File Coverage

blib/lib/Gtk2/Ex/NumAxis.pm

Criterion	Covered	Total	%
statement	9	11	81.8
branch			n/a
condition			n/a
subroutine	4	4	100.0
pod			n/a
total	13	15	86.6

# Copyright 2007, 2008, 2009, 2010, 2011, 2014, 2017 Kevin Ryde

# This file is part of Gtk2-Ex-NumAxis.
#
# Gtk2-Ex-NumAxis is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# Gtk2-Ex-NumAxis 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 General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Gtk2-Ex-NumAxis.  If not, see .

package Gtk2::Ex::NumAxis;
use 5.008;
use strict;
use warnings;
use Gtk2 1.220;
use List::Util qw(min max);
use Math::Round ();
use POSIX qw(floor ceil);
use Gtk2::Ex::AdjustmentBits;

# uncomment this to run the ### lines
#use Smart::Comments;

our $VERSION = 6;

use Glib::Ex::SignalBits;
use Glib::Ex::SignalIds;

use Glib::Object::Subclass
  'Gtk2::DrawingArea',
  signals => { expose_event      => \&_do_expose_event,
               size_request      => \&_do_size_request,
               style_set         => \&_do_style_or_direction,
               direction_changed => \&_do_style_or_direction,
               scroll_event      => \&_do_scroll_event,

               'set-scroll-adjustments' =>
               { param_types => ['Gtk2::Adjustment',
                                 'Gtk2::Adjustment'],
                 return_type => undef,
                 class_closure => \&_do_set_scroll_adjustments },

               'number-to-text' =>
               { param_types => ['Glib::Double','Glib::Int'],
                 return_type => 'Glib::String',
                 flags       => ['run-last'],
                 accumulator => \&Glib::Ex::SignalBits::accumulator_first_defined,
                 class_closure => \&_do_number_to_text },

               # Glib::ParamSpec->scalar
               # ('transform',
               #  'transform',
               #  '',
               #  Glib::G_PARAM_READWRITE),
               #
               # Glib::ParamSpec->scalar
               # ('untransform',
               #  'untransform',
               #  '',
               #  Glib::G_PARAM_READWRITE),
             },
  properties => [Glib::ParamSpec->object
                 ('adjustment',
                  'Adjustment object',
                  'The adjustment object to display values from.',
                  'Gtk2::Adjustment',
                  Glib::G_PARAM_READWRITE),

                 Glib::ParamSpec->int
                 ('min-decimals',
                  'Minimum decimals',
                  'A minimum number of decimal places to display.',
                  # range limited to 1000 decimals to try to catch garbage
                  # going in and to try to stop calculated width becoming
                  # something wild
                  0, 1000,  # min, max
                  0,        # default
                  Glib::G_PARAM_READWRITE),

                 Glib::ParamSpec->boolean
                 ('inverted',
                  (do { # translation from GtkScrollbar
                    my $str = 'Inverted';
                    eval { require Locale::Messages;
                           Locale::Messages::dgettext('gtk20-properties',$str)
                           } || $str }),
                  'Invert the scale so numbers are drawn increasing from the bottom up, instead of the default top down.',
                  0,       # default
                  Glib::G_PARAM_READWRITE),

                 Glib::ParamSpec->enum
                 ('orientation',
                  (do { # translation from GtkOrientable
                    my $str = 'Orientation';
                    eval { require Locale::Messages;
                           Locale::Messages::dgettext('gtk20-properties',$str)
                           } || $str }),
                  'Horizontal or vertical display and scrolling.',
                  'Gtk2::Orientation',
                  'vertical',
                  Glib::G_PARAM_READWRITE),

                ];


# as fraction of digit width
# these not documented, could be properties or style properties
use constant { TICK_WIDTH_FRAC => 0.8,
               TICK_GAP_FRAC   => 0.5,
               TICK_HEIGHT_FRAC  => 0.4,
               TICK_VGAP_FRAC    => 0.1,
             };
# right-margin 0.2    between number and right edge of window

sub INIT_INSTANCE {
  my ($self) = @_;
  $self->{'min_decimals'} = 0; # default
  $self->{'decided_done_for'} = 'x';
}

sub SET_PROPERTY {
  my ($self, $pspec, $newval) = @_;
  my $pname = $pspec->get_name;
  ### SET_PROPERTY: $pname, $newval
  $self->{$pname} = $newval;  # per default GET_PROPERTY

  if ($pname eq 'adjustment') {
    my $adj = $newval;
    $self->{'adjustment_ids'} = $adj && do {
      Scalar::Util::weaken (my $weak_self = $self);
      Glib::Ex::SignalIds->new
          ($adj,
           $newval->signal_connect (value_changed => \&_do_adj_value_changed,
                                    \$weak_self),
           $newval->signal_connect (changed => \&_do_adj_other_changed,
                                    \$weak_self));
    };
  }

  $self->{'decided_done_for'} = 'x';
  $self->queue_resize;
  $self->queue_draw;
}

# 'set-scroll-adjustments' class closure
sub _do_set_scroll_adjustments {
  my ($self, $hadj, $vadj) = @_;
  $self->set (adjustment => ($self->get('orientation') eq 'horizontal'
                             ? $hadj : $vadj));
}

# my %direction_to_orientation = (up    => 'vertical',
#                                 down  => 'vertical',
#                                 left  => 'horizontal',
#                                 right => 'horizontal');

# 'scroll-event' class closure
sub _do_scroll_event {
  my ($self, $event) = @_;
  ### NumAxis _do_scroll_event(): $event->direction
  if (my $adj = $self->{'adjustment'}) {
    _adjustment_scroll_event ($adj, $event, $self->{'inverted'});
  }
  return $self->signal_chain_from_overridden ($event);
}

my %direction_inverted = (up => 1,
                          down => 0,
                          left => 1,
                          right => 0);
# $event is a Gtk2::Gdk::Event::Scroll
sub _adjustment_scroll_event {
  my ($adj, $event, $inverted) = @_;
  my $inctype = ($event->state & 'control-mask'
                 ? 'page_increment'
                 : 'step_increment');
  my $add = $adj->$inctype;
  unless ((!$inverted) ^ $direction_inverted{$event->direction}) {
    $add = -$add;
  }
  Gtk2::Ex::AdjustmentBits::scroll_value ($adj, $add);
}

# 'size-request' class closure
sub _do_size_request {
  my ($self, $req) = @_;
  ### NumAxis _do_size_request()
  ### orientation: $self->get('orientation')

  if ($self->get('orientation') eq 'horizontal') {
    $req->width (0);
    $req->height (_decide_height ($self));
  } else {
    $req->width (_decide_width ($self));
    $req->height (0);
  }
  ### NumAxis _do_size_request() return: $req->width . 'x' . $req->height
}

# 'number-to-text' class closure
sub _do_number_to_text {
  my ($self, $number, $decimals) = @_;
  ### _do_number_to_text()
  ### $number
  ### $decimals
  return sprintf ('%.*f', $decimals, $number);
}

sub identity {
  return $_[0];
}

my %wh = (horizontal => 'width',
          vertical   => 'height');

sub _do_expose_event {
  my ($self, $event) = @_;
  ### NumAxis _do_expose_event(): $self->get_name
  ### decided width: $self->{'decided_width'}

  my $adj = $self->{'adjustment'} || do {
    ### no adjustment, no draw
    return Gtk2::EVENT_PROPAGATE;
  };
  my $page_size = $adj->page_size || do {
    ### zero height page, no draw
    return Gtk2::EVENT_PROPAGATE;
  };

  my $lo = $adj->get_value;
  my ($unit, $unit_decimals) = _decide_unit ($self, $lo);
  ### $unit
  ### $unit_decimals
  if ($unit == 0) {
    ### unit zero, no draw
    return Gtk2::EVENT_PROPAGATE;
  }
  my $hi = $lo + $page_size;
  ### $lo
  ### $hi

  my $layout     = _layout($self);
  my $decimals   = $self->{'min_decimals'};
  my $state      = $self->state;
  my $style      = $self->style;
  my $win        = $self->window;
  my $orientation = $self->get('orientation');
  my $win_pixels = do {
    my $method = $wh{$orientation};
    $self->allocation->$method
  };
  my $clip_rect = $event->area;

  my $factor    = $win_pixels / $page_size;
  my $offset    = 0;
  if ($self->{'inverted'}) {
    $factor = -$factor;
    $offset = $win_pixels;
    ### invert
    ### $factor
    ### $offset
  }
  $offset += -$lo * $factor;

  my $digit_height  = $self->{'digit_height'};
  $decimals = max ($decimals, $unit_decimals);
  my $widen = $digit_height / abs($factor);
  $lo -= $widen;
  $hi += $widen;
  ### $win_pixels
  ### $factor
  ### digit_height pixels: $digit_height
  ### which is widen value: $widen
  ### widen to: "lo=$lo hi=$hi"
  ### $unit
  ### $decimals

  my $tick_gc = $style->fg_gc($state);
  my $transform   = $self->{'transform'}   || \&identity;
  my $untransform = $self->{'untransform'} || \&identity;

