Provided by: libmotif-dev_2.3.8-3_amd64 
NAME
XmForm — The Form widget class "XmForm" "widget class" "Form"
SYNOPSIS
#include <Xm/Form.h>
DESCRIPTION
Form is a container widget with no input semantics of its own. Constraints are placed on
children of the Form to define attachments for each of the child's four sides. These
attachments can be to the Form, to another child widget or gadget, to a relative position
within the Form, or to the initial position of the child. The attachments determine the
layout behavior of the Form when resizing occurs.
The default value for XmNinitialFocus is the value of XmNdefaultButton.
Following are some important considerations in using a Form:
• Every child must have an attachment on either the left or the right. If
initialization or XtSetValues leaves a widget without such an attachment, the result
depends upon the value of XmNrubberPositioning.
If XmNrubberPositioning is False, the child is given an XmNleftAttachment of
XmATTACH_FORM and an XmNleftOffset equal to its current x value.
If XmNrubberPositioning is True, the child is given an XmNleftAttachment of
XmATTACH_POSITION and an XmNleftPosition proportional to the current x value
divided by the width of the Form.
In either case, if the child has not been previously given an x value, its x
value is taken to be 0 (zero), which places the child at the left side of the
Form.
• If you want to create a child without any attachments, and then later (for example,
after creating and managing it, but before realizing it) give it a right attachment
through XtSetValues, you must set its XmNleftAttachment to XmATTACH_NONE at the same
time.
• The XmNresizable resource controls only whether a geometry request by the child will
be granted. It has no effect on whether the child's size can be changed because of
changes in geometry of the Form or of other children.
• Every child has a preferred width, based on geometry requests it makes (whether they
are granted or not).
• If a child has attachments on both the left and the right sides, its size is
completely controlled by the Form. It can be shrunk below its preferred width or
enlarged above it, if necessary, due to other constraints. In addition, the child's
geometry requests to change its own width may be refused.
• If a child has attachments on only its left or right side, it will always be at its
preferred width (if resizable, otherwise at is current width). This may cause it to
be clipped by the Form or by other children.
• If a child's left (or right) attachment is set to XmATTACH_SELF, its corresponding
left (or right) offset is forced to 0 (zero). The attachment is then changed to
XmATTACH_POSITION, with a position that corresponds to the x value of the child's
left (or right) edge. To fix the position of a side at a specific x value, use
XmATTACH_FORM or XmATTACH_OPPOSITE_FORM with the x value as the left (or right)
offset.
• Unmapping a child has no effect on the Form except that the child is not mapped.
• Unmanaging a child unmaps it. If no other child is attached to it, or if all
children attached to it and all children recursively attached to them are also all
unmanaged, all of those children are treated as if they did not exist in determining
the size of the Form.
• When using XtSetValues to change the XmNx resource of a child, you must
simultaneously set its left attachment to either XmATTACH_SELF or XmATTACH_NONE.
Otherwise, the request is not granted. If XmNresizable is False, the request is
granted only if the child's size can remain the same.
• A left (or right) attachment of XmATTACH_WIDGET, where XmNleftWidget (or
XmNrightWidget) is NULL, acts like an attachment of XmATTACH_FORM.
• If an attachment is made to a widget that is not a child of the Form, but an
ancestor of the widget is a child of the Form, the attachment is made to the
ancestor.
All these considerations are true of top and bottom attachments as well, with top acting
like left, bottom acting like right, y acting like x, and height acting like width.
Classes
Form inherits behavior, resources, and traits from Core, Composite, Constraint, XmManager,
and XmBulletinBoard.
The class pointer is xmFormWidgetClass.
The class name is XmForm.
New Resources
The following table defines a set of widget resources used by the programmer to specify
data. The programmer can also set the resource values for the inherited classes to set
attributes for this widget. To reference a resource by name or by class in a .Xdefaults
file, remove the XmN or XmC prefix and use the remaining letters. To specify one of the
defined values for a resource in a .Xdefaults file, remove the Xm prefix and use the
remaining letters (in either lowercase or uppercase, but include any underscores between
words). The codes in the access column indicate if the given resource can be set at
creation time (C), set by using XtSetValues (S), retrieved by using XtGetValues (G), or is
not applicable (N/A).
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RELATED
Composite(3), Constraint(3), Core(3), XmBulletinBoard(3), XmCreateForm,
XmCreateFormDialog(3), XmManager(3), XmVaCreateForm, and XmVaCreateManagedForm.
XmForm(3)