UIL(file formats) UIL(file formats)
NAME [Toc] [Back]
UIL - The user interface language file format
SYNOPSIS [Toc] [Back]
MODULE module_name
[ NAMES = CASE_INSENSITIVE | CASE_SENSITIVE ]
[ CHARACTER_SET = character_set ]
[ OBJECTS = { widget_name = GADGET | WIDGET; [...] } ]
{ [
[ value_section ] |
[ procedure_section ] |
[ list_section ] |
[ object_section ] |
[ identifier_section ]
[ ... ]
] }
END MODULE;
DESCRIPTION [Toc] [Back]
The UIL language is used for describing the initial state of a user
interface for a widget based application. UIL describes the widgets
used in the interface, the resources of those widgets, and the
callbacks of those widgets. The UIL file is compiled into a UID file
using the command uil or by the callable compiler Uil(). The contents
of the compiled UID file can then be accessed by the various Motif
Resource Management (MRM) functions from within an application
program.
The UID file is independent of the platform on which the Motif program
will eventually be run. In other words, the same UID file can be used
on any system that can run Motif.
File [Toc] [Back]
A UIL file consists of a single complete module, described in the
syntax description above, or, if the file is to be included in a
larger UIL file, one complete "section," as described below. UIL uses
five different kinds of sections: value, procedure, list, object, and
identifier.
UIL is a free-form language. This means that high-level constructs
such as object and value declarations do not need to begin in any
particular column and can span any number of lines. Low-level
constructs such as keywords and punctuation characters can also begin
in any column; however, except for string literals and comments, they
cannot span lines.
The UIL compiler accepts input lines up to 132 characters in length.
MODULE module_name
The name by which the UIL module is known in the UID file.
This name is stored in the UID file for later use in the
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retrieval of resources by the MRM. This name is always
stored in uppercase in the UID file.
NAMES = CASE_INSENSITIVE | CASE_SENSITIVE
Indicates whether names should be treated as case sensitive
or case insensitive. The default is case sensitive. The
case-sensitivity clause should be the first clause in the
module header, and in any case must precede any statement
that contains a name. If names are case sensitive in a UIL
module, UIL keywords in that module must be in lowercase.
Each name is stored in the UIL file in the same case as it
appears in the UIL module. If names are case insensitive,
then keywords can be in uppercase, lowercase, or mixed case,
and the uppercase equivalent of each name is stored in the
UID file.
CHARACTER_SET = character_set
Specifies the default character set for string literals in
the module that do not explicitly set their character set.
The default character set, in the absence of this clause is
the codeset component of the LANG environment variable, or
the value of XmFALLBACK_CHARSET if LANG is not set or has no
codeset component. The value of XmFALLBACK_CHARSET is
defined by the UIL supplier, but is usually ISO8859-1
(equivalent to ISO_LATIN1). Use of this clause turns off
all localized string literal processing turned on by the
compiler flag -s or the Uil_command_type data structure
element use_setlocale_flag.
OBJECTS = { widget_name = GADGET | WIDGET; }
Indicates whether the widget or gadget form of the control
specified by widget_name is used by default. By default the
widget form is used, so the gadget keyword is usually the
only one used. The specified control should be one that has
both a widget and gadget version: XmCascadeButton, XmLabel,
XmPushButton, XmSeparator, and XmToggleButton. The form of
more than one control can be specified by delimiting them
with semicolons. The gadget or widget form of an instance
of a control can be specified with the GADGET and WIDGET
keywords in a particular object declaration.
value_section
Provides a way to name a value expression or literal. The
value name can then be referred to by declarations that
occur elsewhere in the UIL module in any context where a
value can be used. Values can be forward referenced. Value
sections are described in more detail later in the reference
page.
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procedure_section
Defines the callback routines used by a widget and the
creation routines for user-defined widgets. These
definitions are used for error checking. Procedure sections
are described in more detail later in the reference page.
list_section
Provides a way to group together a set of arguments,
controls (children), callbacks, or procedures for later use
in the UIL module. Lists can contain other lists, so that
you can set up a hierarchy to clearly show which arguments,
controls, callbacks, and procedures are common to which
widgets. List sections are described in more detail later
in the reference page.
object_section
Defines the objects that make up the user interface of the
application. You can reference the object names in
declarations that occur elsewhere in the UIL module in any
context where an object name can be used (for example, in a
controls list, as a symbolic reference to a widget ID, or as
the tag_value argument for a callback procedure). Objects
can be forward referenced. Object sections are described in
more detail later in the reference page.
identifier_section
Defines a run-time binding of data to names that appear in
the UIL module. Identifier sections are described in more
detail later in the reference page.
The UIL file can also contain comments and include directives, which
are described along with the main elements of the UIL file format in
the following sections.
Comments [Toc] [Back]
Comments can take one of two forms, as follows:
+ The comment is introduced with the sequence /* followed by the
text of the comment and terminated with the sequence */. This
form of comment can span multiple source lines.
+ The comment is introduced with an ! (exclamation point),
followed by the text of the comment and terminated by the end of
the source line.
Neither form of comment can be nested.
Value sections [Toc] [Back]
A value section consists of the keyword VALUE followed by a sequence
of value declarations. It has the following syntax:
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VALUE value_name : [ EXPORTED | PRIVATE ] value_expression | IMPORTED
value_type ;
Where value_expression is assigned to value_name or a value_type is
assigned to an imported value name. A value declaration provides a
way to name a value expression or literal. The value name can be
referred to by declarations that occur later in the UIL module in any
context where a value can be used. Values can be forward referenced.
EXPORTED A value that you define as exported is stored in the UID
file as a named resource, and therefore can be referenced by
name in other UID files. When you define a value as
exported, MRM looks outside the module in which the exported
value is declared to get its value at run time.
PRIVATE A private value is a value that is not imported or exported.
A value that you define as private is not stored as a
distinct resource in the UID file. You can reference a
private value only in the UIL module containing the value
declaration. The value or object is directly incorporated
into anything in the UIL module that references the
declaration.
IMPORTED A value that you define as imported is one that is defined
as a named resource in a UID file. MRM resolves this
declaration with the corresponding exported declaration at
application run time.
By default, values and objects are private. The following is a list
of the supported value types in UIL:
+ ANY
+ ARGUMENT
+ BOOLEAN
+ COLOR
+ COLOR_TABLE
+ COMPOUND_STRING
+ FLOAT
+ FONT
+ FONT_TABLE
+ FONTSET
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+ ICON
+ INTEGER
+ INTEGER_TABLE
+ KEYSYM
+ REASON
+ SINGLE_FLOAT
+ STRING
+ STRING_TABLE
+ TRANSLATION_TABLE
+ WIDE_CHARACTER
+ WIDGET
Procedure sections [Toc] [Back]
A procedure section consists of the keyword PROCEDURE followed by a
sequence of procedure declarations. It has the following syntax:
PROCEDURE
procedure_name [ ( [ value_type ]) ];
Use a procedure declaration to declare
+ A routine that can be used as a callback routine for a widget
+ The creation function for a user-defined widget
You can reference a procedure name in declarations that occur later in
the UIL module in any context where a procedure can be used.
Procedures can be forward referenced. You cannot use a name you used
in another context as a procedure name.
In a procedure declaration, you have the option of specifying that a
parameter will be passed to the corresponding callback routine at run
time. This parameter is called the callback tag. You can specify the
data type of the callback tag by putting the data type in parentheses
following the procedure name. When you compile the module, the UIL
compiler checks that the argument you specify in references to the
procedure is of this type. Note that the data type of the callback tag
must be one of the valid UIL data types. You can use a widget as a
callback tag, as long as the widget is defined in the same widget
hierarchy as the callback, that is they have a common ancestor that is
in the same UIL hierarchy.
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The following list summarizes how the UIL compiler checks argument
type and argument count, depending on the procedure declaration.
No parameters
No argument type or argument count checking occurs. You can
supply either 0 or one arguments in the procedure reference.
( ) Checks that the argument count is 0 (zero).
(ANY) Checks that the argument count is 1. Does not check the
argument type. Use the ANY type to prevent type checking on
procedure tags.
(type) Checks for one argument of the specified type.
(class_name)
Checks for one widget argument of the specified widget
class.
While it is possible to use any UIL data type to specify the type of a
tag in a procedure declaration, you must be able to represent that
data type in the programming language you are using. Some data types
(such as integer, Boolean, and string) are common data types
recognized by most programming languages. Other UIL data types (such
as string tables) are more complicated and may require that you set up
an appropriate corresponding data structure in the application in
order to pass a tag of that type to a callback routine.
You can also use a procedure declaration to specify the creation
function for a user-defined widget. In this case, you specify no
formal parameters. The procedure is invoked with the standard three
arguments passed to all widget creation functions. (See the Motif
Toolkit documentation for more information about widget creation
functions.)
List sections [Toc] [Back]
A list section consists of the keyword LIST followed by a sequence of
list declarations. It has the following syntax:
LIST
list_name: { list_item; [...] }
[...]