  $lo = $transform->($lo);
  $hi = $transform->($hi);
  my $n = Math::Round::nhimult ($unit, $lo);
  ### loop: "$lo to $hi, starting $n"


  # ENHANCE-ME: stop looping when a string goes past the end of the
  # $clip_rect, in whichever direction

  if ($orientation eq 'horizontal') {
    my $decided_height = _decide_height($self);
    my $tick_height = ceil (TICK_HEIGHT_FRAC * $digit_height);
    my $text_y = $tick_height + ceil (TICK_VGAP_FRAC * $digit_height);

    for ( ; $n <= $hi; $n += $unit) {
      my $str = $self->signal_emit ('number-to-text', $n, $decimals);
      $layout->set_text ($str);
      my ($str_width, $str_height) = $layout->get_pixel_size;

      my $u = $untransform->($n);
      my $x = floor ($factor * $u + $offset);
      my $text_x = $x - int ($str_width/2); # left of text to centre
      ### $x
      ### $text_x

      $win->draw_rectangle ($tick_gc,
                            1,              # filled
                            $x,             # x
                            0,              # y
                            1,              # width==1
                            $tick_height);  # height
      $style->paint_layout ($win,
                            $state,
                            1,  # use_text, for the text gc instead of the fg one
                            $clip_rect,
                            $self,       # widget
                            __PACKAGE__, # style detail string
                            $text_x,
                            $text_y,
                            $layout);

      if ($x >= 0 && $x < $win_pixels  # only values more than half in window
          && ($str_height += $text_y) > $decided_height) {
        ### draw is higher than decided_height: "str=$str, height=$str_height cf decided_height=$decided_height"
        $decided_height = $self->{'decided_height'} = $str_height;
        $self->queue_resize;
      }
    }

  } else { # vertical
    my $decided_width = _decide_width($self);
    my $digit_width = $self->{'digit_width'};
    my $tick_width = ceil (TICK_WIDTH_FRAC * $digit_width);
    my $text_x = $tick_width + ceil (TICK_GAP_FRAC * $digit_width);

    for ( ; $n <= $hi; $n += $unit) {
      my $str = $self->signal_emit ('number-to-text', $n, $decimals);
      $layout->set_text ($str);
      my ($str_width, $str_height) = $layout->get_pixel_size;

      my $u = $untransform->($n);
      my $y = floor ($factor * $u + $offset);
      ### $str
      ### $y
      ### $str_width

      my $text_y = $y - int ($str_height/2); # top of text
      if ($text_y >= $win_pixels || $y + $str_height <= 0) {
        ### outside window, skip
        next;
      }

      $win->draw_rectangle ($tick_gc,
                            1,            # filled
                            0,            # x
                            $y,           # y
                            $tick_width,  # width
                            1);           # height==1
      $style->paint_layout ($win,
                            $state,
                            1,  # use_text, for the text gc instead of the fg one
                            $clip_rect,
                            $self,       # widget
                            __PACKAGE__, # style detail string
                            $text_x,
                            $text_y,
                            $layout);

      if ($y >= 0 && $y < $win_pixels  # only values more than half in window
          && ($str_width += $text_x) > $decided_width) {
        ### draw is wider than decided_width: "str=$str, width=$str_width cf decided_width=$decided_width"
        $decided_width = $self->{'decided_width'} = $str_width;
        $self->queue_resize;
      }
    }
  }

  return Gtk2::EVENT_PROPAGATE;
}

sub _decide_width {
  my ($self) = @_;
  ### NumAxis _decide_width()

  my $adj = $self->{'adjustment'};
  my $for = ($adj
             ? join(',', $adj->lower, $adj->upper, $adj->page_size)
             : '');
  if ($self->{'decided_done_for'} eq $for) {
    return $self->{'decided_width'};
  }

  ### old decided width: $self->{'decided_width'}
  ### was for: $self->{'decided_done_for'}
  ### now for: $for
  $self->{'decided_done_for'} = $for;

  my $layout = _layout($self);
  my $decimals = $self->{'min_decimals'};
  my $digit_width = $self->{'digit_width'};
  my $width = $digit_width * $decimals;

  if ($adj) {
    my $lower = $adj->lower;
    my ($unit, $unit_decimals) = _decide_unit ($self, $lower);
    ### $unit
    ### $unit_decimals
    $decimals = max ($decimals, $unit_decimals);
    my $transform = $self->{'transform'} || \&identity;

    # my $n = Math::Round::nhimult ($unit, $lo);

    foreach my $un ($lower,
                    $adj->upper - $adj->page_size) {
      my $n = $transform->($un);
      # increase $n to 99.999 etc per its integer part and $decimals
      $n = ($n < 0 ? '-' : '')
        . ('9' x _num_integer_digits($n))
          . '.'
            . ('9' x $decimals);
      my $str = $self->signal_emit ('number-to-text', $n, $decimals);
      $layout->set_text ($str);
      $width = max ($width, ($layout->get_pixel_size)[0]);
      ### this str: $str
      ### gives width pixels: $width
    }
  }

  $width += ceil (TICK_WIDTH_FRAC * $digit_width)
    + ceil (TICK_GAP_FRAC * $digit_width);
  ### tick width: ceil (TICK_WIDTH_FRAC * $digit_width)
  ### tick gap:   ceil (TICK_GAP_FRAC * $digit_width)
  ### _decide_width() result: $width
  return ($self->{'decided_width'} = $width);
}

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

  if ($self->{'decided_done_for'} eq '1') {
    return $self->{'decided_height'};
  }
  $self->{'decided_done_for'} = 1;

  my $adj = $self->{'adjustment'};
  ### _decide_height()

  my $layout = _layout($self);
  my $decimals = $self->{'min_decimals'};
  my $transform = $self->{'transform'} || \&identity;
  my $digit_height = $self->{'digit_height'};

  my $height = $digit_height;
  foreach my $un ($adj
                  ? ($adj->lower, $adj->upper - $adj->page_size)
                  : (0)) {
    my $n = $transform->($un);
    my $str = $self->signal_emit ('number-to-text', $n, $decimals);
    $layout->set_text ($str);
    $height = max ($height, ($layout->get_pixel_size)[1]);
    ### this str: $str
    ### this height: ($layout->get_pixel_size)[1]
    ### gives height pixels: $height
  }
  $height += ceil(TICK_HEIGHT_FRAC * $digit_height)
    + ceil(TICK_VGAP_FRAC * $digit_height);

  ### tick height: ceil (TICK_HEIGHT_FRAC * $digit_height)
  ### tick vgap:   ceil (TICK_VGAP_FRAC * $digit_height)
  ### _decide_height() result: $height
  return ($self->{'decided_height'} = $height);
}

# return ($step, $decimals)
sub _decide_unit {
  my ($self, $value) = @_;
  ### _decide_unit(): "value=$value"

  my ($win, $adj, $page_size);
  unless (($win = $self->window)
          && ($adj = $self->{'adjustment'})
          && ($page_size = $adj->page_size) != 0) {
    return (0, 0);
  }

  my $transform = $self->{'transform'} || \&identity;
  my $min_decimals = $self->{'min_decimals'};
  ### $min_decimals

  if ($self->get('orientation') eq 'horizontal') {
    my $win_width = $self->allocation->width;
    my $layout = _layout($self);
    my @samples = ($adj->value + 0.05 * $adj->page_size,
                   $adj->value + 0.95 * $adj->page_size);
    for (;;) {
      my $str_width = max (map {
        $layout->set_text ($self->signal_emit
                           ('number-to-text', $_, $min_decimals));
        ($layout->get_pixel_size)[0]
      } @samples);

      my $untrans_min_step = 2.0 * $adj->page_size * $str_width / $win_width;
      ### page_size: $adj->page_size
      ### $win_width
      ### $str_width
      ### $untrans_min_step

      my $low_step =  abs ($transform->($value)
                           - $transform->($value + $untrans_min_step));
      my $high_step = abs ($transform->($value + $page_size)
                           - $transform->($value + $page_size
                                          - $untrans_min_step));
      ### $low_step
      ### $high_step
      my ($unit, $decimals) = round_up_2_5_pow_10 (max ($low_step, $high_step));
      if ($decimals <= $min_decimals) {
        return ($unit, $decimals);
      }
      $min_decimals = $decimals;
    }
  } else {
    my $win_height = $self->allocation->height;
    my $str_height = $self->{'digit_height'};
    my $untrans_min_step = 2.0 * $adj->page_size * $str_height / $win_height;
    ### page_size: $adj->page_size
    ### win_height: $win_height
    ### $str_height
    ### $untrans_min_step
    my $low_step =  abs ($transform->($value)
                         - $transform->($value + $untrans_min_step));
    my $high_step = abs ($transform->($value + $page_size)
                         - $transform->($value + $page_size
                                        - $untrans_min_step));
    ### $low_step
    ### $high_step
    return round_up_2_5_pow_10 (max ($low_step, $high_step));
  }

