Facing issue with paint method for QPushButton when used QStyledItemDelegate-CodePudding

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CodePudding user response：

The reason for having to click a cell 3 times to change the value is because you need a double click to edit (which creates the editor) and another click to call UpdateUseButton. You don't need to do it this way, you can instead perform the click when you create your editor. In fact, you don't even need the UpdateUseButton as you can make the necessary changes in setModelData. Add the following slot to your PushButtonDelegate:

void commitAndCloseEditor();

and then implement the class like this:

QWidget* PushButtonDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const { if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse) { const auto btn = new QPushButton(parent); const auto value = index.data().toString(); btn->setCheckable(true); btn->setChecked(value == "Yes" ? true : false); btn->setFocusPolicy(Qt::NoFocus); // You don't need this, you can update your data in setModelData instead // connect(btn, SIGNAL(clicked(bool)), this, SLOT(UpdateUseButton(bool))); // the click will commit the data and close the editor // we connect it with a queued connection so that the slot is called after this function exits connect(btn, &QPushButton::clicked, this, &PushButtonDelegate::commitAndCloseEditor, Qt::QueuedConnection); emit btn->clicked(false); // perform a click programatically to that the commitAndCloseEditor will be called after we exit this function return btn; } else { return QStyledItemDelegate::createEditor(parent, option, index); } } void PushButtonDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const { if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse) { //nothing to do when you are in your delegate column } else { QStyledItemDelegate::setEditorData(editor, index); } } void PushButtonDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const { if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse) { // set your model data here model->setData(index, (index.data().toString() == "Yes") ? "No" : "Yes"); } else { QStyledItemDelegate::setModelData(editor, model, index); } } void PushButtonDelegate::commitAndCloseEditor() { auto* editor = qobject_cast<QWidget*>(sender()); emit commitData(editor); emit closeEditor(editor); }

Notice that I've used a Qt::QueuedConnnection for connecting the clicked signal. This ensures that the commitAndCloseEditor slot will be called after both createEditor and setEditorData have exited (easy to check by using print statements in the beginning of each function). If you remove the queued connection, then the commitAndCloseEditor will be called before createEditor returns the actual editor, hence the slot will do nothing as the editor is not open yet.

Now, for the paint method... it would seem that btn_->setChecked is the reason for not properly showing the background color in the buttons. I'm not sure why it behaves like that, but a workaround would be to use stylesheets like so:

void PushButtonDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const { if (index.model()->headerData(index.column(), Qt::Horizontal, Qt::DisplayRole).toString() == constants::kUse) { painter->save(); btn_->setGeometry(option.rect); const auto value = index.data().toString(); btn_->setText(value); QString stylesheet = QString("background-color: %1").arg((value == "Yes") ? "green" : "red" ); btn_->setStyleSheet(stylesheet); const QPixmap map = btn_->grab(); painter->drawPixmap(option.rect.x(), option.rect.y(), map); painter->restore(); } else { QStyledItemDelegate::paint(painter, option, index); } }

Toggling the value should now work with a double click and the result (on my Windows box) looks like this: