Porting Applications to KDE 2.0

Last Modified on March 23, 2000

This document contains the changes you have to apply to programs written for KDE1.1 when you want to port them to KDE2.0.

As a start you should have a look at doc/porting.doc in the Qt package.

Table of Contents

General

We did our best to clean up the header files of kdelibs, so they do not include unnecessary bloat for your application. As a consequence, you may notice that some header files are missing from your source files as they have been included before by kapp.h for example. There is a script in kdesdk/scripts called "fixheaders" that takes care of most of these cases. Just call "make -k 2>&1 | perl .../fixheaders" and it will try to look after the error messages and add includes as it recognize the errors.

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Starting other programs

In KDE 2.0 there are several ways to start other programs from within your application. Here is a short summary of your options with reasons why you should or should not use them.

1. fork + exec

You never want to use this unless you have a very good reason why it is impossible to use KProcess.

2. KProcess

You want to use this if you need to start a new process which needs to be a child of your process, e.g. because you want to catch stdout/stderr or need to send it data via stdin. You should never use this to start other KDE applications unless your application is called kgdb :-)

3. startServiceByDesktopPath

Preferred way to launch desktop (KDE/Gnome/X) applications or KDE services. The application/service must have a .desktop file. It will make use of KDEinit for increased startup performance and lower memory usage. These benefits only apply to applications available as KDEinit loadable module (KLM)

4. KRun

Generic way to open documents/applications/shell commands. Will use startServiceBy.... where applicable (in the future). Offers the additional benefit of startup-notification.

Currently the difference between the roles of KRun and startServiceBy... are not completely clear. KDE 1.x only had KRun and with KDE 2.0 a lot of the functionality has migrated to startServiceBy....

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khtmlw

khtmlw has been replaced with khtml.

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KIntegerLine, KIntLineEdit

KIntegerLine and KIntLineEdit have been replaced by KIntNumInput. The new header file is called knuminput.h.

The new KIntNumInput can have an optional slider attached, ensures that the entered value is in a given range (use MAX_INT or similar if you don't care about the range) and can maintain a descriptive label and also a unit for the edited value.

The API is almost the same and it simplifies existing code a bit, so give it a try. If you need more functionality, please contact me (Dirk A. Mueller <mueller@kde.org>).

The additional class KDoubleNumInput gives you the same look & feel, but allows you to edit floating point numbers.

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KLocale

i18n is no longer a macro

KApplication::getApplication()->getLocale()->translate

but a function on it's own. klocale is obsolete and replace every call to klocale->translate with i18n.

The return value of i18n is also no longer a const char*, but a unicode qstring.

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KApplication

doesn't hold any longer a KLocale instance. With this getLocale() and isLocaleInstantiated are now replaced by KGlobal::locale()

it also doesn't hold a KiconLoader instance. As this also getIconLoader() has been removed. Replace kapp->getIconLoader()->loadIcon() with BarIcon() or use KGlobal::iconLoader() instead of getIconLoader()

kde_*dir() have been removed as they require a unique top level directory for all applications (KDEDIR). This concept doesn't exist in KDE 2.0 any more.

Replace code that uses kde_*dir() + filename with calls to locate(filetype, filename) where filetype is what * used to be in kde_*dir(). locate is defined as function in kstddirs.h to call KGlobal::dirs()->findResource

generalFont() and fixedFont() are deprecated and will be removed soon. Please use KGlobal::generalFont() and KGlobal::fixedFont() instead.

appName() is deprecated. Please use QApplication::name() or instanceName instead.

The methods tempSaveName() and checkRecoverFile() return QString now. The returned values must _not_ be free()d.

helpMenu() has been moved to KTMainWindow. aboutKDE(), aboutApp() and appHelpActivated() have all been removed See section for KTMainWindow for more info.

The KApplication constructor has changed. Command line arguments and program name should no longer be passed to KApplication but to KCmdLineArgs. KCmdLineArgs performs command line parsing and a command line help. See kdelibs/kdecore/kcmdlineargs for more info.

