GTRANS

The GTRANS module allows to manage language translations. The language of an application can be changed dynamically during run-time using the GTRANS module.

API reference

The API reference of the GTRANS module can be found here.

Intended usage

Each translation is specified by a transTable struct which is essentially a table of strings:

typedef struct transTable {
    unsigned numEntries;     // The number of strings that this table contains
    const char** strings;    // The translated strings
} transTable;

A translatable application needs to have a base language. All translations happen relative to that base language. The base language is specified using gtransSetBaseLanguage(). The current language of the application is set using gtransSetLanguage(). The actual translations take place by calling gtransString(). A string contained in the translation table of the base language is passed to gtransString(). The function returns the corresponding string of the current language that was set using gtransSetLanguage() or the passed string if none was found.

A wrapper macro named gt() around gtransString() is available to make writing and reading translatable applications easier:

#define gt(str) gtransString(str)

Example

#include "gfx.h"
 
static const char* EnglishStrings[] = {
    "Welcome",
    "The number %s has the value %d",
    "Goodbye"
};
static const transTable EnglishTranslation = { sizeof(EnglishStrings)/sizeof(EnglishStrings[0]), EnglishStrings };
 
static const char* GermanStrings[] = {
    "Herzlich Willkommen",
    "Die Zahl %s hat den Wert %d",
    "Auf Wiedersehen"
};
static const transTable GermanTranslation = { sizeof(GermanStrings)/sizeof(GermanStrings[0]), GermanStrings };
 
int main(void)
{
    size_t i, j;
    font_t font;
 
    gfxInit();
    gdispClear(Silver);
 
    font = gdispOpenFont("*");
 
    gtransSetBaseLanguage(&EnglishTranslation);
    gtransSetLanguage(&GermanTranslation);
 
    gtransSetLanguage(&EnglishTranslation);
    i = 0;
    for (j = 0; j < EnglishTranslation.numEntries; j++) {
        gdispFillStringBox(20+300*i, 35*j, 300, 35, gtransIndex(j), font, Black, Silver, justifyLeft);
    }
 
    gtransSetLanguage(&GermanTranslation);
    i = 1;
    for (j = 0; j < EnglishTranslation.numEntries; j++) {
        gdispFillStringBox(20+300*i, 35*j, 300, 35, gtransIndex(j), font, Black, Silver, justifyLeft);
    }
 
    gdispFillStringBox(20, 300, 300, 25, gt("Welcome"), font, Black, Silver, justifyLeft);
 
	while (TRUE) {
		gfxSleepMilliseconds(500);
	}
 
	return 0;
}