  # return round_up_2_5_pow_10 (2 * $str_height / $factor);
}

sub _layout {
  my ($self) = @_;
  my $layout = ($self->{'layout'} ||= do {
    my $l = $self->create_pango_layout ('');
    $l->set_alignment ('center');  # perhaps a 'justify' prop like GtkLabel?
    $l
  });
  if (! defined $self->{'digit_width'}) {
    ($self->{'digit_width'}, $self->{'digit_height'})
      = layout_digit_size ($layout);
  }
  return $layout;
}

# 'style-set' and 'direction-changed' class closures
#
sub _do_style_or_direction {
  my ($self, $prev_style) = @_;

  # context_changed() as advised by gtk_widget_create_pango_layout()
  if (my $layout = $self->{'layout'}) {
    $layout->context_changed;
    delete @{$self}{'digit_width','digit_height'}; # hash slice
  }

  $self->{'decided_done_for'} = 'x';  # possible new font or kerning
  $self->queue_resize;
  $self->queue_draw;
  return shift->signal_chain_from_overridden(@_);
}

# 'value-changed' on the adjustment
sub _do_adj_value_changed {
  my ($adj, $ref_weak_self) = @_;
  ### _do_adj_value_changed(), queue_draw
  my $self = $$ref_weak_self || return;
  $self->queue_draw;
}

# 'changed' on the adjustment
sub _do_adj_other_changed {
  my ($adj, $ref_weak_self) = @_;
  my $self = $$ref_weak_self || return;
  ### _do_adj_other_changed(), resize
  $self->queue_resize; # possible width for new upper/lower
  $self->queue_draw;   # possible new page-size
}

#------------------------------------------------------------------------------
# mostly generic

# Return ($digit_width, $digit_height) which is the size in pixels of a
# digit in the given $layout.
#
sub layout_digit_size {
  my ($layout) = @_;
  my $digit_width = 0;
  my $digit_height = 0;
  foreach my $n (0 .. 9) {
    $layout->set_text ($n);
    my ($str_width, $str_height) = $layout->get_pixel_size;
    $digit_width  = max ($digit_width,  $str_width);
    $digit_height = max ($digit_height, $str_height);
  }
  return ($digit_width, $digit_height);
}

# Round $n up to the next higher unit of the form 10^k, 2*10^k or 5*10^k
# (for an integer k, possibly negative) and return two values "($unit,
# $decimals)", where $decimals is how many decimal places are necessary to
# represent that unit.  For instance,
#
#     round_up_2_5_pow_10(0.0099) = (0.01, 2)
#     round_up_2_5_pow_10(0.15)   = (0.2, 1)
#     round_up_2_5_pow_10(3.5)    = (5, 0)
#     round_up_2_5_pow_10(60)     = (100, 0)
#
sub round_up_2_5_pow_10 {
  my ($n) = @_;
  my $k = ceil (POSIX::log10 ($n));
  my $unit = POSIX::pow (10, $k);

  # at this point $unit is the next higher value of the form 10^k, see if
  # either 5*10^(k-1) or 2*10^(k-1) would suffice to be bigger than $n
  if ($unit * 0.2 >= $n) {
    $unit *= 0.2;
    $k--;
  } elsif ($unit * 0.5 >= $n) {
    $unit *= 0.5;
    $k--;
  }
  ### $unit
  ### $k
  ### decimals: max (-$k, 0)
  return ($unit, max (-$k, 0));
}

# Return the number of digits in the integer part of $n, so for instance
#     _num_integer_digits(0) == 1
#     _num_integer_digits(99) == 2
#     _num_integer_digits(100.25) == 3
# Just the absolute value is used, so the results are the same for negatives,
#     num_integer_digits(-100.25) == 3
#
sub _num_integer_digits {
  my ($n) = @_;
  return 1 + max (0, floor (POSIX::log10 (abs ($n))));
}



#                configure_event => \&_do_configure_event,
# # 'configure-event' class closure
# sub _do_configure_event {
#   my ($self, $event) = @_;
#   $self->queue_draw;
#   return shift->signal_chain_from_overridden(@_);
# }

1;
__END__