TABLE OF CONTENTS

Group.mui/Group.mui
Group.mui/MUIA_Group_ActivePage
Group.mui/MUIA_Group_Child
Group.mui/MUIA_Group_ChildList
Group.mui/MUIA_Group_Columns
Group.mui/MUIA_Group_Horiz
Group.mui/MUIA_Group_HorizSpacing
Group.mui/MUIA_Group_LayoutHook
Group.mui/MUIA_Group_PageMode
Group.mui/MUIA_Group_Rows
Group.mui/MUIA_Group_SameHeight
Group.mui/MUIA_Group_SameSize
Group.mui/MUIA_Group_SameWidth
Group.mui/MUIA_Group_Spacing
Group.mui/MUIA_Group_VertSpacing
Group.mui/MUIM_Group_ExitChange
Group.mui/MUIM_Group_InitChange
Group.mui/Group.mui

	Group class is responsible for the complete layout
	of a MUI window. A group may contain any number of
	child objects, maybe buttons, cycle gadgets or
	even other groups.

	Some attributes of group class define how the children
	of a group are layouted. You can e.g. tell your group
	to place its children horizontally (in a row) or
	vertically (in a column). Since every MUI object knows
	about its minimum and maximum dimensions, group class
	has everything it needs to do that job.

	More sophisticated layout is possible by assigning
	different weights to objects in a group or by
	making a group two-dimensional.

	Beneath the layout issues, a group object passes
	attributes and methods through to all of its
	children. Thus, you can talk and listen to any
	child of a group by talking and listening to the
	group itself.
Group.mui/MUIA_Group_ActivePage

    NAME
	MUIA_Group_ActivePage -- (V5 ) [ISG], LONG

    SPECIAL INPUTS
	MUIV_Group_ActivePage_First
	MUIV_Group_ActivePage_Last
	MUIV_Group_ActivePage_Prev
	MUIV_Group_ActivePage_Next
	MUIV_Group_ActivePage_Advance

    FUNCTION
	Set (or get) the active page of a page group.
	Only this active page is displayed, all others
	are hidden.

	The value may range from 0 (for the first child)
	to numchildren-1 (for the last child). Children are
	adressed in the order of creation:

	PageGroup,
	   Child, Page_0_Object,
	   Child, Page_1_Object,
	   Child, Page_2_Object,
	   Child, Page_3_Object,
	   End;

	Note: You may *never* supply an incorrect page value!

    SEE ALSO
	MUIA_Group_PageMode
Group.mui/MUIA_Group_Child

    NAME
	MUIA_Group_Child -- (V4 ) [I..], Object *

    FUNCTION
	You supply a pointer to a previously created MUI object
	here. This object will be treated as child of the group,
	the group is responsible for positioning the object.

	Of course you can specify any number of child objects,
	limited only by available memory.

	Normally, the value for a MUIA_Group_Child tag is
	a direct call to another MUI_NewObject(), children
	are generated "on the fly".

	When a group is disposed, all of its children will also
	get deleted. If you supply a NULL pointer as child,
	the group object will fail and previously dispose all
	valid children found in the taglist.

	This behaviour makes it possible to generate a complete
	application within one single (but long) MUI_NewObject()
	call. Error checking is not necessary since every error,
	even if it occurs in a very deep nesting level, will
	cause the complete call to fail without leaving back
	any previously created object.

   EXAMPLES
	Please have a look at some of the supplied example
	programs.

   SEE ALSO
	MUIA_Group_Horiz
Group.mui/MUIA_Group_ChildList

    NAME
	MUIA_Group_ChildList -- (V4 ) [..G], struct List *

    FUNCTION
	This attribute returns a pointer to a struct List in which
	a group manages its children.

	The only thing you are allowed to do with this list is
	to traverse through the children. You *must* use
	intuition.library/NextObject() for this purpose!

	Never add or remove member directly, use the 
	OM_ADDMEMBER/OM_REMMEMBER methods instead!

    SEE ALSO
	MUIA_Group_Child
Group.mui/MUIA_Group_Columns

    NAME
	MUIA_Group_Columns -- (V4 ) [IS.], LONG

    FUNCTION
	Indicate number of columns in a two dimensional group.
	If you use this tag, the total number of children must
	be dividable by the number of columns.

	The children will be positioned in a two dimensional
	array, e.g. allowing easy creation of button fields
	(maybe for calculator).

	The children in your taglist are always read line 
	by line.

	When MUI layouts two-dimensional groups, it does
	actually two layout calculations, one for the rows
	and one the columns. Parameters like weights and
	dimensions are handled this way:

	- the minimum width of a column/row is the maximum
	  minimum width of all objects in this column/row.

	- the maximum width of a column/row is the minimum
	  maximum width of all objects in this column/row.

	- the weight of a column/row is the sum of all
	  objects in this column/row.

	Actually, there is no difference if you use
	MUIA_Group_Columns or MUIA_Group_Rows.

    EXAMPLE

	/* group of labeled string gadgets */

	GroupObject,
	   MUIA_Group_Columns, 2,
	   MUIA_Group_Child  , label1,
	   MUIA_Group_Child  , string1,
	   MUIA_Group_Child  , label2,
	   MUIA_Group_Child  , string2,
	   MUIA_Group_Child  , label3,
	   MUIA_Group_Child  , string3,
           ...
	   End;

    SEE ALSO
	MUIA_Group_Rows, MUIA_Group_Horiz
Group.mui/MUIA_Group_Horiz

    NAME
	MUIA_Group_Horiz -- (V4 ) [I..], BOOL

    FUNCTION
	Boolean value to indicate whether the objects in
	this group shall be layouted horizontally or
	vertically. Defaults to FALSE.

	This is the easy way of telling your group how
	it has to look like. If you want two-dimensional
	groups, you have to use MUIA_Group_Columns
	or MUIA_Group_Rows.

    EXAMPLE
	GroupObject,
	   MUIA_Group_Horiz, TRUE,
	   MUIA_Group_Child, obj1,
	   MUIA_Group_Child, obj2,
	   MUIA_Group_Child, obj3,
	   End;

    SEE ALSO
	MUIA_Group_Columns, MUIA_Group_Rows, MUIA_Group_Child
Group.mui/MUIA_Group_HorizSpacing

    NAME
	MUIA_Group_HorizSpacing -- (V4 ) [ISG], LONG

    FUNCTION
	Number of pixels to be inserted between horizontal
	elements of a group.

	Please use this tag wisely, you will override the
	user's prefered default setting!

    SEE ALSO
	MUIA_Group_Spacing, MUIA_Group_VertSpacing
Group.mui/MUIA_Group_LayoutHook

    NAME
	MUIA_Group_LayoutHook -- (V11) [I..], struct Hook *

    FUNCTION
	Since version 11 of muimaster.library, you have the
	ability to customize the way objects are placed in a
	group. Altough MUI features a very powerful builtin
	layout algorithm which serves well for almost all
	GUI related purposes, it might sometimes become
	handy to override this with custom code.

	Imagine you want to build a multimedia document
	viewer which contains text objects, bitmap objects
	and buttons. An easy way for doing this is to simply
	create a sub class of group class which contains all
	the documents elements as MUI objects and which
	specifies a custom layout hook for the parent group.
	This hook is then responsible for placing the
	objects within the bounds of the parent group.

	As soon as you specify a MUIA_Group_LayoutHook, the
	builtin layout calculation is skipped and your hook
	is called whenever MUI needs some information.
	Register A2 will contain a pointer to the parent
	group object and register A1 will contain a pointer
	to a struct MUI_LayoutMsg. The lm_Type field of
	this structure determines which kind of action MUI
	wants you to perform (see below), the lm_Children
	field is a pointer to a list of your groups
	children. By traversing through list list with the
	intuition function NextObject(), you can retrieve
	the children of the group.

	If lm_Type == MUILM_ASKMINMAX, MUI wants you to
	calculate your groups minimum, maximum and default
	sizes. At this time, the children of your group have
	already been asked for their dimensions. This allows
	you to traverse through the list of children and do
	some calculations depending on their min/max sizes.
	Use the macros _minwidth(child), _maxwidth(child),
	_minheight(child), _maxheight(child) for this
	purpose. Place the result of your calculations in
	the structure lm_MinMax of the MUI_LayoutMsg and
	exit your hook with a return value of 0.

