Scrollbar overlaps border of Widget with colored border

[JCarpenter]

Hi!

I am currently trying to create a qss file to enhance the look of a certain software. A big part of my changes is adding a color to the various borders of elements and also giving some of the corners a radius. As i had to learn: if i change the style of most widgets, i also have to create a style for the scrollbars. If i don't do that then some widgets use the windows scrollbars and some don't.

The problem i encountered is that the scrollbar in QListWidget somehow overlaps the border of the QListWidget and i can't get rid of this. This is pretty annoying as my border-color is some kind of blue and the overlapping part is gray. My first thought was that i made a mistake with the scrollbar stylesheet but it also happens when i only change the border color and use the default scrollbar.

scrollbar.png

the stylesheet looks like that:

QListWidget , QTreeWidget, QTextEdit{
	border: 1px solid #4D6999;
}

QListWidget , QTreeWidget, QTextEdit{
	border: 1px solid #4D6999;
}

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Does anybody have any idea how to get rid of this or how i could at least get to something that would count as workaround? (sure... changing the border color to that gray might work but i'd like to keep the colored border)

Thanks in advance for any comment on this

[Ashkan_s]

You can try to create your own style you can start by reading this example http://doc.qt.io/qt-4.8/widgets-styles.html
If you just need to change border colors QStyle::drawPrimitive is the method you need to re-implement.
Note that this way you may not be able to use stylesheets anymore

Warning: Qt style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.

this warning is from Qt 4.7

[JCarpenter]

Thanks for your answer!

Unfortunately I don't have access to any code and thus need to stick to stylesheets. Or at least I don't see any other option. Do you?

[Ashkan_s]

Found something in docs of QApplication::QApplication:

-style= style, sets the application GUI style. Possible values are motif, windows, and platinum. If you compiled Qt with additional styles or have additional styles as plugins these will be available to the -style command line option.

If I didn't misunderstood it might help.

[ChrisW67]

Does anybody have any idea how to get rid of this or how i could at least get to something that would count as workaround? (sure... changing the border color to that gray might work but i'd like to keep the colored border)

I thought adding "padding: 3px" to the style might have helped but it continues to do this for me on Qt 4.8.0 Windows XP and 7. On Linux it works fine with the native style but fails in the same way when told to use the Windows style.

See bug report https://bugreports.qt-project.org/browse/QTBUG-20672

[JCarpenter]

For a second there I was hoping that i could do something like "xyz.exe -style cleanlooks -stylesheet=style.qss". Unfortunately: no! Still getting the gray line there. If I could find out how to change that color then I might have a lot of work to get rid of the then-changed occurences of this element but at least that border might be rendered correctly.

Does anybody have any suggestions where that gray color could be defined?

[Ashkan_s]

As I know all the colors come form style classes such as QWindowsVistaStyle or QWindowsXPStyle.

P.S.
I can't say I'm 100% sure, You can implement your own style as a plugin and then force the program to use it via -style. There's no need to change the program.

I have created one. It is working, I don't say I'm 100% sure because for now I can use the plugin only when it is in Qt's plugins directory (a sub-directory of Qt SDK installation directory). It is my first plugin, so I think it can be easily solved

[Ashkan_s]

I created a directory named styles in the directory of the program's executable and put the plugin inside it, now it is working. Now I'm 100% sure that it is possible, however it needs more work than stylesheets.

[JCarpenter]

Thanks again, Ashkan_s!
I still don't think that I will be able to convince the right people of the need for a style. At the moment I feel like Stylesheets are the only way for me to get some "wow, nice!" into that application. So I'm still searching for any ideas how to get rid of that strange behaviour.

I noticed something: if i take a QTextEdit with for example 3 lines and start writing into it until the scrollbar appears, than everything looks fine. Once that QTextEdit looses the focus, that ugly 1px line is back. If I then remove enough content for the scrollbar to disappear (focus still inside the QTextEdit) that line is still there. But once the QTextEdit looses focus again: ugly line is gone.
O.o

[JCarpenter]

Just to let you know: i found something that you could call a workaround.

as the unwanted line is colored like the background of the widget, i set the background-color to the border-color (blue) and used a 1x1 pixel image as white background for the widget. As i am using rounded edges it is still visible if you know about the problem but it is still a huge improvement.

[caogtaa]

Hi JCarpenter,
I met exactly same issue as you did.

I tried to subclass QTextEdit:: paintEvent() and do the border painting work myself,
but I found QTextEdit:: paintEvent is actually the Paint handler for QTextEdit::viewport() who has installed an eventfilter, NOT for painting QTextEdit itselft.

On my way of testing I found a solution

bool AttachmentListEdit::event(QEvent* e)
{
#ifdef Q_OS_WIN
	switch (e->type())
	{
	case QEvent::Paint:
		// skip QFrame::paintEvent() to prevent buggy border painting
		e->accept();
		return true;
	default:
		break;
	}
#endif
 
	return QTextEdit::event(e);
}

bool AttachmentListEdit::event(QEvent* e)
{
#ifdef Q_OS_WIN
	switch (e->type())
	{
	case QEvent::Paint:
		// skip QFrame::paintEvent() to prevent buggy border painting
		e->accept();
		return true;
	default:
		break;
	}
#endif

	return QTextEdit::event(e);
}

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Though it works for me, I can not explain it exactly.
I've no idea who finally paint the border but I'm going to dig out.
I'm using Qt4.7.4