NAME
FvwmScript - module to build graphic user interface
SYNOPSIS
FvwmScript must be spawned by Fvwm. It will not work from the command
line.
DESCRIPTION
FvwmScript is a module which allows you to build many graphical
applications such as desktop accessories, button panel with pop up
menus, modal dialogs... At the startup, FvwmScript reads the file which
is specified on the command line. This file contains the script. This
script is not included in the configuration file of Fvwm.
An FvwmScript script is fully controllable by using the keyboard.
(Shift)-Tab circulates around the widgets, Return simulates a mouse
click, the arrows move the cursor or change the values of the widget
and Escape "cancels" for Menu and PopupMenu.
INVOCATION
FvwmScript can be invoked by inserting the line ‘Module FvwmScript
name_of_script’ in the .fvwm2rc file. The file "name_of_script" can
start with a slash, in which case, it’s a fully qualified path, and the
file is read. If "name_of_script" does not start with a slash,
FvwmScript will look in a few different places. If the .fvwm2rc
contained the command line ‘*FvwmScript: Path
path_of_the_script_directory’, FvwmScript will try that directory. If
that doesn’t work, FvwmScript tries the system configuration directory
and the user configuration directory as described under the "Read"
command in the fvwm man page.
The command to start FvwmScript can be placed on a line by itself, if
FvwmScript is to be spawned during fvwm’s initialization, or can be
bound to a menu or mouse button or keystroke to invoke it later.
CONFIGURATION OPTIONS
The following commands can be used in the config file (see fvwm(1),
section MODULE COMMANDS for details). They are used only if the
corresponding script commands are not used in the script.
*FvwmScript: DefaultFont font
Specifies the default font to be used. If not specified with
this command or in the script with the Font command, fixed font
is assumed.
*FvwmScript: DefaultFore color
Specifies the default foreground color to be used. If not
specified with this command or in the script with the ForeColor
command, black is used.
*FvwmScript: DefaultBack color
Specifies the default background color to be used. If not
specified with this command or in the script with the BackColor
command, grey85 is used.
*FvwmScript: DefaultHilight color
Specifies the default hilight color to be used. If not specified
with this command or in the script with the HilightColor
command, grey100 is used.
*FvwmScript: DefaultShadow color
Specifies the default shadow color to be used. If not specified
with this command or in the script with the ShadowColor command,
grey55 is used.
*FvwmScript: DefaultColorset colorset
Tells the module to use colorset colorset as the default
colorset. Refer to the FvwmTheme man page for details about
colorsets.
ANATOMY OF A SCRIPT
FvwmScript uses a particular programming language. A script is composed
of five parts. Heading contains general characteristics of the window
and default properties for all widgets. The second part contains
instructions whom are executed at the startup of the script. The third
part contains periodic tasks which are executed every second. The
fourth part contains instructions which are executed at exit. And the
last part contains the description of widgets. A widget consists of
eleven types of items: text labels, single-line text inputs, radio
buttons, checkbox, push buttons, horizontal and vertical scrollbars,
rectangles, pop up menus, swallowexecs and mini scrollbars.
HEADING OF A SCRIPT
The syntax is as follows:
WindowTitle string
This option sets the window title.
WindowSize width height
This option sets window size. width and height are numerical
value.
WindowPosition x y
This option sets window position. x and y are numerical value.
ForeColor {color}
This option sets the default foreground color for all widgets.
BackColor {color}
This option sets the default background color for all widgets.
HilightColor {color}
This option sets the default hilight color for all widgets.
ShadowColor {color}
This option sets the default shadow color for all widgets.
Colorset {n}
This option sets the default colorset for all widgets.
Font {font}
This option sets the default font for all widgets.
UseGettext [locale_path]
Enable the use of the gettext mechanism which is used by the
WindowLocaleTitle, LocaleTitle, ChangeLocaleTitle instructions
and the Gettext function. If no argument is given, the default
FvwmScript locale catalog is used. This catalog is under the
locale fvwm installation directory and the text domain is
FvwmScript
(install_prefix/share/locale/*/LC_MESSAGES/FvwmScript.mo). You
can reset this catalog or add some catalogs exactly in the same
way than with the LocalePath fvwm command (see the fvwm manual
page). This instruction should be placed before the
WindowLocaleTitle instruction.
WindowLocaleTitle string
This option sets the window title, but use the locale catalog(s)
defined with UseGettext.
INITIALISATION
This part contains instructions which will be executed at the startup.
For example:
Init
Begin
Do "Exec cat tada.voc > /dev/dsp"
WarpPointer 1
Set $ToDo=Restart
End
These instructions are used to play a sound, move the pointer to widget
1 and to initialize $ToDo to "Restart" at every startup.
PERIODIC TASKS
This part of the script contains instructions that are executed every
second. For example:
PeriodicTasks
Begin
If (RemainderOfDiv (GetTime) 10)==0 Then
Do {Exec xcalc}
End
This example shows how to launch xcalc every 10 seconds.
THE QUIT FUNCTION
This part of the script contains instructions that are executed when
the script exits (after the Quit instruction or if you close the window
with the Close, Delete or Destroy fvwm command). For Example
QuitFunc
Begin
Do {Echo bye, bye}
End
Be aware that if you used the KillModule fvwm command to close the
script, some instructions or functions which rely on the existence of a
communication link between the script and fvwm will not be executed
(for example the Do command). To smoothly kill a script with an fvwm
command see the COMMANDS section.
MAIN OF A SCRIPT
The second part of the script contains the description for every widget
in the script. Each widget description has two parts. The first part
describes initial properties, the second part contains instructions
that are executed when the widget receives messages. All widgets can
send and receive messages. All messages are identified by a number.
The message "UserAction" is sent to a widget when the user operates the
widget. The syntax for the first part is:
Widget id # A number between 1 and 999 inclusive
Property
Type string
Size width height
Position x y
Title { string }
Value int
MaxValue int
MinValue int
Font string
ForeColor { color }
BackColor { color }
HilightColor { color }
ShadowColor { color }
Colorset int
Flags flagsOpt
The flagsOpt option to Flags is a space separated list containing one
or more of the keywords Hidden, NoReliefString, NoFocus, Left /
Center / Right. Hidden is used to specify if the widget is hidden at
startup. NoReliefString specifies if strings are drawn with relief or
not. NoFocus specifies if the widget can get the keyboard focus or
not. By default all widgets take focus, except Rectangle, HDipstick
and VDipstick which cannot. Moreover, the NoFocus widgets are skipped
when you circulate around the widgets with the (Shift-)Tab short cut.
Left / Center / Right specifies the text position. These apply only to
ItemDraw, List, Menu, PopupMenu and PushButton. The default is Center
for ItemDraw and PushButton and Left for the other widgets.
LocaleTitle can be used in place of Title, for using the locale
catalog(s) defined with UseGettext.
The position of every widget must be specified.
The syntax for the second part is:
Main
Case message of
SingleClic:
Begin
# list of instructions which will be
# executed when widget receives
# message "SingleClic". This message is
# generated by the user.
End
1 :
Begin
# list of instructions which will be
# executed when widget receives
# message 1
End
End
LIST OF WIDGETS
There is fifteen types of widgets.
CheckBox: Display check box with a string.
Title: title of the check box.
Value: if Value is equal to 1, the box is checked else it is
not.
The Size property is ignored.
HDipstick: Display a horizontal dipstick.
This widget can be used to display disk usage.
Value: specify the current value of the dipstick.
MinValue: specify the minimum value of the dipstick.
MaxValue: specify the maximum value of the dipstick.
A minimum size of 30x11 is imposed.
HScrollBar: Display an horizontal scrollbar.
Value: position of the thumb.
MaxValue: upper limit of Value.
MinValue: lower limit of Value.
The height property is ignored and a minimum width is imposed.
The width should be at least the range plus 37 if all values are
to be selectable e.g. a min of 0 and max of 10 has a range of
11 and therefore should have a minimum width of 48.
ItemDraw: Display an icon and/or a string.
Title: string to display.
Icon: icon to display.
MaxValue: x coordinate of the cursor.
MinValue: y coordinate of the cursor.
