oracular (3) PDF::Builder::Content::Text.3pm.gz
NAME
PDF::Builder::Content::Text - additional specialized text-related formatting methods. Inherits from
PDF::Builder::Content
Note: If you have used some of these methods in PDF::Builder with a graphics type object (e.g.,
$page->gfx()->method()), you may have to change to a text type object (e.g., $page->text()->method()).
METHODS
Single Lines from a String
text_left
$width = $content->text_left($text, %opts)
Alias for "text". Implemented for symmetry, for those who use a lot of "text_center" and
"text_right", and desire a matching "text_left".
Adds text to the page (left justified), at the current position. Note that there is no maximum
width, and nothing to keep you from overflowing the physical page on the right! The width used (in
points) is returned.
text_center
$width = $content->text_center($text, %opts)
As "text", but centered on the current point.
Adds text to the page (centered). The width used (in points) is returned.
text_right
$width = $content->text_right($text, %opts)
As "text", but right-aligned to the current point.
Adds text to the page (right justified). Note that there is no maximum width, and nothing to keep
you from overflowing the physical page on the left! The width used (in points) is returned.
text_justified
$width = $content->text_justified($text, $width, %opts)
As "text", but stretches text using "wordspace", "charspace", and (as a last resort) "hscale", to
fill the desired (available) $width. Note that if the desired width is less than the natural width
taken by the text, it will be condensed to fit, using the same three routines.
The unchanged $width is returned, unless there was some reason to change it (e.g., overflow).
Options:
'nocs' => value
If this option value is 1 (default 0), do not use any intercharacter spacing. This is useful for
connected characters, such as fonts for Arabic, Devanagari, Latin cursive handwriting, etc. You
don't want to add additional space between characters during justification, which would
disconnect them.
Word (interword) spacing values (explicit or default) are doubled if nocs is 1. This is to make
up for the lack of added/subtracted intercharacter spacing.
'wordsp' => value
The percentage of one space character (default 100) that is the maximum amount to add to (each)
interword spacing to expand the line. If "nocs" is 1, double "value".
'charsp' => value
If adding interword space didn't do enough, the percentage of one em (default 100) that is the
maximum amount to add to (each) intercharacter spacing to further expand the line. If "nocs" is
1, force "value" to 0.
'wordspa' => value
If adding intercharacter space didn't do enough, the percentage of one space character (default
100) that is the maximum additional amount to add to (each) interword spacing to further expand
the line. If "nocs" is 1, double "value".
'charspa' => value
If adding more interword space didn't do enough, the percentage of one em (default 100) that is
the maximum additional amount to add to (each) intercharacter spacing to further expand the line.
If "nocs" is 1, force "value" to 0.
'condw' => value
The percentage of one space character (default 25) that is the maximum amount to subtract from
(each) interword spacing to condense the line. If "nocs" is 1, double "value".
'condc' => value
If removing interword space didn't do enough, the percentage of one em (default 10) that is the
maximum amount to subtract from (each) intercharacter spacing to further condense the line. If
"nocs" is 1, force "value" to 0.
If expansion (or reduction) wordspace and charspace changes didn't do enough to make the line fit the
desired width, use "hscale()" to finish expanding or condensing the line to fit.
Multiple Lines from a String
The string is split at regular blanks (spaces), x20, to find the longest substring that will fit the
$width. If a single word is longer than $width, it will overflow. To stay strictly within the desired
bounds, set the option "spillover"=>0 to disallow spillover.
Hyphenation
If hyphenation is enabled, those methods which split up a string into multiple lines (the "text fill",
paragraph, and section methods) will attempt to split up the word that overflows the line, in order to
pack the text even more tightly ("greedy" line splitting). There are a number of controls over where a
word may be split, but note that there is nothing language-specific (i.e., following a given language's
rules for where a word may be split). This is left to other packages.
There are hard coded minimums of 2 letters before the split, and 2 letters after the split. See
"Hyphenate_basic.pm". Note that neither hyphenation nor simple line splitting makes any attempt to
prevent widows and orphans, prevent splitting of the last word in a column or page, or otherwise engage
in more desirable paragraph shaping.
'hyphenate' => value
0: no hyphenation (default), 1: do basic hyphenation. Always allows splitting at a soft hyphen
(\xAD). Unicode hyphen (U+2010) and non-splitting hyphen (U+2011) are ignored as split points.
'spHH' => value
0: do not split at a hard hyphen (x\2D), 1: OK to split (default)
'spOP' => value
0: do not split after most punctuation, 1: OK to split (default)
'spDR' => value
0: do not split after a run of one or more digits, 1: OK to split (default)
'spLR' => value
0: do not split after a run of one or more ASCII letters, 1: OK to split (default)
'spCC' => value
0: do not split in camelCase between a lowercase letter and an uppercase letter, 1: OK to split
(default)
'spRB' => value
0: do not split on a Required Blank ( ), is default. 1: OK to split on Required Blank. Try to
avoid this; it is a desperation move!
'spFS' => value
0: do not split where it will just fit (middle of word!), is default. 1: OK to split to just fit the
available space. Try to avoid this; it is a super desperation move, and the split will probably make
no linguistic sense!
'min_prefix' => value
Minimum number of letters before word split point (hyphenation point). The default is 2.
'min_suffix' => value
Minimum number of letters after word split point (hyphenation point). The default is 3.
Methods
text_fill_left, text_fill
($width, $leftover) = $content->text_fill_left($string, $width, %opts)
Fill a line of 'width' with as much text as will fit, and outputs it left justified. The width
actually used, and the leftover text (that didn't fit), are returned.
($width, $leftover) = $content->text_fill($string, $width, %opts)
Alias for text_fill_left().
text_fill_center
($width, $leftover) = $content->text_fill_center($string, $width, %opts)
Fill a line of 'width' with as much text as will fit, and outputs it centered. The width actually
used, and the leftover text (that didn't fit), are returned.
text_fill_right
($width, $leftover) = $content->text_fill_right($string, $width, %opts)
Fill a line of 'width' with as much text as will fit, and outputs it right justified. The width
actually used, and the leftover text (that didn't fit), are returned.
text_fill_justified
($width, $leftover) = $content->text_fill_justified($string, $width, %opts)
Fill a line of 'width' with as much text as will fit, and outputs it fully justified (stretched or
condensed). The width actually used, and the leftover text (that didn't fit), are returned.
Note that the entire line is fit to the available width via a call to "text_justified". See
"text_justified" for options to control stretch and condense. The last line is unjustified (normal
size) and left aligned by default, although the option
Options:
'last_align' => place
where place is 'left' (default), 'center', or 'right' (may be shortened to first letter) allows
you to specify the alignment of the last line output.
Larger Text Segments
paragraph
($overflow_text, $unused_height) = $txt->paragraph($text, $width,$height, $continue, %opts)
($overflow_text, $unused_height) = $txt->paragraph($text, $width,$height, %opts)
$overflow_text = $txt->paragraph($text, $width,$height, $continue, %opts)
$overflow_text = $txt->paragraph($text, $width,$height, %opts)
Print a single string into a rectangular area on the page, of given width and maximum height. The
baseline of the first (top) line is at the current text position.
Apply the text within the rectangle and return any leftover text (if could not fit all of it within
the rectangle). If called in an array context, the unused height is also returned (may be 0 or
negative if it just filled the rectangle).
$continue is optional, with a default value of 0. An %opts list may be given after the fixed
parameters, whether or not $continue is explicitly given.
If $continue is 1, the first line does not get special treatment for indenting or outdenting, because
we're printing the continuation of the paragraph that was interrupted earlier. If it's 0, the first
line may be indented or outdented.
Options:
'pndnt' => $indent
Give the amount of indent (positive) or outdent (negative, for "hanging") for paragraph first
lines). This setting is ignored for centered text.
'align' => $choice
$choice is 'justified', 'right', 'center', 'left'; the default is 'left'. See "text_justified"
call for options to control how a line is expanded or condensed if $choice is 'justified'.
$choice may be shortened to the first letter.
'last_align' => place
where place is 'left' (default), 'center', or 'right' (may be shortened to first letter) allows
you to specify the alignment of the last line output, but applies only when "align" is
'justified'.
'underline' => $distance
'underline' => [ $distance, $thickness, ... ]
If a scalar, distance below baseline, else array reference with pairs of distance and line
thickness.
'spillover' => $over
Controls if words in a line which exceed the given width should be "spilled over" the bounds, or
if a new line should be used for this word.
$over is 1 or 0, with the default 1 (spills over the width).
Example:
$txt->font($font,$fontsize);
$txt->leading($leading);
$txt->translate($x,$y);
$overflow = $txt->paragraph( 'long paragraph here ...',
$width,
$y+$leading-$bottom_margin );
Note: if you need to change any text treatment within a paragraph (bold or italicized text, for
instance), this can not handle it. Only plain text (all the same font, size, etc.) can be typeset
with "paragraph()". Also, there is currently very limited line splitting (hyphenation) to better fit
to a given width, and nothing is done for "widows and orphans".
section, paragraphs
($overflow_text, $continue, $unused_height) = $txt->section($text, $width,$height, $continue, %opts)
$overflow_text = $txt->section($text, $width,$height, $continue, %opts)
The $text contains a string with one or more paragraphs $width wide, starting at the current text
position, with a newline \n between each paragraph. Each paragraph is output (see "paragraph") until
the $height limit is met (a partial paragraph may be at the bottom). Whatever wasn't output, will be
returned. If called in an array context, the unused height and the paragraph "continue" flag are
also returned.
$continue is 0 for the first call of section(), and then use the value returned from the previous
call (1 if a paragraph was cut in the middle) to prevent unwanted indenting or outdenting of the
first line being printed.
For compatibility with recent changes to PDF::API2, paragraphs is accepted as an alias for "section".
Options:
'pvgap' => $vertical
Additional vertical space (unit: pt) between paragraphs (default 0). Note that this space will
also be added after the last paragraph printed.
See "paragraph" for other %opts you can use, such as "align" and "pndnt".
Alternate name: paragraphs
This is for compatibiity with PDF::API2.
textlabel
$width = $txt->textlabel($x,$y, $font, $size, $text, %opts)
Place a line of text at an arbitrary "[$x,$y]" on the page, with various text settings (treatments)
specified in the call.
$font
A previously created font.
$size
The font size (points).
$text
The text to be printed (a single line).
Options:
'rotate' => $deg
Rotate $deg degrees counterclockwise from due East.
'color' => $cspec
A color name or permitted spec, such as "#CCE840", for the character fill.
'strokecolor' => $cspec
A color name or permitted spec, such as "#CCE840", for the character outline.
'charspace' => $cdist
Additional distance between characters.
'wordspace' => $wdist
Additional distance between words.
'hscale' => $hfactor
Horizontal scaling mode (percentage of normal, default is 100).
'render' => $mode
Character rendering mode (outline only, fill only, etc.). See "render" call.
'left' => 1
Left align on the given point. This is the default.
'center' => 1
Center the text on the given point.
'right' => 1
Right align on the given point.
'align' => $placement
Alternate to left, center, and right. $placement is 'left' (default), 'center', or 'right'.
Other options available to "text", such as underlining, can be used here.
The width used (in points) is returned.
Please note that "textlabel()" was not designed to interoperate with other text operations. It is a
standalone operation, and does not leave a "next write" position (or any other setting) for another
"text" mode operation. A following write will likely be at "(0,0)", and not at the expected location.
"textlabel()" is intended as an "all in one" convenience function for single lines of text, such as a
label on some graphics, and not as part of putting down multiple pieces of text. It is possible to figure
out the position of a following write (either "textlabel" or "text") by adding the returned width to the
original position's x value (assuming left-justified positioning).
Complex Column Output with Markup
column
($rc, $next_y, $unused) = $text->column($page, $text, $grfx, $markup, $txt, %opts)
This method fills out a column of text on a page, returning any unused portion that could not be fit,
and where it left off on the page.
Tag names, CSS entries, markup type, etc. are case-sensitive (usually lower-case letters only). For
example, you cannot give a <P> paragraph in HTML or a P selector in CSS styling.
$page is the page context. Currently, its only use is for page annotations for links ('md1' []() and
'html' <a>), so if you're not using those, you may pass anything such as "undef" for $page if you
wish.
$text is the text context, so that various font and text-output operations may be performed. It is
often, but not necessarily always, the same as the object containing the "column" method.
$grfx is the graphics (gfx) context. It may be a dummy (e.g., undef) if no graphics are to be drawn,
but graphical items such as the column outline ('outline' option) and horizontal rule (<hr> in HTML
markup) use it. Currently, text-decoration underline (default for links, 'md1' "[]()" and 'html'
"<a>") or line-through or overline use the text context, but may in the future require a valid
graphics context. Images (when implemented) will require a graphics context.
$markup is information on what sort of markup is being used to format and lay out the column's text:
'pre'
The input material has already been processed and is already in the desired form. $txt is an
array reference to the list of hashes. This must be used when you are calling "column()" a second
(or later) time to output material left over from the first call. It may also be used when the
caller application has already processed the text into the appropriate format, and other markup
isn't being used.
'none'
If none is specified, there is no markup in use. At most, a blank line or a new text array
element specifies a new paragraph, and that's it. $txt may be a single string, or an array (list)
of strings.
The input txt is a list (anonymous array reference) of strings, each containing one or more
paragraphs. A single string may also be given. An empty line between paragraphs may be used to
separate the paragraphs. Paragraphs may not span array elements.
'md1'
This specifies a certain flavor of Markdown compatible with Text::Markdown:
* or _ italics, ** bold, *** bold+italic;
bulleted list *, numbered list 1. 2. etc.;
#, ## etc. headings and subheadings;
---, ===, ___ horizontal rule;
[label](URL) external links (to HTML page or within this document, see 'a')
` (backticks) enclose a "code" section
HTML (see below) may be mixed in as desired (although not within "code" blocks marked by
backticks, where <, >, and & get turned into HTML entities, disabling the intended tags).
Markdown will be converted into HTML, which will then be interpreted into PDF. Note that
Text::Markdown may produce HTML for certain features, that is not yet supported by HTML
processing (see 'html' section below). Let us know if you need such a feature!
The input txt is a list (anonymous array reference) of strings, each containing one or more
paragraphs and other markup. A single string may also be given. Per Markdown formatting, an empty
line between paragraphs may be used to separate the paragraphs. Separate array elements will
first be glued together into a single string before processing, permitting paragraphs to span
array elements if desired.
There are other flavors of Markdown, so other mdn flavors may be defined in the future, such as
POD from Perl code.
'html'
This specifies that a subset of HTML markup is used, along with some attributes and CSS.
