Development/Tutorials/First program/nl: Difference between revisions
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name=Hello World| | name=Hello World| | ||
pre=[http://mindview.net/Books/TICPP/ThinkingInCPP2e.html C++], [ | pre=[http://mindview.net/Books/TICPP/ThinkingInCPP2e.html C++], [https://www.qt.io/ Qt], [[Special:myLanguage/Getting_Started/Build|Building KDE]]| | ||
next=[[Development/Tutorials/Using_KXmlGuiWindow|Tutorial 2 - KXmlGuiWindow]]| | next=[[Special:myLanguage/Development/Tutorials/Using_KXmlGuiWindow|Tutorial 2 - KXmlGuiWindow]]| | ||
reading=[[Special:myLanguage/Development/Tutorials/CMake|CMake]] | |||
reading=[[Development/Tutorials/CMake|CMake]] | |||
}} | }} | ||
==Samenvatting== | ==Samenvatting== | ||
Your first program shall greet the world with a friendly "Hello World", what else? For that, we will use a {{class|KMessageBox}} and customise one of the buttons. | |||
[[image:Introtokdetutorial1-kf5.png|frame|center]] | |||
{{Tip|Als je meer informatie wilt over een klasse die je tegenkomt, kun je de 'kde'-zoekmachine gebruiken. Om bijvoorbeeld meer te weten te komen over een KMessageBox, typ je "kde:kmessagebox" in Konqueror, rekonq of KRunner, waarna de documentatie verschijnt.}} | {{Tip|Als je meer informatie wilt over een klasse die je tegenkomt, kun je de 'kde'-zoekmachine gebruiken. Om bijvoorbeeld meer te weten te komen over een KMessageBox, typ je "kde:kmessagebox" in Konqueror, rekonq of KRunner, waarna de documentatie verschijnt.}} | ||
{{Tip| | {{Tip| | ||
You might want to use [[Special:myLanguage/KDevelop|KDevelop]] or [[Special:myLanguage/qtcreator|QtCreator]] as IDE for your projects. | |||
}} | }} | ||
== De code == | == De code == | ||
All the code we need will be in one file, <tt>main.cpp</tt>. Create that file with the code below: | |||
<syntaxhighlight lang="cpp-qt"> | <syntaxhighlight lang="cpp-qt"> | ||
#include <cstdlib> | #include <cstdlib> | ||
#include < | #include <QApplication> | ||
#include <QCommandLineParser> | |||
#include <KAboutData> | #include <KAboutData> | ||
#include < | #include <KLocalizedString> | ||
#include <KMessageBox> | #include <KMessageBox> | ||
int main (int argc, char *argv[]) | int main (int argc, char *argv[]) | ||
{ | { | ||
QApplication app(argc, argv); | |||
KLocalizedString::setApplicationDomain("tutorial1"); | |||
KAboutData aboutData( | KAboutData aboutData( | ||
// The program name used internally. | // The program name used internally. (componentName) | ||
"tutorial1" | QStringLiteral("tutorial1"), | ||
// A displayable program name string. (displayName) | |||
i18n("Tutorial 1"), | |||
// The program version string. (version) | |||
// A displayable program name string. | QStringLiteral("1.0"), | ||
// Short description of what the app does. (shortDescription) | |||
// The program version string. | i18n("Displays a KMessageBox popup"), | ||
"1.0", | |||
// Short description of what the app does. | |||
// The license this code is released under | // The license this code is released under | ||
KAboutLicense::GPL, | |||
// Copyright Statement | // Copyright Statement (copyrightStatement = QString()) | ||
i18n("(c) 2015"), | |||
// Optional text shown in the About box. | // Optional text shown in the About box. | ||
// Can contain any information desired. | // Can contain any information desired. (otherText) | ||
i18n("Some text..."), | |||
// The program homepage string. | // The program homepage string. (homePageAddress = QString()) | ||
"http://example.com/", | QStringLiteral("http://example.com/"), | ||
// The bug report email address | // The bug report email address | ||
// (bugsEmailAddress = QLatin1String("[email protected]") | |||
QStringLiteral("[email protected]")); | |||
aboutData.addAuthor(i18n("Name"), i18n("Task"), QStringLiteral("[email protected]"), | |||
QStringLiteral("http://your.website.com"), QStringLiteral("OSC Username")); | |||
KAboutData::setApplicationData(aboutData); | |||
QCommandLineParser parser; | |||
aboutData.setupCommandLine(&parser); | |||
parser.process(app); | |||
aboutData.processCommandLine(&parser); | |||
KGuiItem yesButton( i18n( "Hello" ), QString(), | KGuiItem yesButton( i18n( "Hello" ), QString(), | ||
i18n( "This is a tooltip" ), | i18n( "This is a tooltip" ), | ||
i18n( "This is a WhatsThis help text." ) ); | i18n( "This is a WhatsThis help text." ) ); | ||
KMessageBox ::questionYesNo | return | ||
KMessageBox::questionYesNo | |||
(0, i18n( "Hello World" ), i18n( "Hello" ), yesButton ) | (0, i18n( "Hello World" ), i18n( "Hello" ), yesButton ) | ||
== KMessageBox ::Yes? EXIT_SUCCESS: EXIT_FAILURE; | == KMessageBox::Yes? EXIT_SUCCESS: EXIT_FAILURE; | ||
} | } | ||
</syntaxhighlight> | </syntaxhighlight> | ||
First we need to create a [http://doc.qt.io/qt-5/qapplication.html QApplication] object. This needs to be done exactly once in each program since it is needed for things such as [[Development/Tutorials/Localization/i18n|i18n]]. It also should be created before any other KDE or Qt object. A call to {{class|KLocalizedString}}::setApplicationDomain() is required to properly set the translation catalog and must be done before the next step happens. | |||
The first KDE specific object we create in this program is {{class|KAboutData}}. This is the class used to store information about the program such as a short description, authors or license information. Pretty much every KDE application should use this class. We then call {{class|KAboutData}}::setApplicationData() to initialize the properties of the [http://doc.qt.io/qt-5/qapplication.html QApplication] object. | |||
Then we come to [http://doc.qt.io/qt-5/qcommandlineparser.html QCommandLineParser]. This is the class one would use to specify command line switches to, for example, open the program with a specific file. However, in this tutorial, we simply initialise it with the {{class|KAboutData}} object we created so we can use the <tt>--version</tt> or <tt>--author</tt> switches. | |||
We zijn nu klaar met alle nodige KDE-instellingen, en we kunnen verdergaan met interessantere dingen. We maken een popup, maar daarbij passen we één van de knoppen aan. Om deze wijziging aan te brengen, moeten we een {{class|KGuiItem}}-object gebruiken. Het eerste argument in de constructor van {{class|KGuiItem}} is de tekst die op het item komt te staan (in ons geval dus de knop). Dan hebben we een optie om een icoontje op de knop te zetten; dat willen we niet en dus geven we alleen een <tt>QString()</tt> mee. Dan stellen we de tooltip in (de tekst die verschijnt als je met de muis boven een item hangt) en ten slotte de "Wat is dit?"-tekst (die je krijgt door met de rechtermuisknop te klikken of op Shift-F1 te drukken). | We zijn nu klaar met alle nodige KDE-instellingen, en we kunnen verdergaan met interessantere dingen. We maken een popup, maar daarbij passen we één van de knoppen aan. Om deze wijziging aan te brengen, moeten we een {{class|KGuiItem}}-object gebruiken. Het eerste argument in de constructor van {{class|KGuiItem}} is de tekst die op het item komt te staan (in ons geval dus de knop). Dan hebben we een optie om een icoontje op de knop te zetten; dat willen we niet en dus geven we alleen een <tt>QString()</tt> mee. Dan stellen we de tooltip in (de tekst die verschijnt als je met de muis boven een item hangt) en ten slotte de "Wat is dit?"-tekst (die je krijgt door met de rechtermuisknop te klikken of op Shift-F1 te drukken). | ||
Line 96: | Line 107: | ||
=== CMakeLists.txt === | === CMakeLists.txt === | ||
Create a file named CMakeLists.txt in the same directory as main.cpp with this content: | |||
<syntaxhighlight lang="cmake"> | <syntaxhighlight lang="cmake"> | ||
cmake_minimum_required(VERSION 3.0) | |||
project (tutorial1) | project (tutorial1) | ||
find_package( | |||
include ( | set(QT_MIN_VERSION "5.3.0") | ||
set(KF5_MIN_VERSION "5.2.0") | |||
find_package(ECM 1.0.0 REQUIRED NO_MODULE) | |||
set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake) | |||
include(KDEInstallDirs) | |||
include(KDECMakeSettings) | |||
include(KDECompilerSettings NO_POLICY_SCOPE) | |||
include(FeatureSummary) | |||
# Find Qt modules | |||
find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS | |||
Core # QCommandLineParser, QStringLiteral | |||
Widgets # QApplication | |||
) | |||
# Find KDE modules | |||
find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS | |||
CoreAddons # KAboutData | |||
I18n # KLocalizedString | |||
WidgetsAddons # KMessageBox | |||
) | |||
feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES) | |||
set(tutorial1_SRCS main.cpp) | set(tutorial1_SRCS main.cpp) | ||
target_link_libraries(tutorial1 | add_executable(tutorial1 ${tutorial1_SRCS}) | ||
install(TARGETS tutorial1 ${ | |||
<!--T:54--> | |||
target_link_libraries(tutorial1 | |||
Qt5::Widgets | |||
KF5::CoreAddons | |||
KF5::I18n | |||
KF5::WidgetsAddons | |||
) | |||
install(TARGETS tutorial1 ${KDE_INSTALL_TARGETS_DEFAULT_ARGS}) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
The <tt>find_package()</tt> function locates the package that you ask it for (in this case ECM, Qt5, or KF5) and sets some variables describing the location of the package's headers and libraries. ECM, or Extra CMake Modules, is required to import special CMake files and functions for building KDE applications. | |||
Here we try to find the modules for Qt 5 and KDE Frameworks 5 required to build our tutorial. The necessary files are included by CMake so that the compiler can see them at build time. Minimum version numbers are set at the very top of CMakeLists.txt file for easier reference. | |||
Daarna maken we een variabele <tt>tutorial1_SRCS</tt> met behulp van de functie <tt>set()</tt>. In dit geval stellen we de variabele in op de naam van ons enige bronbestand. | Daarna maken we een variabele <tt>tutorial1_SRCS</tt> met behulp van de functie <tt>set()</tt>. In dit geval stellen we de variabele in op de naam van ons enige bronbestand. | ||
Then we use <tt>add_executable()</tt> to create an executable called <tt>tutorial1</tt> from the source files listed in our <tt>tutorial1_SRCS</tt> variable. Afterwards, we link our executable to the necessary libraries using <tt>target_link_libraries()</tt> function. The line starting with <tt>install</tt> writes a default "install" target into the Makefile. | |||
== Make aanroepen en uitvoeren == | |||
To compile, link and install your program, you must have several software installed, e.g. | To compile, link and install your program, you must have several software installed, e.g. cmake, make and gcc-c++, and the Qt 5 and KDE Frameworks development files. To be sure you have everything, best follow [[Special:myLanguage/Getting_Started/Build/Environment|this install guide]]. | ||
While you can run cmake directly inside the source code directory itself, it is a best practice, and actually enforced in some KDE software, to use a separate build directory and run cmake from there: | |||
<syntaxhighlight lang="bash"> | <syntaxhighlight lang="bash"> | ||
mkdir build && cd build | |||
</syntaxhighlight> | </syntaxhighlight> | ||
You can invoke CMake and make manually: | |||
<syntaxhighlight lang="bash"> | <syntaxhighlight lang="bash"> | ||
cmake .. && make | |||
</syntaxhighlight> | </syntaxhighlight> | ||
And launch it with: | And launch it with: | ||
<syntaxhighlight lang="bash"> | <syntaxhighlight lang="bash"> | ||
./tutorial1 | ./tutorial1 | ||
</syntaxhighlight> | </syntaxhighlight> | ||
== | == De volgende stappen == | ||
Nu kun je verdergaan met de volgende tutorial, over het [[Development/Tutorials/Using_KXmlGuiWindow|gebruik van KXmlGuiWindow]]. | |||
{{Tip||The source code on this page applies only the current KDE Frameworks 5 ("KF5") version. For the older KDE Development Platform ("KDE4"), See [[Special:myLanguage/Development/Tutorials/First_program/KDE4]]}} | |||
[[Category:C++]] | [[Category:C++]] |
Revision as of 09:53, 10 February 2019
Tutorial Series | Beginner Tutorial |
Previous | C++, Qt, Building KDE |
What's Next | Tutorial 2 - KXmlGuiWindow |
Further Reading | CMake |
Samenvatting
Your first program shall greet the world with a friendly "Hello World", what else? For that, we will use a KMessageBox and customise one of the buttons.
De code
All the code we need will be in one file, main.cpp. Create that file with the code below:
#include <cstdlib>
#include <QApplication>
#include <QCommandLineParser>
#include <KAboutData>
#include <KLocalizedString>
#include <KMessageBox>
int main (int argc, char *argv[])
{
QApplication app(argc, argv);
KLocalizedString::setApplicationDomain("tutorial1");
KAboutData aboutData(
// The program name used internally. (componentName)
QStringLiteral("tutorial1"),
// A displayable program name string. (displayName)
i18n("Tutorial 1"),
// The program version string. (version)
QStringLiteral("1.0"),
// Short description of what the app does. (shortDescription)
i18n("Displays a KMessageBox popup"),
// The license this code is released under
KAboutLicense::GPL,
// Copyright Statement (copyrightStatement = QString())
i18n("(c) 2015"),
// Optional text shown in the About box.
// Can contain any information desired. (otherText)
i18n("Some text..."),
// The program homepage string. (homePageAddress = QString())
QStringLiteral("http://example.com/"),
// The bug report email address
// (bugsEmailAddress = QLatin1String("[email protected]")
QStringLiteral("[email protected]"));
aboutData.addAuthor(i18n("Name"), i18n("Task"), QStringLiteral("[email protected]"),
QStringLiteral("http://your.website.com"), QStringLiteral("OSC Username"));
KAboutData::setApplicationData(aboutData);
QCommandLineParser parser;
aboutData.setupCommandLine(&parser);
parser.process(app);
aboutData.processCommandLine(&parser);
KGuiItem yesButton( i18n( "Hello" ), QString(),
i18n( "This is a tooltip" ),
i18n( "This is a WhatsThis help text." ) );
return
KMessageBox::questionYesNo
(0, i18n( "Hello World" ), i18n( "Hello" ), yesButton )
== KMessageBox::Yes? EXIT_SUCCESS: EXIT_FAILURE;
}
First we need to create a QApplication object. This needs to be done exactly once in each program since it is needed for things such as i18n. It also should be created before any other KDE or Qt object. A call to KLocalizedString::setApplicationDomain() is required to properly set the translation catalog and must be done before the next step happens.
The first KDE specific object we create in this program is KAboutData. This is the class used to store information about the program such as a short description, authors or license information. Pretty much every KDE application should use this class. We then call KAboutData::setApplicationData() to initialize the properties of the QApplication object.
Then we come to QCommandLineParser. This is the class one would use to specify command line switches to, for example, open the program with a specific file. However, in this tutorial, we simply initialise it with the KAboutData object we created so we can use the --version or --author switches.
