Creating custom widget to be promoted in Qt designer - qt

Question

I am developing a GUI application in Qt, and I have some difficulties embedding a custom widget in my ui. From Qt's documentation I can see it is possible to promote such a widget. However, I am still a little confused about how this should be done.
My widget QTreeWidget is heavily inspired by Qt's torrent example, where I want to embed this in my application:
So I have for my FilesView class (not included the src code, because it is trivial):
#include <QTreeWidget>
#include <QUrl>
#include <QFile>
#include <QDragMoveEvent>
#include <QDropEvent>
// FilesView extends QTreeWidget to allow drag and drop.
class FilesView : public QTreeWidget
{
Q_OBJECT
public:
FilesView(QWidget *parent = 0);
signals:
void fileDropped(const QString &fileName);
protected:
void dragMoveEvent(QDragMoveEvent *event);
void dropEvent(QDropEvent *event);
};
To this is a TorrentViewDelegate class (comment the progressbar for testing purposes)
#include <QItemDelegate>
#include <QMainWindow>
#include <QApplication>
// TorrentViewDelegate is used to draw the progress bars.
class TorrentViewDelegate : public QItemDelegate
{
Q_OBJECT
public:
inline TorrentViewDelegate(QMainWindow *mainWindow) : QItemDelegate(mainWindow) {}
inline void paint(QPainter *painter, const QStyleOptionViewItem &option,
const QModelIndex &index ) const
{
if (index.column() != 2) {
QItemDelegate::paint(painter, option, index);
return;
}
// Set up a QStyleOptionProgressBar to precisely mimic the
// environment of a progress bar.
QStyleOptionProgressBar progressBarOption;
progressBarOption.state = QStyle::State_Enabled;
progressBarOption.direction = QApplication::layoutDirection();
progressBarOption.rect = option.rect;
progressBarOption.fontMetrics = QApplication::fontMetrics();
progressBarOption.minimum = 0;
progressBarOption.maximum = 100;
progressBarOption.textAlignment = Qt::AlignCenter;
progressBarOption.textVisible = true;
// Set the progress and text values of the style option.
//int progress = qobject_cast<MainWindow *>(parent())->clientForRow(index.row())->progress();
int progress = 40;
progressBarOption.progress = progress < 0 ? 0 : progress;
progressBarOption.text = QString().sprintf("%d%%", progressBarOption.progress);
// Draw the progress bar onto the view.
QApplication::style()->drawControl(QStyle::CE_ProgressBar, &progressBarOption, painter);
}
};
In the example the embed the widget in MainWindow as:
filesView = new FilesView(this);
filesView->setItemDelegate(new TorrentViewDelegate(this));
filesView->setHeaderLabels(headers);
filesView->setSelectionBehavior(QAbstractItemView::SelectRows);
filesView->setAlternatingRowColors(true);
filesView->setRootIsDecorated(false);
ui->verticalLayout_Filebox->addWidget(filesView);
How can I do this from the Qt designer?

Answer 1

Place an empty widget where you want to have your FilesView
Right click on it and select Promote to
Set the promoted class name to FilesView press Add and then Promote
You cannot set the delegate from QtDesigner
For more info have a look here:
http://qt-project.org/doc/qt-4.8/designer-using-custom-widgets.html
The second option you have is to create a plugin for your widget which will allow you to set its properties through designer. If you are not going to use your widget multiple times I do not suggest it. For more details check the following link:
http://qt-project.org/doc/qt-4.8/designer-creating-custom-widgets.html