www.carfield.com.hk

PracticalJMS.doc

2008-09-10T15:33:28Z

ObjectTemplate.pm

2008-03-17T17:25:12Z

package ObjectTemplate;
require Exporter;
@ObjectTemplate::ISA = qw(Exporter);
@ObjectTemplate::EXPORT = qw(attributes);

my $debugging = 0; # assign 1 to it to see code generated on the fly

# Create accessor functions, and new()
sub attributes {
    my ($pkg) = caller;
    @{"${pkg}::_ATTRIBUTES_"} = @_;
    my $code = "";
    foreach my $attr (get_attribute_names($pkg)) {
        # If a field name is "color", create a global list in the
        # calling package called @color
        @{"${pkg}::_$attr"} = ();

# Define accessor only if it is not already present
        unless ($pkg->can("$attr")) {
            $code .= _define_accessor ($pkg, $attr);
        } 
    }
    $code .= _define_constructor($pkg);
    eval $code;
    if ($@) {
       die  "ERROR defining constructor and attributes for '$pkg':" 
            . "\n\t$@\n" 
            . "-----------------------------------------------------"
            . $code;
    }
}

# $obj->set_attributes (name => 'John', age => 23);     
# Or, $obj->set_attributes (['name', 'age'], ['John', 23]);
sub set_attributes {
    my $obj = shift;
    my $attr_name;
    if (ref($_[0])) {
       my ($attr_name_list, $attr_value_list) = @_;
       my $i = 0;
       foreach $attr_name (@$attr_name_list) {
            $obj->$attr_name($attr_value_list->[$i++]);
       }
    } else {
       my ($attr_name, $attr_value);
       while (@_) {
           $attr_name = shift;
           $attr_value = shift;
           $obj->$attr_name($attr_value);
       }
    }
}

# @attrs = $obj->get_attributes (qw(name age));
sub get_attributes {
    my $obj = shift;
    my (@retval);
    map $obj->${_}(), @_;
}

sub get_attribute_names {
    my $pkg = shift;
    $pkg = ref($pkg) if ref($pkg);
    my @result = @{"${pkg}::_ATTRIBUTES_"};
    if (defined (@{"${pkg}::ISA"})) {
        foreach my $base_pkg (@{"${pkg}::ISA"}) {
           push (@result, get_attribute_names($base_pkg));
        }
    }
    @result;
}

sub set_attribute {
    my ($obj, $attr_name, $attr_value) = @_;
    my ($pkg) = ref($obj);
    ${"${pkg}::_$attr_name"}[$$obj] = $attr_value;
}

sub get_attribute {
    my ($obj, $attr_name, $attr_value) = @_;
    my ($pkg) = ref($obj);
    return ${"${pkg}::_$attr_name"}[$$obj];
}

sub DESTROY {
    # release id back to free list
    my $obj = $_[0];
    my $pkg = ref($obj);
    local *_free = *{"${pkg}::_free"};
    my $inst_id = $$obj;
    # Release all the attributes in that row
    local(*attributes) = *{"${pkg}::_ATTRIBUTES_"};
    foreach my $attr (@attributes) {
        undef ${"${pkg}::_$attr"}[$inst_id];
    }
    $_free[$inst_id] = $_free;
    $_free = $inst_id;
}

sub initialize { }; # dummy method, if subclass doesn�t define one.

#################################################################

sub _define_constructor {
    my $pkg = shift;
    my $code = qq {
        package $pkg;
        sub new {
            my \$class = shift;
            my \$inst_id;
            if (defined(\$_free[\$_free])) {
                \$inst_id = \$_free;
                \$_free = \$_free[\$_free];
                undef \$_free[\$inst_id];
            } else {
                \$inst_id = \$_free++;
            }
            my \$obj = bless \\\$inst_id, \$class;
            \$obj->set_attributes(\@_) if \@_;
            \$obj->initialize;
            \$obj;

}
    };
    $code;
}

sub _define_accessor {
    my ($pkg, $attr) = @_;

# This code creates an accessor method for a given
    # attribute name. This method  returns the attribute value 
    # if given no args, and modifies it if given one arg.
    # Either way, it returns the latest value of that attribute

# qq makes this block behave like a double-quoted string
    my $code = qq{
        package $pkg;
        sub $attr {                                      # Accessor ...
            \@_ > 1 ? \$_${attr} \[\${\$_[0]}] = \$_[1]  # set
                    : \$_${attr} \[\${\$_[0]}];          # get
        }
        if (!defined \$_free) {
            # Alias the first attribute column to _free
            \*_free = \*_$attr;
            \$_free = 0;
        };

};
    $code;
}

col.pl

2008-03-17T17:25:12Z

#!/opt/bin/perl
# Extracts columns of text from a file
# Usage : col [-s<n>] col-range1, col-range2, files ...
# where col-range is specified as col1-col2 (column 1 through column2) 
#         or col1+n, where n is the number of columns.
$size = 0;          # 0 => line-oriented input, else fixed format.
@files = ();        # List of files
$open_new_file = 1; # Force get_next_line() to open the first file
$debugging = 0;     # Enable with -d commmand line flag

generate_part1();  
generate_part2();
generate_part3();
col();           # sub col has now been generated. Call it !
exit(0);

#------------------------------------------------------------------
sub generate_part1 {
    # Generate the initial invariant code of sub col()
    $code  = 'sub col { my $tmp;';           # Note the single quotes
    $code .= 'while (1) {$s = get_next_line(); $col = "";';
    $delimiter = '|';
}

#------------------------------------------------------------------
sub generate_part2 {
    # Process arguments
    foreach $arg (@ARGV) {
        if (($col1, $col2) = ($arg =~ /^(\d+)-(\d+)/)) {
            $col1--;# Make it 0 based
            $offset = $col2 - $col1;
            add_range($col1, $offset);
        } elsif (($col1, $offset) = ($arg =~ /^(\d+)\+(\d+)/)) {
            $col1--;
            add_range($col1, $offset);
        } elsif ($size = ($arg =~ /-s(\d+)/)) {
            # noop
        } elsif ($arg =~ /^-d/) {
            $debugging = 1;
        } else {
            # Must be a file name
            push (@files, $arg);
        }
    }
}

#------------------------------------------------------------------
sub generate_part3 {
    $code .= 'print $col, "\n";}}';

print $code if $debugging; # -d flag enables debugging.
    eval $code;
    if ($@) {
        die "Error ...........\n $@\n $code \n";
    }
}

#------------------------------------------------------------------
sub add_range { 
    my ($col1, $numChars) = @_;
    # substr complains (under -w) if we look past the end of a string
    # To prevent this, pad the string with spaces if necessary.
    $code .= "\$s .= ' ' x ($col1 + $numChars - length(\$s))";
    $code .= "    if (length(\$s) < ($col1+$numChars));";
    $code .= "\$tmp = substr(\$s, $col1, $numChars);";
    $code .= '$tmp .= " " x (' . $numChars .  ' - length($tmp));';
    $code .= "\$col .= '$delimiter' . \$tmp; ";
}

#------------------------------------------------------------------
sub get_next_line {
    my($buf);

NEXTFILE:
    if ($open_new_file) {
        $file = shift @files || exit(0);
        open (F, $file) || die "$@ \n";
        $open_new_file = 0;
    }
    if ($size) {
        read(F, $buf, $size);
    } else {
        $buf = <F>;
    }
    if (! $buf) {
        close(F);
        $open_new_file = 1;
        goto NEXTFILE;
    }
    chomp($buf);
    # Convert tabs to spaces (assume tab stop width == 8)

# expand leading tabs first � the common case
    $buf =~ s/^(\t+)/' ' x (8 * length($1))/e;

# Now look for nested tabs. Have to expand them one at a time - hence
    # the while loop. In each iteration, a tab is replaced by the number of
    # spaces left till the next tab-stop. The loop exits when there are
    # no more tabs left
    1 while ($buf =~ s/\t/' ' x (8 - length($`)%8)/e);

$buf;
}

METRICS.JAVA

2008-03-17T17:25:10Z

// This example is from the book _Java AWT Reference_ by John Zukowski.
// Written by John Zukowski.  Copyright (c) 1997 O'Reilly & Associates.
// You may study, use, modify, and distribute this example for any purpose.
// This example is provided WITHOUT WARRANTY either expressed or
import java.awt.*;
public class metrics extends Frame {
    metrics () {
        super ("metrics");
        setFont (new Font ("TimesRoman", Font.BOLD | Font.ITALIC, 48));
        resize (225, 175);
    }
    public boolean handleEvent (Event e) {
        if (e.id == Event.WINDOW_DESTROY) {
            dispose();
            System.exit (1);
        }
        return super.handleEvent (e);
    }
    public void update (Graphics g) {
        paint(g);
    }
    public void paint (Graphics g) {
        g.translate (insets().left, insets().top);
        FontMetrics fm = null;
        int ascent, descent, leading, width1, width2, height;
        String string1 = "O'Reilly";
        String string2 = "紑eilly";
        int xPos = 25, yPos = 50;
        fm = g.getFontMetrics();
        ascent  = fm.getAscent();
        descent = fm.getDescent();
        leading = fm.getLeading();
        height  = fm.getHeight();
        width1  = fm.stringWidth (string1);
        width2  = fm.stringWidth (string2);
        g.drawString (string1, xPos, yPos);
        g.drawLine (xPos, yPos - ascent - leading,
                    xPos + width1, yPos - ascent - leading);
        g.drawLine (xPos, yPos - ascent,
                    xPos + width1, yPos - ascent);
        g.drawLine (xPos, yPos,
                    xPos + width1, yPos);
        g.drawLine (xPos, yPos + descent,
                    xPos + width1, yPos + descent);
        g.drawString (string2, xPos, yPos+height);
        g.drawLine (xPos, yPos - ascent - leading + height,
                    xPos + width2, yPos - ascent - leading + height);
        g.drawLine (xPos, yPos - ascent + height,
                    xPos + width2, yPos - ascent + height);
        g.drawLine (xPos, yPos + height,
                    xPos + width2, yPos + height);
        g.drawLine (xPos, yPos + descent + height,
                    xPos + width2, yPos + descent + height);

    }
    public static void main (String[] args) {
        Frame f = new metrics ();
        f.show();
    }
}

team-list.html

2007-04-25T09:21:28Z

using-plugins.html

2007-04-25T09:21:28Z

writing-plugins.html

2007-04-25T09:21:28Z

simple-project.html

2007-04-25T09:21:26Z

site-generation.html

2007-04-25T09:21:26Z

source-repository.html

2007-04-25T09:21:26Z

reporting.html

2007-04-25T09:21:24Z

repository.html

2007-04-25T09:21:24Z

settings-details.html

2007-04-25T09:21:24Z

project-info.html

2007-04-25T09:21:22Z

project-summary.html

2007-04-25T09:21:22Z

properties.html

2007-04-25T09:21:22Z

pom-details.html

2007-04-25T09:21:20Z

pom-relationships.html

2007-04-25T09:21:20Z

profiles.html

2007-04-25T09:21:20Z

lifecycle.html

2007-04-25T09:21:18Z

mail-lists.html

2007-04-25T09:21:18Z

plugin-apis.html

2007-04-25T09:21:18Z

introduction.html

2007-04-25T09:21:16Z

issue-tracking.html

2007-04-25T09:21:16Z

j2ee.html

2007-04-25T09:21:16Z