choice objects and can function stand-alone, it is documented
here.

XPopups are simple transient windows that show a number of choices the
user can click on to select the desired option.

@ifnottex

@menu
* Creating XPopups:        Creating XPopups
* XPopup Interaction:      XPopup Interaction
* Other XPopup Routines:   Other XPopup Routines
* XPopup Attributes:       XPopup Attributes
* Remarks:                 XPopup Remarks
@end menu

@end ifnottex


@node Creating XPopups
@subsection Creating XPopups

To define a new popup, use the following routines
@findex fl_newpup()
@anchor{fl_newpup()}
@findex fl_defpup()
@anchor{fl_defpup()}
@example
int fl_newpup(Window parent);
int fl_defpup(Window parent, const char *str, ...);
@end example
@noindent
Both functions allocate and initialize a new popup menu and return the
XPopup identifier (or -1 on failure). @code{@ref{fl_defpup()}} in
addition accepts a pointer @code{str} to the texts for menu items
(optionally also some more arguments, see below). More than one item
can be specified by using a vertical bar (@code{|}) between the items,
e.g.@: @code{"foo|bar"} adds two menu items. The @code{parent}
parameter specifies the window to which the XPopup belongs. In a
situation where the XPopup is used inside an object callback
@code{FL_ObjWin(obj)} will do. If @code{parent} is @code{None} the
root window will be used.

Calling @code{@ref{fl_defpup()}} with the @code{str} argument set to
@code{NULL} is equivalent to calling @code{@ref{fl_newpup()}}.

It is possible to specify XPopup and item properties, such as
shortcuts, callbacks etc., together with the items texts using a
format string system similar as used for e.g.@: @code{oprint(3)}. If
XPopup or item properties require arguments, they must be passed to
@code{@ref{fl_defpup()}} following the @code{str} argument.

The following item properties are supported:
@table @code
@item %t
Marks the item text as the XPopup title string.

@item %F
Binds a callback function to the XPopup as a whole that is called for
every selection made from this XPopup. You must specify the function
to be invoked in the parameters following @code{str}. The value of the
selected item is passed as the only argument to the invoked callback
function. The callback function must return a non-negative integer. If
such a callback function has been registered for a XPopup and you
select its third item, in the simplest case 3 will be passed as a
parameter to the callback function (more complicated situations would
involve that the item had been assigned a different value. e.g. using
@code{%x}, see below, or that there's also a callback bound to the
item itself, in which case the global XPopup callback would receive
the return value of the items callback function).

@item %f
Binds a callback to this particular item which is invoked if the item
is selected. The routine must be supplied in the parameters following
@code{str}. It has to return a non-negative integer. The value of the
selected item is passed as a parameter to this function. If you have
also bound the entire XPopup to a callback function via @code{%F},
then the function specified via @code{%f} is called first with the
items value and its return value (if larger then @code{0} is then
passed as the parameter to to the function bound to the whole XPopup
(as set via @code{%F}).

@item %i
Disables and greys-out the item. @code{%d} can be used instead of @code{%i}.

@item %l
Adds a line under the current entry. This is useful in providing
visual clues to groups of entries

@item %m
Whenever this item is selected another (already defined) XPopup is
bound to the item so that the sub-XPopup is opened when the user moves
the mouse onto the item, This can be used to create cascading menus.
The identifier of the sub-XPopup to be shown must be provided in the
arguments following @code{str}. It is the programmers responsibility
to make sure that the item values of the sub-XPopup don't clash with
those of the higher-level XPopup or it may be impossible to determine
which item was selected.

@item %h
Specify a "hotkeys" that can be used to select this item. Hotkeys must
be given in the arguments following @code{str} as a pointer to a
string. Use @code{#} to specify that a key must be pressed together
with the @code{<Alt>} key, @code{^} for simultaneous pressing of
@code{<Ctrl>} and @code{&n} for the function key @code{Fn}.

@code{%s} can be used instead of @code{%h}.

@item %xn
Assigns a numerical value to this item. This value must be positive.
This new value overrides the default position-based value assigned to
this item. Different from most other flags, the value @code{n} must be
entered as part of the text string (i.e.@: do not try to use the
arguments following @code{str} to specify this value!) and must be
number larger than 0. It is the programmers responsibility to make
sure that the items value does not clash with those of other items of
the XPopup or determining which item was selected may be impossible.

@item %b
Indicates this item is "binary item" (toggle), currently in off state.
When displayed, binary items will be drawn with a small box to the
left. See also @code{FL_PUP_BOX}.

@item %B
Same as @code{%b} except that it also signifies that this item is in
on or "true" state and consequently is drawn with a checked box on the
left. See also @code{FL_PUP_BOX | FL_PUP_CHECK}.

@item %rg
Specifies this menu item is a "radio item" belonging to group with
number @code{g}, currently not being selected. The group number
@code{g}, that must be part of the string directly following @code{%r}
(and not specified via the arguments following the string), must be a
non-zero, positive number. Radio items are drawn with a small diamond
box to the left (empty while not active). See also
@code{FL_PUP_RADIO}.

@item %Rg
Same as @code{%rg} except that it also sets the state of the radio
item as selected or "pushed", the item is drawn with a filled diamond
box to the left. See also @code{@ref{fl_setpup_selection()}}. See also
@code{FL_PUP_RADIO | FL_PUP_CHECK}.

@item %%
Use this if you need a @code{%} character in the string.
@item <Ctrl>H (@code{\010})
Same as @code{%l} except that the character must precede the item
label, i.e., use @code{"\010Abc"} and not @code{"Abc\010"}.
@end table

Due to the use of variable arguments error checking can only be
minimal. Also note that if @code{%x} is used to specify a value that
happens to be identical to a position-based value, the result is
unpredictable when subsequent references to these items are made.
There is currently a limit of
@tindex FL_MAXPUPI
@code{FL_MAXPUPI} (64) items per popup.

Tabs characters (@code{'\t'}) can be embedded in the item string to
align different fields.

You can add more items to an existing XPopup using the following
routine
@findex fl_addtopup()
@anchor{fl_addtopup()}
@example
int fl_addtopup(int popup_id, const char *str, ...);
@end example
@noindent
where @code{popup_id} is the value returned by
@code{@ref{fl_newpup()}} or @code{@ref{fl_defpup()}} for the XPopup.
Again, @code{str} can contain information for one or more new items,
including the special sequences described earlier. The function
returns -1 if invalid arguments are detected (as far as possible for a
function with a variable number of arguments).

To display a popup, use
@findex fl_dopup()
@anchor{fl_dopup()}
@example
int fl_dopup(int popup_id);
@end example
@noindent
This function displays the specified XPopup until the user makes a
selection or clicks somewhere outside of the XPopups box. The value
returned is the value of the item selected or -1 if no item (or a
disabled one) was selected. However, if there is a function bound to
the XPopup as a whole or to the selected item itself, this function is
invoked with the item value as the argument and the value returned by
@code{@ref{fl_dopup()}} is then the return value of this function. If
a callback function for both the selected item and the XPopup as a
whole exists, the callback function for the item is called first with
the item value as the argument and then the return value of this item
specific callback function is passed to the XPopups callback function.
@code{@ref{fl_dopup()}} then finally returns the return value of this
second function call.

Normally a XPopup get opened when the left mouse button has been
pressed down and get closed again when the left mouse button is
released. But there are a number of ways to achieve a "hanging"
XPopup, i.e.@: that the XPopup that says open, even though the left
mouse button isn't pressed down anymore. This happens e.g.@: when the
user releases the mouse button in the title area of the XPopup or when
the XPopup was opened via a keyboard shortcut. In that case it's also
possible to navigate through the items and select via the keyboard.

A typical procedure may look as follows:
@example
int item3_cb(int n) @{
     return n + 7;
@}

/* define the menu */
int menu = fl_newpup(parent);
fl_addtopup(menu, "Title %t|Item1%rg1|Item2%Rg1|Item3%x10%f|Item4",
            item3_cb);

switch (fl_dopup(menu)) @{
    case 1:   /* item1 is selected */
        /* handle it */
        break;

    case 2:
        /* handle it */
        break;

    case 4:
        /* handle it */

    case 17:
        /* item 3 call back has been executed */
@}
@end example
@noindent
Here callback function @code{item3_cb()} is bound to the third item
and this item has been assigned the number 10. Thus, when it is
selected @code{@ref{fl_dopup()}} does not return 3 or 10. Instead the
callback function @code{item3_cb()} is invoked with 10 as its
argument. And this function in turn returns @code{10 + 7}, which is
the value @code{@ref{fl_dopup()}} finally returns.

Note also that items 1 and 2 both are radio items, belonging to the
same group (numbered 1). Item 2 is currently the active item of this
group.

Sometimes it might be necessary to obtain the popup ID inside an item
callback function. To this end, the following function available:
@findex fl_current_pup()
@anchor{fl_current_pup()}
@example
int fl_current_pup(void);
@end example
@noindent
If no popup is active, the function returns -1. Until all callback
functions have been run the function returns the ID of the XPopup the
items belong to.

To destroy a popup menu and release all memory used, use the following
routine
@findex fl_freepup()
@anchor{fl_freepup()}
@example
void fl_freepup(int popup_id);
@end example

For most applications, the following simplified API may be easier to
use
@findex fl_setpup_entries()
@anchor{fl_setpup_entries()}
@example
void fl_setpup_entries(int popup_id, FL_PUP_ENTRIES *entries);
@end example
where @code{popup_id} is the popup ID returned by
@code{@ref{fl_newpup()}} or @code{@ref{fl_defpup()}} and
@code{entries} is an array of the following structures
@tindex FL_PUP_ENTRY
@example
typedef struct @{
    const char * item_text; /* item text label */
    FL_PUP_CB    callback;  /* item callback routine */
    const char * shortcut;  /* shortcut for this item */
    unsigned int mode;      /* item mode */
@} FL_PUP_ENTRY;
@end example
@noindent
The meaning of each member of the structure is as follows:
@table @code
@item text
This is the text of a XPopup item. If text is @code{NULL}, it
signifies the end of this popup menu. The first letter of the text
string may have a special meaning if it is one of the following:
@table @code

@item '/'
This indicates the beginning of a sub-popup, starting with the next
item and ending with the next item with @code{text} being @code{NULL}.
@item '_'
Indicates that a line should be drawn below this item (typically as a
visual reminder of logical groupings of items).
@end table

@item callback
This is the callback function that will be called when this particular
item is selected by the user. @code{@ref{fl_dopup()}} returns the
value returned by this callback. If the callback is @code{NULL}, the
item number will be returned directly by @code{@ref{fl_dopup()}}.

@item shortcut
Specifies the keyboard shortcut.

@item mode
Specifies special attributes of this item. This can be one or a
combination by bitwise OR of one of the following:
@table @code
@tindex FL PUP NONE
@item FL PUP NONE
No special characteristics, the default.
@tindex FL_PUP_GREY
@item FL_PUP_GREY
Item is greyed-out an can't be selected. Trying to select it results
in @code{@ref{fl_dopup()}} returning -1.
@tindex FL_PUP_BOX
@item FL_PUP_BOX
"Binary item", drawn with a little box to its left.
@tindex FL_PUP_RADIO
@item FL_PUP_RADIO
"Radio item", drawn with a little diamond-shaped box to its left. All
radio items of the XPopup belong to the same group.
@tindex FL_PUP_CHECK
@item FL_PUP_CHECK
OR this value with @code{FL_PUP_BOX} or @code{FL_PUP_RADIO} to have
the box to the left drawn as checked or pushed.
@end table
@end table

With this simplified API, popup item values start from 1 and are the
index in the entries array for the item plus 1. For example, the third
element (with index 2) of the array of structure has an item value of
3. Please note that also elements of the array that end a submenu and
thus don't appear as visible items in the XPopup get counted. This
way, the application can relate the value returned by fl_dopup() to
the array easily. See demo program @file{popup.c} for an example use
of the API.

To illustrate the usage of @code{@ref{fl_setpup_entries()}}, Fig 21.2
shows the popup created with the array of structures defined in the
following code example:
@example
FL_PUP_ENTRY entries[ ] = @{
   @{"Top item1",  callback@},      /* item number 1 */
   @{"Top item2",  callback@},
   @{"Top item3",  callback@},
   @{"/Top item4", callback@},
     @{"Sub1 item1",  callback@},   /* item number 5 */
     @{"Sub1 item2",  callback@},
     @{"Sub1 item3",  callback@},
     @{"Sub1 item4",  callback@},
     @{"/Sub1 item5", callback@},
       @{"Sub2 item1",  callback@}, /* item number 10 */
       @{"Sub2 item2",  callback@},
       @{"Sub2 item3",  callback@},
       @{NULL,         NULL     @}, /* end of level2, item number 13 */
     @{NULL,           NULL   @},   /* end of sublevel1, item nuber 14 */
   @{"Top item5",  callback@},      /* item number 15 */
   @{NULL,         NULL    @}       /* end of popup */
@};
@end example


@node XPopup Interaction
@subsection XPopup Interaction

To select an item, move the mouse to the item to be selected while
keeping the mouse button pressed down and then release the mouse
button on top of the item to be selected. If you don't want to make a
selection release the mouse button somewhere outside the area of the
XPopup.

