how to use QWebPage in a non-GUI application

问题

I want to use QWebPage in a non-GUI Qt application. By that, I mean that I don't want to communicate with the window server at all. Using QtGui is not a problem, though.

QWebPage internally creates some QWidget instances. Thus, using QCoreApplication is not possible.

When creating a QApplication instance though, I already immediately get a MacOSX dock icon. And I don't want that. It also means that it somehow registers itself in Cocoa as a GUI application.

My question is not Mac-only. I would like to know if there is an "official" way for Qt to do this. Only if there is not, I would like to know specific ways to do this, e.g. on Mac for now.

Somewhat more specific about Mac:

There is also the LSBackgroundOnly property which can be set for an App bundle and which goes into the direction to what I want (whereby I'm still not sure if it is really truly console-only, e.g. would also work without Quartz, etc.). However, I don't have an App bundle at all; it's just a simple binary (to be used as a command-line-tool in shells).

For now, I have a small workaround to hide the dock icon but that is quite ugly as it first pops up and then goes aways: (Python code but that doesn't really matter...)

def hideMacDockIcon():
    # http://stackoverflow.com/a/9220857/133374
    import AppKit
    # https://developer.apple.com/library/mac/#documentation/AppKit/Reference/NSRunningApplication_Class/Reference/Reference.html
    NSApplicationActivationPolicyRegular = 0
    NSApplicationActivationPolicyAccessory = 1
    NSApplicationActivationPolicyProhibited = 2
    AppKit.NSApp.setActivationPolicy_(NSApplicationActivationPolicyProhibited)

app = QApplication(sys.argv)
if sys.platform == "darwin":
    hideMacDockIcon()

Also, I'm not sure if it also works in other environments, maybe as a system daemon or so.

回答1:

You can do this with QPA. This happens to be how PhantomJS achieved headlessness. The QT preconfig file was modified to specify QPA:

QT_CFG +=' -qpa' # X11-less with QPA (aka Lighthouse)

Also something about QMinimalWindowSurface.

https://github.com/ariya/phantomjs/commit/6c8a1c2dc1 https://github.com/ariya/phantomjs/commit/c78ae190a9

回答2:

QApplication initializes static variables that are used by QWidgets. So you will not be able to create any widgets until you create an QApplication instance.

If you need a browser try using Webkit, Chromium, Berkelium, Awesomium(commersial) or chromiumoffscreenrenderer(LGPL fork)

回答3:

Have you tried passing the 'no gui' flag to QApplication?

QApplication ( int & argc, char ** argv, bool GUIenabled )

回答4:

I am afraid there is no simple way of not using QtGui. If you look at the source code of QWebPage, you see that a QPainter is used, as some exported methods\objects from QtGui. This was expected as you have functions like QWidget* QWebPage::view() const in the API.

You can hack the source code thought but then your Qt libraries are unique and incompatible .That is a burden.

回答5:

What is it that you want to use QWebPage for? Maybe there is a class better suited for your needs?
If not: Copy and pasting from QWebPage's source code is an option.

Update:
Do you want to create something like a command line browser? Or just something that looks like a browser to a web server?
In these cases you might just hide the QWidget so nothing appears in the dock bar (not sure if this is how it works on OS X; on Windows it's possible to have windows with no task-bar entry, I think).

回答6:

PyPhantomJs is a headless webrowser using pyqt, and even IT uses QApplication: http://code.google.com/p/phantomjs/source/browse/python/pyphantomjs/pyphantomjs.py?name=4ec8df3a84&r=4dc051a60ec3d59bf125838a5caa2a24d59bd0ee

You can always just Use the various window flags that make the app run as a system tray app

update

since I see you are using osx, you can add this setting to your apps plist to make it launch as a system service with no icons: http://www.cocoadev.com/index.pl?LSBackgroundOnly

I use this for an app that sits in the taskbar on the top and provides a spotlight style interface

来源：https://stackoverflow.com/questions/9213215/how-to-use-qwebpage-in-a-non-gui-application

标签

qt4

qwebkit

qwebpage