Provided by: libace-perl_1.92-7_amd64 bug


       Ace::Graphics::Glyph - Base class for Ace::Graphics::Glyph objects


       See Ace::Graphics::Panel.


       Ace::Graphics::Glyph is the base class for all glyph objects.  Each glyph is a wrapper
       around an Ace::Sequence::Feature object, knows how to render itself on an
       Ace::Graphics::Panel, and has a variety of configuration variables.

       End developers will not ordinarily work directly with Ace::Graphics::Glyph, but may want
       to subclass it for customized displays.


       This section describes the class and object methods for Ace::Graphics::Glyph.

       Ace::Graphics::Glyph objects are constructed automatically by an
       Ace::Graphics::GlyphFactory, and are not usually created by end-developer code.

       $glyph = Ace::Graphics::Glyph->new(-feature=>$feature,-factory=>$factory)
           Given a sequence feature, creates an Ace::Graphics::Glyph object to display it.  The
           -feature argument points to the Ace::Sequence::Feature object to display.  -factory
           indicates an Ace::Graphics::GlyphFactory object from which the glyph will fetch all
           its run-time configuration information.

           A standard set of options are recognized.  See OPTIONS.

       Once a glyph is created, it responds to a large number of methods.  In this section, these
       methods are grouped into related categories.

       Retrieving glyph context:

       $factory = $glyph->factory
           Get the Ace::Graphics::GlyphFactory associated with this object.  This cannot be
           changed once it is set.

       $feature = $glyph->feature
           Get the sequence feature associated with this object.  This cannot be changed once it
           is set.

       Retrieving glyph options:

       $fgcolor = $glyph->fgcolor
       $bgcolor = $glyph->bgcolor
       $fontcolor = $glyph->fontcolor
       $fillcolor = $glyph->fillcolor
           These methods return the configured foreground, background, font and fill colors for
           the glyph in the form of a GD::Image color index.

       $width = $glyph->width
           Return the maximum width allowed for the glyph.  Most glyphs will be smaller than

       $font = $glyph->font
           Return the font for the glyph.

       $option = $glyph->option($option)
           Return the value of the indicated option.

       $index = $glyph->color($color)
           Given a symbolic or #RRGGBB-form color name, returns its GD index.

       Retrieving information about the sequence:

       $start = $glyph->start
       $end   = $glyph->end
           These methods return the start and end of the glyph in base pair units.

       $offset = $glyph->offset
           Returns the offset of the segment (the base pair at the far left of the image).

       $length = $glyph->length
           Returns the length of the sequence segment.

       Retrieving formatting information:

       $top = $glyph->top
       $left = $glyph->left
       $bottom = $glyph->bottom
       $right = $glyph->right
           These methods return the top, left, bottom and right of the glyph in pixel

       $height = $glyph->height
           Returns the height of the glyph.  This may be somewhat larger or smaller than the
           height suggested by the GlyphFactory, depending on the type of the glyph.

       $scale = $glyph->scale
           Get the scale for the glyph in pixels/bp.

       $height = $glyph->labelheight
           Return the height of the label, if any.

       $label = $glyph->label
           Return a human-readable label for the glyph.

       These methods are called by Ace::Graphics::Track during the layout process:

           Move the glyph in pixel coordinates by the indicated delta-x and delta-y values.

       ($x1,$y1,$x2,$y2) = $glyph->box
           Return the current position of the glyph.

       These methods are intended to be overridden in subclasses:

           Calculate the height of the glyph.

           Calculate the left side of the glyph.

           Calculate the right side of the glyph.

           Optionally offset the glyph by the indicated amount and draw it onto the GD::Image

           Draw the label for the glyph onto the provided GD::Image object, optionally offsetting
           by the amounts indicated in $left and $right.

       These methods are useful utility routines:

       $pixels = $glyph->map_pt($bases);
           Map the indicated base position, given in base pair units, into pixels, using the
           current scale and glyph position.

           Draw a filled rectangle with the appropriate foreground and fill colors, and pen width
           onto the GD::Image object given by $gd, using the provided rectangle coordinates.

           As above, but draws an oval inscribed on the rectangle.

       The following options are standard among all Glyphs.  See individual glyph pages for more

         Option      Description               Default
         ------      -----------               -------

         -fgcolor    Foreground color          black

         -outlinecolor                         black
                     Synonym for -fgcolor

         -bgcolor    Background color          white

         -fillcolor  Interior color of filled  turquoise

         -linewidth  Width of lines drawn by   1

         -height     Height of glyph           10

         -font       Glyph font                gdSmallFont

         -label      Whether to draw a label   false

       You may pass an anonymous subroutine to -label, in which case the subroutine will be
       invoked with the feature as its single argument.  The subroutine must return a string to
       render as the label.

SUBCLASSING Ace::Graphics::Glyph

       By convention, subclasses are all lower-case.  Begin each subclass with a preamble like
       this one:

        package Ace::Graphics::Glyph::crossbox;

        use strict;
        use vars '@ISA';
        @ISA = 'Ace::Graphics::Glyph';

       Then override the methods you need to.  Typically, just the draw() method will need to be
       overridden.  However, if you need additional room in the glyph, you may override
       calculate_height(), calculate_left() and calculate_right().  Do not directly override
       height(), left() and right(), as their purpose is to cache the values returned by their
       calculating cousins in order to avoid time-consuming recalculation.

       A simple draw() method looks like this:

        sub draw {
         my $self = shift;
         my $gd = shift;

         # and draw a cross through the box
         my ($x1,$y1,$x2,$y2) = $self->calculate_boundaries(@_);
         my $fg = $self->fgcolor;

       This subclass draws a simple box with two lines criss-crossed through it.  We first call
       our inherited draw() method to generate the filled box and label.  We then call
       calculate_boundaries() to return the coordinates of the glyph, disregarding any extra
       space taken by labels.  We call fgcolor() to return the desired foreground color, and then
       call $gd->line() twice to generate the criss-cross.

       For more complex draw() methods, see Ace::Graphics::Glyph::transcript and


       Please report them.


       Ace::Sequence, Ace::Sequence::Feature, Ace::Graphics::Panel, Ace::Graphics::Track,
       Ace::Graphics::Glyph::anchored_arrow, Ace::Graphics::Glyph::arrow,
       Ace::Graphics::Glyph::box, Ace::Graphics::Glyph::primers, Ace::Graphics::Glyph::segments,
       Ace::Graphics::Glyph::toomany, Ace::Graphics::Glyph::transcript,


       Lincoln Stein <>.

       Copyright (c) 2001 Cold Spring Harbor Laboratory

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  See DISCLAIMER.txt for disclaimers of warranty.