[Qt-interest] QVBoxLayout with 100s of items is hanging

[Sean Harmer]

Hi,

Qt Quest wrote:
> OK, I've changed the code to a list view and great performance!
> Now in each line I show a checkbox and HTML text. I want the user to be 
> able to check the checkbox and press the links in the HTML text.
> I'm trying to use a delegate, but I have few problems:
> 
> 1. The HTML links in the label are not selectable - the cursor does not 
> change to a pointer, and no event is generated. This is true also for 
> the checkbox.
> 2. paint() function of delegate is the only one called..
> 
> I'm using:
> ui.list->setItemDelegate(new MyDelegate());
>  
> 
> void MyDelegate::paint(QPainter *painter, const QStyleOptionViewItem 
> &option, const QModelIndex &index ) const
> 
> {
> 
> QStyleOptionProgressBar progressBarOption;
> 
> QCheckBox *check = new QCheckBox();
> 
> check->setChecked(true);
> 
> check->render(painter , QPoint(0,0));
> 
> check->setMaximumSize(QSize(14,14));
> 
> QLabel *label = new QLabel();
> 
> label->setText("this <a href=\"b\">is a <b>test</b></a>");
> 
> label->render(painter , QPoint(14,0));
> 
> }

Why do it like this? Just use the Qt::CheckStateRole in your model's 
data()/setData() functions. If you then also set the 
Qt::ItemIsUserCheckable flag in the flags() function, the default 
delegate will take care of drawing checkboxes for you.

Then as Andre suggested, you could derive a custom delegate to draw your 
rich text and make the links interactive.

HTH,

Sean