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gtk-server.cfg

Section: User Commands (1)
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NAME

gtk-server.cfg - Configfile for the gtk-server.  

SYNOPSIS

gtk-server.cfg  

DESCRIPTION

The 'gtk-server.cfg' file is a configfile which is used by the GTK-server. If the 'gtk-server.cfg' file is available in the same directory as your client script, the GTK-server will read this local configfile (preferred). This way each client program can use it's own GTK configuration. If the configfile is not available locally, the GTK-server will follow the next logic:

1) try reading the environment variable GTK_SERVER_CONFIG. This variable should contain the full path and name to the configfile.

2) try finding the (hidden) configfile in the homedir of the user. The name of the configfile should be preceded by a dot, e.g. '.gtk-server.cfg'.

3) try finding the configfile in the /etc directory.

4) try finding the configfile in the /usr/local/etc directory.

The 'gtk-server.cfg' file contains the decriptions of the GTK functions which will be used by your client script. The format of the file is <KEYWORD = VALUE>. Lines starting with a hash '#' will be skipped. The keywords must be written using capitals.

The following keywords are recognized by the GTK-server:

LIB_NAME = <library name 1, library name 2, ...>
Describes the name of the libraries (.so or .dll) to open. This keyword may occur multiple times in the configfile. At a maximum 64 libraries can be opened simultanously. The library name should end with the plain 'so' suffix. If the GTK-server cannot find the library, it automatically will append a numeric suffix to the original name varying from 0 to 99 and attempt to open these library names also, until the correct numeric suffix was found.

Example: LIB_NAME = libgtk-x11-2.0.so, libgdk-x11-2.0.so, libglib-2.0.so, libgobject-2.0.so

INCLUDE = <file>
Define an additional configuration file with additional GTK function descriptions or macros.

Example: INCLUDE = /etc/gtk-extra.cfg

SEQUENCE = <maximum>
When opening a library, the GTK-server will search and attempt to use subsequent library version numbers up to this definition. The default value is 100.

Example: SEQUENCE = 10

FUNCTION_NAME = <func>, <callback>, <type>, <amount>, <arg1>...<argx>
Every GTK function used by a script must be described here. First the name of the function itself must be mentioned, after that a callback signal if applicable. The real names for the GTK callback signals must be used here. Then the type of the returnvalue must be specified. The type can be one of the following: NONE, VOID, WIDGET, POINTER, BOOL, STRING, INT, LONG, DOUBLE, FLOAT or ADDRESS. After that, it must be clear how many arguments the GTK function needs. Finally, the type of each indivdual argument must be declared. The type of the arguments can be one of the following: NULL, WIDGET, POINTER, BOOL, STRING, INT, LONG, DOUBLE, FLOAT, ENUM, STR, CLASS, MACRO, DATA, BASE64 or VARARGS.

The ADDRESS return type is used to return the address of a function in memory.

The BASE64 argument type is used to send base64 encoded binary data to the GTK-server. The POINTER argument type can be used for generic pointers and non-GTK libraries.

The MACRO argument type can be used in case a user function needs to be registered. In case GTK must execute a user function, the described macro will be used. A MACRO type always needs a DATA type, in which additional data can be specified. Macros are explained in the MACRO section of this manpage.

The ENUM and STR argument types refer to their correspending ENUM_NAME and STR_NAME definitions (see below). Instead of ENUM, the types INT or LONG may be used as well. Similarly, instead of STR, it is allowed to plainly use STRING.

The CLASS argument type refers to Motif widget classes. These are hardcoded and cannot be configured in the GTK-server configuration file.

The VARARGS argument defines the variable arguments list. The client script can enter a variable amount of arguments, but each argument should be prefixed with a type indication: i means int, l means long, s means string and so on. The NULL does not need a prefix.

The 'gtk-server.cfg' file may not contain duplicate function definitions. This is verified by the GTK-server during startup. Examples:


FUNCTION_NAME = gtk_window_new, delete-event, WIDGET, 1, LONG
FUNCTION_NAME = XtVaCreateWidget, NONE, WIDGET, 4, STRING, CLASS, WIDGET, VARARGS

ENUM_NAME = <name>, <integer>
The GTK and also the XForms API use a lot of predefined constants and enumerations. With this optional configuration line these can be defined also. The clientscript can use the same enumeration name, and the GTK-server will substitute to the corresponding value automatically. Values may be entered in decimal, octal or hexadecimal format. With octal use a preceding '0', and hexadecimal a preceding '0x' or '0X'.

Please note that enumeration names only may contain integer values. So in a defined GTK function, only at arguments defined as 'INT', 'LONG' or 'ENUM' the GTK-server will check for an enumeration name. If it cannot match an enumeration name, it is assumed there is a real value.

Duplicate enumeration names are not allowed. This is verified by the GTK-server during startup.

Example: ENUM_NAME = GTK_WINDOW_TOPLEVEL, 0

STR_NAME = <name>, <string>
The Motif API uses a lot of predefined strings. With this optional configuration line these strings can be set to their real names. The clientscript can use the original string name, and the GTK-server will substitute to the corresponding real string value automatically.

The GTK-server will lookup the string names in any argument defined as a STRING.

Duplicate string names are not allowed. This is verified by the GTK-server during startup.

Example: STR_NAME = XmNactivateCallback, activateCallback

ALIAS_NAME = <alias>, <real name>
Some functions in external libraries may have the same name as an existing statement in a programming language. For example, shell scripts can use the statement 'read', while the function 'read' also can be imported from libc. In order to avoid the client interpreter mixing up these statements, it is possible to define an alias. So instead of using the real name, the client program can use the defined alias to invoke the external function.

Aliasing also allows the programmer to rename external functions so they comply to the standard of the client language.

Duplicate alias names are not allowed. This is verified by the GTK-server during startup.

Example: ALIAS_NAME = libc_read, read

MACRO <name> <...> ENDMACRO
For an explanation on macros see below.
 

Pointer arguments

Some GTK functions return a result in their pointer arguments. The way to retrieve the value from such arguments is to create a definition for the GTK function with special parameters. For example:

FUNCTION_NAME = gdk_window_get_pointer, NONE, WIDGET, 4, WIDGET, PTR_INT, PTR_INT, NULL

In this case, a call to 'gdk_window_get_pointer' will return a widget but also the values stored in the second and third argument. The returned result will be formatted in S-expression syntax, just as the GTK-server also accepts S-expression syntax. Next to the type PTR_INT the types PTR_LONG, PTR_FLOAT, PTR_DOUBLE, PTR_STRING, PTR_BOOL, PTR_SHORT, PTR_WIDGET and PTR_BASE64 can be used.

When actually invoking the defined function, a dummy argument can be used in case of the numeric PTR argument types. Also the PTR_BASE64 type should have a dummy argument in place.

The PTR_STRING and PTR_WIDGET argument types however assume a pointer with sufficiently allocated memory.

In case of the PTR_BASE64 type, the function argument will return a Base64 encoded string which contains binary data. Before invoking the actual function, make sure to first set the memory layout of the binary data with the internal gtk_server_data_format function. After that, the returned Base64 string can be decoded using the internal gtk_server_unpack function.

 

Macros

In GTK sometimes more than one function is needed to define a widget. These functions can be grouped into a macro. From a clientscript the name of the macro can be used to invoke the macro. A macro can have the following layout:

MACRO <name>
$a : GTK_function
GTK_function $1 $2 $3
...
RETURN <value>
ENDMACRO

Each line in the macro may contain only one GTK function. A macro can be invoked with arguments. Within the macro these arguments are denoted with $1, $2, $3 an so on. The $0 points to the macroname itself. It is possible to refer to all arguments at once with $@. A macro can accept up to 9 arguments. If there are more arguments then these are ignored.

Macros may also use variables. Variablenames must start with a dollarsign '$'. After that, only the first letter of the variablename is important, which means that there are at most 26 variables in each macro (lowercase).

Within a macro, it is possible to assign a result of a GTK function to a variable. However, it is important that the colon symbol, which is the assignment operator, is not attached to the variablename or the GTK functionname. For example:

$window : gtk_window_new GTK_WINDOW_TOPLEVEL

Also it is possible to assign a string to a variable. To do this, the string should be preceded by the '&' sign. For example:

$var : &Hello world

Variables in macros are initialized to zero automatically, but keep their values after the macro object has been executed. Afterwards the variables can be retrieved in your clientscript by using the call 'gtk_server_macro_var'. For example:

gtk_server_macro_var <macroname> var

There are a few commands to use in macros. These should be written in capitals. For example, it is possible to perform a relative jump on the condition of the value of a variable. The command 'VALUE' jumps when a variable contains a value not equal to zero, and the command 'EMPTY' jumps when a variable is zero. The command 'JUMP' always jumps, no matter what condition. For example:

$var VALUE 3

In this example, the GTK-server will jump three statements forward in case the variable 'var' is not equal to zero. The commands 'EMPTY', 'VALUE' and 'JUMP' can jump forward and backward, but only within the macro object. Jumps outside the macro will just go to the end of the macro, or to the beginning if the jump is negative.

Next to jumps, a comparison between variables can be made with 'COMPARE'. When two variables are compared, the result of the comparison will be put into the local z-variable. So if the contents of the compared variables are equal, the z-variable will be '0'. Else the local z-variable will be '1'. For example:

$event COMPARE $window
$z EMPTY -5

Also it is possible to setup associative arrays. An associative array is globally visible to all macro's. With associative arrays the main returnvalue of a macro can be connected to another value. This way multiple results can be returned from a macro. An array with one element can be defined as follows:

$ebox ASSOC $pix

If, to another macro, the 'ebox' is passed as an argument, the associated value can be retrieved in that macro as follows:

$pix GET $1

In this example, the 'pix' variable will be assigned the value associated to the first argument of the macro. There is no limit to the amount of associations; associative arrays can be of endless length, for example:

$ebox ASSOC $pix
$pix ASSOC $widget
$widget ASSOC $window
[...]

All values can be retrieved using an inverse GET:

$pix GET $1
$widget GET $pix
$window GET $widget
[...]

Note that with all operator commands, which are 'GET', 'ASSOC', 'COMPARE', 'VALUE', 'EMPTY', and the ':', the left operand must be a variable.

It is not allowed to define a macro within a macro. Also, duplicate macro names are not allowed. However, macros may invoke other macros. Also, macros may return a value to the client script with the keyword 'RETURN'. For example:

RETURN $window

To find out which value is assigned to a variable, the command DEBUG can be used. This will print the result in the logfile, if logging is enabled. Example:

DEBUG $button

The Highlevel Universal GUI (HUG) defined in the GTK-server configfile is implemented using macro objects.  

EXAMPLES

An example of a 'gtk-server.cfg' file can be found in the sourcepackage.  

LICENSE

GPL license.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.  

SEE ALSO

gtk-server(1), stop-gtk-server(1)  

AUTHORS

Orignal concept, design and implementation by Peter van Eerten, e-mail : peter@gtk-server.org

Current version of the GTK-server was created with help of many others - see the CREDITS file in the sourcepackage for credits.


 

Index

NAME
SYNOPSIS
DESCRIPTION
Pointer arguments
Macros
EXAMPLES
LICENSE
SEE ALSO
AUTHORS

This document was created by man2html, using the manual pages.
Time: 11:37:10 GMT, December 16, 2017