Balance word spacing within the consecutive lines to get uniform grayness and less rivers for better readability, enabled by the new paragraph property com::sun::star::text::ParaComposer and the following developments: * Add Paragraph Composer checkbox on Alignment pane of the paragraph formatting dialog window (not default yet); * Implement paragraph composer: big word spacing of a line is decreased by shifting the last word from the previous line, only if the word spacing is better, than before, and the increased word spacing in the previous line doesn't exceed the Maximum word spacing (limited paragraph composer); * When Maximum word spacing is not greater than the Desired word spacing, shifting of the last word is not limited by the Maximum word spacing (unlimited paragraph composer) * Add loext:paragraph-composer attribute, as LibreOffice ODF extension; * Add ODF unit tests for the limited and not limited paragraph composer. Note: "Smart justify" line breaking algorithm chooses space shrinking (limited by Minimum word spacing) only if shifting the last word isn't better based on the desired word spacing. This was still a greedy line breaking algorithm, resulting big word spacing in the lines before a longer word. The paragraph composer shifts the last word (or the first part of the hyphenated last word) from the previous line to decrease big word spacing in the actual line. Note: balancing very big word spacing in narrow consecutive lines can result vertical rivers. To avoid this, use limited paragraph composer by setting maximum word spacing. Follow-up to "smart justify", word spacing, letter spacing and glyph scaling developments. Selected commits: commit529755f091"tdf#166113 sw smart justify: adjust algorithm for interoperability", commit7d08767b89"tdf#130088 "tdf#119908 smart justify: fix DOCX line count + compat opt.", commit7d6696757d"tdf#159923 sw cui offapi xmloff: add custom word spacing", commit5a48070f59"tdf#126154 sw offapi xmloff cui: add min/max word spacing", commitf83a04c510"tdf#167648 cui offapi xmloff sw: add DTP-feature maximum letter spacing", commit3c53797210"tdf#167648 sw letter spacing: implement minimum letter spacing", commit45ec7bd761"tdf#168251 cui offapi xmloff sw glyph scaling: extend UNO/UX/ODF". Change-Id: I727caad70536c86be524bc9d9b52bc71208c202a Reviewed-on: https://gerrit.libreoffice.org/c/core/+/203288 Reviewed-by: László Németh <nemeth@numbertext.org> Tested-by: Jenkins
ODF Import and Export Filter Logic
The main library "xo" contains the basic ODF import/export filter
implementation for most applications. The document is accessed
via its UNO API, which has the advantage that the same import/export
code can be used for text in all applications (from/to Writer/EditEngine).
The filter consumes/produces via SAX UNO API interface (implemented in
"sax"). Various bits of the ODF filters are also implemented in
applications, for example [git:sw/source/filter/xml].
There is a central list of all element or attribute names in
[git:include/xmloff/xmltoken.hxx]. The main class of the import filter
is SvXMLImport, and of the export filter SvXMLExport.
The Import filter maintains a stack of contexts for each element being read. There are many classes specific to particular elements, derived from SvXMLImportContext.
Note that for export several different versions of ODF are supported, with the default being the latest ODF version with "extensions", which means it may contain elements and attributes that are only in drafts of the specification or are not yet submitted for specification. Documents produced in the other (non-extended) ODF modes are supposed to be strictly conforming to the respective specification, i.e., only markup defined by the ODF specification is allowed.
There is another library "xof" built from the source/transform directory, which is the filter for the OpenOffice.org XML format. This legacy format is a predecessor of ODF and was the default in OpenOffice.org 1.x versions, which did not support ODF. This filter works as a SAX transformation from/to ODF, i.e., when importing a document the transform library reads the SAX events from the file and generates SAX events that are then consumed by the ODF import filter.
OpenOffice.org XML File Format
There is some stuff in the "dtd" directory which is most likely related to the OpenOffice.org XML format but is possibly outdated and obsolete.
Add New XML Tokens
When adding a new XML token, you need to add its entry in the following three files:
[git:include/xmloff/xmltoken.hxx][git:xmloff/source/core/xmltoken.cxx][git:xmloff/source/token/tokens.txt]