tablewidget and pixmap

[magoo]

Hi, using Qt 4.2.1, I'd like to display images on one of the fourth column of my tablewidget. Anyone could give me hints on how I can do this ? it's a display-only table.

thanks

[wysota]

Set the icon of the item to the pixmap you wish to display (using QTableWidgetItem::setIcon().

[magoo]

yes, but i'd like to display the pixmap at a fixed size and not a tiny icon... how can I do this ?

many thanks

[wysota]

Provide a new item delegate which will render your pixmap and return a proper size for the item so that the pixmap can fit it. See QAbstractItemDelegate for more info.

[magoo]

that's cool and I was able to make it works. Another problem I have, why do I have to call resizeColumnsToContents() and resizeRowsToContents() if I add more than one rows to my TableWidget ? The cells size seems to reset after I add new TableWidgetItem to the table... There's probably a way for the table to remember the size of the cells that are already in the table...

Also, calling scrollToBottom() doesn't actually scroll anything...

as an example :

mainwindow.cpp :


...

t = new QTableWidget();
t->setSelectionMode(QAbstractItemView::NoSelection);
t->setColumnCount(2);
t->setHorizontalHeaderLabels(labels);
t->setItemDelegateForColumn(1, new ImageDelegate(this));

QTableWidgetItem *item[100][2];

for(int i=0;i < 100; i++)
{
t->insertRow(i);

item[i][0] = new QTableWidgetItem(s.arg(i));
item[i][0]->setFlags(item[i][0]->flags() & ~Qt::ItemIsEditable);
t->setItem(i, 0, item[i][0]);

item[i][1] = new QTableWidgetItem(":/icons/unknown.png");
item[i][1]->setData(Qt::UserRole, ":/icons/unknown.png");
item[i][1]->setFlags(item[i][1]->flags() & ~Qt::ItemIsEditable);
t->setItem(i, 1, item[i][1]);

//i tried a bunch of stuff... resizeColumnToContents() and resizeRowToContents() works,
//but only without any parameters and I guess it's not very good to recalculate everything
//everytime I add something ? I'd like to just resize the inserted row AND that the already
//inserted row keep their size.

//t->resizeColumnToContents(0);
//t->resizeColumnToContents(1);
//t->resizeRowToContents(i);
//t->resizeColumnsToContents();
//t->resizeRowsToContents();
//t->setColumnWidth(1,140);
//t->setRowHeight(i,200);

//t->scrollToBottom();
}


imagedelegate.cpp:


#include <QtGui>

#include "imagedelegate.h"

ImageDelegate::ImageDelegate(QObject *parent)
: QAbstractItemDelegate(parent)
{
}

void ImageDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
const QModelIndex &index) const
{
QPixmap pixmap(index.model()->data(index).toString());
painter->save();
painter->drawPixmap(option.rect, pixmap);
painter->restore();
}

QSize ImageDelegate::sizeHint(const QStyleOptionViewItem & /* option */,
const QModelIndex & /* index */) const
{
return(QSize(140,200));
}

[wysota]

Another problem I have, why do I have to call resizeColumnsToContents() and resizeRowsToContents() if I add more than one rows to my TableWidget ? The cells size seems to reset after I add new TableWidgetItem to the table... There's probably a way for the table to remember the size of the cells that are already in the table...

Provide a correct size hint in the delegate. For example:


QSize myDelegate::sizeHint(const QStyleOptionViewItem & /* option */,
const QModelIndex & index) const {
return index.data(Qt::DecorationRole).toPixmap().size()+Q Size(4,4);
}

[magoo]

I've put a qDebug() inside the sizeHint() method of the delegate and it's never actually called.

I've try adding
item[i][1]->setData(Qt::SizeHintRole, QSize(140,200)); in my mainwindow.cpp but the cells are still sizing incorrectly. if I call the sizeHint() method of the TableWidgetItem, it returns the correct value but the delegate sizeHint() is never call with or without adding the SizeHintRole data.

[wysota]

Try subclassing QItemDelegate instead of the abstract delegate.