1XtDisplayInitialize(3) XT FUNCTIONS XtDisplayInitialize(3)
2
6 XtDisplayInitialize, XtOpenDisplay, XtDatabase, XtScreenDatabase,
7 XtCloseDisplay - initialize, open, or close a display
8
10 void XtDisplayInitialize(XtAppContext app_context, Display *display,
11 String application_name, String application_class, XrmOptionDe‐
12 scRec *options, Cardinal num_options, int *argc, String *argv);
13 Display *XtOpenDisplay(XtAppContext app_context, String display_string,
15 String application_name, String application_class, XrmOptionDe‐
16 scRec *options, Cardinal num_options, int *argc, String *argv);
17 void XtCloseDisplay(Display *display);
19 XrmDatabase XtDatabase(Display *display);
21 XrmDatabase XtScreenDatabase(Screen* screen);
23
25 argc Specifies a pointer to the number of command line parameters.
26 argv Specifies the command line parameters.
28 app_context
30 Specifies the application context.
31 application_class
33 Specifies the class name of this application, which usually
34 is the generic name for all instances of this application.
35 application_name
37 Specifies the name of the application instance.
38 display Specifies the display. Note that a display can be in at most
40 one application context.
41 num_options
43 Specifies the number of entries in the options list.
44 options Specifies how to parse the command line for any application-
46 specific resources. The options argument is passed as a
47 parameter to XrmParseCommand. For further information, see
48 Xlib - C Language X Interface.
49 screen Specifies the screen whose resource database is to be
51 returned.
52
54 The XtDisplayInitialize function builds the resource database, calls
55 the Xlib XrmParseCommand function to parse the command line, and per‐
56 forms other per display initialization. After XrmParseCommand has been
57 called, argc and argv contain only those parameters that were not in
58 the standard option table or in the table specified by the options
59 argument. If the modified argc is not zero, most applications simply
60 print out the modified argv along with a message listing the allowable
61 options. On UNIX-based systems, the application name is usually the
62 final component of argv[0]. If the synchronize resource is True for
63 the specified application, XtDisplayInitialize calls the Xlib XSynchro‐
64 nize function to put Xlib into synchronous mode for this display con‐
65 nection. If the reverseVideo resource is True, the Intrinsics exchange
66 XtDefaultForeground and XtDefaultBackground for widgets created on this
67 display. (See Section 9.6.1).
68 The XtOpenDisplay function calls XOpenDisplay the specified display
70 name. If display_string is NULL, XtOpenDisplay uses the current value
71 of the -display option specified in argv and if no display is specified
72 in argv, uses the user's default display (on UNIX-based systems, this
73 is the value of the DISPLAY environment variable).
74 If this succeeds, it then calls XtDisplayInitialize and pass it the
76 opened display and the value of the -name option specified in argv as
77 the application name. If no name option is specified, it uses the
78 application name passed to XtOpenDisplay. If the application name is
79 NULL, it uses the last component of argv[0]. XtOpenDisplay returns the
80 newly opened display or NULL if it failed.
81 XtOpenDisplay is provided as a convenience to the application program‐
83 mer.
84 The XtCloseDisplay function closes the specified display as soon as it
86 is safe to do so. If called from within an event dispatch (for exam‐
87 ple, a callback procedure), XtCloseDisplay does not close the display
88 until the dispatch is complete. Note that applications need only call
89 XtCloseDisplay if they are to continue executing after closing the dis‐
90 play; otherwise, they should call XtDestroyApplicationContext or just
91 exit.
92 The XtDatabase function returns the fully merged resource database that
94 was built by XtDisplayInitialize associated with the display that was
95 passed in. If this display has not been initialized by XtDisplay‐
96 Initialize, the results are not defined.
97 The XtScreenDatabase function returns the fully merged resource data‐
99 base associated with the specified screen. If the screen does not
100 belong to a Display initialized by XtDisplayInitialize, the results are
101 undefined.
102
104 XtAppCreateShell(3), XtCreateApplicationContext(3)
105 X Toolkit Intrinsics - C Language Interface
106 Xlib - C Language X Interface
107X Version 11 libXt 1.1.4 XtDisplayInitialize(3)