I wrote a short code to test combination of Qt and plasma.

I just used this code in my Qt widget:

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Plasma::WindowEffects::overrideShadow(winId(), true);


I received linker error: (I'm not developing a plasma applet. just wanna use plasma API's on my Qt program)

undefined reference to Plasma::WindowEffects::overrideShadow(unsigned long, bool);

I (searched and) couldn't find which library I should use. And even couldn't find s.th like "related libraries" on KDE TechBase. any help!?

Plasma functions are contained in libplasma, which is a component of kdelibs. In particular, you need to link aganist libplasma.so.

oh really thanks man! Today I test it and it solved the linkage problem with plasma. but now there's another error that I have no idea about:

/usr/lib/libkdeui.so.5: undefined reference to `QString::isRightToLeft() const'
/usr/lib/libkdeui.so.5: undefined reference to `QIcon::name() const'

I'm using Qt 4.7-snapshot and KDE 4.5 rc2

Unusual issue. Make sure you are linking to QtCore and QtGui.

soulless

How are you compiling?

I'm using Qt Creator (I press run and it compile the project..) and created a new Qt GUI project on that.
( I just wanna test EnableBlurBehind() on my very basic QWidget )

Ok, that is strange - QtC should create a valid makefiles.

You can try manually invoking 'run qmake' (I don't remember in what menu exactly it is) and you should check whether .pro file is valid. (you could also post it here)

here's my main file that use the plasma:

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#include <QtGui/QApplication>
#include "widget.h"
#include <KDE/Plasma/WindowEffects>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    Plasma::WindowEffects::enableBlurBehind(w.winId(), true);
    w.show();
    return a.exec();
}


and here's my pro file:

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QT       += core gui

TARGET = blurtest
TEMPLATE = app


SOURCES += main.cpp\
        widget.cpp

HEADERS  += widget.h

FORMS    += widget.ui

LIBS += -L/usr/lib -lplasma


Ok, it looks like QtCreator is trying to link to an older version of Qt (4.6 or earlier)

I'm almost sure that there's no Qt older than 4.6.2 version installed on my computer!

I misspelled - 4.6.x or earlier - so it is trying to link to them while kdelibs are compiled with 4.7.

QString::isRightToLeft() and QIcon::name() are introduced in 4.7.

I was using 4.7beta1 then changed it to beta 2 and now everything works fine. Really thanks to both of you