1XtDisplayInitialize(3) XT FUNCTIONS XtDisplayInitialize(3)
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6 XtDisplayInitialize, XtOpenDisplay, XtDatabase, XtScreenDatabase,
7 XtCloseDisplay - initialize, open, or close a display
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10 #include <X11/Intrinsic.h>
11 void XtDisplayInitialize(XtAppContext app_context, Display *display,
13 const char *application_name, const char *application_class, Xr‐
14 mOptionDescRec *options, Cardinal num_options, int *argc, char
15 **argv);
16 Display *XtOpenDisplay(XtAppContext app_context, const char *dis‐
18 play_string, const char *application_name, const char *applica‐
19 tion_class, XrmOptionDescRec *options, Cardinal num_options, int
20 *argc, char **argv);
21 void XtCloseDisplay(Display *display);
23 XrmDatabase XtDatabase(Display *display);
25 XrmDatabase XtScreenDatabase(Screen* screen);
27
29 argc Specifies a pointer to the number of command line parameters.
30 argv Specifies the command line parameters.
32 app_context
34 Specifies the application context.
35 application_class
37 Specifies the class name of this application, which usually
38 is the generic name for all instances of this application.
39 application_name
41 Specifies the name of the application instance.
42 display Specifies the display. Note that a display can be in at most
44 one application context.
45 num_options
47 Specifies the number of entries in the options list.
48 options Specifies how to parse the command line for any application-
50 specific resources. The options argument is passed as a pa‐
51 rameter to XrmParseCommand. For further information, see
52 Xlib - C Language X Interface.
53 screen Specifies the screen whose resource database is to be re‐
55 turned.
56
58 The XtDisplayInitialize function builds the resource database, calls
59 the Xlib XrmParseCommand function to parse the command line, and per‐
60 forms other per display initialization. After XrmParseCommand has been
61 called, argc and argv contain only those parameters that were not in
62 the standard option table or in the table specified by the options ar‐
63 gument. If the modified argc is not zero, most applications simply
64 print out the modified argv along with a message listing the allowable
65 options. On UNIX-based systems, the application name is usually the
66 final component of argv[0]. If the synchronize resource is True for
67 the specified application, XtDisplayInitialize calls the Xlib XSynchro‐
68 nize function to put Xlib into synchronous mode for this display con‐
69 nection. If the reverseVideo resource is True, the Intrinsics exchange
70 XtDefaultForeground and XtDefaultBackground for widgets created on this
71 display. (See Section 9.6.1).
72 The XtOpenDisplay function calls XOpenDisplay the specified display
74 name. If display_string is NULL, XtOpenDisplay uses the current value
75 of the -display option specified in argv and if no display is specified
76 in argv, uses the user's default display (on UNIX-based systems, this
77 is the value of the DISPLAY environment variable).
78 If this succeeds, it then calls XtDisplayInitialize and pass it the
80 opened display and the value of the -name option specified in argv as
81 the application name. If no name option is specified, it uses the ap‐
82 plication name passed to XtOpenDisplay. If the application name is
83 NULL, it uses the last component of argv[0]. XtOpenDisplay returns the
84 newly opened display or NULL if it failed.
85 XtOpenDisplay is provided as a convenience to the application program‐
87 mer.
88 The XtCloseDisplay function closes the specified display as soon as it
90 is safe to do so. If called from within an event dispatch (for exam‐
91 ple, a callback procedure), XtCloseDisplay does not close the display
92 until the dispatch is complete. Note that applications need only call
93 XtCloseDisplay if they are to continue executing after closing the dis‐
94 play; otherwise, they should call XtDestroyApplicationContext or just
95 exit.
96 The XtDatabase function returns the fully merged resource database that
98 was built by XtDisplayInitialize associated with the display that was
99 passed in. If this display has not been initialized by XtDisplay‐
100 Initialize, the results are not defined.
101 The XtScreenDatabase function returns the fully merged resource data‐
103 base associated with the specified screen. If the screen does not be‐
104 long to a Display initialized by XtDisplayInitialize, the results are
105 undefined.
106
108 XtAppCreateShell(3), XtCreateApplicationContext(3)
109 X Toolkit Intrinsics - C Language Interface
110 Xlib - C Language X Interface
111X Version 11 libXt 1.2.1 XtDisplayInitialize(3)