The size is made large enough to contain the title and/or the
icon.
List: Display a list.
List lets user to choose between various options.
Value: specify which option is selected.
MinValue: First visible option.
Title: title contains options displayed in the list. The syntax
is the following: {Option 1|Option 2|...|Option N}. All menus
are displayed at the top of window.
A minimum height of three items is imposed and the width is made
to be at least 108.
Menu: Display a menu whom lets user to choose a option.
Items of type Menu are layed out from left to right along the
top of the window. The size and position properties are ignored.
Value: specify which option is selected.
Title: title contains options displayed in the menu. The syntax
is the following: {Option 1|Option 2|...|Option N}.
MiniScroll: Display a very small vertical scrollbar.
Value: position of the thumb.
MaxValue: upper limit of Value.
MinValue: lower limit of Value.
The size is set to 19x34.
PopupMenu: Display a pop up menu.
Value: specify what option is selected.
Title: the title has the following syntax: {Option 1|Option
2|...|Option N}."Option 1|Option 2|...|Option N" is the pop up
menu which is displayed when pressing mouse button.
The size property is ignored.
PushButton: Display push button with an icon and/or a string.
Title: this string has the following syntax {Title of the
button|Option 1|Option 2|Option3|...|Option N}. "Option 1|Option
2|...|Option N" is the pop up menu which is displayed when
pressing the right button.
Icon: icon to display.
The button is made large enough to fit the icon and or label.
RadioButton: Display radio button with a string.
Title: title of the radio button.
Value: if Value is equal to 1, the box is checked else it is
not.
The size property is ignored
Rectangle: Display a rectangle.
This type of widget can be used to decorate window.
SwallowExec
This type of widget causes FvwmScript to spawn an process, and
capture the first window whose name or resource is equal to
Title, and display it in the script window.
Title: specify the window name which be captured and displayed
in the script window.
SwallowExec: specify the command line to execute to spawn the
process. Modules can also be swallowed.
Value: specify the looking of the border. Possible value: -1, 0,
1.
The size is made to be at least 30x30
TextField: Display a text input field.
The text input field can be used to edit a single-line string.
Title: content of text field.
Value: position of the insert point.
MinValue: position of the end of the selection.
MaxValue: first visible character of the title
The height property is ignored, the width is made to be at least
40 pixels wider than the initial contents.
VDipstick: Display a vertical dipstick.
Value: specify the current value of the dipstick.
MinValue: specify the minimum value of the dipstick.
MaxValue: specify the maximum value of the dipstick.
The size is made to be at least 11x30.
VScrollBar: Display a vertical scrollbar.
Value: position of the thumb.
MaxValue: upper limit of Value.
MinValue: lower limit of Value.
The width property is ignored and a minimum height is imposed.
The height should be at least the range plus 37 if all values
are to be selectable e.g. a min of 0 and max of 10 has a range
of 11 and therefore should have a minimum height of 48.
INSTRUCTIONS
Here is the description of all instructions.
HideWidget id : hide the widget numbered id.
ShowWidget id: show the widget numbered id.
ChangeValue id1 id2
Set the value of the widget numbered id1 to id2.
ChangeMaxValue id1 id2
Set the maximum value of the widget numbered id1 to id2.
ChangeMinValue id1 id2
Set the minimum value of the widget numbered id1 to id2.
ChangeTitle id1 id2
Set the title of the widget numbered id1 to id2.
ChangeWindowTitle string
Set the title of the window to string.
ChangeWindowTitleFromArg numarg
Set the title of the window to the value of the numarg-th script
argument.
ChangeLocaleTitle id1 id2
As ChangeTitle but use the locale catalog(s) defined with
UseGettext.
ChangeIcon id1 id2
Set the icon of the widget numbered id1 to id2.
ChangeForeColor id1 {color}
Set the foreground color of the widget numbered id1 to {color}.
ChangeBackColor id1 {color}
Set the background color of the widget numbered id1 to {color}.
ChangeColorSet id1 id2
Set the colorset of the widget numbered id1 to id2. Specifying
widget 0 sets the main window colorset.
ChangePosition id1 x y
Move the widget numbered id1 to position (x,y).
ChangeSize id1 width height
Set the size of the widget numbered id1 to (width,height).
ChangeFont id1 newfont
Set the font of the widget numbered id1 to newfont.
WarpPointer id
Warp the mouse pointer into the widget numbered id.
WriteToFile filename {str1} {str2} etc
Write to the file filename the string which is the concatenation
of all arguments str1, str2, etc.
Do {command args}
Execute the fvwm command inside the Do block. Any fvwm command
as described in the fvwm2 man page can be used. Commands are
sent from this module to the fvwm main program for processing.
The length of the command and arguments can not exceed 988
characters.
Set $var={str1} {str2} etc
Concatenate all arguments to a string and set the variable $var
to this string.
Quit: quit the program.
SendSignal id1 id2
Send a message numbered id2 to widget id1.
SendToScript id_script {str11} {str2} etc
Send a message to the script identified by id_script. The
message is the concatenation of str1, str2...
Key Keyname Modifier id sig str1 str2 etc
Binds a keyboard key to the instruction
SendSignal id sig
and sets the "last string" to the concatenation of str1, str2...
(see the LastString function). The Keyname and Modifiers fields
are defined as in the fvwm Key command.
ARGUMENTS
Most of commands use arguments. There are two kinds of arguments:
numbers and strings. A numerical argument is a value which is between
-32000 and +32000. A string is always surrounded with braces. Variables
always begin with the character "$" and can contain both numbers and
strings.
FUNCTIONS
All functions use arguments. Functions can return both a string and a
number. The syntax is:
(function argument1 argument2 etc)
Here is the complete list of arguments:
(GetTitle id)
Return the title of the widget numbered id.
(GetValue id)
Return the current value of the widget numbered id.
(GetMinValue id)
Return the current Min value of the widget numbered id.
(GetMaxValue id)
Return the current Max value of the widget numbered id.
(GetFore id)
Return the current RGB foreground value of the widget numbered
id in the hex format RRGGBB.
(GetBack id)
Return the current RGB background value of the widget numbered
id in the hex format RRGGBB.
(GetHilight id)
Return the current RGB hilight value of the widget numbered id
in the hex format RRGGBB.
(GetShadow id)
Return the current RGB shadow value of the widget numbered id in
the hex format RRGGBB.
(GetOutput {str} int1 int2)
Executes the command str, gets the standard output and returns
the word which is in the line int1 and in the position int2. If
int2 is equal to -1, GetOutput returns the complete line.
(NumToHex int)
Return the hexadecimal value of int.
(HexToNum {str})
Return the decimal value of str, str must be an hexadecimal
value.
(Add int1 int2)
Return the result of (int1+int2).
(Mult int1 int2)
Return the result of (int1*int2).
(Div int1 int2)
Return the result of (int1/int2).
(StrCopy {str} int1 int2)
Return the string whom is between position int1 and int2. For
example, (StrCopy {Hello} 1 2) returns {He}
(LaunchScript {str})
This function launches the script named str and returns an
identification number. This number is necessary to use the
functions SendToScript and ReceiveFromScript. The string str
contains the script name and some arguments.
(GetScriptArgument {int})
This function returns the argument script used in the function
LaunchScript. If int is equal to zero, GetScriptArgument
returns the name of the script.
(GetScriptFather)
This function returns the identification number of the script
father.
(ReceivFromScript {int})
This function returns the message sent by the script numbered
int.
(RemainderOfDiv {int1 int2}): t
This function returns the remainder of the division (int1/int2).
(GetTime)
This function returns the time in seconds.
(GetPid)
This function returns the process id of the script.
(Gettext {str})
This function return the translation of str by using the locale
catalog(s) defined with UseGettext.
(SendMsgAndGet {comId} {cmd} bool)
Sends the command cmd with identifier comId to an external
program ready to communicate with the script using a protocol
specific to FvwmScript. If bool is 0 FvwmScript does not wait
for an answer from the external program. In this case the
returned value is 1 if the message can be sent to the external
program and 0 if this is not the case. If bool is 1, then
FvwmScript waits for an answer from the external program and the
return value is this answer (a line of no more than 32000
characters). If the communication fails, the returned value is
0. See the section A COMMUNICATION PROTOCOL for a description
of the communication protocol used.
(Parse {str} int)
where str must be a string of the form:
X1S1X2S2X3S3...SnXn
where the Xn are numbers containing four decimal digits and
where Sn are strings of length exactly Xn. The returned value is
the string Sint. If int is out of range (e.g., >n) the returned
value is the empty string. If str is not of the specified form,
the return value is unpredictable (but empty in the average).
This function is useful to handle strings returned by the
SendMsgAndGet function.
(LastString)
This function returns the "current working string" for the Key
instruction and the SendString command (see the COMMANDS
section). At startup this string is empty, but when a Key
binding is detected (respectively, a SendString command is
received), then this string is set to the string associated to
the instruction (respectively, to the command).
CONDITIONAL LOOPS
There are three kinds of conditional loops. The instruction "If-Then-
Else" has the following syntax:
If $ToDo=={Open xcalc} Then
Do {Exec xcalc &} # List of instructions
Else
Begin
Do {Exec killall xcalc &} # List of instructions
Do {Exec echo xcalc killed > /dev/console}
End
The second part "Else-Begin-End" is optional. If the loop contains only
one instruction, Begin and End can be omitted. The instruction "While-
Do" has the following syntax:
While $i<5 Do
Begin
Set $i=(Add i 1) # List of instructions
End
Two strings can be compared with "==" and two numbers can be compared
with "<", "<=", "==", ">=", ">". The loop "For-Do-Begin-End" has the
following syntax:
For $i=1 To 20 Do
Begin
Do {Exec xcalc &} # List of instructions
End
COMMANDS
The following fvwm command may be executed at any time
SendToModule ScriptName SendString id sig str
it sends to any module with alias or name which matches ScriptName the
string
SendString id sig str
When an FvwmScript receives such a message it sends to the Widget id
the signal numbered sig and the string str can be obtained with the
LastString function. Let us give an example. Say that you have a
script MyScript with the widget:
Widget 50
Property
Type PushButton
Title {Quit}
...
Main
Case message of
SingleClic:
Begin
Quit
End
1 :
Begin
Set $str = (LastString)
If $str == {Quit} Then
Quit
Else
ChangeTitle 33 $str
End
End
Then the command
SendToModule MyScript SendString 50 1 str
forces MyScript to exit if str is equal to "Quit" and if not it changes
the title of Widget 33 to str.
This command can be used to change the window title
SendToModule ScriptName ChangeWindowTitle newTitle [oldTitle]
it causes that any module with alias or name which matches ScriptName
changes its associated window title to newTitle. The optional argument
oldTitle makes sense when there are several instances of the same
script. It permits to avoid changing the name of all these instances
by specifying the name of the window associated to the target script
(see the example below).
+ I Module FvwmScript FvwmStorageSend "/dev/hda6"
+ I Wait FvwmStorageSend
+ I SendToModule FvwmStorageSend ChangeWindowTitle HDA6
+ I Module FvwmScript FvwmStorageSend "/dev/hda1"
+ I Wait FvwmStorageSend
+ I SendToModule FvwmStorageSend ChangeWindowTitle HDA1 FvwmStorageSend
Without the FvwmStorageSend argument in the last case, the SendToModule
command would have changed to HDA1 the name of both instances of
FvwmStorageSend.
EXAMPLES
You will find examples of scripts in the fvwm configuration directory.
FvwmScript-BellSetup, FvwmScript-KeyboardSetup, FvwmScript-PointerSetup
and FvwmScript-ScreenSetup are a set of scripts that modify X settings.
These scripts save preferences into a file named ~/.xinit-fvwmrc (If
you want to use another file name, give it as the first argument of the
script). If you want to load these preferences at every startup, you
have to include the line ".xinit-fvwmrc" in your .xinitrc (or
.xsession) file before starting fvwm.
FvwmScript-BaseConfig modifies fvwm focus and paging mouse policy,
window placement, opacity and other features of the move and resize
commands, snap attraction and shading animation. This script saves
preferences into a file named .FvwmBaseConfig in the user’s data
directory (i.e., $HOME/.fvwm or $FVWM_USERDIR if set). If you want to
load these preferences at every startup you must add the line "Read
.FvwmBaseConfig" in your fvwm configuration file. If you want to use
another file name, give it as the first argument of the script. When
you click on Ok or Apply an fvwm function that you may define named
BaseConfigOkFunc or BaseConfigApplyFunc is called. This allows for
reloading specific application styles that the script has destroyed
(e.g., AddToFunc BaseConfigOkFunc I Read MyAppStyle).
FvwmScript-Buttons is a buttons panel which can replace FvwmButtons
(this script supports popup menus and requires xload, xclock,
FvwmPager, TkDesk). FvwmScript-Colorset allows you to edit your
colorset (see FvwmTheme). FvwmScript-Date allows you to set date and
time. FvwmScript-FileBrowser is a file browser used by the other
scripts. FvwmScript-Find is an elementary front-end to find.
FvwmScript-Quit allows to quit fvwm, restart fvwm or some other window
manager, or shut down and reboot the computer. FvwmScript-ScreenDump
is a screen dumper. FvwmScript-WidgetDemo is a pure example script. See
the next section for FvwmScript-ComExample.
A COMMUNICATION PROTOCOL
FvwmScript is a weak (but simple) programming language. If you need to
deal with a lot of data and/or you need to use complex algorithms you
should use an external program (in perl for example) and "send" the
desired information to your FvwmScript script. The first approach is to
use the GetOutput function. This is simple but you should rerun your
external program each time you need information from it (and this may
cause performances problems). The second approach is to use the
SendMsgAndGet function which extends FvwmScript by using any
programming language which can deal with named pipes (fifos). We
describe this solution in this section. (A third approach is to use
fvwm-themes-com from the fvwm-themes package, but in fact the
SendMsgAndGet method is an implementation of fvwm-themes-com inside
FvwmScript and this gives better performance).
Basically, you start an "external" program (the program for short) from
your FvwmScript script (the script for short). This program runs in the
background and you use the SendMsgAndGet function in your script to ask
questions or to give instructions to the program. The program must
strictly respect a certain communication protocol. First of all there
is an identifier comId for the communication, it should contain the
process id of the script for a good implementation of the protocol (use
the GetPid function and pass the comId via an option to the program).
The protocol uses two fifos, in the fvwm user directory, named: .tmp-
com-in-comId and .tmp-com-out-comId. The program should create and
listen on the .tmp-com-in-comId fifo. Then, when FvwmScript executes a
function of the form:
Set $answer = (SendMsgAndGet {comId} {cmd} bool)
FvwmScript writes the cmd on this fifo. This way the program can read
the cmd and can execute the appropriate action (it should remove the in
fifo to support multi-communications). If bool is 0, FvwmScript does
not wait for an answer from the program and return 1 if the previous
actions succeed and 0 if they failed (then the program should "go back"
to the in fifo). If bool is 1, then FvwmScript waits (20 sec) for an
answer from the program and in turn returns the answer to the script
(note that bool is not passed to the program as it must know which
commands need an answer). To answer, the program creates the .tmp-com-
out-comId fifo and writes the answer on it. The program should wait
until FvwmScript reads the answer and then it should remove the out
fifo and go back to the in fifo. The answer should consist of one line
of no more than 32000 characters (take a look at the Parse function to
handle multiple lines as one line).
A simple way to understand this protocol and to write scripts and
programs that use it is to take a look at the (not useful) example
FvwmScript-ComExample and fvwm-script-ComExample.pl (that can found in
the fvwm data directory). Moreover, this implementation of the protocol
solves questions as: What to do if the script exits for a bad reason?
What to do if the program exits for a bad reason? ...etc.
BUGS
FvwmScript crashes if widgets are accessed that have not been defined.
AUTHOR
Frederic Cordier (cordie97@cui.unige.ch or f-cord96@univ-
lyon1.fr).
CONTRIBUTOR
Eddy J. Gurney (eddy@gizmo.aa.ans.net).