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XtDisplayInitialize(3Xt)
X11R6
NAME
  XtDisplayInitialize, XtOpenDisplay, XtDatabase, XtScreenDatabase,
  XtCloseDisplay - initialize, open, or close a display

SYNOPSIS
  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;
	  int *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;
	  int *argc;
	  String *argv;

  void XtCloseDisplay(display)
	  Display *display;

  XrmDatabase XtDatabase(display)
	  Display *display;

  XrmDatabase XtScreenDatabase(screen)
	  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.

NOTES
  In internationalized applications, the XtSetLanguageProc function sets the
  language procedure for XtDisplayInitialize.  In such applications, the
  catopen call must execute following the call to XtDisplayInitialize.
  (Remember that XtAppInitialize indirectly calls XtDisplayInitialize through
  XtOpenDisplay).

  If the catopen call executes after XtSetLanguageProc but before the call
  that initializes the display, the application does not access translated
  messages when these are available for the language setting.

SEE ALSO
  catopen(3), XtAppCreateShell(3Xt), XtAppInitialize(3Xt),
  XtCreateApplicationContext(3Xt)

  X Toolkit Intrinsics -- C Language Interface

  Xlib -- C Language X Interface

Index for Section 3Xt

Alphabetical listing for X

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