I'm building a custom QAbstractItemModel model.
The first column contains icons, the second one - text.
This is the code of the data method:
QVariant data ( const QModelIndex & index, int role = Qt::DisplayRole ) const
{
if(role != Qt::DisplayRole )
return QVariant();
int col = index.column();
if (col == 0)
{
return iconProvider->icon(QFileIconProvider::Folder);
}
else if (col == 1)
{
return "TEXT";
}
}
But all I get in the resulting Table View is just text in the second column. There's no folder icon in the first column.
Am I missing something here?
Qt::DisplayRole is only for text. Add:
if ( role == Qt::DecorationRole ) {
return iconProvider->icon(QFileIconProvider::Folder);
}
Related
I try to implement a table view with two columns. The right columns shows parameters, which should not be changed by runtime, and left column shows values, that should be updated constantly at runtime. For this I implement a data model (derived from QAbstractTableModel). After setting up this I got a table with 3 rows and 2 columns and the right columns shows the parameters. The left columns however remains empty. And after hours I didn't find a solution for this.
This is the relevant code of my data model I think:
QVariant DataTableModel::data(const QModelIndex& index, int role) const
{
if (!index.isValid()) {
return QVariant();
}
if (index.row() >= m_parameter.size()) {
return QVariant();
}
if (role == Qt::DisplayRole || role == Qt::EditRole) {
switch (index.column()) {
case 0:
return m_parameter.at(index.row());
break;
case 1:
return m_value.at(index.row());
break;
}
}
return QVariant();
}
bool DataTableModel::setData(const QModelIndex& index, const QVariant& value, int role)
{
if (!index.isValid() && role != Qt::EditRole) {
return false;
}
//change only values in column 1
if (index.column() == 1) {
m_value.replace(index.row(), value.toString());
emit dataChanged(index, index, { role });
return true;
}
return true;
}
bool DataTableModel::insertRows(int row, int count, const QModelIndex& parent)
{
//the following two methods emits signals that tells the view that the data should be changed
beginInsertRows(QModelIndex(), row, row + count - 1);
for (int i = 0; i < count; ++i) {
m_parameter.insert(row, "");
m_value.insert(row, "");
}
endInsertRows();
return true;
}
In the main class I have a function that calles the functions of the model:
void QVideoMeter::QAddTableContent()
{
QVariant value(QValueList());
m_tableDataModel->insertRows(0, 3, QModelIndex()); //insert 3 rows
m_tableDataModel->AddData(QParameterList());
m_tableDataModel->setData(QModelIndex(), value, 2);
}
QList<QString> QVideoMeter::QValueList()
{
QList<QString> values;
values.append("Test");
values.append("Hallo");
values.append("Welt");
return values;
}
Please, can someone of you review my code and tell me what I'm doing wrong?
Refer to the below two links. They provide the necessary concepts and examples:
QAbstractItemModel Subclass
Editable Tree Model Example
An editable model needs to provide implementations of setData() and
setHeaderData(), and must return a suitable combination of flags from
its flags() function.
Since this example allows the dimensions of the model to be changed,
we must also implement insertRows(), insertColumns(), removeRows(),
and removeColumns().
void MainWindow::insertRow()
{
const QModelIndex index = view->selectionModel()->currentIndex();
QAbstractItemModel *model = view->model();
if (!model->insertRow(index.row()+1, index.parent()))
return;
updateActions();
for (int column = 0; column < model->columnCount(index.parent()); ++column) {
const QModelIndex child = model->index(index.row() + 1, column, index.parent());
model->setData(child, QVariant(tr("[No data]")), Qt::EditRole);
}
}
I display an SQL table in a view using a QSqlTableModel.
I want to display an additional status column based on the row data, for that I use a custom QIdentityProxyModel where I increase the columnCount and return data for that new virtual column which does not exist in the QSqlTableModel.
int MyProxyModel::columnCount(const QModelIndex& parent) const
{
return sourceModel() ? (sourceModel()->columnCount() + 1) : 0;
}
QVariant MyProxyModel::headerData(int section, Qt::Orientation orientation, int role) const
{
if (section == columnCount()-1 &&
orientation == Qt::Horizontal &&
role == Qt::DisplayRole)
{
return tr("MyHeader");
}
return QIdentityProxyModel::headerData(section, orientation, role);
}
QVariant MyProxyModel::data(const QModelIndex &proxyIndex, int role) const
{
qDebug() << "data " << proxyIndex.row() << proxyIndex.column();
// ...never called for my extra column (== columnCount()-1)
if (proxyIndex.column() == columnCount()-1 && role == Qt::DisplayRole)
return QString("I am virtual");
return QIdentityProxyModel::data(proxyIndex, role);
}
Edit: I changed the code for something more simple regarding to the comments. I still have the same problem.
My problem is that the view never asks data for my virtual column, it calls data() for all other columns of the actual SQL table but not the last virtual one, what have I missed ?
Also, the header data is working well for my extra column, the problem is only with the data. The view draws the extra column, but content is empty (even alternating row background is not painted).
Thx !
The view needs to get the QModelIndex objects for the virtual column, so I also needed to override the index function in the proxy :
QModelIndex MyProxyModel::index(int row, int column, const QModelIndex &parent) const
{
if (column == columnCount()-1)
return createIndex(row, column);
return QIdentityProxyModel::index(row, column);
}
I didn't mind the parent because I only have a table (from database), though I do not know how it could be dealt with if needed because createIndex does not allow to specify a parent.
The m_mySqlTableColumnCount member is unnecessary. You'd have to ensure it's always correct by listening to the source model's signals that update the column count. Alas, it's unnecessary. You want to pass the column count request through to the source model:
int MyProxyModel::columnCount(const QModelIndex& parent) const
{
return sourceModel() ? (QIdentityProxyModel::columnCount() + 1) : 0;
}
Then:
QVariant MyProxyModel::headerData(int section, Qt::Orientation orientation, int role) const
{
if (section == columnCount()-1 &&
orientation == Qt::Horizontal &&
role == Qt::DisplayRole)
{
return tr("MyHeader");
}
return QIdentityProxyModel::headerData(section, orientation, role);
}
QVariant MyProxyModel::data(const QModelIndex &proxyIndex, int role) const
{
if (proxyIndex.column() == columnCount()-1) {
qDebug() << proxyIndex.row() << proxyIndex.column();
...
}
return QIdentityProxyModel::data(proxyIndex, role);
}
In my project, I have a QTreeView displaying a location on my drive. I need to change all the icons of the files to a custom icon but leave the folders alone.
I reimplemented QFileSystemModel and I was able to change ALL the icons. Any way to limit the change to only files instead of folders?
QVariant MyQFileSystemModel::data(const QModelIndex& index, int role) const
{
if(role == Qt::DecorationRole)
return QPixmap(":/icons/TAG_Int.png");
return QFileSystemModel::data(index, role);
}
This:
Becomes:
How can I only change the icon of the files?
Thanks for your time :)
I answered my own question:
QVariant MyQFileSystemModel::data( const QModelIndex& index, int role ) const {
if( role == Qt::DecorationRole )
{
QFileInfo info = MyQFileSystemModel::fileInfo(index);
if(info.isFile())
{
if(info.suffix() == "dat")
return QPixmap(":/icons/File_Icon.png");//I pick the icon depending on the extension
else if(info.suffix() == "mcr")
return QPixmap(":/icons/Region_Icon.png");
}
}
return QFileSystemModel::data(index, role);
}
Try to get filename and check is it a file or not. So it should be something like that:
QVariant MyQFileSystemModel::data(const QModelIndex& index, int role) const
{
if(role == Qt::DecorationRole)
{
QString name = index.data();//get filename
QFileInfo info(name);
if(info.isFile()) //check
return QPixmap(":/icons/TAG_Int.png");//return image if file
}
return QFileSystemModel::data(index, role); //if not, standard processing
}
I'm trying to show an image in a QTreeView together with some other data. To to this I've created an QAbstractItemModel. In the data method, I return some strings for column index 0 and 1 and for the third I wish to return an image. This image however, is not being displayed.
When I return the image as a decoration it displays fine but I wish to add click listeners to the image that will trigger some events. I also wish to position my image to the far right in the treeview and this seems to require a custom delegate. For these reasons I've created a separate column for the image instead.
Image is created in constructor like this: mEditImage = QImage(":/images/myImage.png");
MyModel
QVariant MyModel::data(const QModelIndex &index, int role) const {
if (!index.isValid()) {
return QVariant();
}
if(role == Qt::FontRole) {
return fontData(index);
}
if(role == Qt::ForegroundRole) {
return foreGroundData(index);
}
MyModelItem *item = getItem(index);
/*
* Use decoration to display image. Probably needs a
* custom delegate to be able to position the image correctly.
* (http://www.qtcentre.org/threads/49639-decoration-position-and-alignment)
* (https://qt-project.org/forums/viewthread/24493)
*
* Will use extra column for now instead. Might help with click
* listeners as well.
*
* if(role == Qt::DecorationRole && item->parent() != mRootItem) {
return index.column() == 1 ? mEditImage : QVariant();
}*/
if(role == Qt::SizeHintRole) {
return mEditImage.size();
}
if (role == Qt::DisplayRole) {
QString id = QString::number(item->id());
QString name = item->name();
if(item->parent() != mRootItem && index.column() == 2) {
return mEditImage;
}
if(item->parent() == mRootItem){
return index.column() == 0 ? name : "";
} else {
return index.column() == 0 ? id : name;
}
} else if(role == Qt::BackgroundRole) {
return QVariant();
}
I've had a look here:
http://www.qtcentre.org/threads/29550-How-do-I-display-a-picture-on-a-QTableView-cell
How to set an image for a row?
I've tried changing the image to a QPixmap and QIcon and also tried embedding it in a QLabel (which could not be converted to a QVariant) without luck. Changing the image to a QString displays the string so the row/column logic seems fine. Removing the SizeHintRole logic doesn't make any difference either.
Any help in understanding how to display image data in a QTreeView would be helpful. I seem to be going at this from the wrong direction.
Cheers.
It doesn't matter, how to store image. QPixmap is prefferable for speed drawing.
QVariant MyModel::data(const QModelIndex &index, int role) const
{
item = itemFromIndex( index ); // Your item implementation
...
case Qt::DisplayRole:
return item->getText();
case Qt::DecorationRole:
return item->getImage();
}
Read Qt docs about roles, it's good - http://doc.qt.io/qt-4.8/qt.html#ItemDataRole-enum
I have a QTableView (model based) and I want to disable the editing capability of a particular cell, let's say row 0, column 1.
How can I do this? Please note that I still want other cells in this row enabled for editing.
If you are using a custom table model, you can implement the Qt::ItemFlags QAbstractItemModel::flags ( const QModelIndex & index ) const method and return a set of flags where the Qt::ItemIsEditable flag is not set for the cells you do not want to edit. Suppose MyTableModel is inherited from QAbstractTableModel:
Qt::ItemFlags MyTableModel::flags ( const QModelIndex & index ) const {
Qt::ItemFlags flags = Qt::NoItemFlags;
if (index.row() == 0 && index.column() == 1) {
return flags;
}
return flags | Qt::ItemIsEditable;
}