Axis.pm

package Chart::Clicker::Axis;
use Moose;

extends 'Chart::Clicker::Container';
with 'Chart::Clicker::Positioned';

use Chart::Clicker::Data::Range;

use Graphics::Color::RGB;

use Graphics::Primitive::Font;

use Layout::Manager::Absolute;

use Math::Trig ':pi';

has 'tick_label_angle' => (
    is => 'rw',
    isa => 'Num'
);
has 'baseline' => (
    is  => 'rw',
    isa => 'Num',
);
# Remove for border...
has 'brush' => (
    is => 'rw',
    isa => 'Graphics::Primitive::Brush',
    default => sub {
        Graphics::Primitive::Brush->new(
            color => Graphics::Color::RGB->new(
                red => 1, green => 0, blue => 1, alpha => 1
            ),
            width => 1
        )
    }
);
has '+color' => (
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);
has 'format' => ( is => 'rw', isa => 'Str|CodeRef' );
has 'fudge_amount' => ( is => 'rw', isa => 'Num', default => 0 );
has 'hidden' => ( is => 'rw', isa => 'Bool', default => 0 );
has 'label' => ( is => 'rw', isa => 'Str' );
has 'label_color' => (
    is => 'rw',
    isa => 'Graphics::Color',
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);
has 'label_font' => (
    is => 'rw',
    isa => 'Graphics::Primitive::Font',
    default => sub { Graphics::Primitive::Font->new }
);
has '+layout_manager' => ( default => sub { Layout::Manager::Absolute->new });
has '+orientation' => (
    required => 1
);
has '+position' => (
    required => 1
);
has 'range' => (
    is => 'rw',
    isa => 'Chart::Clicker::Data::Range',
    default => sub { Chart::Clicker::Data::Range->new }
);
has 'show_ticks' => ( is => 'rw', isa => 'Bool', default => 1 );
has 'staggered' => ( is => 'rw', isa => 'Bool', default => 0 );
has 'skip_range' => (
    is => 'rw',
    isa => 'Chart::Clicker::Data::Range',
    predicate => 'has_skip_range'
);
has 'tick_font' => (
    is => 'rw',
    isa => 'Graphics::Primitive::Font',
    default => sub { Graphics::Primitive::Font->new }
);
has 'tick_label_color' => (
    is => 'rw',
    isa => 'Graphics::Color',
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);
has 'tick_labels' => (
    is => 'rw',
    isa => 'ArrayRef',
);
has 'tick_values' => (
    traits => [ 'Array' ],
    is => 'rw',
    isa => 'ArrayRef',
    default => sub { [] },
    handles => {
        'add_to_tick_values' => 'push',
        'clear_tick_values' => 'clear',
        'tick_value_count' => 'count'
    }
);
has 'ticks' => ( is => 'rw', isa => 'Int', default => 5 );

sub BUILD {
    my ($self) = @_;

    $self->padding(3);
}

override('prepare', sub {
    my ($self, $driver) = @_;

    $self->clear_components;

    # The BUILD method above establishes a 5px padding at instantiation time.
    # That saves us setting it elsewhere, but if 'hidden' feature is used,
    # then we have to unset the padding.  hidden (as explained below) is
    # basically a hack as far as G:P is concerned to render an empty Axis.
    # We want it to render because we need it prepared for other elements
    # of the chart to work.
    if($self->hidden) {
        $self->padding(0);
        # Hide the border too, jic
        $self->border->width(0);
    }

    super;

    if($self->range->span == 0) {
        die('This axis has a span of 0, that\'s fatal!');
    }

    if(defined($self->baseline)) {
        if($self->range->lower > $self->baseline) {
            $self->range->lower($self->baseline);
        }
    } else {
        $self->baseline($self->range->lower);
    }

    if($self->fudge_amount) {
        my $span = $self->range->span;
        my $lower = $self->range->lower;
        $self->range->lower($lower - abs($span * $self->fudge_amount));
        my $upper = $self->range->upper;
        $self->range->upper($upper + ($span * $self->fudge_amount));
    }

    if($self->show_ticks && !scalar(@{ $self->tick_values })) {
        $self->tick_values($self->range->divvy($self->ticks + 1));
    }

