[sword-devel] Sword Locales / German Umlaut Issues / Android Build

Troy A. Griffitts scribe at crosswire.org
Sun Jan 31 12:11:23 EST 2021

Dear Tobias,

My apologies for taking so long to respond to this, but I wanted to give
a thorough answer.  See the summary at the end if you don't care about
the details.

So, SWORD has a class StringMgr, which manages strings within SWORD, and
by default SWORD includes a very basic implementation, which doesn't
necessarily know about or support anything beyond what the basic C
string methods support.

I am sure this invokes a sense of horror from you at first, so let me
explain a bit how we properly handle character sets.  First, short
background: since we existed well before the Unicode world, we have
multiple locale files for each language, which you will still see in the
locales.d/ folder, each specifying their character encoding, and most of
the time SWORD doesn't need to manipulate characters, so simply holding
data, and passing that data to a display frontend, and specifying a font
which will handle that encoding was enough in the old world.  IMPORTANT:
the one place we do need to manipulate character data is to perform
case-insensitive comparisons.  We did this in the past by converting a
string to uppercase before comparison.  You'll notice this in the
section for Bible book abbreviation in each locale-- the partial match
key must be in a toupper state.

Today, everything in SWORD prefers Unicode and specifically, encoded as
UTF-8.  To support this:

First, we have utility functions within SWORD for working with Unicode
encoded strings, see:



SWBuf assureValidUTF8(const char *buf);
SW_u32 getUniCharFromUTF8(const unsigned char **buf, bool skipValidation = false);
SWBuf *getUTF8FromUniChar(SW_u32 uchar, SWBuf *appendTo);
SWBuf utf8ToWChar(const char *buf);
SWBuf wcharToUTF8(const wchar_t *buf);

To wrap this up, by subclassing StringMgr, SWORD supports implementing
character encoding by linking to other libraries, e.g., ICU, Qt, etc. to
handle full Unicode support.  And while the StringMgr interface allow
implementation of many string functions, upperUTF8 is the only real
method the SWORD engine needs to work completely.  Some utilities use
the other methods in there, but the engine, only needs this method.

In summary, on Android, you are likely not linking to ICU when you build
the native SWORD binary-- which I don't do either for Bishop.  The
Cordova SWORD plugin uses the SWORD java-jni bindings, which use the
Java VM to implement StringMgr:

Search for: AndroidStringMgr

And on iOS the Cordova plugin uses the Swift libraries to do the same. 
This is done by using the SWORD flatapi call to
org_crosswire_sword_StringMgr_setToUpper to provide a Swift
implementation to uppercase a string.


I hope this give you the information you need to get things working for
you.  Please don't hesitate to ask if you need help,


On 1/17/21 11:59 AM, Tobias Klein wrote:
> Dear Troy,
> I'm playing with an Android Build of Sword and I get issues with the
> German Umlauts.
> So I have issues with Bible book names like Römer, Könige, etc.
> The Umlauts are shown as ?.
> I'm configuring the SWORD build with CMake like below (without ICU!)
> I remember having similar issues on Linux when building without ICU.
> How do you build SWORD for Bishop? Any suggestions?
> Best regards,
> Tobias
> -- Check for working CXX compiler:
> /opt/Android/SDK/ndk/r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++
> -- Check for working CXX compiler:
> /opt/Android/SDK/ndk/r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++
> -- works
> -- Detecting CXX compiler ABI info
> -- Detecting CXX compiler ABI info - done
> -- Detecting CXX compile features
> -- Detecting CXX compile features - done
> -- Check for working C compiler:
> /opt/Android/SDK/ndk/r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
> -- Check for working C compiler:
> /opt/Android/SDK/ndk/r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
> -- works
> -- Detecting C compiler ABI info
> -- Detecting C compiler ABI info - done
> -- Detecting C compile features
> -- Detecting C compile features - done
> -- Configuring your system to build libsword.
> -- SWORD Version 1008900000
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