Specifies the list of widget children to add to the managed set.
num_manage_children
Specifies the number of entries in the manage_children list.
unmanage_children
Specifies the list of widget children to remove from the managed set.
num_unmanage_children
Specifies the number of entries in the unmanage_children list.
do_change_proc
Specifies the post unmanage, pre manage hook procedure to invoke.
client_data
Specifies the client data to be passed to the hook procedure.
DESCRIPTION
The
XtManageChildren
function performs the following:
*
Issues an error if the children do not all have the same parent or
if the parent is not a subclass of
compositeWidgetClass.
*
Returns immediately if the common parent is being destroyed;
otherwise, for each unique child on the list,
XtManageChildren
ignores the child if it already is managed or is being destroyed
and marks it if not.
*
If the parent is realized and after all children have been marked,
it makes some of the newly managed children viewable:
-
Calls the change_managed routine of the widgets' parent.
-
Calls
XtRealizeWidget
on each previously unmanaged child that is unrealized.
-
Maps each previously unmanaged child that has map_when_managed
True.
Managing children is independent of the ordering of children and
independent of creating and deleting children.
The layout routine of the parent
should consider children whose managed field is
True
and should ignore all other children.
Note that some composite widgets, especially fixed boxes, call
XtManageChild
from their insert_child procedure.
If the parent widget is realized,
its change_managed procedure is called to notify it
that its set of managed children has changed.
The parent can reposition and resize any of its children.
It moves each child as needed by calling
XtMoveWidget,
which first updates the x and y fields and then calls
XMoveWindow
if the widget is realized.
The
XtManageChild
function constructs a
WidgetList
of length one and calls
XtManageChildren.
The
XtUnmanageChildren
function performs the following:
*
Issues an error if the children do not all have the same parent
or if the parent is not a subclass of
compositeWidgetClass.
*
Returns immediately if the common parent is being destroyed;
otherwise, for each unique child on the list,
XtUnmanageChildren
performs the following:
-
Ignores the child if it already is unmanaged or is being destroyed
and marks it if not.
-
If the child is realized,
it makes it nonvisible by unmapping it.
*
Calls the change_managed routine of the widgets' parent
after all children have been marked
if the parent is realized.
XtUnmanageChildren
does not destroy the children widgets.
Removing widgets from a parent's managed set is often a temporary banishment,
and, some time later, you may manage the children again.
The
XtUnmanageChild
function constructs a widget list
of length one and calls
XtUnmanageChildren.
The
XtChangeManagedSet
function performs the following:
*
Issues an error if the widgets specified in the manage_children
and the unmanage_children lists to no all have the same parent, or
if that parent is not a subclass of compositeWidgetClass.
*
Returns immediately if the common parent is being destroyed.
*
If no
CompositeClassExtension
is defined, or a
CompositeClassExtension
is defined but with an allows_change_managed_set field with a
value of
False,
and
XtChangeManagedSet
was invoked with a non-NULL do_change_proc procedure
then
XtChangeManagedSet
performs the following:
Calls
XtManageChildren
(manage_children, num_manage_children) and then returns
immediately.
*
Otherwise, if a
CompositeClassExtension
is defined with an allows_change_managed_set field with a value of
True,
or if no
CompositeClassExtension
is defined, and
XtChangeManagedSetwas
do_change_proc procedure, then the following is
performed:
-
For each child on the unmanage_children list; if the child is
already unmanaged or is being destroyed it is ignored, otherwise it
is marked as being unmanaged and if it is realized it is made nonvisible
by being unmapped.
-
If the do_change_proc procedure is non-NULL then
it is invoked as specified.
-
For each child on the manage_children list; if the child is
already managed or it is being destroyed it is ignored, otherwise it
is marked as managed
*
If the parent is realized and after all children have been marked, the
change_managed method of the parent is invoked and subsequently some
of the newly managed children are made viewable by:
-
Calling
XtRealizeWidget
on each of the previously unmanaged child that is unrealized.
-
Mapping each previously unmanaged child that has map_when_managedTrue.
The
XtIsManaged
function returns
True
if the specified widget is of class RectObj or any subclass thereof and
is managed, or
False
otherwise.
SEE ALSO
XtMapWidget(3Xt),
XtRealizeWidget(3Xt)
X Toolkit Intrinsics - C Language Interface Xlib - C Language X Interface