If you have a "hanging" XPopup, i.e.@: a XPopup that's open even
though the mouse button isn't pressed anymore you can select by
clicking on an item or use the cursor @code{Up} and @code{Down} keys
to navigate through the items and select by pressing the
@code{<Return>} key. The @code{<Home>} and @code{<End>} keys allow you
to jump to the first or last selectable item, respectively. Use
@code{<Esc>} to close the popup without selecting an item.

It is also possible to use convenience functions to bind keyboard keys
to items (the "hotkeys") instead of using @code{%s} with
@code{@ref{fl_defpup()}}:
@findex fl_setpup_shortcut()
@anchor{fl_setpup_shortcut()}
@example
void fl_setpup_shortcut(int popup_id, int item_val,
                        const char *hotkeys);
@end example
@noindent
where @code{item_val} is the value associated with the item (either
due to its position or set with @code{%x}) and hotkeys is a string
specifying all the hotkey combinations. @xref{Shortcuts}, for details.
Briefly, within that string @code{#} and @code{^} denote the
@code{<Alt>} and @code{<Ctrl>} keys, respectively. @code{&n} with
@code{n = 1, 2} etc.@: can be used to denote the function key numbered
@code{n}. Thus if hotkeys is set to @code{"#a^A}, both @code{<Ctrl>A}
and @code{<Alt>A} are bound to the item. One additional property of
the hotkey is the underlining of corresponding letters in the item
string. Again, only the first key in the hotkey string is used.
Therefore, the hotkey strings @code{"Cc"}, @code{"#C"} and @code{"^C"}
will result in the character @code{C} in the item string @code{"A
Choice"} being underlined, while the the hotkey strings @code{"cC"}
and @code{"#c"} will not since there's no @code{c} in the item string.
There is a limit of maximum 8 shortcut keys.

Two convenience functions are available to set the callback functions
for items of a XPopup and the XPopup as a whole (called whenever a
selection is made):
@tindex FL_PUP_CB
@findex fl_setpup_itemcb()
@anchor{fl_setpup_itemcb()}
@findex fl_setpup_menucb()
@anchor{fl_setpup_menucb()}
@example
typedef int (*FL_PUP_CB)(int);
FL_PUP_CB fl_setpup_itemcb(int popup_id, int item_val, FL_PUP_CB cb);
FL_PUP_CB fl_setpup_menucb(int popup_id, FL_PUP_CB cb);
@end example
These functions thus allow to change the popup and item callback
functions set at creation of the popup with @code{%F} and @code{%f}.
As usual, @code{popup_id} is the ID of the XPopup, @code{item_val} the
value associated with the item (position or value set via @code{%x}),
and @code{cb} is the address of the callback function.

Please note that Xpopup objects are a bit special in XForms. Normal
objects get returned by e.g.@: @code{@ref{fl_do_forms()}} (or an
associated callback gets invoked). But since Xpopup objects are meant
to be sub-objects of other objects (like @code{FL_CHOICE} and
@code{L_MENU} objects) and don't get invoked directly by a call of
e.g.@: @code{@ref{fl_do_forms()}} but instead by a call of
@code{@ref{fl_dopup()}} they can't get returned to the application.
Instead the caller of @code{@ref{fl_dopup()}} (normally some internal
function of a @code{FL_CHOICE} or @code{FL_MENU} object) has to deal
with the return value.

