XtManageChildren(3Xt) XT FUNCTIONS XtManageChildren(3Xt)
NAME
XtManageChildren, XtManageChild, XtUnmanageChildren, XtUnmanageChild,
XtChangeManagedSet, XtIsManaged - manage and unmanage children
SYNTAX
typedef Widget *WidgetList;
void XtManageChildren(children, num_children)
WidgetList children;
Cardinal num_children;
void XtManageChild(child)
Widget child;
void XtUnmanageChildren(children, num_children)
WidgetList children;
Cardinal num_children;
void XtUnmanageChild(child)
Widget child;
void XtChangeManagedSet(unmanage_children, num_unmanage_children,
manage_children, num_manage_children, post_unmanage_pre_manage_hook,
client_data)
WidgetList unmanage_children;
Cardinal num_unmanage_children;
WidgetList manage_children;
Cardinal num_manage_children;
XtCSMProc post_unmanage_pre_manage_hook;
XtPointer client_data;
Boolean XtIsManaged(widget)
Widget widget
ARGUMENTS
child Specifies the child.
children Specifies a list of child widgets.
num_children
Specifies the number of children.
widget Specifies the widget.
manage_children
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.
post_unmanage_pre_manage_hook
Specifies the post unmanage, pre manage hook procedure to invoke.
client_data
Specifies the client data to be passed to the hook precedure.
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; other-
wise, 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 indepen-
dent 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; other-
wise, for each unique child on the list, XtUnmanageChildren performs
the following:
- Ignores the child if it already is unmanaged or is being des-
troyed 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
post_unmanage_pre_manage_hook procedure then XtChangeManagedSet per-
forms the following:
- Calls XtUnmanageChildren (unmanage_children,
num_unmanage_children).
- Calls the post_unmanage_pre_manage_hook specified.
- 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 Compo-
siteClassExtension is defined, and XtChangeManagedSetwas
post_unmanage_pre_manage_hook procedure, then the following is per-
formed:
- 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 post_unmanage_pre_manage_hook procdedure 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_managed
True.
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