1dfb68debb
Background: External SD cards are only partially supported by the Android system, with a great deal of fragmentation on implementation across manufacturers and android versions. There is no official support for OTG devices. This commit adds: 1) External SD card support 2) OTG device support Caveats: 1) Not tested on Android 6. Emulator crashes when opening files on Android 6, using an unmodified build of the master branch. 2) OTG support currently works only if there is write access to the OTG directory. The user must be aware of exact OTG directory path or be able to navigate to it as well. 3) External SD card provider currently lacks file filtering. Approach: ----- Added new document providers. External SD cards: There are 2 different document providers external sd cards, one for Android 4.4 and above, and the other for older versions. 1) New Android 4.4 and above require usage of the DocumentFile wrapper class to access files in external storage. Actual file paths are no longer obtainable. As such, the underlying file will be cloned in a cache, allowing us to get an actual file path and use LOK. Some differences exist between 4.4 & 5+. The document provider handles each case separately. 2) Legacy Android 4.3 and below do not support the DocumentFile wrapper. File object can be used in these versions, allowing actual file paths to be obtained. The document provider guesses the root directory of the SD card. If the guessing fails, the user is to navigate to this directory himself. OTG: The OTG document provider resembles the legacy external SD card document provider, requiring the user to locate the directory himself. The document provider does not guess the root directory of the OTG device as the location varies with manufacturer implementation. ----- Supplementary Notes: Attempting to use the internal app cache as the file cache like in the ownCloud document provider did not work. Using the external app cache works fine though. It could be because initializing LOK wipes the internal app cache. Would be good to test the ownCloud document provider to confirm if it works. Change-Id: Ie727cca265107bc49ca7e7b57130470f7fc52e06 Reviewed-on: https://gerrit.libreoffice.org/20738 Reviewed-by: Tomaž Vajngerl <quikee@gmail.com> Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>
LibreOffice
LibreOffice is an integrated office suite based on copyleft licenses and compatible with most document formats and standards. Libreoffice is backed by The Document Foundation, which represents a large independent community of enterprises, developers and other volunteers moved by the common goal of bringing to the market the best software for personal productivity. LibreOffice is open source, and free to download, use and distribute.
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 to develop an extension, for which you can read the API docs here and here. This re-uses the (extremely generic) UNO APIs that are also used by 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:
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:
| Module | Description |
|---|---|
| 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 |
| framework | UNO framework, responsible for building toolbars, menus, status bars, and the chrome around the document using widgets from VCL, and XML descriptions from /uiconfig/ files |
| sfx2/ | legacy core framework used by Writer/Calc/Draw: document model / load/save / signals for actions etc. |
| svx/ | drawing model related helper code, including much of Draw/Impress |
Then applications
| Module | Description |
|---|---|
| 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:
| Module | Description |
|---|---|
| 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/ | View code to render drawable objects 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.