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KCmdLineArgs

KCmdLineArgs is a new class that handles command line parsing and command line help. It is now required that your application specifies at least:

KCmdLineArgs itself will add the command line options supported by Qt and KApplication.

You can also use the KAboutData class to specify name, description and version.

In return for this information you can query KCmdLineArgs whether an certain option was specified on the command line and your application now automatically supports --help and --version. It aborts with a usefull error message when the command line contains a syntax error. See kdelibs/kdecore/kcmdlineargs for more info.

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KDNDIcon, KDNDDropZone, KDNDWidget, kdecore/drag.h

KDE Drag and Drop is Dead. Long live Qt Xdnd.

Xdnd is better anyway, because it has been adopted by all the other major GUI toolkits still under active development (this precludes Motif, but maybe we can convince the lesstif guys!). Some changes are necessary to convert your old KDND-based stuff to Qt DND.

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KConfigBase, KConfig, KSimpleConfig

These classes have been largely re-implemented. The external API remains mostly the same, with the single notable change that the groupIterator and entryIterator methods have been removed and instead replaced by groupList (which returns a QStringList of groups) and entryMap(const QString &group) (which returns a QMap of entries in the specified group). This is due to internal changes in KConfig which would make providing iterators possibly rather difficult.

Much more extensive documentation on the KConfig and friends API can be found in the kdoc generated documentation from the header files, and in kdecore/KCONFIG_DESIGN.

To use the new iterator, you will probably want to do something like this:


  QMap<QString, QString> tmpMap = config-<entryMap(myGroup);
  QMap<QString, QString>::Iterator aIt(tmpMap.begin());

  for (; aIt != tmpMap.end(); ++aIt) {
   // body here.  Access iterator key as aIt.key(),
   // data as *aIt.
  }

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libkfm has disappeared

Lots of other functionalities have been taken out of kfm, some being now in libkio, some in libkonq.

Replacement table :

KFM::download -> KIONetAccess::download (kdelibs/kio/kio_netaccess.h)
KFM::removeTempFile -> KIONetAccess::removeTempFile
refreshDesktop, sortDesktop, selectRootIcons : removed; kdesktop handles it
KFM::configure -> see konqueror interface (IDL, soon DCOP)
KFM::openURL -> "(void) new KRun (url)" (kdelibs/kio/krun.h)
KFM::refreshDirectory -> not needed anymore since konqy/kdesktop use KDirWatch
KFM::openProperties -> "(void) new PropertiesDialog (url)" (kdebase/libkonq/kpropsdlg.h)
KFM::exec -> "(void) new KRun (url)" (kdelibs/kio/krun.h)
KFM::copy, KFM::move -> KIOJob (async, see kio_job.h)
or KIONetAccess (sync, see kio_netaccess.h)
DlgLocation -> Use KLineEditDlg (kdeui/klineeditdlg.h) instead

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KGlobal: access to KDE global objects.

KGlobal allows centralized access to KDE global objects without including extraneous headers. object creation is deferred if possible.

All methods are static and headers for returned types are not included. You must have created a KApplication object before the methods can be used.

      #include <kglobal.h>
      #include <kconfig.h>      // Needed to use KConfig
      #include <klocale.h>      // Needed to use KLocale
      #include <kiconloader.h>  // Needed to use KIconLoader
    
    ...
        	KConfig *appcfg = KGlobal::config();
	        QString mystr	 = i18n( "This is a string" );


		KIconLoader *loader = KGlobal::iconLoader();

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KIconLoader

KIconLoader in 1.1 used to mix icons for applications and for toolbars. This has changed, so you may notice that your application doesn't find the right icons. loadIcon (used by BarIcon) returns only toolbar icons.

If you need icons for applications, use loadApplicationIcon.

loadMiniIcon and loadApplicationMiniIcon have been removed, instead loadApplicationIcon now takes a "size" argument where you can specify the size of the icon (small, medium, large).

The other big change you may notice, is that ICON and Icon have been removed as they caused big confusion for not loading application icons (see above). For this we added BarIcon which does the same as ICON before. The third change in this row is that loadIcon doesn't need the extension anymore, but looks for standard extensions (png, xpm) itself. If you hard- coded .xpm, loadIcon will issue a warning at runtime, but will still work in stripping off the .xpm part

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KDialog

KDialog is no longer defined in kwizard.h. Include kdialog.h instead.

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KTMainWidget

view_* public variables do no longer exist. There is really no reason for an app to use this information. If you do need it anyway, use mainViewGeometry() instead.

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automoc

automoc has been removed from the admin directory. It has been replaced by am_edit which provides a lot of additional features.

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kcharsets

The kcharsets class has been completely rewritten, and most of it has vanished, since support for it moved to Qt.

Most applications will only need to replace kapp->getKCharsets() with KGlobal::charsets().

For conversion of various input formats to QStrings, please have a look at QTextCodec and classes derived from it.

Character entities are now converted from and to QChars. The name has changed from convertTag to fromEntity and toEntity.

To get a font, which can display a certain charset (if such a font exists), you can use the KCharsets::setQFont methods. Input is a font and a charset. Kcharsets tries to find an output font, which matches the input font most closely, but can display the given charset.

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KWizard, KNoteBook

KWizard is based on QWizard now. The API has changed. Consult Qt's documentation and kdelibs/kdetest/kwizardtest.cpp for an example use.

KNoteBook (deeply entwined with the former KWizard) has been removed until someone is willing to port it to work with the new wizard. If you want to use it you'll find the necessary files in kdegraphics/kiconedit.

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KSpinBox, KNumericSpinBox

These classes have been replaced by QSpinBox. API is almost the same HINTS:

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KClipboard

KClipboard has been removed. In case you've been using KClipboard, QClipboard is the way to go now, as it has all the functionality the K version had, and more.

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KPanner, KNewPanner

KPanner and KNewPanner have been removed. QSplitter does everything KPanner did and more. The api is similar, but not compatible. Basically to set it up so that you have a vertical splitter between a listbox, a listview and multi line editor, you would do something like this:

QSplitter *split = new QSplitter( parent );
QListBox *lb = new QListBox( split );
KListView *lv = new KListView( split );
QMultiLineEdit *ed = new QMultiLineEdit( split );
As you can see you are not limited to two children. Additionally, you do not have to call activate when you are done, and opaque resizing is possible if you call setOpaqueResize(true).

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KTreeList, KTreeListItem

Use KListView, QListViewItem instead. API is almost the same, you only need to add a Column (KListView::addColum) before KListView is useable.

KListView has no addChild(), insertItem() and removeItem() calls. Inserting a root item is done by constructing a QListViewItem with the KListView passed as the parent widget. adding a child item is done by constructing a QListViewItem with the parent item as parameter. removeItem() should be replaced by delete <pointer to item>.

The root items are not shown in a tree fashion by default. to get this, use KListView::setDecorativeRoot(true).

Expanding and collapsing can by done by using QListViewItem::setOpen(bool).

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KMsgBox

KMsgBox has been superseded by QMessageBox. Which has been superseded by KMessageBox.

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KCombo

KCombo has been removed. Use QComboBox instead, it is completely compatible with the old KCombo API. The method that you may have problems with is the old KCombo::setText. This has been renamed to KCombo::setEditText.

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KQuickHelp

KQuickHelp, the "super-tooltip" widget, has been replaced by QWhatsThis. It provides a compatible API and almost the same look and feel, in addition to some new functionality.

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KPixmap::gradientFill

Instead of old KPixmap::gradientFill, use:

KPixmapEffect::gradient(KPixmap&, QColor, QColor, enum KPixmapEffect::GradientType, int)

Hence:

pix.gradientFill(ca, cb, direction, ncols)

becomes, for direction == true :

KPixmapEffect::gradient(pix, ca, cb, KPixmapEffect::VerticalGradient, ncols)

There are now:

KPixmapEffect::
 [Vertical,
Horizontal,
Diagonal,
CrossDiagonal,
Rectangle,
Pyramid,
PipeCross,
Elliptic]
Gradients. See kdelibs/kdetest/kgradienttest & kunbalancedgradienttest for information on how they actually look.

Look further in this document for other info about pixmap effect code reorganization (essentially, all effects are now in libkdeui.so: gradient(), unbalancedGradient(), hash(), desaturate(), pattern(), fade(), blend() etc.

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KTabListBox

This widget has been replaced by the almighty KListView. Everything said about KTreeList could be repeated here. The good thing is, that you now can combine TreeView's and normal Tablists without problems.

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KToolBarButton & KRadioGroup

If you need to do anything with KToolBarButton you now need to include <ktoolbarbutton.h> KRadioGroup has been renamed to KToolBarRadioGroup and requires you to include <ktoolbarradiogroup.h>

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KAccel

The functions keyToString() and stringToKey() which were previously declared globally in kaccel.h are now static methods in KAccel.

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KIO

All of the UDS_XXX and ERR_XXX constants are now in the KIO class. This class is just a namespace, so you can either inherit from it, or reference the constants as KIO::UDS_XXX. The names of all of the classes have been changed to start with a 'k', this prevents namespace pollution. This should not cause too many problems as most of the KIO classes now inherit the namespace. Finally you should not longer include userpaths.h, it has been renamed to kuserpaths.h, the old include will work for a while, but you will get a warning message. If you have any questions about the changes then mail me (rich@kde.org).

Conversion table (new names on the left) :

KUDSAtom -> UDSAtom
KIOProtocol -> IOProtocol
KUDSEntry -> UDSEntry;
KIOConnection -> Connection
KIOConnectionSignals -> ConnectionSignals
KIOConnectionSlots -> ConnectionSlots
KIOJobBase -> IOJob
KIOSlave -> Slave
KIOFilter -> Filter

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kstring.h / KString

The KString class is obsolete and is not defined in kstring.h anymore. The header file only existed for compatibility reasons. The file has been removed completely, use QString instead. (mirko@kde.org)

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ktopwidget.h / KTopWidget

KTMainWindow replaces this class completly. In most cases, it should be enough to simply replace the declaration of your former KTopWidget with KTMainWindow, as it is source compatible. ktopwidget.h does not exist in KDE 2. (mirko@kde.org)

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kbutton.h / KButton

Since Qt 2.0, the class QToolButton provides the functionality of buttons that raise when the mouse is moved over them, so there is no reason to have a class providing the same feature in KDE libs. All occurrences of KButton in the KDE CVS have been replaced by QToolButtons, but for applications not in the CVS it has to be done by the respective developer. (mirko@kde.org)

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kcolorgroup.h / KColorGroup

KColorGroup was not used in sources in the KDE CVS, and its functionality is provided by Qt. It has been removed. (mirko@kde.org)

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kcharsets.h / KCharsets

This functionality is removed from the KDE core and used from Qt, so it has been removed. Use QStrings (unicode) for this purpose. (mirko@kde.org)

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Methods for getting the value of a member object named getXy*() are renamed to xy*()

If your code does not compile and complains about missing member functions, you should check for methods that started with get...(). These methods have been renamed to xy*().

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kled.h, kledlamp.h / KLed, KLedLamp

There where two different classes for showing an LED lamp. Both are merged to the KLed class, but THE USER INTERFACE IS DIFFERENT, as both where more or less broken.

Please adjust your code accordingly.

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KTMainWindow

helpMenu() has been moved to KTMainWindow from KApplication (kapp).

Both the "About KDE" and the "About <Application>" dialog boxes are now modeless. "About KDE" is a completely new widget.

