XtDisplayInitialize(3Xt) XtDisplayInitialize(3Xt)
NAME
XtDisplayInitialize, XtOpenDisplay, XtDatabase,
XtCloseDisplay - initialize, open, or close a display
SYNOPSIS
void XtToolkitInitialize()
void XtDisplayInitialize(app_context, display,
application_name, application_class, options,
num_options, argc, argv)
XtAppContext app_context;
Display *display;
String application_name;
String application_class;
XrmOptionDescRec *options;
Cardinal num_options;
Cardinal *argc;
String *argv;
Display *XtOpenDisplay(app_context, display_string,
application_name, application_class, options,
num_options, argc, argv)
XtAppContext app_context;
String display_string;
String application_name;
String application_class;
XrmOptionDescRec *options;
Cardinal num_options;
Cardinal *argc;
String *argv;
void XtCloseDisplay(display)
Display *display;
XrmDatabase XtDatabase(display)
Display *display;
ARGUMENTS
argc Specifies a pointer to the number of command
line parameters.
argv Specifies the command line parameters.
app_context
Specifies the application context.
application_class
Specifies the class name of this application,
which usually is the generic name for all
instances of this application.
application_name
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XtDisplayInitialize(3Xt) XtDisplayInitialize(3Xt)
Specifies the name of the application
instance.
display Specifies the display. Note that a display
can be in at most one application context.
num_options
Specifies the number of entries in the
options list.
options Specifies how to parse the command line for
any application-specific resources. The
options argument is passed as a parameter to
XrmParseCommand. For further information,
see the Xlib Programming Manual.
DESCRIPTION
The XtDisplayInitialize function builds the resource
database, calls the Xlib XrmParseCommand function to
parse the command line, and performs other per display
initialization. After XrmParseCommand has been called,
argc and argv contain only those parameters that were
not in the standard option table or in the table
specified by the options argument. If the modified
argc is not zero, most applications simply print out
the modified argv along with a message listing the
allowable options. On UNIX-based systems, the
application name is usually the final component of
argv[0]. If the synchronize resource is True for the
specified application, XtDisplayInitialize calls the
Xlib XSynchronize function to put Xlib into synchronous
mode for this display connection. If the reverseVideo
resource is True, the Intrinsics exchange
XtDefaultForeground and XtDefaultBackground for widgets
created on this display.
The XtOpenDisplay function calls XOpenDisplay the
specified display name. If display_string is NULL,
XtOpenDisplay uses the current value of the -display
option specified in argv and if no display is specified
in argv, uses the user's default display (on UNIX-based
systems, this is the value of the DISPLAY environment
variable).
If this succeeds, it then calls XtDisplayInitialize and
pass it the opened display and the value of the -name
option specified in argv as the application name. If
no name option is specified, it uses the application
name passed to XtOpenDisplay. If the application name
is NULL, it uses the last component of argv[0].
XtOpenDisplay returns the newly opened display or NULL
if it failed.
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XtDisplayInitialize(3Xt) XtDisplayInitialize(3Xt)
XtOpenDisplay is provided as a convenience to the
application programmer.
The XtCloseDisplay function closes the specified
display as soon as it is safe to do so. If called from
within an event dispatch (for example, a callback
procedure), XtCloseDisplay does not close the display
until the dispatch is complete. Note that applications
need only call XtCloseDisplay if they are to continue
executing after closing the display; otherwise, they
should call XtDestroyApplicationContext or just exit.
The XtDatabase function returns the fully merged
resource database that was built by XtDisplayInitialize
associated with the display that was passed in. If
this display has not been initialized by
XtDisplayInitialize, the results are not defined.
SEE ALSO
XtAppCreateShell(3Xt), XtCreateApplicationContext(3Xt)
X Toolkit Intrinsics Programming Manual
Xlib Programming Manual
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