Axis.pm

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

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

# ABSTRACT: An X or Y Axis

use Class::Load;

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

use English qw(-no_match_vars);

use Graphics::Color::RGB;

use Graphics::Primitive::Font;

use Layout::Manager::Absolute;

use Math::Trig ':pi';

=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({
    label_font  => Graphics::Primitive::Font->new,
    orientation => 'vertical',
    position => 'left',
    brush => Graphics::Primitive::Brush->new,
    visible => 1,
  });

=attr height

The height of the axis.

=attr width

This axis' width.

=attr tick_label_angle

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

has 'tick_label_angle' => (
    is  => 'rw',
    isa => 'Num'
);

=attr tick_division_type

Selects the algorithm for dividing the graph axis into labelled ticks.

The currently included algorithms are:
L<Chart::Clicker::Data::DivisionType::Exact/Exact>,
L<Chart::Clicker::Data::DivisionType::RoundedLinear/RoundedLinear>.

You may write your own by providing a Moose Role which includes Role
L<Chart::Clicker::Data::DivisionType> and prefixing the module name
with + when setting tick_division_type.

 Chart::Clicker::Axis->new(tick_division_type => '+MyApp::TickDivision');

This value should only be set once per axis.

=cut

has 'tick_division_type' => ( is => 'rw', isa => 'Str', default => 'Exact' );

# The above tick division type is loaded on the first call to divvy()
has '_tick_division_type_loaded' => ( is => 'ro', isa => 'Bool', lazy_build => 1 );

=attr 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'.

=cut

has 'baseline' => (
    is  => 'rw',
    isa => 'Num',
);

=attr brush

The brush for this axis.  Expects a L<Graphics::Primitve::Brush>.

=cut

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
        )
    }
);

=attr color

The color of the axis' border.  Expects a L<Graphics::Color::RGB> object.
Defaults to black.

=cut

has '+color' => (
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);

=attr 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); });

=cut

has 'format' => ( is => 'rw', isa => 'Str|CodeRef', default => '%s' );

=attr 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.

=cut

has 'fudge_amount' => ( is => 'rw', isa => 'Num', default => 0 );

=attr hidden

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

=cut

has 'hidden' => ( is => 'rw', isa => 'Bool', default => 0 );

=attr label

The label of the axis.

=cut

has 'label' => ( is => 'rw', isa => 'Str' );

=attr label_color

The color of the Axis' labels. Expects a L<Graphics::Color::RGB> object.

=cut

has 'label_color' => (
    is => 'rw',
    isa => 'Graphics::Color',
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);

=attr label_font

The font used for the axis' label. Expects a L<Graphics::Primitive::Font> object.

=cut

has 'label_font' => (
    is => 'rw',
    isa => 'Graphics::Primitive::Font',
    default => sub { Graphics::Primitive::Font->new }
);

=attr layout_manager

Set/Get the Layout Manager.  Defaults to L<Layout::Manager::Absolute>.

=cut

has '+layout_manager' => ( default => sub { Layout::Manager::Absolute->new });

=attr orientation

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

=cut

has '+orientation' => (
    required => 1
);

=attr position

The position of the axis on the chart.

=cut

has '+position' => (
    required => 1
);

=attr range

The Range for this axis. Expects a L<Chart::Clicker::Data::Range> object.
You may use this to explicitly set an upper and lower bound for the chart:

  $axis->range->max(1000);
  $axis->range->min(1);

=cut

has 'range' => (
    is => 'rw',
    isa => 'Chart::Clicker::Data::Range',
    default => sub { Chart::Clicker::Data::Range->new }
);

=attr show_ticks

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

=cut

has 'show_ticks' => ( is => 'rw', isa => 'Bool', default => 1 );

=attr staggered

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.

=cut

has 'staggered' => ( is => 'rw', isa => 'Bool', default => 0 );

=attr 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.

=cut

has 'skip_range' => (
    is => 'rw',
    isa => 'Chart::Clicker::Data::Range',
    predicate => 'has_skip_range'
);

=attr tick_font

The font used for the axis' ticks. Expects a L<Graphics::Primitive::Font> object.

=cut

has 'tick_font' => (
    is => 'rw',
    isa => 'Graphics::Primitive::Font',
    default => sub { Graphics::Primitive::Font->new }
);

=attr tick_label_color

The color of the tick labels. Expects a L<Graphics::Color::RGB> object.

=cut

has 'tick_label_color' => (
    is => 'rw',
    isa => 'Graphics::Color',
    default => sub {
        Graphics::Color::RGB->new({
            red => 0, green => 0, blue => 0, alpha => 1
        })
    }
);

=attr 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.

=cut

has 'tick_labels' => (
    is => 'rw',
    isa => 'ArrayRef',
);

=attr tick_values

The arrayref of values show as ticks on this Axis.

=method add_to_tick_values

Add a value to the list of tick values.

=method clear_tick_values

Clear all tick values.

=method tick_value_count

Get a count of tick values.

=cut

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'
    }
);

=attr 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.

=cut

has 'ticks' => ( is => 'rw', isa => 'Int', default => 5 );

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

    $self->padding(3);
}

sub _build__tick_division_type_loaded {
    my $self = shift;

    # User modules are prefixed with a +.
    my $divisionTypeModule;
    my $extensionOf = 'Chart::Clicker::Axis::DivisionType';
    if ( $self->tick_division_type =~ m/^\+(.*)$/xmisg ) {
        $divisionTypeModule = $1;
    }
    else {
        $divisionTypeModule = sprintf( '%s::%s', $extensionOf, $self->tick_division_type );
    }

    # Try to load the DivisionType module. An error is thrown when the class is
    # not available or cannot be loaded
    Class::Load::load_class($divisionTypeModule);

    # Apply the newly loaded role to this class.
    Moose::Util::apply_all_roles( $self => $divisionTypeModule );
    if ( not $self->does($extensionOf) ) {
        die("Module $divisionTypeModule does not extend $extensionOf");
    }

    return 1;
}

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->divvy);
    }

    # 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)) {
            if (defined $self->tick_labels->[$i]) {
                $label = $self->tick_labels->[$i];
            }
            else {
                $label = "";
            }
        } 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,
            horizontal_align => 'center'
        );
        $label->name('label');
        use Graphics::Color::RGB;
        $label->border->color(Graphics::Color::RGB->new(r => 0, g => 0, b => 0));
        

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

    return 1;
});

=method mark

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

=cut

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

    return undef if not defined $value;
    if($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) = @_;

    if($self->hidden) {
        # Call the callback, just in case it matters.
        super;
        return;
    }

    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);

            # Adjust text on the Y axis to fit when it is
            # too close to the edges
            my $standardYOrigin = $iy - ($label->height / 2);
            #my $lowerYOrigin = $iy - $label->height;
            my $lowerYOrigin = $ioy + $iheight - $label->height;
            my $upperYOrigin = $ioy;
            if($standardYOrigin >= $lowerYOrigin) {
                # The first label (being at the bottom) needs to be
                # skooched up a bit to fit.
                $label->origin->y($lowerYOrigin);
            } elsif($standardYOrigin <= $upperYOrigin) {
                # The last label (being at the top) can be positioned
                # exactly at the mark.
                $label->origin->y($upperYOrigin);
            } else {
                $label->origin->y($standardYOrigin);
            }

            if($self->is_left) {
                $label->origin->x($iox + $iwidth - $label->width);
            } else {
                $label->origin->x($iox);
            }
            # 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;
                }
            }

            # Adjust the X-origin value to ensure it is within the graph
            # and does not get snipped when too close to the edge.
            my $standardXOrigin = $ix - ($label->width / 1.8);
            my $lowerXOrigin = $iox;
            my $upperXOrigin = $iox + $iwidth - $label->width;
            if($standardXOrigin <= $lowerXOrigin) {
                $label->origin->x($lowerXOrigin);
            } elsif($standardXOrigin >= $upperXOrigin) {
                $label->origin->x($upperXOrigin);
            } else {
                $label->origin->x($standardXOrigin);
            }

            if($self->is_top) {
                $label->origin->y($ioy + $iheight - $label->height - $bump);
            } else {
                $label->origin->y($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);
            }
        }
    }

    super;
});

=method format_value

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

=cut

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);
        }

    }
}

=method divvy

Retrieves the divisions or ticks for the axis.

=cut

sub divvy {
    my $self = shift;

    # Loads the divvy module once and only once
    # which implements _real_divvy()
    $self->_tick_division_type_loaded;
    return $self->_real_divvy();
}

__PACKAGE__->meta->make_immutable;

no Moose;

1;