Furthermore, also callback functions can be set that get invoked
whenever an item in the XPopup is entered or left, even without a
selection being made. The following functions can be used to register
these item enter/leave callbacks:
@tindex FL_PUP_ENTERCB
@tindex FL_PUP_LEAVECB
@findex fl_setpup_entercb()
@anchor{fl_setpup_entercb()}
@findex fl_setpup_leavecb()
@anchor{fl_setpup_leavecb()}
@example
typedef void (*FL_PUP_ENTERCB)(int item_val, void *data);
typedef void (*FL_PUP_LEAVECB)(int item_val, void *data);

FL_PUP_ENTERCB fl_setpup_entercb(int popup_id,
                                 FL_PUP_ENTERCB cb, void *data);
FL_PUP_LEAVECB fl_setpup_leavecb(int popup_id,
                                 FL_PUP_LEAVECB cb, void *data);
@end example
@noindent
The function @code{cb} will be called when the mouse enters or leaves
an (non-disabled) item of the XPopup @code{popup_id}. Two parameters
are passed to the callback function. The first parameter is the item
number enter/leave applies to and the second parameter is a data
pointer. To remove an enter/leave callback, call the functions with
the callback function argument @code{cb} set to @code{NULL}.

There is also a function to associate a XPopup item with a sub-XPopup
@findex fl_setpup_submenu()
@anchor{fl_setpup_submenu()}
@example
void fl_setpup_submenu(int popup_id, int item_val, int subpopup_id);
@end example
@noindent
If a sub-XPopup is associated with item @code{item_val} that item
can't be selected anymore (releasing the mouse button on this item
makes @code{@ref{fl_dopup()}} return -1 but instead a new XPopup is
opened beside the item and you can now make selections within this
sub-XPopup. It is the programmers responsibility to make sure that the
item values of the sub-XPopup don't clash with those of the
higher-level XPopup or it may be impossible to determine which item
was selected.


@node Other XPopup Routines
@subsection Other XPopup Routines

Note that most of the setpup/getpup routines are recursive in nature
and the function will search the menu and all its submenus for the
item.

It is possible to modify the display characteristics of a given XPopup
item after its creation using the following routine
@findex fl_setpup_mode()
@anchor{fl_setpup_mode()}
@example
void fl_setpup_mode(int popup_id, int item_val, unsigned mode);
@end example
@noindent
As usual @code{popup_id} is the XPopup ID as returned by
@code{@ref{fl_newpup()}} or @code{@ref{fl_defpup()}} and
@code{item_val} the value of the item. @code{mode} is one of @code{FL
PUP NONE}, @code{FL PUP GREY}, @code{FL PUP BOX} or @code{FL PUP
RADIO} (one of the later two can be bitwise ORed with
@code{FL_PUP_CHECK}, as already discussed above.

To obtain the mode of a particular menu item, use the following
routine
@findex fl_getpup_mode()
@anchor{fl_getpup_mode()}
@example
unsigned int fl_getpup_mode(int popup_id, int item_val)
@end example
@noindent
This comes in handy to check if a binary or radio item is set
@example
if (fl_getpup_mode(popupd, item_val) & FL_PUP_CHECK)
    /* item is set */
@end example

There exists also a routine that can be used to obtain an items text
@findex fl_getpup_text()
@anchor{fl_getpup_text()}
@example
const char *fl_getpup_text(int popup_id, int item_val);
@end example

In some situations, especially when the popup is activated by
non-pointer events (e.g.@: as a result of a keyboard shortcut), the
default placement of popups based on mouse location might not be
adequate or appropriate, thus XPopup provides the following routine to
override the default placement
@findex fl_setpup_position()
@anchor{fl_setpup_position()}
@example
void fl_setpup_position(int x, int y);
@end example
@noindent
where @code{x} and @code{y} specify the location where the top-left
corner of the popup should be. @code{x} and @code{y} must be given in
screen coordinates (i.e.@: relative to the root window) with the
origin at the top-left corner of the screen. This routine should be
used immediately before invoking @code{@ref{fl_dopup()}}, the position
is not remembered afterwards.

If @code{x} or @code{y} is negative, the absolute value is taken to
mean the desired location relative to the right or bottom corner of
the popup (not the screen!).

A radio item in a group can be initialized to be in "pushed" state by
using @code{%R}. But you can also switch a such a radio item to
"pushed state also programmatically using
@findex fl_setpup_selection()
@anchor{fl_setpup_selection()}
@example
void fl_setpup_selection(int popup_id, int item_val);
@end example
@noindent
Of course, other radio items of the XPopup belonging to the same group
are reset to "unpushed" state.

To obtain the number of items in a popup, use the following routine
@findex fl_getpup_items()
@anchor{fl_getpup_items()}
@example
int fl_getpup_items(int popup_id)
@end example


@node XPopup Attributes
@subsection XPopup Attributes

Use the following routines to modify the default popup font style,
font size and border width:
@findex fl_setpup_default_fontsize()
@anchor{fl_setpup_default_fontsize()}
@findex fl_setpup_default_fontstyle()
@anchor{fl_setpup_default_fontstyle()}
@findex fl_setpup_default_bw();
@anchor{fl_setpup_default_bw()}
@example
int fl_setpup_default_fontsize(int size);
int fl_setpup_default_fontstyle(int style);
int fl_setpup_default_bw(int bw);
@end example
@noindent
The functions return the old size, style or border width value,
respectively.

All XPopups by default use a right arrow cursor. To change the default
cursor, use
@findex fl_setpup_default_cursor()
@anchor{fl_setpup_default_cursor()}
@example
Cursor fl_setpup_default_cursor(int cursor);
@end example
@noindent
where you can use for @code{cursor} any of the standard cursors
defined in @code{<X11/cursorfont.h>} like @code{XC_watch} etc.
The function returns the previously cursor.

To change the cursor of a particular XPopup only , use the following
routine
@findex fl_setpup_cursor()
@anchor{fl_setpup_cursor()}
@example
Cursor fl_setpup_cursor(int popup_id, int cursor);
@end example
@noindent
For example, after the following sequence,
@example
id = fl_defpup(win, "item1|item2");
fl_setpup_cursor(id, XC_hand2);
@end example
@noindent
the popup with ID @code{id} will use a "hand" instead of the default
arrow cursor.

In versions before 1.0.91 XPopups were drawn with a heavy shadow
around the box. Drawing of this shadow could be controlled via
@findex fl_setpup_shadow()
@anchor{fl_setpup_shadow()}
@example
void fl_setpup_shadow(int popup_id, int yes_no);
@end example
@noindent
Nowadays this function still exists for backward-compatibility but
does nothing.

The appearance of XPopups (and their associated sub-popups) can be
change by the following routines:
@findex fl_setpup_bw()
@anchor{fl_setpup_bw()}
@findex fl_setpup_softedge()
@anchor{fl_setpup_softedge()}
@example
void fl_setpup_bw(int popup_id, int bw);
void fl_setpup_softedge(int pupup_id, int yes_no);
@end example
@noindent
The first sets the border width for a XPopup. Calling
@code{@ref{fl_setpup_softedge()}} with a true argument for
@code{yes_no} has the same effect as using a negative border width
while using a false (0) argument is equivalent to using a positive one
(so this function isn't very useful).


The background color and text color of a popup can be changed using
@findex fl_setpup_default_color()
@anchor{fl_setpup_default_color()}
@example
void fl_setpup_default_color(FL_COLOR bgcolor, FL_COLOR tcolor);
@end example
@noindent
By default, the background color @code{bgcolor} is @code{FL_COL1} and
the text color @code{tcolor} is @code{FL_BLACK}.

For "binary" or radio items, that have check box associated with them,
the "checked" or "pushed" color (default is @code{FL_BLUE}) can be
changed with the following routine
@findex fl_setpup_default_checkcolor()
@anchor{fl_setpup_default_checkcolor()}
@example
void fl_setpup_default_checkcolor(FL_COLOR checkcolor);
@end example

There is by default a limit of 32 XPopups per process. To enlarge the
number of XPopups allowed, use the following routine
@findex fl_setpup_maxpups()
@anchor{fl_setpup_maxpups()}
@example
int fl_setpup_maxpups(int new_max);
@end example
@noindent
The function returns the previous limit.

It is possible to use XPopups as a message facility using the
following routines
@findex fl_showpup()
@anchor{fl_showpup()}
@findex fl_hidepup()
@anchor{fl_hidepup()}
@example
void fl_showpup(int popup_id);
void fl_hidepup(int popup_id);
@end example
@noindent
No interaction takes place with a XPopup shown by
@code{@ref{fl_showpup()}} and it can only be removed from the screen
programmatically via @code{@ref{fl_hidepup()}}.


@node XPopup Remarks
@subsection Remarks

Take care to make sure all items, including the items on submenus,
of a XPopup have unique values and are positive.

XPopups are used indirectly in the demo programs @file{menu.c},
@file{boxtype.c}, @file{choice.c} and others. For a direct pop-up demo
see @file{popup.c}.
