qpainter

I am trying to fade in and fade out a QLabel or for that matter any QWidget subclass. I have tried with QGraphicsEffect , but unfortunately it works well only on Windows and not on Mac. The only other solution which can work on both Mac & Windows seems to be having my own custom paintEvent where I set the opacity of QPainter and also define a Q_PROPERTY for "opacity" in my derived QLabel and change the opacity through QPropertyAnimation . I am pasting below the relevant code snippet for your reference. I still see an issue here - reusing the QLabel::paintEvent doesn't seem to be working, it

i'm having difficulties implementing custom widget rendering in a QListView . I currently have a QListView displaying my custom model called PlayQueue based on QAbstractListModel . This is working fine with simple text, but now I would like to display a custom widget for each element. So I subclassed a QStyledItemDelegate to implement the paint method like this: void QueueableDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const { if (option.state & QStyle::State_Selected) painter->fillRect(option.rect, option.palette.highlight()); QWidget

I've been working on a physics simulation with circles in Qt. Thus far the easiest way to define circles I found is to make a QRect object and then draw the ellipse with that rectangle as a "blueprint". Now I've just got the problem that it paints a circle but the hit box for the hit detection is still a square, which looks rather awkward. I've not been able to find a solution for it thus far and hope to find some help here. QRectF Ball::boundingRect() const { return QRect(0,0,20,20); } void Ball::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { QRectF rec =

I would like---with Python and Qt4---to rotate a QPushButton (or at least its text) so it can stand vertically. I've seen some documentation online , but I couldn't make much sense out of it---it's in C and I'm C-illiterate. From what I read though, one needs to re-implement the paintEvent() handler, instantiate and rotate a QPainter(). What I can't figure out however is how to do this for the one QString or QPushButton I need only. I assumed the QPaintEvent would have a "sender" attribute, like signals do, but it hasn't. All I can seem to get from this event is a QRect or QRegion. How can I

I want to draw a rectangle with rounded corners (border radius same for all 4 corners) with a specific color filling the entire rectangle, and a separate border color (say border is 1 px wide). From my observation, Qt provides three methods - fillRect and drawRect and drawRoundedRect . I have tried them, they don't work like I want to. There is no method like fillRoundedRect . Which means that I can draw a rounded rectangle but it won't be filled with the color I want. How do I do it? And also, I read that due to some aliasing problems, the corners are often rendered as unequal. How do I set

As a follow up of Qt load indicator by animated image (aka preloader) or alternative? I try to paint inside a QTableView . But when I initialize the QPainter I get the following warnings. QWidget::paintEngine: Should no longer be called QPainter::begin: Paint device returned engine == 0, type: 1 Here is the code (SO answer, with a button it seems to work ): void CDerivedFromQTableView::paintEvent(QPaintEvent *event) { QTableView::paintEvent(event); // draw original content QPainter p(this); // Problem: QPainter::begin: Paint device returned engine == 0, type: 1 const QPixmap pm(QPixmap:

I am currently doing the following for putting a circular mask on my image. As a result only circular region of my image is displayed.This works fine however the image tends to have jagged edges (border). Any suggestion on how I could do this. From the documentation of QPixmap you can learn: The hasAlpha(), setMask() and mask() functions are legacy and should not be used. They are potentially very slow. Apart from being slow, they operate on a binary mask ( QBitmap ) which does not support anti-aliasing, each pixel is either fully opaque or fully transparent. This results in jagged edges. The