How do I remove white border around QScrollArea?
I'm trying to edit the source of an app called qcomicbook ( http://qcomicbook.linux-projects.net/ ), to remove an annoying 1px white border which persists in full-screen mode.
First I tried changing the background of the main window black, but it had no effect. Here is the newly compiled app against the designer preview:
I tried also setting some border and margin style information but the white border remained, so I looked at the cpp source, searched the Qt docs, and made a few simple edits, but they had no effect.
At first I thought this would be a quick cosmetic fix, but now I assume the developer could not find the cause.
He has this inside PageViewBase.cpp:
@PageViewBase::PageViewBase(QWidget *parent, int physicalPages, const ViewProperties &props)
context_menu = new QMenu(this);
connect(&this->props, SIGNAL(changed()), this, SLOT(propsChanged()));
This inside ContinuousPageView.cpp:
ContinuousPageView::ContinuousPageView(QWidget *parent, int physicalPages, const ViewProperties& props)
: PageViewBase(parent, physicalPages, props)
QWidget *w = new QWidget(this);
// w->setColor(QPalette::Background, Qt::black);
// adding above line didn't work
m_layout = new QVBoxLayout(w);
m_layout->setContentsMargins(0, 0, 0, 0);
// changing above line didn't change anything
recreatePageWidgets(); recalculatePageSizes(); setWidget(w); setWidgetResizable(true); setBackground(props.background()); setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored); // track scrollbar range changes to restore its relative position connect(verticalScrollBar(), SIGNAL(rangeChanged(int, int)), this, SLOT(scrollbarRangeChanged(int, int)));
And this inside ComicMainWindow.cpp:
const int n = (sink != NULL ? sink->numOfImages() : 0);
const ViewProperties props;
view = new ContinuousPageView(this, n, props);
view = new SimplePageView(this, n, props);
setCentralWidget(view); view->setFocus(); reconfigureDisplay(); connect(actionPageTop, SIGNAL(triggered(bool)), view, SLOT(scrollToTop())); ...
tony last edited by
QScrollArea is a QFrame descendant. If you set the frame shape to QFrame::NoFrame
it should disappear ... did I understand your point?
Tony, thanks, but this did not remove the border.
In Qt, is QFrame the only class which has paints a border?
tony last edited by
Well, I'm not sure that's the only one. QFrame is a QWidget with a border, so I guess that any widget that'd like to be surrounded by a border, can descend directly from QFrame.
Anyway, it's really strange that your border does not disappear. If you place a QScrollArea on a QWidget with Qt Designer, you can test it by yourself and it works (are you sure it's a QScrollArea???)
I can just think about two causes:
a) a particular stylesheet is present, and it draws a border. In this case, you should remove it there.
b) it has a custom paint event. It shouldn't be so difficult to remove any suspicious drawRect inside that method.
Ok, setFrameShape did work actually. The other day I was running make from vi in the wrong dir.
Thanks for the help.