XtDisplayInitialize(3)

NAME

       XtDisplayInitialize, XtOpenDisplay, XtDatabase, XtScreenDatabase,
       XtCloseDisplay - initialize, open, or close a display

SYNTAX

       void XtDisplayInitialize(XtAppContext app_context, Display *display,
              String application_name, String application_class, XrmOptionDe-
              scRec *options, Cardinal num_options, int *argc, String *argv);

       Display *XtOpenDisplay(XtAppContext app_context, String display_string,
              String application_name, String application_class, XrmOptionDe-
              scRec *options, Cardinal num_options, int *argc, String *argv);

       void XtCloseDisplay(Display *display);

       XrmDatabase XtDatabase(Display *display);

       XrmDatabase XtScreenDatabase(Screen* screen);

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
                 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
                 Xlib - C Language X Interface.

       screen    Specifies the screen whose resource database is to be
                 returned.

DESCRIPTION

       The XtDisplayInitialize function builds the resource database, calls
       the Xlib XrmParseCommand function to parse the command line, and per-
       forms 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 XSynchro-
       nize function to put Xlib into synchronous mode for this display con-
       nection.  If the reverseVideo resource is True, the Intrinsics exchange
       XtDefaultForeground and XtDefaultBackground for widgets created on this
       display.  (See Section 9.6.1).

       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.

       XtOpenDisplay is provided as a convenience to the application program-
       mer.

       The XtCloseDisplay function closes the specified display as soon as it
       is safe to do so.  If called from within an event dispatch (for exam-
       ple, 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 dis-
       play; 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 XtDisplay-
       Initialize, the results are not defined.

       The XtScreenDatabase function returns the fully merged resource data-
       base associated with the specified screen. If the screen does not
       belong to a Display initialized by XtDisplayInitialize, the results are
       undefined.

XtDisplayInitialize(3)

NAME

SYNTAX

ARGUMENTS

DESCRIPTION

SEE ALSO