NAME
XtManageChildren, XtManageChild, XtUnmanageChildren, XtUnmanageChild,
XtChangeManagedSet, XtIsManaged - manage and unmanage children
SYNTAX
typedef Widget *WidgetList;
void
XtManageChildren(WidgetList children, Cardinal
num_children);
void
XtManageChild(Widget child);
void
XtUnmanageChildren(WidgetList children, Cardinal
num_children);
void
XtUnmanageChild(Widget child);
void
XtChangeManagedSet(WidgetList unmanage_children, Cardinal
num_unmanage_children, XtDoChangeProc do_change_proc, XtPointer
client_data, WidgetList manage_children, Cardinal
num_manage_children);
Boolean
XtIsManaged(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.
- 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 XtUnmanageChildren ( unmanage_children,
num_unmanage_children).
- -
- Calls the do_change_proc 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 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_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(3), XtRealizeWidget(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface