;;; ox-beamer.el --- Beamer Back-End for Org Export Engine -*- lexical-binding: t; -*-
;; Copyright (C) 2007-2023 Free Software Foundation, Inc.
;; Author: Carsten Dominik <carsten.dominik AT gmail DOT com>
;; Nicolas Goaziou <n.goaziou AT gmail DOT com>
;; Maintainer: Nicolas Goaziou <mail@nicolasgoaziou.fr>
;; Keywords: org, wp, tex
;; This file is part of GNU Emacs.
;; GNU Emacs 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 of the License, or
;; (at your option) any later version.
;; GNU Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; This library implements both a Beamer back-end, derived from the
;; LaTeX one and a minor mode easing structure edition of the
;; document. See Org manual for more information.
;;; Code:
(require 'org-macs)
(org-assert-version)
(require 'cl-lib)
(require 'ox-latex)
;; Install a default set-up for Beamer export.
(unless (assoc "beamer" org-latex-classes)
(add-to-list 'org-latex-classes
'("beamer"
"\\documentclass[presentation]{beamer}"
("\\section{%s}" . "\\section*{%s}")
("\\subsection{%s}" . "\\subsection*{%s}")
("\\subsubsection{%s}" . "\\subsubsection*{%s}"))))
;;; User-Configurable Variables
(defgroup org-export-beamer nil
"Options specific for using the beamer class in LaTeX export."
:tag "Org Beamer"
:group 'org-export
:version "24.2")
(defcustom org-beamer-frame-level 1
"The level at which headlines become frames.
Headlines at a lower level will be translated into a sectioning
structure. At a higher level, they will be translated into
blocks.
If a headline with a \"BEAMER_env\" property set to \"frame\" is
found within a tree, its level locally overrides this number.
This variable has no effect on headlines with the \"BEAMER_env\"
property set to either \"ignoreheading\", \"appendix\", or
\"note\", which will respectively, be invisible, become an
appendix or a note.
This integer is relative to the minimal level of a headline
within the parse tree, defined as 1."
:group 'org-export-beamer
:type 'integer)
(defcustom org-beamer-frame-default-options ""
"Default options string to use for frames.
For example, it could be set to \"allowframebreaks\"."
:group 'org-export-beamer
:type '(string :tag "[options]"))
(defcustom org-beamer-column-view-format
"%45ITEM %10BEAMER_env(Env) %10BEAMER_act(Act) %4BEAMER_col(Col) %8BEAMER_opt(Opt)"
"Column view format that should be used to fill the template."
:group 'org-export-beamer
:version "24.4"
:package-version '(Org . "8.0")
:type '(choice
(const :tag "Do not insert Beamer column view format" nil)
(string :tag "Beamer column view format")))
(defcustom org-beamer-theme "default"
"Default theme used in Beamer presentations."
:group 'org-export-beamer
:version "24.4"
:package-version '(Org . "8.0")
:type '(choice
(const :tag "Do not insert a Beamer theme" nil)
(string :tag "Beamer theme")))
(defcustom org-beamer-environments-extra nil
"Environments triggered by tags in Beamer export.
Each entry has 4 elements:
name Name of the environment
key Selection key for `org-beamer-select-environment'
open The opening template for the environment, with the following escapes
%a the action/overlay specification
%A the default action/overlay specification
%R the raw BEAMER_act value
%o the options argument, with square brackets
%O the raw BEAMER_opt value
%h the headline text
%r the raw headline text (i.e. without any processing)
%H if there is headline text, that raw text in {} braces
%U if there is headline text, that raw text in [] brackets
close The closing string of the environment."
:group 'org-export-beamer
:version "24.4"
:package-version '(Org . "8.1")
:type '(repeat
(list
(string :tag "Environment")
(string :tag "Selection key")
(string :tag "Begin")
(string :tag "End"))))
(defcustom org-beamer-outline-frame-title "Outline"
"Default title of a frame containing an outline."
:group 'org-export-beamer
:type '(string :tag "Outline frame title"))
(defcustom org-beamer-outline-frame-options ""
"Outline frame options appended after \\begin{frame}.
You might want to put e.g. \"allowframebreaks=0.9\" here."
:group 'org-export-beamer
:type '(string :tag "Outline frame options"))
(defcustom org-beamer-subtitle-format "\\subtitle{%s}"
"Format string used for transcoded subtitle.
The format string should have at most one \"%s\"-expression,
which is replaced with the subtitle."
:group 'org-export-beamer
:version "26.1"
:package-version '(Org . "8.3")
:type '(string :tag "Format string"))
;;; Internal Variables
(defconst org-beamer-column-widths
"0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.0 :ETC"
"The column widths that should be installed as allowed property values.")
(defconst org-beamer-environments-special
'(("againframe" "A")
("appendix" "x")
("column" "c")
("columns" "C")
("frame" "f")
("fullframe" "F")
("ignoreheading" "i")
("note" "n")
("noteNH" "N"))
"Alist of environments treated in a special way by the back-end.
Keys are environment names, as strings, values are bindings used
in `org-beamer-select-environment'. Environments listed here,
along with their binding, are hard coded and cannot be modified
through `org-beamer-environments-extra' variable.")
(defconst org-beamer-environments-default
'(("block" "b" "\\begin{block}%a{%h}" "\\end{block}")
("alertblock" "a" "\\begin{alertblock}%a{%h}" "\\end{alertblock}")
("verse" "v" "\\begin{verse}%a %% %h" "\\end{verse}")
("quotation" "q" "\\begin{quotation}%a %% %h" "\\end{quotation}")
("quote" "Q" "\\begin{quote}%a %% %h" "\\end{quote}")
("structureenv" "s" "\\begin{structureenv}%a %% %h" "\\end{structureenv}")
("theorem" "t" "\\begin{theorem}%a[%h]" "\\end{theorem}")
("definition" "d" "\\begin{definition}%a[%h]" "\\end{definition}")
("example" "e" "\\begin{example}%a[%h]" "\\end{example}")
("exampleblock" "E" "\\begin{exampleblock}%a{%h}" "\\end{exampleblock}")
("proof" "p" "\\begin{proof}%a[%h]" "\\end{proof}")
("beamercolorbox" "o" "\\begin{beamercolorbox}%o{%h}" "\\end{beamercolorbox}"))
"Environments triggered by properties in Beamer export.
These are the defaults - for user definitions, see
`org-beamer-environments-extra'.")
(defconst org-beamer-verbatim-elements
'(code example-block fixed-width inline-src-block src-block verbatim)
"List of element or object types producing verbatim text.
This is used internally to determine when a frame should have the
\"fragile\" option.")
;;; Internal functions
(defun org-beamer--normalize-argument (argument type)
"Return ARGUMENT string with proper boundaries.
TYPE is a symbol among the following:
`action' Return ARGUMENT within angular brackets.
`defaction' Return ARGUMENT within both square and angular brackets.
`option' Return ARGUMENT within square brackets."
(if (not (string-match "\\S-" argument)) ""
(cl-case type
(action (format "<%s>" (org-unbracket-string "<" ">" argument)))
(defaction
(format "[<%s>]"
(org-unbracket-string "<" ">" (org-unbracket-string "[" "]" argument))))
(option (format "[%s]" (org-unbracket-string "[" "]" argument)))
(otherwise (error "Invalid `type' argument to `org-beamer--normalize-argument': %s"
type)))))
(defun org-beamer--element-has-overlay-p (element)
"Non-nil when ELEMENT has an overlay specified.
An element has an overlay specification when it starts with an
`beamer' export-snippet whose value is between angular brackets.
Return overlay specification, as a string, or nil."
(let ((first-object (car (org-element-contents element))))
(when (eq (org-element-type first-object) 'export-snippet)
(let ((value (org-element-property :value first-object)))
(and (string-prefix-p "<" value) (string-suffix-p ">" value)
value)))))
;;; Define Back-End
(org-export-define-derived-backend 'beamer 'latex
:menu-entry
'(?l 1
((?B "As LaTeX buffer (Beamer)" org-beamer-export-as-latex)
(?b "As LaTeX file (Beamer)" org-beamer-export-to-latex)
(?P "As PDF file (Beamer)" org-beamer-export-to-pdf)
(?O "As PDF file and open (Beamer)"
(lambda (a s v b)
(if a (org-beamer-export-to-pdf t s v b)
(org-open-file (org-beamer-export-to-pdf nil s v b)))))))
:options-alist
'((:headline-levels nil "H" org-beamer-frame-level)
(:latex-class "LATEX_CLASS" nil "beamer" t)
(:beamer-subtitle-format nil nil org-beamer-subtitle-format)
(:beamer-column-view-format "COLUMNS" nil org-beamer-column-view-format)
(:beamer-theme "BEAMER_THEME" nil org-beamer-theme)
(:beamer-color-theme "BEAMER_COLOR_THEME" nil nil t)
(:beamer-font-theme "BEAMER_FONT_THEME" nil nil t)
(:beamer-inner-theme "BEAMER_INNER_THEME" nil nil t)
(:beamer-outer-theme "BEAMER_OUTER_THEME" nil nil t)
(:beamer-header "BEAMER_HEADER" nil nil newline)
(:beamer-environments-extra nil nil org-beamer-environments-extra)
(:beamer-frame-default-options nil nil org-beamer-frame-default-options)
(:beamer-outline-frame-options nil nil org-beamer-outline-frame-options)
(:beamer-outline-frame-title nil nil org-beamer-outline-frame-title))
:translate-alist '((bold . org-beamer-bold)
(export-block . org-beamer-export-block)
(export-snippet . org-beamer-export-snippet)
(headline . org-beamer-headline)
(item . org-beamer-item)
(keyword . org-beamer-keyword)
(link . org-beamer-link)
(plain-list . org-beamer-plain-list)
(radio-target . org-beamer-radio-target)
(template . org-beamer-template)))
;;; Transcode Functions
;;;; Bold
(defun org-beamer-bold (bold contents _info)
"Transcode BLOCK object into Beamer code.
CONTENTS is the text being bold. INFO is a plist used as
a communication channel."
(format "\\alert%s{%s}"
(or (org-beamer--element-has-overlay-p bold) "")
contents))
;;;; Export Block
(defun org-beamer-export-block (export-block _contents _info)
"Transcode an EXPORT-BLOCK element into Beamer code.
CONTENTS is nil. INFO is a plist used as a communication
channel."
(when (member (org-element-property :type export-block) '("BEAMER" "LATEX"))
(org-remove-indentation (org-element-property :value export-block))))
;;;; Export Snippet
(defun org-beamer-export-snippet (export-snippet _contents info)
"Transcode an EXPORT-SNIPPET object into Beamer code.
CONTENTS is nil. INFO is a plist used as a communication
channel."
(let ((backend (org-export-snippet-backend export-snippet))
(value (org-element-property :value export-snippet)))
;; Only "latex" and "beamer" snippets are retained.
(cond ((eq backend 'latex) value)
;; Ignore "beamer" snippets specifying overlays.
((and (eq backend 'beamer)
(or (org-export-get-previous-element export-snippet info)
(not (string-match "\\`<.*>\\'" value))))
value))))
;;;; Headline
;;
;; The main function to translate a headline is
;; `org-beamer-headline'.
;;
;; Depending on the level at which a headline is considered as
;; a frame (given by `org-beamer--frame-level'), the headline is
;; either a section (`org-beamer--format-section'), a frame
;; (`org-beamer--format-frame') or a block
;; (`org-beamer--format-block').
;;
;; `org-beamer-headline' also takes care of special environments
;; like "ignoreheading", "note", "noteNH", "appendix" and
;; "againframe".
(defun org-beamer--get-label (headline info)
"Return label for HEADLINE, as a string.
INFO is a plist used as a communication channel.
The value is either the label specified in \"BEAMER_opt\"
property, the custom ID, if there is one and
`:latex-prefer-user-labels' property has a non-nil value, or
a unique internal label. This function assumes HEADLINE will be
treated as a frame."
(cond
((let ((opt (org-element-property :BEAMER_OPT headline)))
(and (stringp opt)
(string-match "\\(?:^\\|,\\)label=\\(.*?\\)\\(?:$\\|,\\)" opt)
(let ((label (match-string 1 opt)))
(if (string-match-p "\\`{.*}\\'" label)
(substring label 1 -1)
label)))))
((and (plist-get info :latex-prefer-user-labels)
(org-element-property :CUSTOM_ID headline)))
(t (format "sec:%s" (org-export-get-reference headline info)))))
(defun org-beamer--frame-level (headline info)
"Return frame level in subtree containing HEADLINE.
INFO is a plist used as a communication channel."
(or
;; 1. Look for "frame" environment in parents, starting from the
;; farthest.
(catch 'exit
(dolist (parent (nreverse (org-element-lineage headline)))
(let ((env (org-element-property :BEAMER_ENV parent)))
(when (and env (member-ignore-case env '("frame" "fullframe")))
(throw 'exit (org-export-get-relative-level parent info))))))
;; 2. Look for "frame" environment in HEADLINE.
(let ((env (org-element-property :BEAMER_ENV headline)))
(and env (member-ignore-case env '("frame" "fullframe"))
(org-export-get-relative-level headline info)))
;; 3. Look for "frame" environment in sub-tree.
(org-element-map headline 'headline
(lambda (hl)
(let ((env (org-element-property :BEAMER_ENV hl)))
(when (and env (member-ignore-case env '("frame" "fullframe")))
(org-export-get-relative-level hl info))))
info 'first-match)
;; 4. No "frame" environment in tree: use default value.
(plist-get info :headline-levels)))
(defun org-beamer--format-section (headline contents info)
"Format HEADLINE as a sectioning part.
CONTENTS holds the contents of the headline. INFO is a plist
used as a communication channel."
(let ((latex-headline
(org-export-with-backend
;; We create a temporary export back-end which behaves the
;; same as current one, but adds "\protect" in front of the
;; output of some objects.
(org-export-create-backend
:parent 'latex
:transcoders
(let ((protected-output
(lambda (object contents info)
(let ((code (org-export-with-backend
'beamer object contents info)))
(if (org-string-nw-p code) (concat "\\protect" code)
code)))))
(mapcar (lambda (type) (cons type protected-output))
'(bold footnote-reference italic strike-through timestamp
underline))))
headline
contents
info))
(mode-specs (org-element-property :BEAMER_ACT headline)))
(if (and mode-specs
(string-match "\\`\\\\\\(.*?\\)\\(?:\\*\\|\\[.*\\]\\)?{"
latex-headline))
;; Insert overlay specifications.
(replace-match (concat (match-string 1 latex-headline)
(format "<%s>" mode-specs))
nil nil latex-headline 1)
latex-headline)))
(defun org-beamer--format-frame (headline contents info)
"Format HEADLINE as a frame.
CONTENTS holds the contents of the headline. INFO is a plist
used as a communication channel."
(let ((fragilep
;; FRAGILEP is non-nil when HEADLINE contains an element
;; among `org-beamer-verbatim-elements'.
(org-element-map headline org-beamer-verbatim-elements 'identity
info 'first-match)))
(concat "\\begin{frame}"
;; Overlay specification, if any. When surrounded by
;; square brackets, consider it as a default
;; specification.
(let ((action (org-element-property :BEAMER_ACT headline)))
(cond
((not action) "")
((string-match "\\`\\[.*\\]\\'" action )
(org-beamer--normalize-argument action 'defaction))
(t (org-beamer--normalize-argument action 'action))))
;; Options, if any.
(let* ((beamer-opt (org-element-property :BEAMER_OPT headline))
(options
;; Collect nonempty options from default value and
;; headline's properties.
(cl-remove-if-not #'org-string-nw-p
(append
(org-split-string
(plist-get info :beamer-frame-default-options) ",")
(and beamer-opt
(org-split-string
;; Remove square brackets if user provided
;; them.
(and (string-match "^\\[?\\(.*\\)\\]?$" beamer-opt)
(match-string 1 beamer-opt))
",")))))
(fragile
;; Add "fragile" option if necessary.
(and fragilep
(not (member "fragile" options))
(list "fragile")))
(label
;; Provide an automatic label for the frame unless
;; the user specified one. Also refrain from
;; labeling `allowframebreaks' frames; this is not
;; allowed by Beamer.
(and (not (member "allowframebreaks" options))
(not (cl-some (lambda (s) (string-match-p "^label=" s))
options))
(list
(let ((label (org-beamer--get-label headline info)))
;; Labels containing colons need to be
;; wrapped within braces.
(format (if (string-match-p ":" label)
"label={%s}"
"label=%s")
label))))))
;; Change options list into a string.
(org-beamer--normalize-argument
(mapconcat #'identity (append label fragile options) ",")
'option))
;; Title.
(let ((env (org-element-property :BEAMER_ENV headline)))
(format "{%s}"
(if (and env (equal (downcase env) "fullframe")) ""
(org-export-data
(org-element-property :title headline) info))))
"\n"
;; The following workaround is required in fragile frames
;; as Beamer will append "\par" to the beginning of the
;; contents. So we need to make sure the command is
;; separated from the contents by at least one space. If
;; it isn't, it will create "\parfirst-word" command and
;; remove the first word from the contents in the PDF
;; output.
(if (not fragilep) contents
(replace-regexp-in-string "\\`\n*" "\\& " (or contents "")))
"\\end{frame}")))
(defun org-beamer--format-block (headline contents info)
"Format HEADLINE as a block.
CONTENTS holds the contents of the headline. INFO is a plist
used as a communication channel."
(let* ((column-width (org-element-property :BEAMER_COL headline))
;; ENVIRONMENT defaults to "block" if none is specified and
;; there is no column specification. If there is a column
;; specified but still no explicit environment, ENVIRONMENT
;; is "column".
(environment (let ((env (org-element-property :BEAMER_ENV headline)))
(cond
;; "block" is the fallback environment.
((and (not env) (not column-width)) "block")
;; "column" only.
((not env) "column")
;; Use specified environment.
(t env))))
(raw-title (org-element-property :raw-value headline))
(env-format
(cond ((member environment '("column" "columns")) nil)
((assoc environment
(append (plist-get info :beamer-environments-extra)
org-beamer-environments-default)))
(t (user-error "Wrong block type at a headline named \"%s\""
raw-title))))
(title (org-export-data (org-element-property :title headline) info))
(raw-options (org-element-property :BEAMER_OPT headline))
(options (if raw-options
(org-beamer--normalize-argument raw-options 'option)
""))
;; Start a "columns" environment when explicitly requested or
;; when there is no previous headline or the previous
;; headline do not have a BEAMER_column property.
(parent-env (org-element-property
:BEAMER_ENV (org-export-get-parent-headline headline)))
(start-columns-p
(or (equal environment "columns")
(and column-width
(not (and parent-env
(equal (downcase parent-env) "columns")))
(or (org-export-first-sibling-p headline info)
(not (org-element-property
:BEAMER_COL
(org-export-get-previous-element
headline info)))))))
;; End the "columns" environment when explicitly requested or
;; when there is no next headline or the next headline do not
;; have a BEAMER_column property.
(end-columns-p
(or (equal environment "columns")
(and column-width
(not (and parent-env
(equal (downcase parent-env) "columns")))
(or (org-export-last-sibling-p headline info)
(not (org-element-property
:BEAMER_COL
(org-export-get-next-element headline info))))))))
(concat
(when start-columns-p
;; Column can accept options only when the environment is
;; explicitly defined.
(if (not (equal environment "columns")) "\\begin{columns}\n"
(format "\\begin{columns}%s\n" options)))
(when column-width
(format "\\begin{column}%s{%s}\n"
;; One can specify placement for column only when
;; HEADLINE stands for a column on its own.
(if (equal environment "column") options "")
(format "%s\\columnwidth" column-width)))
;; Block's opening string.
(when (nth 2 env-format)
(concat
(org-fill-template
(nth 2 env-format)
(nconc
;; If BEAMER_act property has its value enclosed in square
;; brackets, it is a default overlay specification and
;; overlay specification is empty. Otherwise, it is an
;; overlay specification and the default one is nil.
(let ((action (org-element-property :BEAMER_ACT headline)))
(cond
((not action) (list (cons "a" "") (cons "A" "") (cons "R" "")))
((and (string-prefix-p "[" action)
(string-suffix-p "]" action))
(list
(cons "A" (org-beamer--normalize-argument action 'defaction))
(cons "a" "")
(cons "R" action)))
(t
(list (cons "a" (org-beamer--normalize-argument action 'action))
(cons "A" "")
(cons "R" action)))))
(list (cons "o" options)
(cons "O" (or raw-options ""))
(cons "h" title)
(cons "r" raw-title)
(cons "H" (if (equal raw-title "") ""
(format "{%s}" raw-title)))
(cons "U" (if (equal raw-title "") ""
(format "[%s]" raw-title))))))
"\n"))
contents
;; Block's closing string, if any.
(and (nth 3 env-format) (concat (nth 3 env-format) "\n"))
(when column-width "\\end{column}\n")
(when end-columns-p "\\end{columns}"))))
(defun org-beamer-headline (headline contents info)
"Transcode HEADLINE element into Beamer code.
CONTENTS is the contents of the headline. INFO is a plist used
as a communication channel."
(unless (org-element-property :footnote-section-p headline)
(let ((level (org-export-get-relative-level headline info))
(frame-level (org-beamer--frame-level headline info))
(environment (let ((env (org-element-property :BEAMER_ENV headline)))
(or (org-string-nw-p env) "block"))))
(cond
;; Case 1: Resume frame specified by "BEAMER_ref" property.
((equal environment "againframe")
(let ((ref (org-element-property :BEAMER_REF headline)))
;; Reference to frame being resumed is mandatory. Ignore
;; the whole headline if it isn't provided.
(when (org-string-nw-p ref)
(concat "\\againframe"
;; Overlay specification.
(let ((overlay (org-element-property :BEAMER_ACT headline)))
(when overlay
(org-beamer--normalize-argument
overlay
(if (string-match "\\`\\[.*\\]\\'" overlay) 'defaction
'action))))
;; Options.
(let ((options (org-element-property :BEAMER_OPT headline)))
(when options
(org-beamer--normalize-argument options 'option)))
;; Resolve reference provided by "BEAMER_ref"
;; property. This is done by building a minimal
;; fake link and calling the appropriate resolve
;; function, depending on the reference syntax.
(let ((target
(if (string-match "\\`\\(id:\\|#\\)" ref)
(org-export-resolve-id-link
`(link (:path ,(substring ref (match-end 0))))
info)
(org-export-resolve-fuzzy-link
`(link (:path
;; Look for headlines only.
,(if (eq (string-to-char ref) ?*) ref
(concat "*" ref))))
info))))
;; Now use user-defined label provided in TARGET
;; headline, or fallback to standard one.
(format "{%s}" (org-beamer--get-label target info)))))))
;; Case 2: Creation of an appendix is requested.
((equal environment "appendix")
(concat "\\appendix"
(org-element-property :BEAMER_ACT headline)
"\n"
(make-string (org-element-property :pre-blank headline) ?\n)
contents))
;; Case 3: Ignore heading.
((equal environment "ignoreheading")
(concat (make-string (org-element-property :pre-blank headline) ?\n)
contents))
;; Case 4: HEADLINE is a note.
((member environment '("note" "noteNH"))
(concat "\\note"
;; Overlay specification.
(let ((overlay (org-element-property :BEAMER_ACT headline)))
(when overlay
(org-beamer--normalize-argument
overlay
(if (string-match "\\`\\[.*\\]\\'" overlay)
'defaction 'action))))
(format "{%s}"
(concat (and (equal environment "note")
(concat
(org-export-data
(org-element-property :title headline)
info)
"\n"))
(org-trim contents)))))
;; Case 5: HEADLINE is a frame.
((= level frame-level)
(org-beamer--format-frame headline contents info))
;; Case 6: Regular section, extracted from
;; `org-latex-classes'.
((< level frame-level)
(org-beamer--format-section headline contents info))
;; Case 7: Otherwise, HEADLINE is a block.
(t (org-beamer--format-block headline contents info))))))
;;;; Item
(defun org-beamer-item (item contents info)
"Transcode an ITEM element into Beamer code.
CONTENTS holds the contents of the item. INFO is a plist holding
contextual information."
(org-export-with-backend
;; Delegate item export to `latex'. However, we use `beamer'
;; transcoders for objects in the description tag.
(org-export-create-backend
:parent 'beamer
:transcoders
(list
(cons
'item
(lambda (item _c _i)
(let ((action
(let ((first (car (org-element-contents item))))
(and (eq (org-element-type first) 'paragraph)
(org-beamer--element-has-overlay-p first))))
(output (org-latex-item item contents info)))
(if (not (and action (string-match "\\\\item" output))) output
;; If the item starts with a paragraph and that paragraph
;; starts with an export snippet specifying an overlay,
;; append it to the \item command.
(replace-match (concat "\\\\item" action) nil nil output)))))))
item contents info))
;;;; Keyword
(defun org-beamer-keyword (keyword contents info)
"Transcode a KEYWORD element into Beamer code.
CONTENTS is nil. INFO is a plist used as a communication
channel."
(let ((key (org-element-property :key keyword))
(value (org-element-property :value keyword)))
;; Handle specifically BEAMER and TOC (headlines only) keywords.
;; Otherwise, fallback to `latex' back-end.
(cond
((equal key "BEAMER") value)
((and (equal key "TOC") (string-match "\\<headlines\\>" value))
(let ((depth (or (and (string-match "[0-9]+" value)
(string-to-number (match-string 0 value)))
(plist-get info :with-toc)))
(options (and (string-match "\\[.*?\\]" value)
(match-string 0 value))))
(concat
(when (wholenump depth) (format "\\setcounter{tocdepth}{%s}\n" depth))
"\\tableofcontents" options)))
(t (org-export-with-backend 'latex keyword contents info)))))
;;;; Link
(defun org-beamer-link (link contents info)
"Transcode a LINK object into Beamer code.
CONTENTS is the description part of the link. INFO is a plist
used as a communication channel."
(or (org-export-custom-protocol-maybe link contents 'beamer info)
;; Fall-back to LaTeX export. However, prefer "\hyperlink" over
;; "\hyperref" since the former handles overlay specifications.
(let* ((latex-link (org-export-with-backend 'latex link contents info))
(parent (org-export-get-parent-element link))
(attr (org-export-read-attribute :attr_beamer parent))
(overlay (plist-get attr :overlay)))
(cond ((string-match "\\`\\\\hyperref\\[\\(.*?\\)\\]" latex-link)
(replace-match
(format "\\\\hyperlink%s{\\1}"
(or (org-beamer--element-has-overlay-p link) ""))
nil nil latex-link))
((string-match "\\\\include\\(graphics\\|svg\\)\\([[{]?\\)" latex-link)
;; Check for overlay specification and insert if
;; present.
(replace-match
(format "\\\\include\\1%s\\2"
(if overlay overlay ""))
nil nil latex-link))
(t latex-link)))))
;;;; Plain List
;;
;; Plain lists support `:environment', `:overlay' and `:options'
;; attributes.
(defun org-beamer-plain-list (plain-list contents info)
"Transcode a PLAIN-LIST element into Beamer code.
CONTENTS is the contents of the list. INFO is a plist holding
contextual information."
(let* ((type (org-element-property :type plain-list))
(attributes (org-combine-plists
(org-export-read-attribute :attr_latex plain-list)
(org-export-read-attribute :attr_beamer plain-list)))
(latex-type (let ((env (plist-get attributes :environment)))
(cond (env)
((eq type 'ordered) "enumerate")
((eq type 'descriptive) "description")
(t "itemize")))))
(org-latex--wrap-label
plain-list
(format "\\begin{%s}%s%s\n%s\\end{%s}"
latex-type
;; Default overlay specification, if any.
(org-beamer--normalize-argument
(or (plist-get attributes :overlay) "")
'defaction)
;; Second optional argument depends on the list type.
(org-beamer--normalize-argument
(or (plist-get attributes :options) "")
'option)
;; Eventually insert contents and close environment.
contents
latex-type)
info)))
;;;; Radio Target
(defun org-beamer-radio-target (radio-target text info)
"Transcode a RADIO-TARGET object into Beamer code.
TEXT is the text of the target. INFO is a plist holding
contextual information."
(format "\\hypertarget%s{%s}{%s}"
(or (org-beamer--element-has-overlay-p radio-target) "")
(org-export-get-reference radio-target info)
text))
;;;; Template
;;
;; Template used is similar to the one used in `latex' back-end,
;; excepted for the table of contents and Beamer themes.
(defun org-beamer-template (contents info)
"Return complete document string after Beamer conversion.
CONTENTS is the transcoded contents string. INFO is a plist
holding export options."
(let ((title (org-export-data (plist-get info :title) info))
(subtitle (org-export-data (plist-get info :subtitle) info)))
(concat
;; Time-stamp.
(and (plist-get info :time-stamp-file)
(format-time-string "%% Created %Y-%m-%d %a %H:%M\n"))
;; LaTeX compiler
(org-latex--insert-compiler info)
;; Document class and packages.
(org-latex-make-preamble info)
;; Insert themes.
(let ((format-theme
(lambda (prop command)
(let ((theme (plist-get info prop)))
(when theme
(concat command
(if (not (string-match "\\[.*\\]" theme))
(format "{%s}\n" theme)
(format "%s{%s}\n"
(match-string 0 theme)
(org-trim
(replace-match "" nil nil theme))))))))))
(mapconcat (lambda (args) (apply format-theme args))
'((:beamer-theme "\\usetheme")
(:beamer-color-theme "\\usecolortheme")
(:beamer-font-theme "\\usefonttheme")
(:beamer-inner-theme "\\useinnertheme")
(:beamer-outer-theme "\\useoutertheme"))
""))
;; Possibly limit depth for headline numbering.
(let ((sec-num (plist-get info :section-numbers)))
(when (integerp sec-num)
(format "\\setcounter{secnumdepth}{%d}\n" sec-num)))
;; Author.
(let ((author (and (plist-get info :with-author)
(let ((auth (plist-get info :author)))
(and auth (org-export-data auth info)))))
(email (and (plist-get info :with-email)
(org-export-data (plist-get info :email) info))))
(cond ((and author email (not (string= "" email)))
(format "\\author{%s\\thanks{%s}}\n" author email))
((or author email) (format "\\author{%s}\n" (or author email)))))
;; Date.
(let ((date (and (plist-get info :with-date) (org-export-get-date info))))
(format "\\date{%s}\n" (org-export-data date info)))
;; Title
(format "\\title{%s}\n" title)
(when (org-string-nw-p subtitle)
(concat (format (plist-get info :beamer-subtitle-format) subtitle) "\n"))
;; Beamer-header
(let ((beamer-header (plist-get info :beamer-header)))
(when beamer-header
(format "%s\n" (plist-get info :beamer-header))))
;; 9. Hyperref options.
(let ((template (plist-get info :latex-hyperref-template)))
(and (stringp template)
(format-spec template (org-latex--format-spec info))))
;; engrave-faces-latex preamble
(when (and (eq org-latex-src-block-backend 'engraved)
(org-element-map (plist-get info :parse-tree)
'(src-block inline-src-block) #'identity
info t))
(org-latex-generate-engraved-preamble info))
;; Document start.
"\\begin{document}\n\n"
;; Title command.
(org-element-normalize-string
(cond ((not (plist-get info :with-title)) nil)
((string= "" title) nil)
((not (stringp org-latex-title-command)) nil)
((string-match "\\(?:[^%]\\|^\\)%s"
org-latex-title-command)
(format org-latex-title-command title))
(t org-latex-title-command)))
;; Table of contents.
(let ((depth (plist-get info :with-toc)))
(when depth
(concat
(format "\\begin{frame}%s{%s}\n"
(org-beamer--normalize-argument
(plist-get info :beamer-outline-frame-options) 'option)
(plist-get info :beamer-outline-frame-title))
(when (wholenump depth)
(format "\\setcounter{tocdepth}{%d}\n" depth))
"\\tableofcontents\n"
"\\end{frame}\n\n")))
;; Document's body.
contents
;; Creator.
(if (plist-get info :with-creator)
(concat (plist-get info :creator) "\n")
"")
;; Document end.
"\\end{document}")))
;;; Minor Mode
(defvar org-beamer-mode-map
(let ((map (make-sparse-keymap)))
(define-key map "\C-c\C-b" 'org-beamer-select-environment)
map)
"The keymap for `org-beamer-mode'.")
;;;###autoload
(define-minor-mode org-beamer-mode
"Support for editing Beamer oriented Org mode files."
:lighter " Bm")
(when (fboundp 'font-lock-add-keywords)
(font-lock-add-keywords
'org-mode
'((":\\(B_[a-z]+\\|BMCOL\\):" 1 'org-beamer-tag prepend))
'prepend))
(defface org-beamer-tag '((t (:box (:line-width 1 :color "grey40"))))
"The special face for beamer tags."
:group 'org-export-beamer)
(defun org-beamer-property-changed (property value)
"Track the BEAMER_env property with tags.
PROPERTY is the name of the modified property. VALUE is its new
value."
(cond
((equal property "BEAMER_env")
(save-excursion
(org-back-to-heading t)
;; Filter out Beamer-related tags and install environment tag.
(let ((tags (cl-remove-if (lambda (x) (string-match "^B_" x))
(org-get-tags nil t)))
(env-tag (and (org-string-nw-p value) (concat "B_" value))))
(org-set-tags (if env-tag (cons env-tag tags) tags))
(when env-tag (org-toggle-tag env-tag 'on)))))
((equal property "BEAMER_col")
(org-toggle-tag "BMCOL" (if (org-string-nw-p value) 'on 'off)))))
(add-hook 'org-property-changed-functions 'org-beamer-property-changed)
(defun org-beamer-allowed-property-values (property)
"Supply allowed values for PROPERTY."
(cond
((and (equal property "BEAMER_env")
(not (org-entry-get nil (concat property "_ALL") 'inherit)))
;; If no allowed values for BEAMER_env have been defined,
;; supply all defined environments
(mapcar 'car (append org-beamer-environments-special
org-beamer-environments-extra
org-beamer-environments-default)))
((and (equal property "BEAMER_col")
(not (org-entry-get nil (concat property "_ALL") 'inherit)))
;; If no allowed values for BEAMER_col have been defined, supply
;; some.
(split-string org-beamer-column-widths " "))))
(add-hook 'org-property-allowed-value-functions
'org-beamer-allowed-property-values)
;;; Commands
;;;###autoload
(defun org-beamer-export-as-latex
(&optional async subtreep visible-only body-only ext-plist)
"Export current buffer as a Beamer buffer.
If narrowing is active in the current buffer, only export its
narrowed part.
If a region is active, export that region.
A non-nil optional argument ASYNC means the process should happen
asynchronously. The resulting buffer should be accessible
through the `org-export-stack' interface.
When optional argument SUBTREEP is non-nil, export the sub-tree
at point, extracting information from the headline properties
first.
When optional argument VISIBLE-ONLY is non-nil, don't export
contents of hidden elements.
When optional argument BODY-ONLY is non-nil, only write code
between \"\\begin{document}\" and \"\\end{document}\".
EXT-PLIST, when provided, is a property list with external
parameters overriding Org default settings, but still inferior to
file-local settings.
Export is done in a buffer named \"*Org BEAMER Export*\", which
will be displayed when `org-export-show-temporary-export-buffer'
is non-nil."
(interactive)
(org-export-to-buffer 'beamer "*Org BEAMER Export*"
async subtreep visible-only body-only ext-plist (lambda () (LaTeX-mode))))
;;;###autoload
(defun org-beamer-export-to-latex
(&optional async subtreep visible-only body-only ext-plist)
"Export current buffer as a Beamer presentation (tex).
If narrowing is active in the current buffer, only export its
narrowed part.
If a region is active, export that region.
A non-nil optional argument ASYNC means the process should happen
asynchronously. The resulting file should be accessible through
the `org-export-stack' interface.
When optional argument SUBTREEP is non-nil, export the sub-tree
at point, extracting information from the headline properties
first.
When optional argument VISIBLE-ONLY is non-nil, don't export
contents of hidden elements.
When optional argument BODY-ONLY is non-nil, only write code
between \"\\begin{document}\" and \"\\end{document}\".
EXT-PLIST, when provided, is a property list with external
parameters overriding Org default settings, but still inferior to
file-local settings.
Return output file's name."
(interactive)
(let ((file (org-export-output-file-name ".tex" subtreep)))
(org-export-to-file 'beamer file
async subtreep visible-only body-only ext-plist)))
;;;###autoload
(defun org-beamer-export-to-pdf
(&optional async subtreep visible-only body-only ext-plist)
"Export current buffer as a Beamer presentation (PDF).
If narrowing is active in the current buffer, only export its
narrowed part.
If a region is active, export that region.
A non-nil optional argument ASYNC means the process should happen
asynchronously. The resulting file should be accessible through
the `org-export-stack' interface.
When optional argument SUBTREEP is non-nil, export the sub-tree
at point, extracting information from the headline properties
first.
When optional argument VISIBLE-ONLY is non-nil, don't export
contents of hidden elements.
When optional argument BODY-ONLY is non-nil, only write code
between \"\\begin{document}\" and \"\\end{document}\".
EXT-PLIST, when provided, is a property list with external
parameters overriding Org default settings, but still inferior to
file-local settings.
Return PDF file's name."
(interactive)
(let ((file (org-export-output-file-name ".tex" subtreep)))
(org-export-to-file 'beamer file
async subtreep visible-only body-only ext-plist
#'org-latex-compile)))
;;;###autoload
(defun org-beamer-select-environment ()
"Select the environment to be used by beamer for this entry.
While this uses (for convenience) a tag selection interface, the
result of this command will be that the BEAMER_env *property* of
the entry is set.
In addition to this, the command will also set a tag as a visual
aid, but the tag does not have any semantic meaning."
(interactive)
;; Make sure `org-beamer-environments-special' has a higher
;; priority than `org-beamer-environments-extra'.
(let* ((envs (append org-beamer-environments-special
org-beamer-environments-extra
org-beamer-environments-default))
(org-current-tag-alist
(append '((:startgroup))
(mapcar (lambda (e) (cons (concat "B_" (car e))
(string-to-char (nth 1 e))))
envs)
'((:endgroup))
'(("BMCOL" . ?|))))
(org-tag-persistent-alist nil)
(org-use-fast-tag-selection t)
(org-fast-tag-selection-single-key t))
(org-set-tags-command)
(let ((tags (org-get-tags nil t)))
(cond
;; For a column, automatically ask for its width.
((eq org-last-tag-selection-key ?|)
(if (member "BMCOL" tags)
(org-set-property "BEAMER_col" (read-string "Column width: "))
(org-delete-property "BEAMER_col")))
;; For an "againframe" section, automatically ask for reference
;; to resumed frame and overlay specifications.
((eq org-last-tag-selection-key ?A)
(if (equal (org-entry-get nil "BEAMER_env") "againframe")
(progn (org-entry-delete nil "BEAMER_env")
(org-entry-delete nil "BEAMER_ref")
(org-entry-delete nil "BEAMER_act"))
(org-entry-put nil "BEAMER_env" "againframe")
(org-set-property
"BEAMER_ref"
(read-string "Frame reference (*Title, #custom-id, id:...): "))
(org-set-property "BEAMER_act"
(read-string "Overlay specification: "))))
((let* ((tags-re (concat "B_" (regexp-opt (mapcar #'car envs) t)))
(env (cl-some (lambda (tag)
(and (string-match tags-re tag)
(match-string 1 tag)))
tags)))
(and env (progn (org-entry-put nil "BEAMER_env" env) t))))
(t (org-entry-delete nil "BEAMER_env"))))))
;;;###autoload
(defun org-beamer-publish-to-latex (plist filename pub-dir)
"Publish an Org file to a Beamer presentation (LaTeX).
FILENAME is the filename of the Org file to be published. PLIST
is the property list for the given project. PUB-DIR is the
publishing directory.
Return output file name."
(org-publish-org-to 'beamer filename ".tex" plist pub-dir))
;;;###autoload
(defun org-beamer-publish-to-pdf (plist filename pub-dir)
"Publish an Org file to a Beamer presentation (PDF, via LaTeX).
FILENAME is the filename of the Org file to be published. PLIST
is the property list for the given project. PUB-DIR is the
publishing directory.
Return output file name."
;; Unlike to `org-beamer-publish-to-latex', PDF file is generated in
;; working directory and then moved to publishing directory.
(org-publish-attachment
plist
;; Default directory could be anywhere when this function is
;; called. We ensure it is set to source file directory during
;; compilation so as to not break links to external documents.
(let ((default-directory (file-name-directory filename)))
(org-latex-compile
(org-publish-org-to
'beamer filename ".tex" plist (file-name-directory filename))))
pub-dir))
(provide 'ox-beamer)
;; Local variables:
;; generated-autoload-file: "org-loaddefs.el"
;; End:
;;; ox-beamer.el ends here