NAME

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

SYNTAX

       #include <X11/Intrinsic.h>

       void XtDisplayInitialize(XtAppContext app_context, Display *display, const char
              *application_name, const char *application_class, XrmOptionDescRec *options,
              Cardinal num_options, int *argc, char **argv);

       Display *XtOpenDisplay(XtAppContext app_context, const char *display_string, const char
              *application_name, const char *application_class, XrmOptionDescRec *options,
              Cardinal num_options, int *argc, char **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 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.  (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 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.

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

SEE ALSO

       XtAppCreateShell(3), XtCreateApplicationContext(3)
       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface