Provided by: libui-dialog-perl_1.09-1_all 
NAME
UI::Dialog::Backend - simply a collection of primarily internal methods.
SYNOPSIS
use UI::Dialog::Backend;
BEGIN {
use vars qw( @ISA );
@ISA = qw( UI::Dialog::Backend );
}
ABSTRACT
UI::Dialog::Backend is simply a collection of primarily internal methods.
DESCRIPTION
While this module is inherited by all UI::Dialog backend modules, this module itself is
not meant for direct usage. The "STATE METHODS" and "UTILITY METHODS" documentation is
applicable to all backends thus rendering the POD for this class more important to the
end-programmer than the usage of the class itself.
EXPORT
None
INHERITS
None
BACKEND EXTENSIONS
nautilus
EXAMPLE
my @paths = $d->nautilus->paths();
DESCRIPTION
This method gives access to the UI::Dialog::Backend::Nautilus class. This will
automagically try to load the UI::Dialog::Backend::Nautilus module or it will
silently fail.
xosd
EXAMPLE
$d->xosd->line( "a line of text on your screen" );
DESCRIPTION
This method gives access to the UI::Dialog::Backend::XOSD class. This will
automagically try to load the UI::Dialog::Backend::XOSD module or it will
silently fail.
STATE METHODS
attr( )
EXAMPLE
my $value = $self->attr('listheight');
my $new_value = $d->attr('listheight',5);
DESCRIPTION
Either sets and returns the value of the desired attribute, or just returns the
value of the desired attribute.
RETURNS
a single SCALAR.
state( )
EXAMPLE
if ($d->state() eq "OK") {
# the last user response was "OK"
} else {
# something other than an "OK" response
}
DESCRIPTION
Returns the state of the last dialog widget command. The value can be one of
"OK", "CANCEL" or "ESC". The return data is based on the exit codes (return
value) of the last widget displayed. Some backends also support other exit
values than the standard few and these are represented as "EXTRA" \fIs0(3),
"HELP" \fIs0(2), and "ERROR" (255).
RETURNS
a single SCALAR.
ra( )
EXAMPLE
my @array = $d->ra();
DESCRIPTION
Returns the last widget's data as an array.
RETURNS
an ARRAY.
rs( )
EXAMPLE
my $string = $d->rs();
DESCRIPTION
Returns the last widget's data as a (possibly multiline) string.
RETURNS
a SCALAR.
rv( )
EXAMPLE
my $string = $d->rv();
DESCRIPTION
Returns the last widget's exit status, aka: return value. This is the value used
when determining the state() of a widget.
RETURNS
a SCALAR.
CALLBACK FUNCTIONS
PRE
EXAMPLE
sub CB_PRE {
my $widget_args = shift();
print "Caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { PRE => \&CB_PRE } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
before any widget performs any operations.
POST
EXAMPLE
sub CB_POST {
my $widget_args = shift();
my $state = shift();
print "Caller: ".$args->{'caller'}.", State: ".$state."\n";
}
my $d = new UI::Dialog ( callbacks => { POST => \&CB_POST } );
DESCRIPTION
This function recieves a hasref of the current argument values and the one word
state indicator (as reported by state()) and is called after all widget
operations have been performed (including other callback functions).
OK
EXAMPLE
sub CB_OK_FUNC {
my $widget_args = shift();
print "Widget caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { OK => \&CB_OK_FUNC } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
when any widget finishes with a state() of "OK" but before the POST callback.
CANCEL
EXAMPLE
sub CB_CANCEL {
my $widget_args = shift();
print "Caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { CANCEL => \&CB_CANCEL } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
when any widget finishes with a state() of "CANCEL" but before the POST
callback. Be forewarned that with respect to the yesno() type widgets, a user
response of "NO" is interpreted as "CANCEL" and will execute this function.
ESC
EXAMPLE
sub CB_ESC {
my $widget_args = shift();
print "Caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { ESC => \&CB_ESC } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
when any widget finishes with a state() of "ESC" but before the POST callback.
HELP
EXAMPLE
sub CB_HELP {
my $widget_args = shift();
print "Caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { HELP => \&CB_HELP } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
when any widget finishes with a state() of "HELP" but before the POST callback.
The user response of "HELP" is not supported by all backends.
EXTRA
EXAMPLE
sub CB_EXTRA {
my $widget_args = shift();
print "Caller: ".$args->{'caller'}."\n";
}
my $d = new UI::Dialog ( callbacks => { EXTRA => \&CB_EXTRA } );
DESCRIPTION
This function recieves a hasref of the current argument values and is called
when any widget finishes with a state() of "EXTRA" but before the POST callback.
The user response of "EXTRA" is not supported by all backends.
UTILITY METHODS
beep( )
EXAMPLE
$d->beep();
DESCRIPTION
If the beep(1) application can be found, use it to make a beep sound. Otherwise
print "\a" to STDERR which normally is good enough to make some noise.
RETURNS
TRUE \fIs0(1) regardless of result.
clear( )
EXAMPLE
$d->clear();
DESCRIPTION
Clear the terminal screen via STDOUT and the `clear` command. This method is
technically useless for any GUI based dialog variants.
RETURNS
TRUE \fIs0(1) regardless of result.
word_wrap( )
EXAMPLE
my @wrapped_text = $d->word_wrap($cols,$indent,$sub_indent,@text);
DESCRIPTION
Using the Text::Wrap::wrap function, wrap the words in a string (or array of
strings). This is primarily used within the _organize_text() method but may be
of use to the end-programmer.
RETURNS
A word-wrapped version of the given text data.
gen_tempfile_name( )
EXAMPLE
my $tempfile = $d->gen_tempfile_name();
DESCRIPTION
This method returns a temporary file name generated using one of the following
(in order): the File::Temp perl module if detected, the program "mktemp" or an
extremely simplistic built-in name generator.
RETURNS
A temporary file name.
gen_random_string( )
EXAMPLE
my $random_string = $d->gen_random_string(5);
DESCRIPTION
This will return a string of random (printable) characters of an arbitrary user-
definable length (defaults to 5);
RETURNS
A string of random ASCII characters.
WIDGET WRAPPER METHODS
These methods are common methods to most backends as they do not have native support for
the functionality, yet the functionality is achievable by utilizing existing compatible
methods.
fselect( )
EXAMPLE
my $path = $self->fselect( path => $start_path );
DESCRIPTION
Using the menu() and msgbox() widgets we can simulate a file browser interface.
Note: to select a directory, go into it and then pick the '.' entry.
RETURNS
a SCALAR for positive results and FALSE \fIs0(0) for everything else.
dselect( )
EXAMPLE
my $path = $self->dselect( path => $start_path );
DESCRIPTION
Using the fselect() widget we can simulate a directory browser interface. Note:
to select a directory, go into it and then pick the '.' entry.
RETURNS
a SCALAR for positive results and FALSE \fIs0(0) for everything else.
BACKEND METHODS
These methods are only necessary for someone wishing to create more UI::Dialog::Backend::
Modules. These are never needed to be directly used but are none the less documented here
for reference purposes.
command_state( )
EXAMPLE
if ($self->command_state("/some/shell/command")) {
#: command succeeded
} else {
#: command failed
}
DESCRIPTION
This will execute the given command and send STDOUT and STDERR to /dev/null then
analyse the exit code and return accordingly.
RETURNS
TRUE \fIs0(1) for positive results and FALSE \fIs0(0) for anything else.
command_string( )
EXAMPLE
my ($rv,$scalar) = $self->command_string("/some/shell/command");
if ($rv >= 1) {
#: command failed
} else {
#: command succeeded
print "The command results: ".$scalar."\n";
}
DESCRIPTION
This will execute the given command, catch STDOUT and STDERR, then return the
SCALAR data.
RETURNS
a SCALAR for positive results and FALSE \fIs0(0) for anything else.
command_array( )
EXAMPLE
my ($rv,@array) = $self->command_array("/some/shell/command");
if ($rv >= 1) {
#: command failed
} else {
#: command succeeded
foreach my $line_of_output (@array) {
print "The command results: ".$line_of_output."\n";
}
}
DESCRIPTION
This will execute the given command, catch STDOUT and STDERR, then return the
data, split by newlines, as an ARRAY.
RETURNS
an ARRAY for positive results and FALSE \fIs0(0) for anything else.
_pre( )
EXAMPLE
my $args = $self->_pre(@_);
DESCRIPTION
This will use _merge_attrs(), perform any pre-widget-exec things and then return
the current argument list as a hashref. This is used in every widget before
anything is actually done in the widget and is responsible for running the
optional callback function labelled "PRE".
RETURNS
a HASHREF.
_post( )
EXAMPLE
$self->_post( $args );
DESCRIPTION
This method is used in every widget after all operations (for the immediate
widget call) are complete but before the widget actually returns anything. This
method is responsible for running the optional callback funcions labelled "OK",
"ESC", "CANCEL" and "POST" with "POST" being executed absolutely last.
RETURNS
Nothing.
_merge_attrs( )
EXAMPLE
my $args = $self->_merge_attrs(@_);
DESCRIPTION
This will apply the arguments passed in with the defaults stored in
$self->{'_opts'} (which was instantiated upon object construction). The return
result is the "current" options as defined by the defaults with the argument
options overriding them.
RETURNS
a HASHREF.
_find_bin( )
EXAMPLE
my $ZenityBinaryPath = $self->_find_bin('zenity');
DESCRIPTION
This will look in the default path directories for the program of the given
name. The default PATH list is: /bin, /usr/bin, /usr/local/bin, /opt/bin.
RETURNS
a SCALAR.
_esc_text( )
EXAMPLE
my $escaped_text = $self->_esc_text( $raw_text );
DESCRIPTION
This will escape the following with a prefixing '\' character:
Character -> Escaped
" \"
` \`
( \(
) \)
[ \[
] \]
{ \}
} \}
$ \$
< \<
> \>
RETURNS
an SCALAR for positive results and FALSE \fIs0(0) for anything else.
_strip_text( )
EXAMPLE
my $clean_text = $self->_strip_text( $text_with_markup );
DESCRIPTION
This will strip various markup sequences from within the given argument data.
RETURNS
an SCALAR for positive results and FALSE \fIs0(0) for anything else.
_organize_text( )
EXAMPLE
my $final_text1 = $self->_organize_text( $text_with_markup );
my $final_text2 = $self->_organize_text( \@text_with_markup );
DESCRIPTION
This will strip various markup sequences from within the given argument data.
RETURNS
a SCALAR for positive results and FALSE \fIs0(0) for anything else.
_is_bsd( )
EXAMPLE
if ($self->_is_bsd()) {
# do something with BSD specific characteristics
} else {
# do something with general perl characteristics
}
DESCRIPTION
This simply checks (case-insensitively) the perlvar $^0 for the string "bsd".
RETURNS
TRUE \fIs0(1) for positive results and FALSE \fIs0(0) for anything else.
_list_dir( )
EXAMPLE
my $menu_list = $self->_list_dir( '/some/path/to/a/directory',
[ 'optional', 'prefix', 'items' ] );
DESCRIPTION
Gather a list of the contents of a directory and forumlate a list suitable for
use with most (if not all) file/path selection dialog variant widgets. An
optional array reference will have all elements prefixing the directory list.
RETURNS
an ARRAYREF for positive results and FALSE \fIs0(0) for anything else.
_debug( )
EXAMPLE
$self->_debug( $debuging_message_string, $debuging_level );
DESCRIPTION
This method will print to STDERR the debugging message provided if and only if
the debuging level is greater than or equal to the $debuging_level. The
debugging level argument is optional and defaults to a level of 1.
RETURNS
TRUE \fIs0(1) for positive results and FALSE \fIs0(0) for anything else.
_error( )
EXAMPLE
$self->_error( $error_message_string );
DESCRIPTION
This method will print to STDERR the error message provided regardless of
debugging level.
RETURNS
TRUE \fIs0(1) for positive results and FALSE \fIs0(0) for anything else.
SEE ALSO
PERLDOC
UI::Dialog
UI::Dialog::Console
UI::Dialog::GNOME
UI::Dialog::KDE
UI::Dialog::Backend::ASCII
UI::Dialog::Backend::CDialog
UI::Dialog::Backend::GDialog
UI::Dialog::Backend::KDialog
UI::Dialog::Backend::Nautilus
UI::Dialog::Backend::Whiptail
UI::Dialog::Backend::XDialog
UI::Dialog::Backend::XOSD
UI::Dialog::Backend::Zenity
MAN FILES
dialog(1), whiptail(1), zenity(1), gdialog(1), Xdialog(1),
kdialog(1), nautilus(1) and osd_cat(1).
BUGS
Please email the author with any bug reports. Include the name of the module in the
subject line.
AUTHOR
Kevin C. Krinke, <kevin@krinke.ca>
COPYRIGHT AND LICENSE
Copyright (C) 2013 Kevin C. Krinke <kevin@krinke.ca>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA