XmForm(3) LessTif Manuals XmForm(3)NAMEXmForm - Motif-compatible form widget container
SYNOPSIS
#include <Xm/Form.h>
XmForm
XmCreateForm
DESCRIPTIONXmForm is a widget which allows you to specify complicated geometries.
The widget is capable of aligning children widgets with reference to
each other. Widgets can be linked to each other's positions, hooked to
a fixed place, or hooked to the form's edges. Positioning can be rela‐
tive as well as absolute.
The algorithm used to lay out the children is an iterative one. In
development versions of LessTif, the amount of iterations that the wid‐
get supports before it wants to have reached a steady state is 200.
OSF/Motif® uses a much higher number than this; if the low number in
LessTif gives you trouble (it generates a warning message mentioning
"bailout") then either the number is too low or you've discovered a
bug.
X RESOURCES
Name Class Type Default Access
─────────────────────────────────────────────────────────────────────────────────────
XmNmarginWidth XmCMarginWidth HorizontalDimension 0 CSG
XmNmarginHeight XmCMarginHeight VerticalDimension 0 CSG
XmNhorizontalSpacing XmCSpacing HorizontalDimension 0 CSG
XmNverticalSpacing XmCSpacing VerticalDimension 0 CSG
XmNfractionBase XmCMaxValue Int 100 CSG
XmNrubberPositioning XmCRubberPositioning Boolean False CSG
XmNfractionBase is the resource that allows you to specify the refer‐
ence value relative to which values for the constraint resource XmNpo‐
sition are to be used. The default, 100, allows you to specify e.g. 50
to mean that some widget edge should be positioned at 50% of the form's
width (or height).
XmNrubberPositioning is a boolean which determines the default layout
if some of the constraint resources aren't set for children of XmForm.
In the default case (False), children widgets for which the left or top
sides haven't been specified, default their attachment to XmAT‐
TACH_FORM. This means the children will be in the upper left side of
the form. In the other case, the children widgets's left or top
attachments will default to XmATTACH_SELF.
XmNmarginWidth
XmNmarginHeight
XmNhorizontalSpacing
XmNverticalSpacing
CONSTRAINT RESOURCES
The constraint resources for XmForm allow us to specify the layout of
children of the form. These resources should not be set on the form,
they should be set on the children. They don't work unless the parent
of a widget is an XmForm, they also don't work if the widget is a
grandchild of XmForm.
The latter is a mistake often made in the case of scrolled widgets.
Functions such as XmCreateScrolledText create two (or more) widgets,
and return a grandchild of Form if they are called with the form as
parent. In such case, constraint resources should be set on the parent
of the widget returned by XmCreateScrolledText (or similar).
Name Class Type Default Access
───────────────────────────────────────────────────────────────────────
XmNtopAttachment XmCAttachment unsigned char dynamic CSG
XmNbottomAttachment XmCAttachment unsigned char dynamic CSG
XmNleftAttachment XmCAttachment unsigned char dynamic CSG
XmNrightAttachment XmCAttachment unsigned char dynamic CSG
XmNtopWidget XmCWidget Widget NULL CSG
XmNbottomWidget XmCWidget Widget NULL CSG
XmNleftWidget XmCWidget Widget NULL CSG
XmNrightWidget XmCWidget Widget NULL CSG
XmNtopPosition XmCPosition int 0 CSG
XmNbottomPosition XmCPosition int 0 CSG
XmNleftPosition XmCPosition int 0 CSG
XmNrightPosition XmCPosition int 0 CSG
XmNtopOffset XmCOffset int 0 CSG
XmNbottomOffset XmCOffset int 0 CSG
XmNleftOffset XmCOffset int 0 CSG
XmNrightOffset XmCOffset int 0 CSG
XmNresizable XmCBoolean Boolean True CSG
XmNresizable specifies whether this widget can resize itself, if the
geometry request doesn't conflict with attachments. An example of this
is a XmLabel widget which modifies its XmNlabelString, which causes it
to try to resize itself. If XmNresizable is set to False in such a
case, expensive geometry calculations can be avoided.
XmNtopAttachment is the method of attachment for the child's top side
XmNtopWidget is the ID of the widget or gadget that serves as attach‐
ment point for the top of this child. For this to work, XmNtopAttach‐
ment must be set to XmATTACH_WIDGET or to XmATTACH_OPPOSITE_WIDGET.
XmNtopPosition used in conjunction with XmNfractionBase allows you to
calculate the position of the top of a child widget relative to the top
of the Form. This resource only works if XmNtopAttachment has been set
to XmATTACH_POSITION. A position can be a negative number, which
allows you to position a child widget in a place which is either par‐
tially or completely invisible. Values larger than the value of XmN‐
fractionBase, or close to it, have similar effect.
XmNtopOffset is the distance between the child's top edge and the
object it is attached to. This may be the form (XmATTACH_FORM) or
another widget (XmATTACH_WIDGET or XmATTACH_OPPOSITE_WIDGET). In the
latter case (XmATTACH_OPPOSITE_WIDGET), the offset is relative to the
other widget's top. In the other cases, the offset is relative to the
form's top or to the other widget's bottom edge.
As with XmNtopPosition, values can be specified which are either nega‐
tive or large, to position the child widget at a place where it is
either partially or completely invisible.
CLASS HIERARCHYObject(3)Rect(3)UnNamedObj(3)Core(3)Composite(3)Constraint(3)XmManager(3)XmBulletinBoard(3)XmForm(3)CALLBACKSXmForm only has callbacks inherited from its superclasses.
CONVENIENCE FUNCTIONSSEE ALSOLessTif Project April 1998 XmForm(3)