We zijn nu klaar met alle nodige KDE-instellingen, en we kunnen verdergaan met interessantere dingen. We maken een popup, maar daarbij passen we één van de knoppen aan. Om deze wijziging aan te brengen, moeten we een KGuiItem-object gebruiken. Het eerste argument in de constructor van KGuiItem is de tekst die op het item komt te staan (in ons geval dus de knop). Dan hebben we een optie om een icoontje op de knop te zetten; dat willen we niet en dus geven we alleen een QString() mee. Dan stellen we de tooltip in (de tekst die verschijnt als je met de muis boven een item hangt) en ten slotte de "Wat is dit?"-tekst (die je krijgt door met de rechtermuisknop te klikken of op Shift-F1 te drukken).
We hebben nu een item, en nu kunnen we de popup aanmaken. We roepen de functie KMessageBox::questionYesNo() aan, die een venster met een "Ja"- en een "Nee"-knop maakt. Het tweede argument is de tekst die verschijnt in het venster, boven de knoppen. Het derde is de venstertitel, en ten slotte stellen we als KGuiItem de aangemaakte KGuiItem yesButton in voor de (oorspronkelijke) "Ja"-knop.
Merk op dat we alle tekst die zichtbaar is voor de gebruiker door de i18n()-functie sluizen. Dat is nodig om de interface vertaalbaar te maken. Meer informatie over vertaling kun je vinden in de tutorial over vertaling.
We zijn klaar met de code; laten we het programma compileren en uitproberen.
Compilatie
Je kunt het beste CMake gebruiken als compileeromgeving. Je maakt een bestand CMakeLists.txt, en cmake gebruikt dit bestand dan om alle Makefiles te genereren.
CMakeLists.txt
Create a file named CMakeLists.txt in the same directory as main.cpp with this content:
cmake_minimum_required(VERSION 3.0)
project (tutorial1)
set(QT_MIN_VERSION "5.3.0")
set(KF5_MIN_VERSION "5.2.0")
find_package(ECM 1.0.0 REQUIRED NO_MODULE)
set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
include(KDEInstallDirs)
include(KDECMakeSettings)
include(KDECompilerSettings NO_POLICY_SCOPE)
include(FeatureSummary)
# Find Qt modules
find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS
Core # QCommandLineParser, QStringLiteral
Widgets # QApplication
)
# Find KDE modules
find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
CoreAddons # KAboutData
I18n # KLocalizedString
WidgetsAddons # KMessageBox
)
feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)
set(tutorial1_SRCS main.cpp)
add_executable(tutorial1 ${tutorial1_SRCS})
<!--T:54-->
target_link_libraries(tutorial1
Qt5::Widgets
KF5::CoreAddons
KF5::I18n
KF5::WidgetsAddons
)
install(TARGETS tutorial1 ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
The find_package() function locates the package that you ask it for (in this case ECM, Qt5, or KF5) and sets some variables describing the location of the package's headers and libraries. ECM, or Extra CMake Modules, is required to import special CMake files and functions for building KDE applications.
Here we try to find the modules for Qt 5 and KDE Frameworks 5 required to build our tutorial. The necessary files are included by CMake so that the compiler can see them at build time. Minimum version numbers are set at the very top of CMakeLists.txt file for easier reference.
Daarna maken we een variabele tutorial1_SRCS met behulp van de functie set(). In dit geval stellen we de variabele in op de naam van ons enige bronbestand.
Then we use add_executable() to create an executable called tutorial1 from the source files listed in our tutorial1_SRCS variable. Afterwards, we link our executable to the necessary libraries using target_link_libraries() function. The line starting with install writes a default "install" target into the Makefile.
Make aanroepen en uitvoeren
To compile, link and install your program, you must have several software installed, e.g. cmake, make and gcc-c++, and the Qt 5 and KDE Frameworks development files. To be sure you have everything, best follow this install guide.
While you can run cmake directly inside the source code directory itself, it is a best practice, and actually enforced in some KDE software, to use a separate build directory and run cmake from there:
mkdir build && cd build
You can invoke CMake and make manually:
cmake .. && make
And launch it with:
./tutorial1
De volgende stappen
Nu kun je verdergaan met de volgende tutorial, over het gebruik van KXmlGuiWindow.