Currently, HTML tags
'i'/'em' (italic), 'b'/'strong' (bold),
'p' (paragraph),
'font' (font face->font-family, color, size->font-size),
'span' (needs style= attribute with CSS to do anything useful),
'ul', 'ol', 'li' (bulleted, numbered lists),
'img' (TBD, image, empty. hspace->margin-left/right,
vspace->margin-top/bottom, width, height),
'a' (anchor/link, web page URL or this document target #p[-x-y[-z]]),
'pre', 'code' (TBD, preformatted and code blocks),
'h1' through 'h6' (headings)
'hr' (horizontal rule)
'br' (TBD, line break, empty)
'sup', 'sub' (TBD superscript and subscript)
's', 'strike', 'del' (line-through)
'u', 'ins' (underline)
'ovl' (TBD -- non-HTML, overline)
'k' (TBD -- non-HTML, kerning left/right shift)
'blockquote' (block quote)
are supported (fully or in part unless "TBD"), along with limited CSS for color, font-size, font-
family, etc. <style> tags may be placed in an optional <head> section, or within the <body>. In
the latter case, style tags will be pulled out of the body and added (in order) on to the end of
any style tag(s) defined in a head section. Multiple style tags will be condensed into a single
collection (later definitions of equal precedence overriding earlier). These stylings will have
global effect, as though they were defined in the head. As with normal CSS, the hierarchy of a
given property (in decreasing precedence) is
appearance in a style= tag attribute
appearance in a tag attribute (possibly a different name than the property)
appearance in a #IDname selector in a <style>
appearance in a .classname selector in a <style>
appearance in a tag name selector in a <style>
Selectors are quite simple: a single tag name (e.g., body), a single class (.cname), or a single
ID (#iname). There are no combinations (e.g., "p.abstract" or "ol, ul"), hierarchies (e.g., "ol
> li"), specified number of appearance, or other such complications as found in a browser's CSS.
Sorry!
Supported CSS properties:
border-* TBD
color (foreground color)
display (inline/block)
font-family (name as defined to FontManager, e.g. Times)
font-size (pt, bare number = pt, % of current size)
font-style (normal/italic)
font-weight (normal/bold)
height (pt, bare number) thickness of horizontal rule
list-style-position (outside) TBD inside
list-style-type (marker description, see also _marker-before/after)
margin-top/right/bottom/left (pt, bare number = pt, % of font-size)
margin TBD update four margin-* properties
text-decoration (none, underline, line-through, overline)
text-height (leading, as ratio of baseline-spacing to font-size)
text-indent (pt, bare number = pt, % of current font-size)
text-align (left/right) TBD, future also center/justify?
width (pt, bare number) width of horizontal rule
Non-standard CSS "properties". You may want to set these in CSS:
_marker-before (text to insert before <ol> marker, default nothing)
_marker-after (text to insert after <ol> marker, default period)
Non-standard CSS "properties". You normally would not set these in CSS:
_fs (current running font size, in points, on the properties stack)
_href (URL for <a>, normally provided by href= attribute)
_left (running number of points to indent on the left, from margin-left and list nesting)
_right (running number of points to indent on the right, from margin-right)
Sizes may be '%' (of font-size), or 'pt' (the default unit). More support may be added over
time. CAUTION: comments /* and */ are NOT currently supported in CSS -- perhaps in the future.
Numeric entities (decimal &#nnn; and hexadecimal &#xnnn;) are supported, as well as named
entities (— for example).
The input txt is a list (anonymous array reference) of strings, each containing one or more
paragraphs and other markup. A single string may also be given. Per normal HTML practice,
paragraph tags should be used to mark paragraphs. Note that HTML::TreeBuilder is configured to
automatically mark top body-level text with paragraph tags, in case you forget to do so, although
it is probably better to do it yourself, to maintain more control over the processing. Separate
array elements will first be glued together into a single string before processing, permitting
paragraphs to span array elements if desired.
There are other markup languages out there, such as HTML-like Pango, and man page (troff), that might
be supported in the future. It is very unlikely that TeX or LaTeX will ever be supported, as they
both already have excellent PDF output.
$txt is the input text: a string, an array reference to multiple strings, or an array reference to
hashes. See $markup for details.
%opts Options -- a number of these are of course, mandatory.
'rect' => [x, y, width, height]
This defines a column as a rectangular area of a given width and height (both in points) on the
current page. In the future, it is expected that more elaborate non-rectangular areas will be
definable, but for now, a simple rectangle is all that is permitted. The column's upper left
coordinate is "x, y".
