Difference between revisions of "Development/Tutorials/Collaboration/HotNewStuff/Introduction"

Revision as of 18:36, 1 April 2010

Get Hot New Stuff 3 Introduction

Tutorial Series	HotNewStuff
Previous	Getting started with KDE development
What's Next	Get Hot New Stuff 3 - Updates
Further Reading	API Documentation

Overview

Here is a small example of an application that asks openDesktop.org for wallpapers. It lets the user install them into the system wallpaper directory.

The Code

The example consists of just one c++ source file. //khotnewstuff.cpp


include <kapplication.h>
include <kdebug.h>
include <klocale.h>
include <kcmdlineargs.h>
include <kaboutdata.h>

include <knewstuff3/downloaddialog.h>

int main(int argc, char **argv)
{

   KAboutData about("khotnewstuff_example", 0, ki18n("KHotNewStuff"), "0.4");
   about.setProgramIconName("get-hot-new-stuff");
   
   KApplication i;

   KNS3::DownloadDialog dialog(args->arg(0));
   dialog.exec();
   foreach (const KNS3::Entry& e, dialog.changedEntries()) {
       kDebug() << "Changed Entry: " << e.name();
   }

   return 0;

}

The Configuration File (.knsrc)

For this to work, a file that sets up KNewStuff khotnewstuff_example.knsrc is needed. The file has to be in kde/share/config/khotnewstuff_example.knsrc. (The name of the file is taken from the about data).

[KNewStuff3] ProvidersUrl=http://download.kde.org/ocs/providers.xml Categories=KDE Wallpaper 1920x1200,KDE Wallpaper 1600x1200 TargetDir=wallpapers Uncompress=archive

Uncompress can be one of:

always: assume all downloaded files are archives and need to be extracted
never: never try to extract the file
archive: if the file is an archive, uncompress it, otherwise just pass it on

You have different options to set the target install directory:

StandardResource: standard ressouce dir, such as .kde/share/wallpapers. This is what KStandardDirs::locateLocal(name) will return.
TargetDir: a directory in the share/apps section, such as .kde/share/apps/wallpapers. This is what KStandardDirs::locateLocal("data", name) will return.

Downloaded HTML:

A new option has been added for KDE 4.5. By default KNewStuff will ask if the user wants to open downloaded HTML files with a browser instead of trying to install them. This is so since most of the time HTML means a broken link or a link to a page from which the item can be downloaded. If you want to accept html (because your app actually uses KNewStuff to get html files, you should explicitly allow this: AcceptHtmlDownloads=true

Linking in CMakeLists.txt

To link against KNS3, just link against ${KDE4_KNEWSTUFF3_LIBS}. Example:

target_link_libraries(ktexteditor_codesnippets_core ${KDE4_KDEUI_LIBS} ${KDE4_KTEXTEDITOR_LIBS} ${KDE4_KNEWSTUFF3_LIBS})

Using a Widget instead of the Dialog

If you don't like to use an external dialog, you can also use a widget instead. Just replace DownloadDialog with DownloadWidget and you're good to go. This is especially nice as additional page in existing config dialogs.

@@ Line 6: / Line 6: @@
 pre=[[Getting_Started|Getting started with KDE development]]|
 next=[[Development/Tutorials/Collaboration/HotNewStuff/Updates|Get Hot New Stuff 3 - Updates]]|
+reading=[http://api.kde.org/4.x-api/kdelibs-apidocs/knewstuff/html/classKNS3_1_1DownloadDialog.html API Documentation]
 }}