How to set icon center in QTableView? - qt

Question

NetworkPageForm::NetworkPageForm(QWidget *parent) :
QWidget(parent),
ui(new Ui::NetworkPageForm),
devicesModel(NULL)
{
ui->setupUi(this);
devicesModel = new QStandardItemModel(0, 4, parent);
devicesModel->setHeaderData(0, Qt::Horizontal, QObject::tr("IP"));
devicesModel->setHeaderData(1, Qt::Horizontal, QObject::tr("Name"));
devicesModel->setHeaderData(2, Qt::Horizontal, QObject::tr("Last Online"));
devicesModel->setHeaderData(3, Qt::Horizontal, QObject::tr("Status"));
ui->devicesTableView->setModel(devicesModel);
ui->devicesTableView->resizeColumnsToContents();
}
void NetworkPageForm::addDevice(const QString &ip, int device_type) {
bool haveSameItem = false;
for(int i=0; i<devicesModel->rowCount(); i++) {
QStandardItem * ipItem = devicesModel->item(i, 0);
QStandardItem * nameItem = devicesModel->item(i, 1);
if(QString::compare(ipItem->text(), ip)== 0 && QString::compare(nameItem->text(), deviceStr)==0) {
devicesModel->setData(devicesModel->index(i, 2), BaseModel::now());
haveSameItem = true;
}
}
if(!haveSameItem)
{
int last = devicesModel->rowCount();
devicesModel->insertRow(last);
devicesModel->setData(devicesModel->index(last, 0), ip);
devicesModel->setData(devicesModel->index(last, 1), device_type);
devicesModel->setData(devicesModel->index(last, 2), BaseModel::now());
devicesModel->setData(devicesModel->index(last, 3), QIcon(":/res/images/online_icon.png"), Qt::DecorationRole);
// This function does not work, the icon is algin left.
// devicesModel->item(last, 3)->setTextAlignment(Qt::AlignCenter);
}
ui->devicesTableView->resizeColumnsToContents();
}
Is there a way to set QIcon item center in QTableView?
Update:
I create my own QStyledItemDelegate sub class as #RazrFalcon answered.
#include <QStyledItemDelegate>
class MyDelegate : public QStyledItemDelegate
{
Q_OBJECT
public:
MyDelegate(QWidget *parent = 0) : QStyledItemDelegate(parent) {}
void paint(QPainter *painter, const QStyleOptionViewItem &option,
const QModelIndex &index) const;
QSize sizeHint(const QStyleOptionViewItem &option,
const QModelIndex &index) const;
void setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) const;
private slots:
};
void MyDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const {
if(index.column() == 3) {
// TODO
} else {
QStyledItemDelegate::paint(painter, option, index);
}
}
QSize MyDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const {
if(index.column() == 3) {
// TODO
} else {
return QStyledItemDelegate::sizeHint(option, index);
}
}
void MyDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const {
QStyledItemDelegate::setModelData(editor, model, index);
}
And set ui->devicesTableView->setItemDelegate(new MyDelegate);
Could someone help me how to set icon column center in QTableView?

Answer 1

There is no default way. You should implement your own QStyledItemDelegate.
UPD: example added
void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
Q_ASSERT(index.isValid());
QStyleOptionViewItemV4 opt = option;
initStyleOption(&opt, index);
// disable default icon
opt.icon = QIcon();
// draw default item
QApplication::style()->drawControl(QStyle::CE_ItemViewItem, &opt, painter, 0);
const QRect r = option.rect;
// get pixmap
QIcon icon = qvariant_cast<QIcon>(index.data(Qt::DecorationRole));
QPixmap pix = icon.pixmap(r.size());
// draw pixmap at center of item
const QPoint p = QPoint((r.width() - pix.width())/2, (r.height() - pix.height())/2);
painter->drawPixmap(r.topLeft() + p, pix);
}

Answer 2

It's no need to do it in delegate. The delegate will make your style sheet unavailable.
You can paint the icon in the middle of a rectangle pixmap which is as same size as the cell, and return it in the QAbstractItemModel::data() function with Qt::DecorationRole. Like this:
Qt::DecoratoinRole:
QPixmap pixmap(w, h); //w=cell width, h=cell
pixmap.fill(Qt::transparent); // draw a transparent rectangle
QPixmap iconPixmap(":/xx.png");
QPainter painter(&pixmap);
//Calculate the center coordinate x,y for iconPixmap
painter.draw(x, y, iconWidth, iconHeight, iconPixmap);
return pixmap;