The top text baseline is assumed to be relative to the UL corner (based on the determined line
height), and the column outline clips that baseline, as it does additional baselines down the
page (interline spacing is "leading" multiplied by the largest "font_size" or image height needed
on that line).
Currently, 'rect' is required, as it is the only column shape supported.
'relative' => [ x, y, scale(s) ]
'relative' defaults to "[ 0, 0, 1, 1 ]", and allows a column outline (currently only 'rect') to
be either absolute or relative. "x" and "y" are added to each "x,y" coordinate pair, after
scaling. Scaling values:
(none) The scaling defaults to 1 in both x and y dimensions (no change).
scale (one value) The scaling in both the x (width) and y (height) dimensions uses this value.
scale_x, scale_y (two values) There are two separate scaling factors for the x dimension (width)
and y dimension (height).
This permits a generically-shaped outline to be defined, scaled (perhaps not preserving the
aspect ratio) and placed anywhere on the page. This could save you from having to define
similarly-shaped columns from scratch multiple times. If you want to define a relative outline,
the lower left corner (whether or not it contains a point, and whether or not it's the first one
listed) would usually be "0, 0", to have scaling work as expected. In other works, your outline
template should be in the lower left corner of the page.
'start_y' => $start_y
If omitted, it is assumed that you want to start at the top of the defined column (the maximum
"y" value minus the maximum vertical extent of this line). If used, the normal value is the
"next_y" returned from the previous "column()" call. It is the deepest extent reached by the
previous line (plus leading), and is the top-most point of the new first line of this "column()"
call.
Note that the "x" position will be determined by the column shape and size (the left-most point
of the baseline), so there is no place to explicitly set an "x" position to start at.
'font_size' => $font_size
This is the starting font size (in points) to be used. Over the course of the text, it may be
modified by markup.
The starting font size may be set in a number of ways. It may be inherited from a previous
"$text->font(..., font-size)" statement; it may be set via the "font_size" option (overriding any
font method inheritance); it may default to 12pt (if neither explicit way is given). For HTML
markup, it may of course be modified by the "font" tag or by CSS styling "font-size". For
Markdown, it may be modified by CSS styling.
'marker_width' => $marker_width
This is the width of the gutter to the left of a list item, where (for the first line of the
item) the marker lives. The marker contains the symbol (for bulleted/unordered lists) or
formatted number and "before" and "after" text (for numbered/ordered lists). Both have a single
space before the item text starts. The number is a length, in points.
The default is 2 times the font_size passed to "column()", and is not adjusted for any changes of
font_size in the markup. An explicit value passed in is also not changed -- the gutter width for
the marker will be the same in all lists (keeping them aligned). If you plan to have
exceptionally long markers, such as an ordered list of years in Roman numerals, such as
(MCMXCIX), you may want to make this gutter a bit wider.
'leading' => $leading
This is the leading ratio used throughout the column text. The "$x, $y" position through "$x +
width" is assumed to be the first text baseline. The next line down will be "$y -
$leading*$font_size". If the font_size changes for any reason over the course of the column, the
baseline spacing (leading * font_size) will also change. The default leading ratio is 1.125
(12.5% added to font).
'para' => [ $indent, $top-margin ]
When starting a new paragraph, these are the default indentation (in points), and the extra
vertical spacing for a top margin on a paragraph. The default is "[ 1*$font_size, 0 ]". Either
may be overridden by the appropriate CSS settings. An outdent may be defined with a negative
indentation value. These apply to all $markup types.
'outline' => "color string"
You may optionaly request that the column be outlined in a given color, to aid in debugging
fitting problems.
'color' => "color string"
The color to draw the text (or rule or other graphic) in. The default is black (#000000).
'style' => "CSS styling"
You may define CSS (selectors and properties lists) to override the built-in CSS defaults. These
will be applied for the entire "column()" call. You can use this, or "style" tags in 'html', but
for 'none' or 'md1', you will need to use this method to set styling.
