|Tutorial Series||Beginner Tutorial|
|Previous||Python, Qt, KDE4 development environment|
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.
|To get more information about any class you come across, Konqueror offers a quick shortcut. So to look for information about KMessageBox, just type "kde:kmessagebox" into Konqueror and you'll be taken to the documentation.|
|You might want to use an IDE for your projects, which does many nice things like code completion, easy access to API documentation or debugging support. Read this tutorial to set up an IDE correctly for this task. You probably want to check if the setup is working by testing opening an existing KDE 4 application first.|
All the code we need will be in one file, tutorial1.py. Create that file with the code below:
from PyQt4.QtCore import QString
from PyKDE4.kdecore import ki18n, KCmdLineArgs, KAboutData, i18n from PyKDE4.kdeui import KApplication, KGuiItem, KMessageBox
appName = "python-kde-tutorial1"
catalog = ""
programName = ki18n("PyKDE Tutorial 1")
version = "1.0"
description = ki18n("Displays a KMessageBox popup")
license = KAboutData.License_GPL
copyright = ki18n("(c) 2008")
text = ki18n("Some text...")
homePage = "techbase.kde.org"
bugEmail = "firstname.lastname@example.org"
aboutData = KAboutData ( appName, catalog, programName, version, description, license, copyright, text, homePage, bugEmail )
app = KApplication() yesButton = KGuiItem( i18n("Hello"), QString(), i18n("This is a tooltip."), i18n("This is a WhatsThis help text.") ) KMessageBox.questionYesNo( None, i18n("Hello World!"), i18n("Hello"), yesButton )
sys.exit(0) The first KDE specific code we come across 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.
Then we come to KCmdLineArgs. 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.
Now we've done all the necessary KDE setup, we can move on to doing interesting things with our application. We're going to create a popup box but we're going to customise one of the buttons. To do this customisation, we need to use a KGuiItem object. The first argument in the KGuiItem constructor is the text that will appear on the item (in our case, a button). Then we have an option of setting an icon for the button but we don't want one so we just give it QString(). We then set the tooltip (what appears when you hover over an item) and finally the "What's This?" (accessed through right-clicking or Shift-F1) text.
Now we have our item, we can create our popup. We call the KMessageBox.questionYesNo() function which, by default, creates a message box with a "Yes" and a "No" button. The second argument is the text that will appear in the message box above the buttons. The third is the caption the window will have and finally we set the KGuiItem for (what would normally be) the "Yes" button to the KGuiItem we created.
Note that all user-visible text is passed through the i18n() function; this is necessary for the UI to be translatable. More information on localization can be found in the localization tutorial.
We're all done as far as the code is concerned. Now to try it out. Launch it with:
or make it executable and use: