doc/src/examples/helloscript.qdoc
branchRCL_3
changeset 7 3f74d0d4af4c
equal deleted inserted replaced
6:dee5afe5301f 7:3f74d0d4af4c
       
     1 /****************************************************************************
       
     2 **
       
     3 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
       
     4 ** All rights reserved.
       
     5 ** Contact: Nokia Corporation (qt-info@nokia.com)
       
     6 **
       
     7 ** This file is part of the documentation of the Qt Toolkit.
       
     8 **
       
     9 ** $QT_BEGIN_LICENSE:LGPL$
       
    10 ** No Commercial Usage
       
    11 ** This file contains pre-release code and may not be distributed.
       
    12 ** You may use this file in accordance with the terms and conditions
       
    13 ** contained in the Technology Preview License Agreement accompanying
       
    14 ** this package.
       
    15 **
       
    16 ** GNU Lesser General Public License Usage
       
    17 ** Alternatively, this file may be used under the terms of the GNU Lesser
       
    18 ** General Public License version 2.1 as published by the Free Software
       
    19 ** Foundation and appearing in the file LICENSE.LGPL included in the
       
    20 ** packaging of this file.  Please review the following information to
       
    21 ** ensure the GNU Lesser General Public License version 2.1 requirements
       
    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
       
    23 **
       
    24 ** In addition, as a special exception, Nokia gives you certain additional
       
    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception
       
    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
       
    27 **
       
    28 ** If you have questions regarding the use of this file, please contact
       
    29 ** Nokia at qt-info@nokia.com.
       
    30 **
       
    31 **
       
    32 **
       
    33 **
       
    34 **
       
    35 **
       
    36 **
       
    37 **
       
    38 ** $QT_END_LICENSE$
       
    39 **
       
    40 ****************************************************************************/
       
    41 
       
    42 /*!
       
    43     \example script/helloscript
       
    44     \title Hello Script Example
       
    45 
       
    46     The Hello Script example shows the basic use of Qt Script: How to embed
       
    47     a script engine into the application, how to evaluate a script, and how
       
    48     to process the result of the evaluation. The example also shows how to
       
    49     apply internationalization to scripts.
       
    50 
       
    51     \snippet examples/script/helloscript/main.cpp 0
       
    52 
       
    53     The application will load the script file to evaluate from a resource, so
       
    54     we first make sure that the resource is initialized.
       
    55 
       
    56     \snippet examples/script/helloscript/main.cpp 1
       
    57 
       
    58     We attempt to load a translation, and install translation functions in the
       
    59     script engine. How to produce a translation is explained later.
       
    60 
       
    61     \snippet examples/script/helloscript/main.cpp 2
       
    62 
       
    63     A push button is created and exported to the script environment as a
       
    64     global variable, \c button. Scripts will be able to access properties,
       
    65     signals and slots of the button as properties of the \c button script
       
    66     object; the script object acts as a proxy to the C++ button object.
       
    67 
       
    68     \snippet examples/script/helloscript/main.cpp 3
       
    69 
       
    70     The contents of the script file are read.
       
    71 
       
    72     \snippet examples/script/helloscript/helloscript.js 0
       
    73 
       
    74     The script sets the \c text (note that the qTr() function is used to allow
       
    75     for translation) and \c styleSheet properties of the button, and calls the
       
    76     button's \c show() slot.
       
    77 
       
    78     \snippet examples/script/helloscript/main.cpp 4
       
    79 
       
    80     The script is evaluated. Note that the file name is passed as the
       
    81     (optional) second parameter; this makes it possible for the script engine
       
    82     to produce a meaningful backtrace if something goes wrong, and makes the
       
    83     qTr() function be able to resolve the translations that are associated
       
    84     with this script.
       
    85 
       
    86     \snippet examples/script/helloscript/main.cpp 5
       
    87 
       
    88     If the result is an Error object (e.g. the script contained a syntax
       
    89     error, or tried to call a function that doesn't exist), we obtain
       
    90     the line number and string representation of the error and display
       
    91     it in a message box.
       
    92 
       
    93     \snippet examples/script/helloscript/main.cpp 6
       
    94 
       
    95     If the evaluation went well, the application event loop is entered.
       
    96 
       
    97     \section1 Translating the Application
       
    98 
       
    99     The Qt Script internalization support builds on what Qt already provides
       
   100     for C++; see the \l{Hello tr() Example} for an introduction.
       
   101 
       
   102     Since we haven't made the translation file \c helloscript_la.qm, the
       
   103     source text is shown when we run the application ("Hello world!").
       
   104 
       
   105     To generate the translation file, run \c lupdate as follows:
       
   106 
       
   107     \code
       
   108     lupdate helloscript.js -ts helloscript_la.ts
       
   109     \endcode
       
   110 
       
   111     You should now have a file \c helloscript_la.ts in the current
       
   112     directory. Run \c linguist to edit the translation:
       
   113 
       
   114     \code
       
   115     linguist helloscript_la.ts
       
   116     \endcode
       
   117 
       
   118     You should now see the text "helloscript.js" in the top left pane.
       
   119     Double-click it, then click on "Hello world!" and enter "Orbis, te
       
   120     saluto!" in the \gui Translation pane (the middle right of the
       
   121     window). Don't forget the exclamation mark!
       
   122 
       
   123     Click the \gui Done checkbox and choose \gui File|Save from the
       
   124     menu bar. The TS file will no longer contain
       
   125 
       
   126     \snippet doc/src/snippets/code/doc_src_examples_hellotr.qdoc 3
       
   127 
       
   128     but instead will have
       
   129 
       
   130     \snippet doc/src/snippets/code/doc_src_examples_hellotr.qdoc 4
       
   131 
       
   132     To see the application running in Latin, we have to generate a QM
       
   133     file from the TS file. Generating a QM file can be achieved
       
   134     either from within \e {Qt Linguist} (for a single TS file), or
       
   135     by using the command line program \c lrelease which will produce one
       
   136     QM file for each of the TS files listed in the project file.
       
   137     Generate \c hellotr_la.qm from \c hellotr_la.ts by choosing
       
   138     \gui File|Release from \e {Qt Linguist}'s menu bar and pressing
       
   139     \gui Save in the file save dialog that pops up. Now run the \c helloscript
       
   140     program again. This time the button will be labelled "Orbis, te
       
   141     saluto!".
       
   142 */