'substitute' => [ [ 'char or string', 'before', 'replace', 'after'],... ]
When a certain Unicode code point (character) or string is found, insert before text before the
character, replace the character or string with replace text, and insert after text after the
character. This may make it easier to insert HTML code (font, color, etc.) into Markdown text, if
the desired settings and character can not be produced by your Markdown editor. This applies
both to 'md1' and 'html' markup. Multiple substitutions may be defined via multiple array
elements. If you want to leave the original character or string itself unchanged, you should
define the replace text to be the same as 'char or string'. 'before' and/or 'after' text may be
empty strings if you don't want to insert some sort of markup there.
Example: to insert a red cross (X-out) and green tick (check) mark
'substitute' => [
[ '%cross%', '<font face="ZapfDingbats" color="red">', '8', '</font>' ],
[ '%tick%', '<font face="ZapfDingbats" color="green">', '4', '</font>' ],
]
should change "%cross%" in Markdown text ('md1') or HTML text ('html') to "<font
face="ZapfDingbats" color="green">8</font>" and similarly for "%tick%". This is done after the
Markdown is converted to HTML (but before HTML is parsed), so make sure that your macro text
(e.g., "%tick%") isn't something that Markdown will try to interpret by itself! Also, Perl's
regular expression parser seems to get upset with some characters, such as "|", so don't use them
as delimiters (e.g., "|cross|"). You don't have to wrap your macro name in delimiters, but it can
make the text structure clearer, and may be necessary in order not to do substitutions in the
wrong place.
'restore' => flag
This integer flag determines what sort of cleanup "column()" will do upon exit, to restore (or
not) the font state (face, bold or normal weight, italic or normal style, size, and color).
for rc = 0 (all input markup was used up, without running out of column)
restore => 0
This is the default. Upon exiting, "column()" will attempt to restore the state to what
one would see if there was yet more text to be output. Note that this is not necessarily
what one would see if the entire state was restored to entry conditions. The intent is
that another "column()" call can be immediately made, using whatever font state was left
by the previous call, as though the two calls' markup inputs were concatenated.
restore => 1
This value of "restore" commands that no change be made to the font state, that is,
"column()" exits with the font state left in the last text output. This may or may not
be desirable, especially if the last text output left the text in an unexpected state.
restore => 2
This value of "restore" attempts to bring the font state all the way back to what it was
upon entry to the routine, as if it had never been called. Note that if "column()" was
called with no global font settings, that can not be undone, although the color can be
changed back to its original state, usually black.
CAUTION: The Font Manager is not synchronized with whatever state the font is returned
to. You should not request the 'current' font, but should instead explicitly set it to a
specific face, etc., which resets 'current'.
for rc = 1 (ran out of column space before all the input markup was used up)
restore => 0
This is the default. Upon exiting, no changes will be made to the font state. As the code
will be in the middle of some output, the font state is kept the same, so the next
"column()" call (for the overflow) can pick up where the previous call left off, with
regards to the font state.
It is equivalent to "restore = 1".
restore => 1
This is the same as "restore = 0".
restore => 2
This value of "restore" attempts to bring the font state all the way back to what it was
upon entry to the routine, as if it had never been called. Note that if "column()" was
called with no global font settings, that can not be undone, although the color can be
changed back to its original state, usually black.
CAUTION: The Font Manager is not synchronized with whatever state the font is returned
to. You should not request the 'current' font, but should instead explicitly set it to a
specific face, etc., which resets 'current'.
The Font Manager system is used to supply the requested fonts, so it is up to the application to pre-
load the desired font information before "column()" is called. Any request to change the encoding
within "column()" will be ignored, as the fonts have already been specified for a specific encoding.
Needless to say, the encoding used in creating the input text needs to match the specified font
encoding.
Absent any markup changing the font face or styling, whatever is defined by Font Manager as the
current font will be what is used. This way, you may inherit the font from the previous "column()",
or call "$text-"font($pdf->get_font(), size)> to set both the font and size, or just call
"$pdf-"get_font()> to set only the font, relying on the "font_size" option or CSS markup to set the
size.