    # Return now without setting a min height or width and allow 
    # Layout::Manager to to set it for us, this is how we 'hide'
    return if $self->hidden;

    my $tfont = $self->tick_font;

    my $bheight = 0;
    my $bwidth = 0;

    # Determine all this once... much faster.
    my $i = 0;
    foreach my $val (@{ $self->tick_values }) {
        if($self->has_skip_range && $self->skip_range->contains($val)) {
            # If the label falls in inside the skip range, it's not to be
            # used at all.
            next;
        }

        my $label = $val;
        if(defined($self->tick_labels)) {
            $label = $self->tick_labels->[$i];
        } else {
            $label = $self->format_value($val);
        }

        my $tlabel = Graphics::Primitive::TextBox->new(
            text => $label,
            font => $tfont,
            color => $self->tick_label_color,
        );
        if($self->tick_label_angle) {
            $tlabel->angle($self->tick_label_angle);
        }
        my $lay = $driver->get_textbox_layout($tlabel);

        $tlabel->prepare($driver);

        $tlabel->width($lay->width);
        $tlabel->height($lay->height);

        $bwidth = $tlabel->width if($tlabel->width > $bwidth);
        $bheight = $tlabel->height if($tlabel->height > $bheight);

        $self->add_component($tlabel);
        $i++;
    }

    my $big = $bheight;
    if($self->is_vertical) {
        $big = $bwidth;
    }

    my $label_width = 0;
    my $label_height = 0;

    if ($self->label) {

        my $label = Graphics::Primitive::TextBox->new(
            # angle => $angle,
            color => $self->label_color,
            name => 'label',
            font => $self->label_font,
            text => $self->label,
            width => $self->height
        );

        if($self->is_vertical) {
            if ($self->is_left) {
                $label->angle(-&pip2);
            } else {
                $label->angle(&pip2)
            }
        }


        $label->prepare($driver);

        $label->width($label->minimum_width);
        $label->height($label->minimum_height);

        $label_width = $label->width;
        $label_height = $label->height;
        $self->add_component($label);
    }

    if($self->is_vertical) {
        $self->minimum_width($self->outside_width + $big + $label_width);
        $self->minimum_height($self->outside_height + $self->outside_height + $big);
    } else {
        $self->minimum_height($self->outside_height + $big + $label_height);
        $self->minimum_width($self->outside_width + $big + $self->outside_width);
        if($self->staggered) {
            $self->minimum_height($self->minimum_height * 2);
        }
    }

    return 1;
});

sub mark {
    my ($self, $span, $value) = @_;

    if($self->has_skip_range) {
        # We must completely ignore values that fall inside the skip range,
        # so we return an undef.
        return undef if $self->skip_range->contains($value);
        if($value > $self->skip_range->upper) {
            # If the value was outside the range, but above it then we must
            # be sure and substract the range we are skipping so that the
            # value will still fall on the chart.
            $value = $value - $self->skip_range->span;
        }
    }

    # 'caching' this here speeds things up.  Calling after changing the
    # range would result in a messed up chart anyway...
    if(!defined($self->{LOWER})) {
        $self->{LOWER} = $self->range->lower;
        if($self->has_skip_range) {
            # If we have a skip range then the RSPAN is less the skip range's
            # span.
            $self->{RSPAN} = $self->range->span - $self->skip_range->span;
        } else {
            $self->{RSPAN} = $self->range->span;
        }
    }

    return ($span / $self->{RSPAN}) * ($value - $self->{LOWER} || 0);
}

override('finalize', sub {
    my ($self) = @_;

    super;

    return if $self->hidden;

    my $x = 0;
    my $y = 0;

    my $width = $self->width;
    my $height = $self->height;
    my $ibb = $self->inside_bounding_box;
    my $iox = $ibb->origin->x;
    my $ioy = $ibb->origin->y;

    my $iwidth = $ibb->width;
    my $iheight = $ibb->height;

    if($self->is_left) {
        $x += $width;
    } elsif($self->is_right) {
        # nuffin
    } elsif($self->is_top) {
        $y += $height;
    } else {
        # nuffin
    }