If you used in the toplevel window (that is derived from KTMainWindow) "kapp->helpMenu( bool, QString )" to get the help menu you must now change this to "helpMenu( QString )". The QString defaults to QString::null so it is sufficient to write helpMenu().

The old aboutKDE(), aboutApp() and appHelpActivated() of KApplication have all been removed. If you need direct access to these or need access to a help menu in a class that is not derived from KTMainWindow then allocate an instance of the new class KHelpMenu. See KDE 2.0 API reference or khelpmenu.h (kdeui) for additional info.

Espen Sand <espen@kde.org>

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KPixmap, KPixmapEffect

KPixmap::gradientFill, KPixmap::patternFill, KPixmap::tile and KPixmap::mapFill have been moved to KPixmapEffect, which is now part of libkdeui.

KPixmap::tile() has been renamed to KPixmapEffects::createTile().

Dirk A. Mueller <mueller@kde.org>

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KDE Control Center

The format for modules for the KDE Control Center has changed quite a bit. If you want to port your module to the new schema, please consult

kdebase/kcontrol/README

which explains what needs to be done.

Matthias Hoelzer-Kluepfel <hoelzer@kde.org>

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KWMModuleApplication libkdeui/kwmmapp.h

The KWMModuleApplication has been removed. Instead, use the class KWinModule in libkdecore. The API is a bit cleaner but very similar, so you will feel comfortable immediately. One of the advantages of KWinModule is that it doesn't require a special KApplication subclass. This lead to many problems and misunderstandings in the past. KWinModule is now just an object that emits fancy signals (and provides some useful lists, like the list of all managed windows). (ettrich@kde.org)

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kDebug

Use the kDebug* functions to log debug output, warnings and errors in a very flexible way. kdebug has been improved, and the API simplified. kdebug.h provides a small script for automating the conversion. Note that enabling/disabling debug output can now be done with kdebugdialog, which can be found in kdebase. The hidden dialog on C+S+F12 has disappeared. Also, consider using nana for assertions and debugger checks (see nana/*.h). (faure@kde.org)

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KFileDialog - General Stuff

The new (rewritten) KFileDialog (KFD) is a lot more like the new QFileDialog but still looks quite different. Normally you may want to use the static methods provided for convenience (getOpenFileName and getSaveFileName). If you need special features you can configure the dialog extensively. Just create an object and use the different methods.

Werner Trobin <wtrobin@carinthia.com>

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KFileDialog - Preview Mode

There is also a new preview mode which is quite different to the one we had in the KDE 1.x KFD. There are no preview modules you have to register but there is a single method you can use to set a preview widget. This widget has to inherit QWidget and you have to implement a slot (showPreview(const KURL &)) in this class. This slot is called each time the selected file/dir changes. In this slot you have to react appropriate (i.e. show the preview :). The easiest way this can be done is to derive your class from QWidgetStack and add a Object (derived from QWidget) for each file type. In the showPreview method you just raise the matching widget. If you can't find an appropriate widget just hide() the widget stack.

If you need some "inspiration" on how that could be done, please have a look at koffice/lib/kofficecore/koFilterManager.cc (PreviewStack).

Werner Trobin <wtrobin@carinthia.com>

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Image effects

The kFSDither class is now gone. It's functionality was moved to KImageEffect::dither(). Whereas before, you would done:

  kFSDither dither(palette, ncols);
  image = dither.dither(image);

Now do:
  KImageEffect::dither(image, palette, ncols);

Kurt Granroth <granroth@kde.org>

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KAudio (kaudio.h)

The KAudio class no longer exists. Here are your options for porting.

Stefan Westerfeld stefan@space.twc.de

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KImageIO (kimgio.h)

KImageIO has moved from 'kimgio.h' to 'kimageio.h'. LIB_KIMGIO does no longer exists, you need to link against LIB_KSYCOCA instead.

kimgioRegister() has been replaced by KImageIO::registerFormats().

Waldo Bastian bastian@kde.org

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