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.
Attribute Ver ISG Type
----------------------------------- --- --- --------------------
MUIA_Group_ActivePage V5 ISG LONG
MUIA_Group_Child V4 I.. Object *
MUIA_Group_ChildList V4 ..G struct List *
MUIA_Group_Columns V4 IS. LONG
MUIA_Group_Horiz V4 I.. BOOL
MUIA_Group_HorizSpacing V4 ISG LONG
MUIA_Group_LayoutHook V11 I.. struct Hook *
MUIA_Group_PageMode V5 I.. BOOL
MUIA_Group_Rows V4 IS. LONG
MUIA_Group_SameHeight V4 I.. BOOL
MUIA_Group_SameSize V4 I.. BOOL
MUIA_Group_SameWidth V4 I.. BOOL
MUIA_Group_Spacing V4 IS. LONG
MUIA_Group_VertSpacing V4 ISG LONG
Method Ver
----------------------------------- ---
MUIM_Group_ExitChange V11
MUIM_Group_InitChange V11
MUIM_Group_Sort V4
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
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
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
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
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
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
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()
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
a 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
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
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
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
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
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
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
NAME
MUIM_Group_ExitChange (V11)
SYNOPSIS
DoMethod(obj,MUIM_Group_ExitChange);
FUNCTION
Terminates MUIM_Group_InitChange state.
SEE ALSO
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_ExitChange
NAME
MUIM_Group_Sort (V4 )
SYNOPSIS
DoMethod(obj,MUIM_Group_Sort,Object *obj[1]);
FUNCTION
This method rearranges the order of the children stored in
a group object.
INPUTS
- all objects of the group, terminated by NULL.
RESULT
The result value is currently undefined.
NOTES
You must always pass all objects of your group!
EXAMPLE
hgr = HGroup,
Child, o1 = ...,
Child, o2 = ...,
Child, o3 = ...,
Child, o4 = ...,
End;
DoMethod(hgr,MUIM_Group_Sort,o4,o3,o2,o1,NULL);
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