[SOLVED] How to get Visible Rect in QScrallArea's viewport() ?
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Is there any easy way to get "visible" QRect for QScrollArea's viewport() ? I tried to search forum but fails.
Currently I got following codes to get this.@
class MyLabel : public QLabel
{
public:
MyLabel(QWidget* widget=0)
: QLabel(widget)
{
image = new GigBmpImage(this);
image->Open("c:/TestBigImage.bmp");
}
virtual ~MyLabel()
{}
virtual QSize sizeHint(void) const
{
return image->Size();
}
void SetScrollArea(QScrollArea* s)
{
scrollArea = s;
}
protected:
virtual void paintEvent(QPaintEvent* e)
{
QPainter painter(this);
QScrollBar* hb = scrollArea->horizontalScrollBar();
QScrollBar* vb = scrollArea->verticalScrollBar();QPoint viewableTopLeft(hb->value(), vb->value());
QSize viewableSize = scrollArea->size() -
QSize(vb->sizeHint().width(),
hb->sizeHint().height()) -
QSize(2scrollArea->frameWidth(),
2scrollArea->frameWidth());
QRect viewableRect(viewableTopLeft, viewableSize);viewableRect.translate(hb->value(),
vb->value());qDebug() << "drawing Rect : " << e->rect()
<< ", viewable rect : " << viewableRect
<< ", viewport: " << painter.viewport()
<< ", window: " << painter.window();QRect rect = viewableRect;// e->rect());
// rect.adjust(-1,-1,1,1);
if(rect.x()<0) {
rect.setX(0);
}
if(rect.y()<0) {
rect.setY(0);
}
//image->Draw(&painter, rect, rect);__super::paintEvent(e);
}
QScrollArea* scrollArea;
GigBmpImage* image;
};QGigImageViewer::QGigImageViewer(QWidget parent, Qt::WFlags flags)
: QScrollArea(parent)
{
MyLabel label = new MyLabel;
label->SetScrollArea(this);this->setBackgroundRole(QPalette::Dark);
this->setWidget(label);
this->setWindowFlags(flags);
}
@When widget shows up, viewable rect is exactly what I want but, it differs from the correct value after I moving scrollbar handle around. Might be that I do not understand well about scrollbar / scrollarea / viewport relationship.
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