	If lm_Type == MUILM_LAYOUT, MUI has already placed
	the group object somewhere in a window and now wants
	you to place the children of this group. You have to
	traverse through the child list and calculate
	positions and sizes for each child. Use the function
	MUI_Layout() to tell the child where it should
	appear. You have to make sure that you don't place
	child objects outside of the parent group and you
	should generally avoid overlapping objects. Return
	TRUE if all children are placed, return FALSE if you
	were for some reasons unable to place your children.

	If your previous min/max calculations were correct,
	your algorithms should not have problems to place
	all the children in the rectangle defined by the
	parent group. Its size will never be smaller as your
	specified minimum dimensions and never be larger as
	your specified maximum dimensions.

	If your group is a virtual group, the width
	and height your layout hook receives are as big as
	the *visible* part of the virtual group. In this
	case, you are allowed to position your objects
	outside of the visible part, i.e. you are not
	limited to keep your objects inside the given width
	and height. Place them where you wish and set
	lm_Layout.Width and lm_Layout.Height to the width
	and height you really need for your objects before
	exiting. The virtual width and height of your group
	will be adjusted accordingly.

    EXAMPLE
	see MUI demo program Layout.c

    SEE ALSO
	muimaster.library/MUI_Layout()
Group.mui/MUIA_Group_PageMode

    NAME
	MUIA_Group_PageMode -- (V5 ) [I..], BOOL

    FUNCTION
	Settings this attribute to TRUE makes the current group a page
	group. Page groups always display only one of their children, 
	which one can be adjusted with the MUIA_Group_ActivePage 
	attribute.

	Imagine you have a preferences window with several different
	pages, e.g. the MUI preferences with object, frame, image,
	font, screen, keyboard and system prefs. Instead of one
	separate window for each group, you could put all pages into
	one page group and have a cycle gadget for page switching.
	This will make your program easier to use since the user
	won't have to handle a lot of windows. However, he will not
	be able to work with more than one page at the same time.

	Sizes are calculated as follows:

	The minimum width/height of a page group is the maximum
	minimum width/height of all its children.

	The maximum width/height of a page group is the minimum
	maximum width/height of all its children.

	When the maximum width/height of a child in a page group is
	smaller than the minimum width/height of the page group
	(since it contains another child with big minimum width/height),
	the child be centered.

	Page groups are not limited in depth, children of a page
	group may of course be other page groups.

	If you want to have a gadget only visible under certain
	conditions, you could make a page group containing this
	gadget and an empty rectangle object.

	If you want TAB cycling for the objects in a page group,
	simply include all objects in the cycle chain (as if
	they all were visible at the same time).

    EXAMPLE
	demo program "Pages.c"

    SEE ALSO
	MUIA_Group_ActivePage
Group.mui/MUIA_Group_Rows

    NAME
	MUIA_Group_Rows -- (V4 ) [IS.], LONG

    FUNCTION
	Indicate number of rows in a two dimensional group.
	If you use this tag, the total number of children must
	be dividable by the number of rows.

	The children will be positioned in a two dimensional
	array, e.g. allowing easy creation of button fields
	(maybe for calculator).

	The children in your taglist are always read line
	by line.

	When MUI layouts two-dimensional groups, it does
	actually two layout calculations, one for the rows
	and one the columns. Parameters like weights and
	dimensions are handled this way:

	- the minimum width of a column/row is the maximum
	  minimum width of all objects in this column/row.

	- the maximum width of a column/row is the minimum
	  maximum width of all objects in this column/row.

	- the weight of a column/row is the sum of all
	  objects in this column/row.

	Actually, there is no difference if you use
	MUIA_Group_Columns or MUIA_Group_Rows.

    SEE ALSO
	MUIA_Group_Columns, MUIA_Group_Horiz
Group.mui/MUIA_Group_SameHeight

    NAME
	MUIA_Group_SameHeight -- (V4 ) [I..], BOOL

    FUNCTION
	Boolean value to indicate that all children of this
	group shall have the same height.

    BUGS
	Up to version 5 of groupclass, using MUIA_Group_SameHeight
	could make objects larger than their maximum height. This
	has been fixed for version 6.

    SEE ALSO
	MUIA_Group_SameSize, MUIA_Group_SameWidth
Group.mui/MUIA_Group_SameSize

    NAME
	MUIA_Group_SameSize -- (V4 ) [I..], BOOL

    FUNCTION
	This is a shorthand for MUIA_Group_SameWidth and
	MUIA_Group_SameHeight, it sets both of these
	attributes at once.

	Using MUIA_Group_SameSize, you won't need to think
	if your group is horizontal or vertical, both
	cases are handled automatically.

	Forcing all objects of a group to be the same size
	is e.g. useful for a row of buttons. It's visually
	more attractive when these buttons have equal sizes
	instead of being just as big as the text within.

    BUGS
	Up to version 5 of groupclass, using MUIA_Group_SameSize
	could make objects larger than their maximum size. This
	has been fixed for version 6.

    EXAMPLE

	/* three buttons, same size */

	GroupObject,
	   MUIA_Group_Horiz   , TRUE,
	   MUIA_Group_SameSize, TRUE,
	   MUIA_Group_Child   , but1,
	   MUIA_Group_Child   , but2,
	   MUIA_Group_Child   , but3,
	   End;

    SEE ALSO
	MUIA_Group_SameWidth, MUIA_Group_SameHeight
Group.mui/MUIA_Group_SameWidth

    NAME
	MUIA_Group_SameWidth -- (V4 ) [I..], BOOL

    FUNCTION
	Boolean value to indicate that all children of this
	group shall have the same width.

    BUGS
	Up to version 5 of groupclass, using MUIA_Group_SameWidth
	could make objects larger than their maximum width. This
	has been fixed for version 6.

    SEE ALSO
	MUIA_Group_SameSize, MUIA_Group_SameHeight
Group.mui/MUIA_Group_Spacing

    NAME
	MUIA_Group_Spacing -- (V4 ) [IS.], LONG

    FUNCTION
	This is a shorthand for MUIA_Group_HorizSpacing and
	MUIA_Group_VertSpacing, it sets both of these
	attributes at once.

	Using MUIA_Group_Spacing, you won't need to think
	if your group is horizontal or vertical, both
	cases are handled automatically.

	Note that setting a spacing value for a group
	overrides the user's default settings. Please
	use it only if you have a good reason.

    EXAMPLE

	/* no space between obj1 and obj2: */

	GroupObject,
	   MUIA_Group_Horiz  , TRUE,
	   MUIA_Group_Spacing, 0,
	   MUIA_Group_Child  , obj1,
	   MUIA_Group_Child  , obj2,
	   End;

    SEE ALSO
	MUIA_Group_HorizSpacing, MUIA_Group_VertSpacing
Group.mui/MUIA_Group_VertSpacing

    NAME
	MUIA_Group_VertSpacing -- (V4 ) [ISG], LONG

    FUNCTION
	Number of pixels to be inserted between vertical
	elements of a group.

	Please use this tag wisely, you will override the
	user's prefered default setting!

    SEE ALSO
	MUIA_Group_Spacing, MUIA_Group_HorizSpacing
Group.mui/MUIM_Group_ExitChange

    NAME
	MUIM_Group_ExitChange (V11)

    SYNOPSIS
	DoMethod(obj,MUIM_Group_ExitChange,);

    FUNCTION
	Terminates MUIM_Group_InitChange state.

    SEE ALSO
	MUIM_Group_InitChange
Group.mui/MUIM_Group_InitChange

    NAME
	MUIM_Group_InitChange (V11)

    SYNOPSIS
	DoMethod(obj,MUIM_Group_InitChange,);

    FUNCTION
	Prepares a group for dynamic adding/removing of objects.
	MUI 3 offers the possibility to dynamically add/remove
	children from groups, even when the window that contains
	these objects is currently open. To be able to do this,
	you must first put the group into a special "exchange"
	state by using this method. Then, you can add/remove
	children at will. If you're done, use MUIM_Group_ExitChange
	to make MUI recalculate the display.

    RESULT
	returns NULL on failure.

    EXAMPLE
	/* remove two children, add another one */

	if (DoMethod(group,MUIM_Group_InitChange))
	{
	   DoMethod(group,OM_REMMEMBER,somechild);
	   DoMethod(group,OM_REMMEMBER,somechild2);

	   DoMethod(group,OM_ADDMEMBER,somenewchild);

	   DoMethod(group,MUIM_Group_ExitChange);
	}

    SEE ALSO
	MUIM_Group_InitChange