You can also use list sections to group together a set of arguments,
controls (children), callbacks, or procedures for later use in the UIL
module. Lists can contain other lists, so that you can set up a
hierarchy to clearly show which arguments, controls, callbacks, and
procedures are common to which widgets. You cannot mix the different
types of lists; a list of a particular type cannot contain entries of
a different list type or reference the name of a different list type.
A list name is always private to the UIL module in which you declare
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the list and cannot be stored as a named resource in a UID file.
The additional list types are described in the following sections.
Arguments List Structure [Toc] [Back]
An arguments list defines which arguments are to be specified in the
arguments list parameter when the creation routine for a particular
object is called at run time. An arguments list also specifies the
values for those arguments. Argument lists have the following syntax:
LIST
list_name: ARGUMENTS {
argument_name = value_expression;
[...] }
[...]
The argument name must be either a built-in argument name or a userdefined
argument name that is specified with the ARGUMENT function.
If you use a built-in argument name as an arguments list entry in an
object definition, the UIL compiler checks the argument name to be
sure that it is supported by the type of object that you are defining.
If the same argument name appears more than once in a given arguments
list, the last entry that uses that argument name supersedes all
previous entries with that name, and the compiler issues a message.
Some arguments, such as XmNitems and XmNitemCount, are coupled by the
UIL compiler. When you specify one of the arguments, the compiler
also sets the other. The coupled argument is not available to you.
The Motif Toolkit and the X Toolkit (intrinsics) support constraint
arguments. A constraint argument is one that is passed to children of
an object, beyond those arguments normally available. For example,
the Form widget grants a set of constraint arguments to its children.
These arguments control the position of the children within the Form.
Unlike the arguments used to define the attributes of a particular
widget, constraint arguments are used exclusively to define additional
attributes of the children of a particular widget. These attributes
affect the behavior of the children within their parent. To supply
constraint arguments to the children, you include the arguments in the
arguments list for the child.
See Appendix B for information about which arguments are supported by
which widgets. See Appendix C for information about what the valid
value type is for each built-in argument.
Callbacks List Structure [Toc] [Back]
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Use a callbacks list to define which callback reasons are to be
processed by a particular widget at run time. Callback lists have the
following syntax:
LIST list_name : CALLBACKS { reason_name = PROCEDURE procedure_name [
( [ value_expression ] ) ]; | reason_name = procedure_list ; [...] }
[...]
For Motif Toolkit widgets, the reason name must be a built-in reason
name. For a user-defined widget, you can use a reason name that you
previously specified using the REASON function. If you use a built-in
reason in an object definition, the UIL compiler ensures that reason
is supported by the type of object you are defining. Appendix B shows
which reasons each object supports.
If the same reason appears more than once in a callbacks list, the
last entry referring to that name supersedes all previous entries
using the same reason, and the UIL compiler issues a diagnostic
message.
If you specify a named value for the procedure argument (callback
tag), the data type of the value must match the type specified for the
callback tag in the corresponding procedure declaration. When
specifying a widget name as a procedure value expression you must also
specify the type of the widget and a space before the name of the
widget.
Because the UIL compiler produces a UID file rather than an object
module (.o), the binding of the UIL name to the address of the entry
point to the procedure is not done by the loader, but is established
at run time with the MRM function MrmRegisterNames. You call this
function before fetching any objects, giving it both the UIL names and
the procedure addresses of each callback. The name you register with
MRM in the application program must match the name you specified for
the procedure in the UIL module.
Each callback procedure receives three arguments. The first two
arguments have the same form for each callback. The form of the third
argument varies from object to object.
The first argument is the address of the data structure maintained by
the Motif Toolkit for this object instance. This address is called the
widget ID for this object.
The second argument is the address of the value you specified in the
callbacks list for this procedure. If you do not specify an argument,
the address is NULL. Note that, in the case where the value you
specified is a string or an XmString, the value specified in the
callbacks list already represents an address rather than an actual
value. In the case of a simple string, for example, the value is the
address of the first character of that string. In these cases, UIL
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does not add a level of indirection, and the second argument to the
callback procedure is simply the value as specified in the callbacks
list.
The third argument is the reason name you specified in the callbacks
list.
Controls List Structure [Toc] [Back]
A controls list defines which objects are children of, or controlled
by, a particular object. Each entry in a controls list has the
following syntax:
LIST
list_name: CONTROLS {
[child_name: ] [MANAGED | UNMANAGED] object_definition;
[...] }
[...]
If you specify the keyword MANAGED at run time, the object is created
and managed; if you specify UNMANAGED at run time, the object is only
created. Objects are managed by default.
You can use child_name to specify resources for the automatically
created children of a particular control. Names for automatically
created children are formed by appending Xm_ to the name of the child
widget. This name is specified in the documentation for the parent
widget.
Unlike the arguments list and the callbacks list, a controls list
entry that is identical to a previous entry does not supersede the
previous entry. At run time, each controls list entry causes a child
to be created when the parent is created. If the same object
definition is used for multiple children, multiple instances of the
child are created at run time. See Appendix B for a list of which
widget types can be controlled by which other widget types.
Procedures List Structure [Toc] [Back]
You can specify multiple procedures for a callback reason in UIL by
defining a procedures list. Just as with other list types, procedures
lists can be defined in-line or in a list section and referenced by
name.
If you define a reason more than once (for example, when the reason is
defined both in a referenced procedures list and in the callbacks list
for the object), previous definitions are overridden by the latest
definition. The syntax for a procedures list is as follows:
LIST
list_name: PROCEDURES {
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procedure_name [ ( [ value_expression ]) ];
[...] }
[...]
When specifying a widget name as a procedure value expression you must
also specify the type of the widget and a space before the name of the
widget.
Object Sections [Toc] [Back]
An object section consists of the keyword OBJECT followed by a
sequence of object declarations. It has the following syntax:
OBJECT object_name:
[ EXPORTED | PRIVATE | IMPORTED ] object_type
[ PROCEDURE creation_function ]
[ object_name [ WIDGET | GADGET ] | {list_definitions } ]
Use an object declaration to define the objects that are to be stored
in the UID file. You can reference the object name in declarations
that occur elsewhere in the UIL module in any context where an object
name can be used (for example, in a controls list, as a symbolic
reference to a widget ID, or as the tag_value argument for a callback
procedure). Objects can be forward referenced; that is, you can
declare an object name after you reference it. All references to an
object name must be consistent with the type of the object, as
specified in the object declaration. You can specify an object as
exported, imported, or private.
The object definition can contain a sequence of lists that define the
arguments, hierarchy, and callbacks for the widget. You can specify
only one list of each type for an object. When you declare a userdefined
widget, you must include a reference to the widget creation
function for the user-defined widget.
Note: Several widgets in the Motif Toolkit actually consist of two
linked widgets. For example, XmScrolledText and XmScrolledList each
consist of children XmText and XmList widgets under a XmScrolledWindow
widget. When such a widget is created, its resources are available to
both of the underlying widgets. This can occasionally cause problems,
as when the programmer wants a XmNdestroyCallback routine named to act
when the widget is destroyed. In this case, the callback resource will
be available to both sub-widgets, and will cause an error when the
widget is destroyed. To avoid these problems, the programmer should
separately create the parent and child widgets, rather than relying on
these linked widgets.
Use the GADGET or WIDGET keyword to specify the object type or to
override the default variant for this object type. You can use the
Motif Toolkit name of an object type that has a gadget variant (for
example, XmLabelGadget) as an attribute of an object declaration. The
object_type can be any object type, including gadgets. You need to
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specify the GADGET or WIDGET keyword only in the declaration of an
object, not when you reference the object. You cannot specify the
GADGET or WIDGET keyword for a user-defined object; user-defined
objects are always widgets.
Identifier sections [Toc] [Back]
The identifier section allows you to define an identifier, a mechanism
that achieves run-time binding of data to names that appear in a UIL
module. The identifier section consists of the reserved keyword
IDENTIFIER, followed by a list of names, each name followed by a
semicolon.
IDENTIFIER identifier_name; [...;]
You can later use these names in the UIL module as either the value of
an argument to a widget or the tag value to a callback procedure. At
run time, you use the MRM functions MrmRegisterNames and
MrmRegisterNamesInHierarchy to bind the identifier name with the data
(or, in the case of callbacks, with the address of the data)
associated with the identifier.
Each UIL module has a single name space; therefore, you cannot use a
name you used for a value, object, or procedure as an identifier name
in the same module.
The UIL compiler does not do any type checking on the use of
identifiers in a UIL module. Unlike a UIL value, an identifier does
not have a UIL type associated with it. Regardless of what particular
type a widget argument or callback procedure tag is defined to be, you
can use an identifier in that context instead of a value of the
corresponding type.
To reference these identifier names in a UIL module, you use the name
of the identifier wherever you want its value to be used.
Include directives [Toc] [Back]
The include directive incorporates the contents of a specified file
into a UIL module. This mechanism allows several UIL modules to share
common definitions. The syntax for the include directive is as
follows:
INCLUDE FILE file_name;
The UIL compiler replaces the include directive with the contents of
the include file and processes it as if these contents had appeared in
the current UIL source file.
You can nest include files; that is, an include file can contain
include directives. The UIL compiler can process up to 100 references
(including the file containing the UIL module). Therefore, you can
include up to 99 files in a single UIL module, including nested files.
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Each time a file is opened counts as a reference, so including the
same file twice counts as two references.
The file_name is a simple string containing a file specification that
identifies the file to be included. The rules for finding the
specified file are similar to the rules for finding header, or .h
files using the include directive, #include, with a quoted string in
C. The UIL uses the -I option for specifying a search directory for
include files.
o+ If you do not supply a directory, the UIL compiler searches for
the include file in the directory of the main source file.
+ If the compiler does not find the include file there, the
compiler looks in the same directory as the source file.
+ If you supply a directory, the UIL compiler searches only that
directory for the file.
Names and Strings [Toc] [Back]
Names can consist of any of the characters A to Z, a to z, 0 to 9, $
(dollar sign), and _ (underscore). Names cannot begin with a digit (0
to 9). The maximum length of a name is 31 characters.
UIL gives you a choice of either case-sensitive or case-insensitive
names through a clause in the MODULE header. For example, if names
are case sensitive, the names "sample" and "Sample" are distinct from
each other. If names are case insensitive, these names are treated as
the same name and can be used interchangeably. By default, UIL assumes
names are case sensitive.
In CASE-INSENSITIVE mode, the compiler outputs all names in the UID
file in uppercase form. In CASE-SENSITIVE mode, names appear in the
UIL file exactly as they appear in the source.
The following table lists the reserved keywords, which are not
available for defining programmer defined names.
________________________________________________
| Reserved Keywords |
|_______________________________________________|
|ARGUMENTS CALLBACKS CONTROLS END |
|EXPORTED FALSE GADGET IDENTIFIER |
|INCLUDE LIST MODULE OFF |
|ON OBJECT PRIVATE PROCEDURE |
|PROCEDURES TRUE VALUE WIDGET |
|_______________________________________________|
The UIL unreserved keywords are described in the following list and
table. These keywords can be used as programmer defined names,
however, if you use any keyword as a name, you cannot use the UILsupplied
usage of that keyword.
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+ Built-in argument names (for example, XmNx, XmNheight)
+ Built-in reason names (for example, XmNactivateCallback,
XmNhelpCallback)
+ Character set names (for example, ISO_LATIN1, ISO_HEBREW_LR)
+ Constant value names (for example, XmMENU_OPTION,
XmBROWSE_SELECT)
+ Object types (for example, XmPushButton, XmBulletinBoard)
________________________________________________________________________
| Unreserved Keywords |
|_______________________________________________________________________|
|ANY ARGUMENT ASCIZ_STRING_TABLE |
|ASCIZ_TABLE BACKGROUND BOOLEAN |
|CASE_INSENSITIVE CASE_SENSITIVE CHARACTER_SET |
|COLOR COLOR_TABLE COMPOUND_STRING |
|COMPOUND_STRING_COMPONENT COMPOUND_STRING_TABLE FILE |
|FLOAT FONT FONT_TABLE |
|FONTSET FOREGROUND ICON |
|IMPORTED INTEGER INTEGER_TABLE |
|KEYSYM MANAGED NAMES |
|OBJECTS REASON RGB |
|RIGHT_TO_LEFT SINGLE_FLOAT STRING |
|STRING_TABLE TRANSLATION_TABLE UNMANAGED |
|USER_DEFINED VERSION WIDE_CHARACTER |
|WIDGET XBITMAPFILE |
|_______________________________________________________________________|
String literals can be composed of the uppercase and lowercase
letters, digits, and punctuation characters. Spaces, tabs, and
comments are special elements in the language. They are a means of
delimiting other elements, such as two names. One or more of these
elements can appear before or after any other element in the language.
However, spaces, tabs, and comments that appear in string literals are
treated as character sequences rather than delimiters.
Data Types [Toc] [Back]
UIL provides literals for several of the value types it supports. Some
of the value types are not supported as literals (for example, pixmaps
and string tables). You can specify values for these types by using
functions described in the Functions section. UIL directly supports
the following literal types:
+ String literal
+ Integer literal
+ Boolean literal
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+ Floating-point literal
UIL also includes the data type ANY, which is used to turn off compile
time checking of data types.
String Literals [Toc] [Back]
A string literal is a sequence of zero or more 8-bit or 16-bit
characters or a combination delimited by ' (single quotation marks) or
" (double quotation marks). String literals can also contain
multibyte characters delimited with double quotation marks. String
literals can be no more than 2000 characters long.
A single-quoted string literal can span multiple source lines. To
continue a single-quoted string literal, terminate the continued line
with a \ (backslash). The literal continues with the first character
on the next line.
Double-quoted string literals cannot span multiple source lines.
(Because double-quoted strings can contain escape sequences and other
special characters, you cannot use the backslash character to
designate continuation of the string.) To build a string value that
must span multiple source lines, use the concatenation operator
described later in this section.
The syntax of a string literal is one of the following:
'[character_string]'
[#char_set]"[character_string]"
Both string forms associate a character set with a string value. UIL
uses the following rules to determine the character set and storage
format for string literals:
+ A string declared as 'string' is equivalent to
#cur_charset"string", where cur_charset will be the codeset
portion of the value of the LANG environment variable if it is
set or the value of XmFALLBACK_CHARSET if LANG is not set or has
no codeset component. By default, XmFALLBACK_CHARSET is
ISO8859-1 (equivalent to ISO_LATIN1), but vendors may define a
different default.
+ A string declared as "string" is equivalent to #char_set"string"
if you specified char_set as the default character set for the
module. If no default character set has been specified for the
module, then if the -s option is provided to the uil command or
the use_setlocale_flag is set for the callable compiler, Uil(),
the string will be interpreted to be a string in the current
locale. This means that the string is parsed in the locale of
the user by calling setlocale, its charset is
XmFONTLIST_DEFAULT_TAG, and that if the string is converted to a
compound string, it is stored as a locale encoded text segment.
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Otherwise, "string" is equivalent to #cur_charset"string", where
cur_charset is interpreted as described for single quoted
strings.
+ A string of the form "string" or #char_set"string" is stored as
a null-terminated string.
If the char_set in a string specified in the form above is not a
built-in charset, and is not a user-defined charset, the charset of
the string will be set to XmFONTLIST_DEFAULT_TAG, and an informational
message will be issued to the user to note that this substitution has
been made.
The following table lists the character sets supported by the UIL
compiler for string literals. Note that several UIL names map to the
same character set. In some cases, the UIL name influences how string
literals are read. For example, strings identified by a UIL character
set name ending in _LR are read left-to-right. Names that end in a
different number reflect different fonts (for example, ISO_LATIN1 or
ISO_LATIN6). All character sets in this table are represented by 8
bits.
___________________________________________________
| Supported Character Sets |
|__________________________________________________|
|UIL Name Description |
|__________________________________________________|
|ISO_LATIN1 GL: ASCII, GR: Latin-1 Supplement |
|ISO_LATIN2 GL: ASCII, GR: Latin-2 Supplement |
|ISO_ARABIC GL: ASCII, GR: Latin-Arabic |
| Supplement |
|ISO_LATIN6 GL: ASCII, GR: Latin-Arabic |
| Supplement |
|ISO_GREEK GL: ASCII, GR: Latin-Greek |
| Supplement |
|ISO_LATIN7 GL: ASCII, GR: Latin-Greek |
| Supplement |
|ISO_HEBREW GL: ASCII, GR: Latin-Hebrew |
| Supplement |
|ISO_LATIN8 GL: ASCII, GR: Latin-Hebrew |
| Supplement |
|ISO_HEBREW_LR GL: ASCII, GR: Latin-Hebrew |
| Supplement |
|ISO_LATIN8_LR GL: ASCII, GR: Latin-Hebrew |
| Supplement |
|JIS_KATAKANA GL: JIS Roman, GR: JIS Katakana |
|__________________________________________________|
Following are the parsing rules for each of the character sets:
All character sets
Character codes in the range 00...1F, 7F, and 80...9F are
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UIL(file formats) UIL(file formats)
control characters including both bytes of 16-bit
characters. The compiler flags these as illegal characters.
ISO_LATIN1 ISO_LATIN2 ISO_LATIN3 ISO_GREEK ISO_LATIN4 [Toc] [Back]
These sets are parsed from left to right. The escape
sequences for null-terminated strings are also supported by
these character sets.
ISO_HEBREW ISO_ARABIC ISO_LATIN8 [Toc] [Back]
These sets are parsed from right to left. For example, the
string #ISO_HEBREW"012345" will generate a primitive string
of "543210" with character set ISO_HEBREW. The string
direction for such a string would be right-to-left, so when
rendered, the string will appear as "012345." The escape
sequences for null-terminated strings are also supported by
these character sets, and the characters that compose the
escape sequences are in left-to-right order. For example,
you would enter \n, not n\.
ISO_HEBREW_LR ISO_ARABIC_LR ISO_LATIN8_LR [Toc] [Back]
These sets are parsed from left to right. For example, the
string #ISO_HEBREW_LR"012345" generates a primitive string
"012345" with character set ISO_HEBREW. The string direction
for such a string would still be right-to-left, however, so
when rendered, it will appear as "543210." In other words,
the characters were originally typed in the same order in
which they would have been typed in Hebrew (although in
Hebrew, the typist would have been using a text editor that
went from right to left). The escape sequences for nullterminated
strings are also supported by these character
sets.
JIS_KATAKANA [Toc] [Back]
This set is parsed from left to right. The escape sequences
for null-terminated strings are also supported by this
character set. Note that the \ (backslash) may be displayed
as a yen symbol.
In addition to designating parsing rules for strings, character set
information remains an attribute of a compound string. If the string
is included in a string consisting of several concatenated segments,
the character set information is included with that string segment.
This gives the Motif Toolkit the information it needs to decipher the
compound string and choose a font to display the string.
For an application interface displayed only in English, UIL lets you
ignore the distinctions between the two uses of strings. The compiler
recognizes by context when a string must be passed as a nullterminated
string or as a compound string.
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UIL(file formats) UIL(file formats)
The UIL compiler recognizes enough about the various character sets to
correctly parse string literals. The compiler also issues errors if
you use a compound string in a context that supports only nullterminated
strings.
Since the character set names are keywords, you must put them in
lowercase if case-sensitive names are in force. If names are case
insensitive, character set names can be uppercase, lowercase, or mixed
case.
In addition to the built-in character sets recognized by UIL, you can
define your own character sets with the CHARACTER_SET function. You
can use the CHARACTER_SET function anywhere a character set can be
specified.
String literals can contain characters with the eighth (high-order)
bit set. You cannot type control characters (00-1F, 7F, and 80-9F)
directly in a single-quoted string literal. However, you can represent
these characters with escape sequences. The following list shows the
escape sequences for special characters.
\b Backspace
\f Form-feed
\n Newline
\r Carriage return
\t Horizontal tab
\v Vertical tab
\' Single quotation mark
\" Double quotation mark
\\ Backslash
\integer\ Character whose internal representation is given by integer
(in the range 0 to 255 decimal)
Note that escape sequences are processed literally in strings that are
parsed in the current locale (localized strings).
The UIL compiler does not process newline characters in compound
strings. The effect of a newline character in a compound string
depends only on the character set of the string, and the result is not
guaranteed to be a multiline string.
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UIL(file formats) UIL(file formats)
Compound String Literals [Toc] [Back]
A compound string consists of a string of 8-bit, 16-bit, or multibyte
characters, a named character set, and a writing direction. Its UIL
data type is compound_string.
The writing direction of a compound string is implied by the character
set specified for the string. You can explicitly set the writing
direction for a compound string by using the COMPOUND_STRING function.
A compound string can consist of a sequence of concatenated compound
strings, null-terminated strings, or a combination of both, each of
which can have a different character set property and writing
direction. Use the concatenation operator & (ampersand) to create a
sequence of compound strings.
Each string in the sequence is stored, including the character set and
writing direction information.
Generally, a string literal is stored in the UID file as a compound
string when the literal consists of concatenated strings having
different character sets or writing directions, or when you use the
string to specify a value for an argument that requires a compound
string value. If you want to guarantee that a string literal is stored
as a compound string, you must use the COMPOUND_STRING function.
Data Storage Consumption for String Literals [Toc] [Back]
The way a string literal is stored in the UID file depends on how you
declare and use the string. The UIL compiler automatically converts a
null-terminated string to a compound string if you use the string to
specify the value of an argument that requires a compound string.
However, this conversion is costly in terms of storage consumption.
PRIVATE, EXPORTED, and IMPORTED string literals require storage for a
single allocation when the literal is declared; thereafter, storage is
required for each reference to the literal. Literals declared in-line
require storage for both an allocation and a reference.
The following table summarizes data storage consumption for string
literals. The storage requirement for an allocation consists of a
fixed portion and a variable portion. The fixed portion of an
allocation is roughly the same as the storage requirement for a
reference (a few bytes). The storage consumed by the variable portion
depends on the size of the literal value (that is, the length of the
string). To conserve storage space, avoid making string literal
declarations that result in an allocation per use.
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UIL(file formats) UIL(file formats)
______________________________________________
Data Storage Consumption for String Literals |
| __________________________________|
| | | | Storage Requirements |
| | | | Per Use |
| | | |_________________________________|
| | | | An allocation and a reference |
| | | | (within the module) |
| | | | A reference (within the module) |
| | | | A reference (within the UID |
| | | | hierarchy) |
| | | | A reference (within the UID |
| | | | hierarchy) |
| | | | An allocation and a reference |
| | | | (within the module) |
| | | | An allocation and a reference |
| | | | (within the module) |
| | | | A reference (within the UID |
| | | | hierarchy) |
| | | | A reference (within the UID |
| | | | hierarchy) |
| | | | An allocation and a reference |
| | | | (within the module) |
| | | | A reference (within the module) |
| | | | A reference (within the UID |
| | | | hierarchy) |
|__|____|___| |
| | | | A reference (within the UID |
| | | | hierarchy) |
|__|__________________________________________
Integer Literals
An integer literal represents the value of a whole number. Integer
literals have the form of an optional sign followed by one or more
decimal digits. An integer literal must not contain embedded spaces
or commas.
Integer literals are stored in the UID file as 32-bit integers.
Exported and imported integer literals require a single allocation
when the literal is declared; thereafter, a few bytes of storage are
required for each reference to the literal. Private integer literals
and those declared in-line require allocation and reference storage
per use. To conserve storage space, avoid making integer literal
declarations that result in an allocation per use.
The following table shows data storage consumption for integer
literals.
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UIL(file formats) UIL(file formats)
_______________________________________________
|Data Storage Consumption for Integer Literals |
|______________________________________________|
|Declaration | Storage Requirements Per Use |
|____________|_________________________________|
|In-line | An allocation and a |
| | reference (within the |
| | module) |
|Private | An allocation and a |
| | reference (within the |
| | module) |
|Exported | A reference (within the UID |
| | hierarchy) |
|Imported | A reference (within the UID |
| | hierarchy) |
|____________|_________________________________|
Boolean Literal [Toc] [Back]
A Boolean literal represents the value True (reserved keyword TRUE or
On) or False (reserved keyword FALSE or Off). These keywords are
subject to case-sensitivity rules.
In a UID file, TRUE is represented by the integer value 1 and FALSE is
represented by the integer value 0 (zero).
Data storage consumption for Boolean literals is the same as that for
integer literals.
Floating-Point Literal [Toc] [Back]
A floating-point literal represents the value of a real (or float)
number. Floating-point literals have the following form:
[+|-][integer].integer[E|e[+|-]exponent]
For maximum portability, a floating-point literal can represent values
in the range 1.0E-37 to 1.0E+37 with at least 6 significant digits.
On many machines this range will be wider, with more significant
digits. A floating-point literal must not contain embedded spaces or
commas.
Floating-point literals are stored in the UID file as doubleprecision,
floating-point numbers. The following table gives examples
of valid and invalid floating-point notation for the UIL compiler.
_________________________________________________________________
Floating Point Literals
_________________________________________________________________
Valid Floating-Point Literals Invalid Floating-Point Literals
_________________________________________________________________
1.0 1e1 (no decimal point)
3.1415E-2 (equals .031415) 2.87 e6 (embedded blanks)
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UIL(file formats) UIL(file formats)
-6.29e7 (equals -62900000) 2.0e100 (out of range)
_________________________________________________________________
| |
Data storage consumption for floating-point literals is the same as
that for integer literals. |
| |
The purpose of the ANY data type is to shut off the data-type checking
feature of the UIL compiler. You can use the ANY data type for the
following: |
| |
| + Specifying the type of a callback procedure tag |
| |
| + Specifying the type of a user-defined argument |
| |
You can use the ANY data type when you need to use a type not |
supported by the UIL compiler or when you want the data-type |
restrictions imposed by the compiler to be relaxed. For example,|you
might want to define a widget having an argument that can accept |
different types of values, depending on run-time circumstances. |
| |
If you specify that an argument takes an ANY value, the compiler does
not check the type of the value specified for that argument; |
therefore, you need to take care when specifying a value for an |
argument of type ANY. You could get unexpected results at run time if
you pass a value having a data type that the widget does not support
for that argument. |
| |
Expressions |
UIL includes compile-time value expressions. These expressions can
contain refer
|
