XtManageChildren(3XtX Version 11 (Release 6.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.
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XtManageChildren(3XtX Version 11 (Release 6.XtManageChildren(3Xt)
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:
o Issues an error if the children do not all have the
same parent or if the parent is not a subclass of
compositeWidgetClass.
o 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.
o 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
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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:
o Issues an error if the children do not all have the
same parent or if the parent is not a subclass of
compositeWidgetClass.
o 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.
o 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:
o 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.
o Returns immediately if the common parent is being
destroyed.
o 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 performs the following:
- Calls XtUnmanageChildren (unmanage_children,
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num_unmanage_children).
- Calls the post_unmanage_pre_manage_hook specified.
- Calls XtManageChildren (manage_children,
num_manage_children) and then returns immediately.
o 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 post_unmanage_pre_manage_hook
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 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
o 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
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