Qml - QtWebEngine, QtWebKit, QtWebView

[andreaplanet]

Hello,

I am new to QtQuick, QML and I was playing with it to see if it matches the requirments for my new application. One of the needs is to show html code (local or remote). After some tests I am a bit confused about some aspects.

I opened the webview example from Qt 5.4 and ran it on Linux 64bit. I notice it is using the new QtWebEngine module in the .pro file and also in the .cpp code with include QtWebEngine.h

@qtHaveModule(webengine) {
QT += webengine
DEFINES += QT_WEBVIEW_WEBENGINE_BACKEND
}@

What happens if webengine is not available? What component is used? I suppose on Android/IOS the webengine component is not available and it will use a "native" component.

In the qml file I find
@import QtWebView 1.0@

which is underlined with a red line (the Qt Creator-Design cannot find it's definition because qmlplugindump crashed). I suppose QtWebView is the Library name for the new QtWebEngine component. The example runs well without problems.
Can I avoid this error in the QtCreator-Design?

If I comment out the qtHaveModule(webengine) in the pro file and rebuild everything then at run time (Desktop Linux 64bit) the program will crash with a Segmentation Fault after loading the qml file:

@0 QOpenGLContext::handle() const /home/xx/Qt/5.4/gcc_64/lib/libQt5Gui.so.5
1 ?? /home/xx/Qt/5.4/gcc_64/plugins/platforms/libqxcb.so
2 ?? /home/xx/Qt/5.4/gcc_64/qml/QtWebView/../../lib/libQt5WebEngineCore.so@
Why does it crash? Because on Desktop there is no "native" alternative to the QtWebEngine?

It will work again if I replace the import QtWebView 1.0 with import QtWebKit 3.0 without the need to add QT+=webkit to the pro file.
Why it is not necessary to add QT+=webkit?

What is the best approach for both Qt Quick Desktop/Mobile deployment? QtWebEngine or QtWebView?

Last month I made a similar application but using Qt Widgets and at last I had to use QtWebKit because QtWebEngine was crashing sometimes (randomly after some usage).

Thanks,
Andrea