    my $lower = $self->range->lower;
    my $upper = $self->range->upper;

    my @values = @{ $self->tick_values };

    if($self->is_vertical) {

        my $comp_count = 0;
        for(0..$#values) {
            my $val = $values[$_];
            my $mark = $self->mark($height, $val);
            next unless defined($mark);
            my $iy = $height - $mark;
            my $label = $self->get_component($comp_count);

            if($self->is_left) {
                $label->origin->x($iox + $iwidth - $label->width);
                if($val == $lower) {
                    # The first label (being at the bottom) needs to be
                    # skooched up a bit to fit.
                    $label->origin->y($iy - $label->height);
                } elsif($val == $upper) {
                    # The last label (being at the top) can be positioned
                    # exactly at the mark.
                    $label->origin->y($iy);
                } else {
                    $label->origin->y($iy - ($label->height / 2));
                }
            } else {

                $label->origin->x($iox);
                if($val == $lower) {
                    # The first label (being at the bottom) needs to be
                    # skooched up a bit to fit.
                    $label->origin->y($iy - $label->height);
                } elsif($val == $upper) {
                    # The last label (being at the top) can be positioned
                    # exactly at the mark.
                    $label->origin->y($iy);
                } else {
                    $label->origin->y($iy - ($label->height / 2));
                }
            }
            # Keep track of how many components we've actually grabbed, since
            # we could be skipping any that are in a skip range.
            $comp_count++;
        }

        # Draw the label
        # FIXME Not working, rotated text labels...
        if($self->label) {
            my $label = $self->get_component($self->find_component('label'));

            if($self->is_left) {

                $label->origin->x($iox);
                $label->origin->y(($height - $label->height) / 2);
            } else {

                $label->origin->x($iox + $iwidth - $label->width);
                $label->origin->y(($height - $label->height) / 2);
            }
        }
    } else {
        # Draw a tick for each value.
        my $comp_count = 0;
        for(0..$#values) {
            my $val = $values[$_];
            my $ix = $self->mark($width, $val);
            next unless defined($ix);

            my $label = $self->get_component($comp_count);

            my $bump = 0;
            if($self->staggered) {
                if($_ % 2) {
                    $bump = $iheight / 2;
                }
            }

            if($self->is_top) {

                if($val == $lower) {
                    $label->origin->x($ix);
                } elsif($val == $upper) {
                    $label->origin->x($ix - $label->width);
                } else {
                    $label->origin->x($ix - ($label->width / 1.8));
                }
                $label->origin->y($ioy + $iheight - $label->height - $bump);
            } else {
                if($val == $lower) {
                    $label->origin->x($ix);
                } elsif($val == $upper) {
                    $label->origin->x($ix - $label->width);
                } else {
                    $label->origin->x($ix - ($label->width / 1.8));
                }
                $label->origin->y($ioy + $bump);
            }
            # Keep track of how many components we've actually grabbed, since
            # we could be skipping any that are in a skip range.
            $comp_count++;
        }

        # Draw the label
        if($self->label) {
            my $label = $self->get_component($self->find_component('label'));

            my $ext = $self->{'label_extents_cache'};
            if ($self->is_bottom) {
                $label->origin->x(($width - $label->width) / 2);
                $label->origin->y($height - $label->height
                    - ($self->padding->bottom + $self->margins->bottom
                        + $self->border->top->width
                    )
                );
            } else {
                $label->origin->x(($width - $label->width) / 2);
            }
        }
    }
});

sub format_value {
    my $self = shift;
    my $value = shift;

    my $format = $self->format;
    if($format) {
        if(ref($format) eq 'CODE') {
            return &$format($value);
        } else {
            return sprintf($format, $value);
        }

    }
}

__PACKAGE__->meta->make_immutable;

no Moose;

1;
__END__

=head1 NAME

Chart::Clicker::Axis

=head1 DESCRIPTION

Chart::Clicker::Axis represents the plot of the chart.

=head1 SYNOPSIS

  use Chart::Clicker::Axis;
  use Graphics::Primitive::Font;
  use Graphics::Primitive::Brush;

  my $axis = Chart::Clicker::Axis->new({
    font  => Graphics::Primitive::Font->new,
    orientation => 'vertical',
    position => 'left',
    brush => Graphics::Primitive::Brush->new,
    visible => 1,
  });

=head1 ATTRIBUTES

=head2 baseline

The 'baseline' value of this axis.  This is used by some renderers to change
the way a value is marked.  The Bar render, for instance, considers values
below the base to be 'negative'.

=head2 brush

The brush for this axis.

=head2 color

The color of the axis' border.

=head2 format

The format to use for the axis values.

If the format is a string then format is applied to each value 'tick' via
sprintf.  See sprintf perldoc for details!  This is useful for situations
where the values end up with repeating decimals.

If the format is a coderef then that coderef will be executed and the value
passed to it as an argument.

  my $nf = Number::Format->new;
  $default->domain_axis->format(sub { return $nf->format_number(shift); });

=head2 fudge_amount

The amount to 'fudge' the span of this axis.  You should supply a
percentage (in decimal form) and the axis will grow at both ends by the
supplied amount.  This is useful when you want a bit of padding above and
below the dataset.

As an example, a fugdge_amount of .10 on an axis with a span of 10 to 50
would add 5 to the top and bottom of the axis.

=head2 height

The height of the axis.

=head2 hidden

This axis' hidden flag.  If this is true then the Axis will not be drawn.

=head2 label

The label of the axis.

=head2 label_color

The color of the Axis' labels.

=head2 label_font

The font used for the axis' label.

=head2 orientation

The orientation of this axis.  See L<Graphics::Primitive::Oriented>.

=head2 position

The position of the axis on the chart.

=head2 range

The Range for this axis.

=head2 show_ticks

If this is value is false then 'ticks' and their labels will not drawn for
this axis.

=head2 skip_range

Allows you to specify a range of values that will be skipped completely on
this axis.  This is often used to trim a large, unremarkable section of data.
If, for example, 50% of your values fall below 10 and 50% fall above 100 it
is useless to bother charting the 10 to 100 range.  Skipping it with this
attribute will make for a much more useful chart, albeit somewhat visually
skewed.

  $axis->skip_range(Chart::Clicker::Data::Range->new(lower => 10, upper => 100));
  
Note that B<any> data points, including ticks, that fall inside the range
specified will be completely ignored.

=head2 stagger

If true, causes horizontally labeled axes to 'stagger' the labels so that half
are at the top of the box and the other half are at the bottom.  This makes
long, overlapping labels less likely to overlap.  It only does something
useful with B<horizontal> labels.

=head2 tick_font

The font used for the axis' ticks.

=head2 tick_label_angle

The angle (in radians) to rotate the tick's labels.

=head2 tick_label_color

The color of the tick labels.

=head2 tick_values

The arrayref of values show as ticks on this Axis.

=head2 tick_value_count

Get a count of tick values.

=head2 tick_labels

The arrayref of labels to show for ticks on this Axis.  This arrayref is
consulted for every tick, in order.  So placing a string at the zeroeth index
will result in it being displayed on the zeroeth tick, etc, etc.

=head2 ticks

The number of 'ticks' to show.  Setting this will divide the range on this
axis by the specified value to establish tick values.  This will have no
effect if you specify tick_values.

=head2 width

This axis' width.

=head1 METHODS

=head2 new

Creates a new Chart::Clicker::Axis.  If no arguments are given then sane
defaults are chosen.

=head2 add_to_tick_values

Add a value to the list of tick values.

=head2 clear_tick_values

Clear all tick values.

=head2 mark

Given a span and a value, returns it's pixel position on this Axis.

=head2 format_value

Given a value, returns it formatted using this Axis' formatter.

=head2 prepare

Prepare this Axis by determining the size required.  If the orientation is
CC_HORIZONTAL this method sets the height.  Otherwise sets the width.

=head2 draw

Draw this axis.

=head2 BUILD

Documening for POD::Coverage tests, Moose stuff.

=head1 AUTHOR

Cory G Watson <gphat@cpan.org>

=head1 SEE ALSO

perl(1)

=head1 LICENSE

You can redistribute and/or modify this code under the same terms as Perl
itself.