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pod::Prima::Widget::paUser)Contributed Perl Documenpod::Prima::Widget::pack(3)

NAME
       Prima::Widget::pack - Geometry manager that packs around	edges of
       cavity

SYNOPSIS
	 $widget-> pack( args);

	 $widget-> packInfo( args);
	 $widget-> geometry( gt::Pack);

DESCRIPTION
       The pack	method is used to communicate with the packer, a geometry
       manager that arranges the children of a owner by	packing	them in	order
       around the edges	of the owner.

       In this port of Tk::pack	it is normal to	pack widgets one-at-a-time
       using the widget	object to be packed to invoke a	method call.  This is
       a slight	distortion of the original Tcl-Tk interface (which can handle
       lists of	windows	to one pack method call) but Tk	reports	that it	has
       proven effective	in practice.

       The pack	method can have	any of several forms, depending	on Option:

       pack %OPTIONS
	   The options consist of pairs	of arguments that specify how to
	   manage the slave.  See "The packer algorithm" below for details on
	   how the options are used by the packer.  The	following options are
	   supported:

	   after => $other
		   $other must be another window.  Use its master as the
		   master for the slave, and insert the	slave just after
		   $other in the packing order.

	   anchor => anchor
		   Anchor must be a valid anchor position such as n or sw; it
		   specifies where to position each slave in its parcel.
		   Defaults to center.

	   before => $other
		   $other must be another window.  Use its master as the
		   master for the slave, and insert the	slave just before
		   $other in the packing order.

	   expand => boolean
		   Specifies whether the slave should be expanded to consume
		   extra space in their	master.	 Boolean may have any proper
		   boolean value, such as 1 or no.  Defaults to	0.

	   fill	=> style
		   If a	slave's	parcel is larger than its requested
		   dimensions, this option may be used to stretch the slave.
		   Style must have one of the following	values:

		   none	       Give the	slave its requested dimensions plus
			       any internal padding requested with -ipadx or
			       -ipady.	This is	the default.

		   x	       Stretch the slave horizontally to fill the
			       entire width of its parcel (except leave
			       external	padding	as specified by	-padx).

		   y	       Stretch the slave vertically to fill the	entire
			       height of its parcel (except leave external
			       padding as specified by -pady).

		   both	       Stretch the slave both horizontally and
			       vertically.

	   in => $master
		   Insert the slave(s) at the end of the packing order for the
		   master window given by $master. Currently, only the
		   immediate owner can be accepted as master.

	   ipad	=> amount
		   Amount specifies how	much both horizontal and vertical
		   internal padding to leave on	each side of the slave(s).
		   Amount must be a valid screen distance, such	as 2 or	.5c.
		   It defaults to 0.

	   ipadx => amount
		   Amount specifies how	much horizontal	internal padding to
		   leave on each side of the slave(s).	Amount must be a valid
		   screen distance, such as 2 or .5c.  It defaults to 0.

	   ipady => amount
		   Amount specifies how	much vertical internal padding to
		   leave on each side of the slave(s).	Amount	defaults to 0.

	   pad => amount
		   Amount specifies how	much horizontal	and vertical external
		   padding to leave on each side of the	slave(s).  Amount
		   defaults to 0.

	   padx	=> amount
		   Amount specifies how	much horizontal	external padding to
		   leave on each side of the slave(s).	Amount defaults	to 0.

	   pady	=> amount
		   Amount specifies how	much vertical external padding to
		   leave on each side of the slave(s).	Amount defaults	to 0.

	   side	=> side
		   Specifies which side	of the master the slave(s) will	be
		   packed against.  Must be left, right, top, or bottom.
		   Defaults to top.

       If no in, after or before option	is specified then slave	will be
       inserted	at the end of the packing list for its owner unless it is
       already managed by the packer (in which case it will be left where it
       is).  If	one of these options is	specified then slave will be inserted
       at the specified	point.	If the slave are already managed by the
       geometry	manager	then any unspecified options for them retain their
       previous	values rather than receiving default values.

       packForget
	   Removes slave from the packing order	for its	master and unmaps its
	   window.  The	slave will no longer be	managed	by the packer.

       packInfo	[ %OPTIONS ]
	   In get-mode,	returns	a list whose elements are the current
	   configuration state of the slave given by $slave.  The first	two
	   elements of the list	are ``in=>$master'' where $master is the
	   slave's master.

	   In set-mode,	sets all pack parameters, but does not set widget
	   geometry property to	"gt::Pack".

       packPropagate BOOLEAN
	   If boolean has a true boolean value then propagation	is enabled for
	   $master, (see "Geometry propagation"	below).	 If boolean has	a
	   false boolean value then propagation	is disabled for	$master.  If
	   boolean is omitted then the method returns 0	or 1 to	indicate
	   whether propagation is currently enabled for	$master.

	   Propagation is enabled by default.

       packSlaves
	   Returns a list of all of the	slaves in the packing order for
	   $master.  The order of the slaves in	the list is the	same as	their
	   order in the	packing	order.	If $master has no slaves then an empty
	   list/string is returned in array/scalar context, respectively

The packer algorithm
       For each	master the packer maintains an ordered list of slaves called
       the packing list.  The in, after, and before configuration options are
       used to specify the master for each slave and the slave's position in
       the packing list.  If none of these options is given for	a slave	then
       the slave is added to the end of	the packing list for its owner.

       The packer arranges the slaves for a master by scanning the packing
       list in order.  At the time it processes	each slave, a rectangular area
       within the master is still unallocated.	This area is called the
       cavity;	for the	first slave it is the entire area of the master.

       For each	slave the packer carries out the following steps:

       o   The packer allocates	a rectangular parcel for the slave along the
	   side	of the cavity given by the slave's side	option.	 If the	side
	   is top or bottom then the width of the parcel is the	width of the
	   cavity and its height is the	requested height of the	slave plus the
	   ipady and pady options.  For	the left or right side the height of
	   the parcel is the height of the cavity and the width	is the
	   requested width of the slave	plus the ipadx and padx	options.  The
	   parcel may be enlarged further because of the expand	option (see
	   "Expansion" below)

       o   The packer chooses the dimensions of	the slave.  The	width will
	   normally be the slave's requested width plus	twice its ipadx	option
	   and the height will normally	be the slave's requested height	plus
	   twice its ipady option.  However, if	the fill option	is x or	both
	   then	the width of the slave is expanded to fill the width of	the
	   parcel, minus twice the padx	option.	 If the	fill option is y or
	   both	then the height	of the slave is	expanded to fill the width of
	   the parcel, minus twice the pady option.

       o   The packer positions	the slave over its parcel.  If the slave is
	   smaller than	the parcel then	the -anchor option determines where in
	   the parcel the slave	will be	placed.	 If padx or pady is non-zero,
	   then	the given amount of external padding will always be left
	   between the slave and the edges of the parcel.

	   Once	a given	slave has been packed, the area	of its parcel is
	   subtracted from the cavity, leaving a smaller rectangular cavity
	   for the next	slave.	If a slave doesn't use all of its parcel, the
	   unused space	in the parcel will not be used by subsequent slaves.
	   If the cavity should	become too small to meet the needs of a	slave
	   then	the slave will be given	whatever space is left in the cavity.
	   If the cavity shrinks to zero size, then all	remaining slaves on
	   the packing list will be unmapped from the screen until the master
	   window becomes large	enough to hold them again.

Expansion
       If a master window is so	large that there will be extra space left over
       after all of its	slaves have been packed, then the extra	space is
       distributed uniformly among all of the slaves for which the expand
       option is set.  Extra horizontal	space is distributed among the
       expandable slaves whose side is left or right, and extra	vertical space
       is distributed among the	expandable slaves whose	side is	top or bottom.

Geometry propagation
       The packer normally computes how	large a	master must be to just exactly
       meet the	needs of its slaves, and it sets the requested width and
       height of the master to these dimensions.  This causes geometry
       information to propagate	up through a window hierarchy to a top-level
       window so that the entire sub-tree sizes	itself to fit the needs	of the
       leaf windows.  However, the packPropagate method	may be used to turn
       off propagation for one or more masters.	 If propagation	is disabled
       then the	packer will not	set the	requested width	and height.  This may
       be useful if, for example, you wish for a master	window to have a fixed
       size that you specify.

Restrictions on	master windows
       The master for each slave must not be a child of	the slave, and must
       not be present in any other list	of slaves that directly	or indirectly
       refers to the slave.

Packing	order
       If the master for a slave is not	its owner then you must	make sure that
       the slave is higher in the stacking order than the master.  Otherwise
       the master will obscure the slave and it	will appear as if the slave
       hasn't been packed correctly.  The easiest way to make sure the slave
       is higher than the master is to create the master window	first:	the
       most recently created window will be highest in the stacking order.
       Or, you can use the bring_to_front and send_to_back methods to change
       the stacking order of either the	master or the slave.

SEE ALSO
       Prima, Prima::Widget

       Tk::pack	Tk::place

perl v5.24.1			  2017-02-28	   pod::Prima::Widget::pack(3)

NAME | SYNOPSIS | DESCRIPTION | The packer algorithm | Expansion | Geometry propagation | Restrictions on master windows | Packing order | SEE ALSO

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