README.Code

* A quick overview of the LibreOffice code structure.

** Overview

    You can develop for LibreOffice in one of two ways, one
recommended and one much less so. First the somewhat less recommended
way: it is possible to use the SDK, for wihch you can read the API
docs here http://api.libreoffice.org/. This re-uses the (extremely
generic) APIs we provide for macro scripting in StarBasic.

    The best way to add a generally useful feature to LibreOffice
is to work on the code base however. Overall this way makes it easier
to compile and build your code, it avoids any arbitrary limitations of
our scripting APIs, and in general is far more simple and intuitive -
if you are a reasonably able C++ programmer.


** The important bits of code

    Each module should have a README file inside it which has some
degree of documentation for that module; patches are most welcome to
improve those. We have those turned into a web-page here:

    http://docs.libreoffice.org/

    However, there are two hundred modules, many of them of only
peripheral interest for a specialist audience. So - where is the
good-stuff, the code that is most useful. Here is a quick overview of
the most important ones:

    sal/      - this provides a simple System Abstraction Layer
    tools/    - this provides basic internal types: 'Rectangle', 'Color' etc.
    vcl/      - this is the widget toolkit library and one rendering abstraction
    svx/      - graphics related helper code, including much of 'draw' / 'impress'
    sfx2/     - core framework: document model / load/save / signals for actions etc.
    framework - UNO wrappers around the core framework, responsible for building
                toolbars, menus, status bars, and the chrome around the document
                using widgets from VCL, and XML descriptions from */uiconfig/ files

    Then applications

    desktop/  - this is where the 'main' for the application lives, init / bootstrap
                the name dates back to an ancient StarOffice that also drew a desktop
    sw/       - writer.
    sc/       - calc
    sd/       - draw / impress

    There are several other libraries that are helpful from a
graphical perspective:

    basebmp/      - enables a VCL compatible rendering API to render to bitmaps,
                    as used for LibreOffice on-line, Android, iOS etc.
    basegfx/      - algorithms and data-types for graphics as used in the canvas
    canvas/       - new (UNO) canvas rendering model with various backends
    cppcanvas/    - C++ helper classes for using the UNO canvas
    drawinglayer/ - code to render and manage document drawing shapes and break
                    them down into primitives we can render more easily.

** Finding out more

    Beyond this, you can read the README files, send us patches, ask
on the mailing list libreoffice@lists.freedesktop.org (no subscription
required) or poke people on IRC #libreoffice-dev on irc.freenode.net -
we're a friendly and generally helpful mob. We know the code can be
hard to get into at first, and so there are no silly questions.