Move everything into attributes.

Genealogy/Chart/SVG.pm

@@ -9,31 +9,6 @@ use Time::Piece;
 use File::Basename;
 use SVG;
 
-use constant BAR_HEIGHT => 18;
-use constant YEARS => 200;
-use constant PX_PER_YR => 5;
-use constant HEIGHT => 1500;
-
-my @colours = do {
-  no warnings 'qw'; # I know what I'm doing here!
-  map { "rgb($_)" }
-    qw[
-      0
-      255,127,127
-      127,255,127
-      127,127,255
-      255,255,127
-      255,127,255
-      127,255,255
-    ];
-};
-
-my $grey  = 'rgb(127,127,127)';
-my $black = 'rgb(0,0,0)';
-
-my $left = localtime->year;
-my $right = $left - YEARS;
-
 has svg => (
   is  => 'ro',
   isa => 'SVG',
@@ -42,24 +17,91 @@ has svg => (
 );
 
 sub _build_svg {
-  return SVG->new(width => (YEARS * PX_PER_YR), height => HEIGHT);
+  my $self = shift;
+  return SVG->new(
+    width => ($self->years * $self->pixels_per_year),
+    height => $self->height,
+  );
+}
+
+has colours => (
+  is  => 'ro',
+  isa => 'ArrayRef',
+  lazy_build => 1,
+);
+
+sub _build_colours {
+  no warnings 'qw'; # I know what I'm doing here!
+  return [ map { "rgb($_)" }
+             qw(
+                0
+                255,127,127
+                127,255,127
+                127,127,255
+                255,255,127
+                255,127,255
+                127,255,255
+             ) ];
 }
 
+has bar_height => (
+  is  => 'ro',
+  isa => 'Int',
+  default => 18,
+);
+
+has years => (
+  is  => 'ro',
+  isa => 'Int',
+  default => 200,
+);
+
+has pixels_per_year => (
+  is  => 'ro',
+  isa => 'Int',
+  default => 5,
+);
+
+has height => (
+  is  => 'ro',
+  isa => 'Int',
+  default => 1500,
+);
+
+has left => (
+  is  => 'ro',
+  isa => 'Int',
+  default => localtime->year,
+);
+
+has decade_line_colour => (
+  is  => 'ro',
+  isa => 'Str',
+  default => 'rgb(127,127,127)',
+);
+
+has bar_outline_colour => (
+  is  => 'ro',
+  isa => 'Str',
+  default => 'rgb(0,0,0)',
+);
+
 sub BUILD {
   my $self = shift;
 
-  my $curr_y = $left;
+  my $curr_y = $self->left;
   my $x = 0;
   # Draw the decade lines
-  while ($curr_y > ($left - YEARS)) {
+  while ($curr_y > ($self->left - $self->years)) {
     unless ($curr_y % 10) {
-      $self->line(x1 => $x, y1 => 0, x2 => $x, y2 => HEIGHT,
-                  stroke => $grey, stroke_width => 1);
+      $self->line(x1 => $x, y1 => 0, x2 => $x, y2 => $self->height,
+                  stroke => $self->decade_line_colour,
+                  stroke_width => 1);
       $self->text(x => $x + 1, y => 12,
-                 'font-size' => BAR_HEIGHT / 2)->cdata($curr_y);
+                 'font-size' => $self->bar_height / 2)->cdata($curr_y);
     }
     $curr_y--;
-    $x += PX_PER_YR;
+    $x += $self->pixels_per_year;
   }
 
   return $self;
@@ -71,32 +113,40 @@ sub person {
 
   my $gen = gen($n);
 
-  my $until = $d || $left;
+  my $until = $d || $self->left;
 
   my $p = $self->rect(
-            x => ($left - $until) * PX_PER_YR,
-            y => (HEIGHT * y_pos($n)) - (BAR_HEIGHT / 2),
-            width => ($until - $b) * PX_PER_YR,
-            height => BAR_HEIGHT,
-            fill => $colours[$gen],
-            stroke => $black,
+            x => ($self->left - $until) * $self->pixels_per_year,
+            y => ($self->height * y_pos($n)) - ($self->bar_height / 2),
+            width => ($until - $b) * $self->pixels_per_year,
+            height => $self->bar_height,
+            fill => $self->colours->[$gen],
+            stroke => $self->bar_outline_colour,
             'stroke-width' => 1
           );
 
   my $text = "$n: $name ($b - ";
   $text .= $d if $d;
   $text .= ')';
-  $self->text(x => ($left - $until + 2) * PX_PER_YR,
-              y => (HEIGHT * y_pos($n)) + (BAR_HEIGHT / 2) - 3,
-              'font-size' => BAR_HEIGHT - 4)->cdata($text);
+  $self->text(x => ($self->left - $until + 2) * $self->pixels_per_year,
+              y => ($self->height * y_pos($n)) + ($self->bar_height / 2) - 3,
+              'font-size' => $self->bar_height - 4)->cdata($text);
 }
 
+# Get the generation number from an Ahnentafel number.
+# Person 1 is in generation 1
+# Persons 2 & 3 are Person 1's parents and are in generation 2
+# Persons 4, 5, 6 & 7 are Person 1's grandparents and are in generation 3
+# etc ...
 sub gen {
   die unless @_;
 
   return int log($_[0])/log(2) + 1;
 }
 
+# Calculate the y-position for a given person number.
+# Not entirely sure how I did this, to be honest. Need to reverse engineer
+# it and document it!
 sub y_pos {
   die unless @_;
 
@@ -116,4 +166,4 @@ sub den {
 }
 
 
-1;
+1;