XtSetValues()XtSetValues()Name
XtSetValues - set widget resources from an argument list.
Synopsis
void XtSetValues(object, args, num_args)
Widget object;
ArgList args;
Cardinal num_args;
Inputs
object Specifies the object whose resources are to be modified; may
be of class Object or any subclass thereof.
args Specifies an array of name/value pairs that name the
resources to be set and specify their new values.
num_args Specifies the number of elements in args.
DescriptionXtSetValues() sets the resources of object named in args to the values
specified in args. Once these values are copied from args into the
widget, the widget's set_values() methods are called which gives the
widget an opportunity to check the new values for consistency, update
private widget fields to reflect the new state of the resources, or
even to undo some of the changes. The "Background" section below
explains the details of this
process.
UsageXtSetValues() is the primary way for a user to modify widget resources
of a widget once that widget has been created. See XtSetArg() for
information on setting resource names and values into an ArgList.
To set resources specified in a NULL-terminated variable-length argu‐
ment list rather than an ArgList, use XtVaSetValues(). This is often a
more convenient function to use because it does not require you to ini‐
tialize an ArgList array.
Note that not all widget resources may be set with XtSetValues(). Some
may only be set when a widget is created, and others should be treated
as read-only resources. The documentation for the particular widget
should indicate which resources are not settable with XtSetValues().
To query the values of named resources, use XtGetValues() or XtVaGet‐
Values().
Example
You can use XtSetValues() as follows to set widget resources:
Arg args[10];
int i;
XFontStruct *bold_font;
Pixel bright_red;
/*
* set up an argument list, assuming we've already obtained
* the font and the color from somewhere else.
*/
i = 0;
XtSetArg(args[i], XtNlabel, "Quit"); i++;
XtSetArg(args[i], XtNfont, bold_font); i++;
XtSetArg(args[i], XtNforeground, bright_red); i++;
/* set the values */
XtSetValues(s, args, i);
BackgroundXtSetValues() starts with the resources specified for the Object class
fields and proceeds down the subclass chain to the object. At each
stage, it replaces the object resource fields with any values specified
in the argument list. XtSetValues() then calls the set_values() meth‐
ods for the object in superclass-to-subclass order. If the object has
any non-NULL set_values_hook() methods, these are called immediately
after the corresponding set_values() method. This procedure permits
subclasses to set subpart data via XtSetValues(). (Note, though, that
as of Release 4, this can be done directly from the set_values()
method.)
If the class of the object's parent is a subclass of constraintWidget‐
Class, XtSetValues() also updates the object's constraints. It starts
with the constraint resources specified for constraintWidgetClass and
proceeds down the subclass chain to the parent's class. At each stage,
it replaces the constraint resource fields with any values specified in
the argument list. It then calls the constraint set_values() methods
from constraintWidgetClass down to the parent's class. The constraint
set_values() methods are called with widget arguments, as for all
set_values() methods, not just the constraint records, so that they can
make adjustments to the desired values based on full information about
the widget. Any arguments specified that do not match a resource list
entry are silently ignored.
If the object is of a subclass of RectObj, XtSetValues() determines if
a geometry request is needed by comparing the old object to the new
object. If any geometry changes are required, XtSetValues() restores
the original geometry and makes the request on behalf of the widget.
If the geometry manager returns XtGeometryYes, XtSetValues() calls the
object's resize() method. If the geometry manager returns XtGeometry‐
Done, XtSetValues() continues, as the object's resize procedure should
have been called by the geometry manager. If the geometry manager
returns XtGeometryNo, XtSetValues() ignores the geometry request and
continues. If the geometry manager returns XtGeometryAlmost, XtSetVal‐
ues() calls the set_values_almost() method, which determines what
should be done. XtSetValues() then repeats this process, deciding once
more whether the geometry manager should be called.
Finally, if any of the set_values() methods returned True, and the wid‐
get is realized, XtSetValues() causes the widget's expose procedure to
be invoked by calling XClearArea() on the widget's window.
Structures
Arg is defined as follows:
typedef struct {
String name;
XtArgVal value;
} Arg, *ArgList;
See AlsoXtGetValues(1), XtSetArg(1), XtVaGetValues(1), XtVaSetValues(1),
set_values(4), set_values_almost(4), set_values_hook(4).
Xt - Resource Management XtSetValues()
