.TH gs 3erl "gs 1.6.2" "Ericsson AB" "Erlang Module Definition"
.SH NAME
gs \- The Graphics System for Erlang.
.SH DESCRIPTION
.LP

.RS -4
.B
Warning:
.RE
GS is not recommended for use in new applications\&. Instead we recommend WX for applications that need a graphical user interface\&.
.LP
GS is deprecated and will be removed in the 18\&.0 release\&.

.LP
The Graphics System, GS, is easy to learn and designed to be portable to many different platforms\&.
.LP
In the description below, the type \fIgsobj()\fR\& denotes a reference to a graphical object created with GS\&. Such a reference is either a GS object identifier or the name of the object (an atom), if such a name exists\&. The functions all return the specified values or \fI{error,Reason}\fR\& if an error occurs\&.
.LP
Please refer to the GS User\&'s Guide for a description of the different object types and possible options\&.
.SH EXPORTS
.LP
.B
config(GSObj, Options) -> ok
.br
.RS
.LP
Types:

.RS 3
GSOBj = gsobj()
.br
Options = [Option] | Option
.br
 Option = {Key,Value}
.br
.RE
.RE
.RS
.LP
Configures a graphical object according to the specified options\&.
.RE

.LP
.B
create(ObjType, Parent) -> ObjId
.br
.B
create(ObjType, Parent, Options) -> ObjId
.br
.B
create(ObjType, Name, Parent, Options) -> ObjId
.br
.RS
.LP
Types:

.RS 3
ObjType = atom()
.br
Parent = gsobj()
.br
Name = atom()
.br
Options = [Option] | Option
.br
 Option = {Key,Value}
.br
.RE
.RE
.RS
.LP
Creates a new graphical object of the specified type as a child to the specified parent object\&. The object is configured according to the options and its identifier is returned\&. If no options are provided, default option values are used\&.
.LP
If a name is provided, this name can be used to reference the object instead of the object identifier\&. The name is local to the process which creates the object\&.
.LP
The following object types exist: \fIwindow | button | radiobutton | checkbutton | label | frame | entry | listbox | canvas | arc | image | line | oval | polygon | rectangle | text | menubar | menubutton | menu | menuitem | grid | gridline | editor | scale\fR\&
.RE

.LP
.B
create_tree(Parent, Tree) -> ok
.br
.RS
.LP
Types:

.RS 3
Parent = gsobj()
.br
Tree = [Object]
.br
 Object = {ObjType,Options} | {ObjType,Options,Tree} | {ObjType,Name,Options,Tree}
.br
.RE
.RE
.RS
.LP
Creates a hierarchy of graphical objects\&.
.RE

.LP
.B
destroy(GSObj) -> void()
.br
.RS
.LP
Types:

.RS 3
GSObj = gsobj()
.br
.RE
.RE
.RS
.LP
Destroys a graphical object and all its children\&.
.RE

.LP
.B
ObjType(Parent)
.br
.B
ObjType(Parent, Options)
.br
.B
ObjType(Name, Parent, Options)
.br
.RS
.LP
These functions are shorthand equivalents of \fIcreate/2\fR\&, \fIcreate/3\fR\&, and \fIcreate/4\fR\&, respectively\&.
.RE

.LP
.B
read(GSObj, Key) -> Value
.br
.RS
.LP
Types:

.RS 3
GSObj = gsobj()
.br
Key = atom()
.br
Value = term()
.br
.RE
.RE
.RS
.LP
Returns the value of an option key for the specified graphical object\&.
.RE

.LP
.B
start() -> ObjId
.br
.RS
.LP
Starts GS, unless it is already started, and returns its object identifier\&.
.RE

.LP
.B
stop() -> void()
.br
.RS
.LP
Stops GS and closes all windows\&. This function is not the opposite of \fIstart/0\fR\& as it will cause \fIall\fR\& applications to lose their GS objects\&.
.RE