Slicer4:Internationalization of Slicer

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Introduction

This pages contains notes on source code additions and modifications of different modules within Slicer for the internationalization purpose.

QT-based Internationalization

Internationalization is well supported in QT. A lot of modules of Slicer are developed on QT. This has set a good ground for the internationalization of Slicer.

• basic idea

In Qt, tr() is one of the static public members of QObject class, which returns a translated version of input sourceText.

   QString QObject::tr ( const char * sourceText, const char * disambiguation = 0, int n = -1 ) [static]

tr() will search the translation in a so-called translation file. If nothing is found, then the sourceText instead of the translated version will be displayed directly.

• translation file template

The following is an example of the translation file, from English to Chinese.

   <?xml version="1.0" encoding="utf-8"?>
   <!DOCTYPE TS>
   <TS version="2.0" language="zh_CN">
   <context>
   <name>qSlicerMainWindow</name>
   <message>

&File

       <translation>文件</translation>
   </message>
   <message>

&Edit

       <translation>编辑</translation>
   </message>
   <message>

Feedback

       <translation>反馈</translation>
   </message>
   <message>

Import Scene

       <translation>导入场景</translation>
   </message>
   <message>

Add Data

       <translation>添加数据</translation>
   </message>
   </context>
   </TS>

In the above example, all the texts are within the scope of qSlicerMainWindow class. That's why 'qSlicerMainWindo' occurs in section 'name'.

• The following modifications are are needed:

In file \Slicer4\Base\QTCore\qSlicerCoreApplication.h, add the following line:

   #include <QTranslator>

In file \Slicer4\Applications\SlicerQT\main.cxx (around line#230), add the following lines:

   static QTranslator* translator;
   if (translator != NULL)
   {
       qApp->removeTranslator(translator);
       delete translator;
       translator = NULL;
   }
   QString langCode= argv[1];
   translator = new QTranslator;
   QString qmFilename = "lang_" + langCode; 
   if (translator->load(qmFilename))
   {
       qApp->installTranslator(translator);
   }

Scripted Module

Some modules are implemented in Python. Endoscopy is one of the typical examples. In endoscopy.py, if we change the code in line#10

   parent.titel = “Endoscopy”

to

   parent.title = slicer.app.translate(self.__class__.__name__, "Endoscopy")

then "Endoscopy" can be shown in other languages.Similarily, other displayable strings can be handled in the same way.