The specific input method to which this call will be routed is identified on the basis of the current locale. XOpenIM will identify a default input method corresponding to the current locale. That default can be modified using XSetLocaleModifiers for the input method modifier.
The db argument is the resource database to be used by the input method for looking up resources that are private to the input method. It is not intended that this database be used to look up values that can be set as IC values in an input context. If db is NULL, no database is passed to the input method.
The res_name and res_class arguments specify the resource name and class of the application. They are intended to be used as prefixes by the input method when looking up resources that are common to all input contexts that may be created for this input method. The characters used for resource names and classes must be in the X Portable Character Set. The resources looked up are not fully specified if res_name or res_class is NULL.
The res_name and res_class arguments are not assumed to exist beyond the call to XOpenIM. The specified resource database is assumed to exist for the lifetime of the input method.
XOpenIM returns NULL if no input method could be opened.
The XCloseIM function closes the specified input method.
The XSetIMValues function presents a variable argument list programming interface for setting attributes of the specified input method. It returns NULL if it succeeds; otherwise, it returns the name of the first argument that could not be set. Xlib does not attempt to set arguments from the supplied list that follow the failed argument; all arguments in the list preceding the failed argument have been set correctly.
The XGetIMValues function presents a variable argument list programming interface for querying properties or features of the specified input method. This function returns NULL if it succeeds; otherwise, it returns the name of the first argument that could not be obtained.
Each XIM value argument (following a name) must point to a location where the XIM value is to be stored. That is, if the XIM value is of type T, the argument must be of type T*. If T itself is a pointer type, then XGetIMValues allocates memory to store the actual data, and the client is responsible for freeing this data by calling XFree with the returned pointer.
The XDisplayOfIM function returns the display associated with the specified input method.
The XLocaleOfIM function returns the locale associated with the specified input method.
The XRegisterIMInstantiateCallback function registers a callback to be invoked whenever a new input method becomes available for the specified display that matches the current locale and modifiers.
The function returns True if it succeeds; otherwise, it returns False.
The XUnregisterIMInstantiateCallback function removes an input method instantiation callback previously registered. The function returns True if it succeeds; otherwise, it returns False.