Line fitting (paragraph shaping) is currently quite primitive. Words will not be split (hyphenated).
It is planned to eventually add Knuth-Plass paragraph shaping, along with proper language-dependent
hyphenation.
Each change of font automatically supplies its maximum ascender and minimum descender, the extents
above and below the text line's baseline. Each block of text with a given face and variant, or change
of font size, will be given the same vertical extents -- the extents are font-wide, and not
determined on a per-glyph basis. So, unfortunately, a block of text "acemnorsuvwz" will have the same
vertical extents as a block of text "bdfghijklpqty". For a given line of text, the highest ascender
and the lowest descender (plus leading) will be used to position the line at the appropriate distance
below the previous line (or the top of the column). No attempt is made to "fit" projections into
recesses (jigsaw-puzzle like). If there is an inset into the side of a column, or it is otherwise not
a straight vertical line, so long as the baseline fits within the column outline, no check is made
whether descenders or ascenders will fall outside the defined column (i.e., project into the inset).
We suggest that you try to keep font sizes fairly consistent, to keep reasonably consistent text
vertical extents.
Data returned by this call
If there is more text than can be accommodated by the column size, the unused portion is returned,
with a return code of 1. It is an empty list if all the text could be formatted, and the return code
is 0. "next_y" is the y coordinate where any additional text ("column()" call) could be added to a
column (as "start_y") that wasn't completely filled. This would be at the starting point of a new
column (i.e., the last paragraph is ended). Note that the application code should check if this
position is too far down the page (in the bottom margin) and not blindly use it! Also, as 'md1' is
first converted to HTML, any unused portion will be returned as 'pre' markup, rather than Markdown or
HTML. Be sure to specify 'pre' for any continuation of the column (with one or more additional
"column()" calls), rather than 'none', 'md1', or 'html'.
$rc The return code.
'0' A return code of 0 indicates that the call completed, while using up all the input $txt. It
did not run out of defined column space.
NOTE: if "restore" has a value of 1, the "column()" call makes no effort to "restore"
conditions to any starting values. If your last bit of text left the "current" font with some
"odd" face/family, size, italicized, bolded, or colored; that will be what is used by the
next column call (or other PDF::Builder text calls). This is done in order to allow you to
easily chain from one column to the next, without having to manually tell the system what
font, color, etc. you want to return to. On the other hand, in some cases you may want to
start from the same initial coditions as usual. You may want to add "get_font()", "font()",
"fillcolor()", and "strokecolor()" calls as necessary before the next text output, to get the
expected text characteristics. Or, you can simply let "restore" default to 0 to get the same
effect.
'1' A return code of 1 indicates that the call completed by filling up the defined column space.
It did not run out of input $txt. You will need to make one or more calls with empty column
space (to fill), to use up the remaining input text (with "pre" $markup).
If "restore" defaults to 0 (or is set to 1), the text settings in the "current" font are left
as-is, so that whatever you were doing when you ran out of defined column (as regards to font
face/family, size, italic and bold states, and color) should automatically be the same when
you make the next "column()" call to make more output.
Additional return codes may be added in the future, to indicate failures of one sort or another.
$next_y
The next page "y" coordinate to start at, if using the same column definition as the previous
"column()" definition did (i.e., you didn't completely fill the column, and received a return
code of 0). In that case, $next_y would give the page "y" coordinate to pass to "column()" (as
"start_y") to start a new paragraph at.
If the return code $rc was 1 (column was used up), the $next_y returned will be -1, as it would
be meaningless to use it.
$unused
This is the unused portion of the input text (return code $rc is 1), in a format ("pre" $markup)
suitable for input as $txt. It will be a reference to an array of hashes.
If $rc is 0 (all input was used up), $unused is an empty anonymous array. It contains nothing to
be used.