I've started to extend the qGet DownloadManager to emit the progress of a TransferItem, so that i can connect to it. I'm inserting the progress data into a cell of a TableView model for display with an Delegate, finally the delegate paints the progress bar. That works in theory, but i'm running into the following
Problem: when there are multiple downloads in parallel, then i get progress updates from both signals into both cells!
Both progress bars show progress data, but the signal is kind of mixed and not unique to the current index (QModelIndex index / index.row()).
(Please ignore the small transitioning problem between UserRoles (after clicking the download button "ActionCell" is displayed and then "Install", before the "ProgressBar" shows up.). That is not the main problem here. My question is about the index problem.) The text "112" and "113" is the int index.row.
Questions:
How to update a TableView with progress data for multiple ProgressBars?
What must i change to render a progress bar for each download?
Source
Emit progress of a download
I've added the following things to re-emit the signal through the classes, until it bubbles up to the top, where it becomes connectable from the GUI.
a connection from QNetworkReply - downloadProgress(qint64,qint64) to TransferItem - updateDownloadProgress(qint64,qint64)
void TransferItem::startRequest()
{
reply = nam.get(request);
connect(reply, SIGNAL(readyRead()), this, SLOT(readyRead()));
connect(reply, SIGNAL(downloadProgress(qint64,qint64)),
this, SLOT(updateDownloadProgress(qint64,qint64)));
connect(reply, SIGNAL(finished()), this, SLOT(finished()));
timer.start();
}
the SLOT function TransferItem - updateDownloadProgress(qint64,qint64) as receiver calculates the progress and stores it in progress (QMap<QString, QVariant>).
After the calculation the downloadProgress(this) signal is emitted.
// SLOT
void TransferItem::updateDownloadProgress(qint64 bytesReceived, qint64 bytesTotal)
{
progress["bytesReceived"] = QString::number(bytesReceived);
progress["bytesTotal"] = QString::number(bytesTotal);
progress["size"] = getSizeHumanReadable(outputFile->size());
progress["speed"] = QString::number((double)outputFile->size()/timer.elapsed(),'f',0).append(" KB/s");
progress["time"] = QString::number((double)timer.elapsed()/1000,'f',2).append("s");
progress["percentage"] = (bytesTotal > 0) ? QString::number(bytesReceived*100/bytesTotal).append("%") : "0 %";
emit downloadProgress(this);
}
QString TransferItem::getSizeHumanReadable(qint64 bytes)
{
float num = bytes; QStringList list;
list << "KB" << "MB" << "GB" << "TB";
QStringListIterator i(list); QString unit("bytes");
while(num >= 1024.0 && i.hasNext()) {
unit = i.next(); num /= 1024.0;
}
return QString::fromLatin1("%1 %2").arg(num, 3, 'f', 1).arg(unit);
}
When a new download is enqueued, i'm connecting the emitted downloadProgress(this) to the Slot DownloadManager - downloadProgress(TransferItem*). (dl is DownloadItem which extends TransferItem).
void DownloadManager::get(const QNetworkRequest &request)
{
DownloadItem *dl = new DownloadItem(request, nam);
transfers.append(dl);
FilesToDownloadCounter = transfers.count();
connect(dl, SIGNAL(downloadProgress(TransferItem*)),
SLOT(downloadProgress(TransferItem*)));
connect(dl, SIGNAL(downloadFinished(TransferItem*)),
SLOT(downloadFinished(TransferItem*)));
}
Finally, i'm re-emitting the download progress one more time:
void DownloadManager::downloadProgress(TransferItem *item)
{
emit signalProgress(item->progress);
}
Now the TableView with Delegate, doDownload(index) and ProgressBarUpdater
QTableView
with added QSortFilterProxyModel (for case-insensitivity)
with added ColumnDelegate, which renders DownloadButton and ProgressBar based on custom UserRoles. The delegate handles the button click: the SIGNAL downloadButtonClicked(index) is emited from the editorEvent(event, model, option, index) method.
actionDelegate = new Updater::ActionColumnItemDelegate;
ui->tableView->setItemDelegateForColumn(Columns::Action, actionDelegate);
connect(actionDelegate, SIGNAL(downloadButtonClicked(QModelIndex)), this, SLOT(doDownload(QModelIndex)));
The doDownload method receives the index and fetches the download URL from the model. Then the URL is added to the DownloadManager
and i'm setting up a ProgressBarUpdater object to set the progress data to the model at the given index. Finally i'm, connecting downloadManager::signalProgress to progressBar::updateProgress and invoke the downloadManager::checkForAllDone to start the download processing.
void UpdaterDialog::doDownload(const QModelIndex &index)
{
QUrl downloadURL = getDownloadUrl(index);
if (!validateURL(downloadURL)) return;
QNetworkRequest request(downloadURL);
downloadManager.get(request); // QueueMode is Parallel by default
ProgressBarUpdater *progressBar = new ProgressBarUpdater(this, index.row());
progressBar->setObjectName("ProgressBar_in_Row_" + QString::number(index.row()) );
connect(&downloadManager, SIGNAL(signalProgress(QMap<QString, QVariant>)),
progressBar, SLOT(updateProgress(QMap<QString, QVariant>)));
QMetaObject::invokeMethod(&downloadManager, "checkForAllDone", Qt::QueuedConnection);
}
The model update part: the ProgressBarUpdater takes the index and the progress and should update the model at the given index.
ProgressBarUpdater::ProgressBarUpdater(UpdaterDialog *parent, int currentIndexRow) :
QObject(parent), currentIndexRow(currentIndexRow)
{
model = parent->ui->tableView_1->model();
}
void ProgressBarUpdater::updateProgress(QMap<QString, QVariant> progress)
{
QModelIndex actionIndex = model->index(currentIndexRow, UpdaterDialog::Columns::Action);
// set progress to model
model->setData(actionIndex, progress, ActionColumnItemDelegate::DownloadProgressBarRole);
model->dataChanged(actionIndex, actionIndex);
}
The rendering part: i'm rendering the fake ProgressBar from the delegate; fetching the progress data with index.model()->data(index, DownloadProgressBarRole).
void ActionColumnItemDelegate::drawDownloadProgressBar(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
QStyleOptionProgressBarV2 opt;
opt.initFrom(bar);
opt.rect = option.rect;
opt.rect.adjust(3,3,-3,-3);
opt.textVisible = true;
opt.textAlignment = Qt::AlignCenter;
opt.state = QStyle::State_Enabled | QStyle::State_Active;
// get progress from model
QMap<QString, QVariant> progress =
index.model()->data(index, DownloadProgressBarRole).toMap();
QString text = QString::fromLatin1(" %1 %2 %3 %4 %5 ")
.arg(QString::number(index.row()))
.arg(progress["percentage"].toString())
.arg(progress["size"].toString())
.arg(progress["speed"].toString())
.arg(progress["time"].toString());
opt.minimum = 0;
opt.maximum = progress["bytesTotal"].toFloat();
opt.progress = progress["bytesReceived"].toFloat();
opt.text = text;
bar->style()->drawControl(QStyle::CE_ProgressBar,&opt,painter,bar);
}
I've added QString::number(index.row() to the progress bar text, so that each ProgressBar gets its row number rendered. In other words: the rendering is unique to the row, but the incoming progress data is somehow mixed.
I'm stuck on the index problem for a while now. Thank you in advance for your help.
Update: The issue is resolved!
Thank you very much ddriver!! I followed your suggestions and fixed it:
The DownloadManager tracks the progress for all transfers, and you keep each transfer item's data in the respective TransferItem.
The logical thing IMO would be to have a connection from each TransferItem to the corresponding ProgressBarUpdater, and emit from the transfer item.
However, in your case, you are reporting progress not from each individual transfer item, but from the download manager. So each time you are emitting a progress, you are emitting the progress for a particular transfer item to all progress bars.
connect(&downloadManager, SIGNAL(signalProgress(QMap<QString, QVariant>)),
progressBar, SLOT(updateProgress(QMap<QString, QVariant>)));
So instead of a
TransferItem --progress--> CorrespondingUI
you have a:
TransferItem --transferItem--> DownloadManager --progress--> AllUIs
This leads to having one single and varying progress for all progress bars, which corresponds to the last download that happen to report progress before the UI updated. Which is why you get no more variation after the first download is completed, as the manager only updates the progress for the second.
Finally, i'm re-emitting the download progress one more time:
void DownloadManager::downloadProgress(TransferItem *item)
{
emit signalProgress(item->progress);
}
And who exactly needs an anonymous progress, containing no information whatsoever to which transfer it applies? Aside from the bug of course.
Would you be so nice to explain, how to simplify it?
I was at the end of my mental rope yesterday when I commented, on a clear head it doesn't look all that overdone, but still I'd probably go for something more streamlined, involving 3 key components only:
DownloadsManager -> DownloadController -> UI
-> DownloadController -> UI
It just seems redundant to have a DownloadItem and then also a TransferItem, considering that a download is a transfer.
The model and view are totally unnecessary as well, as is storing the progress in the model rather than just having it as a member of the progress bar. You could go with just a regular widget for each download, and place them in a vertical layout.
Update:
The excessive, unnecessary compartmentalization has led to a level of fragmentation which makes it hard to get to the data, needed to make it work once you put everything together. The main issue is you have no way to tie a transfer item to the right progress bar updater, and since you still haven't posted all of the relevant code, the simplest possible solution I can offer involves the following minor changes:
// in DownloadManager
void signalProgress(QMap<QString, QVariant>); // this signal is unnecessary, remove
void DownloadManager::downloadProgress(TransferItem *item) // change this
{
registry[item->request.url()]->updateProgress(item->progress);
}
QMap<QUrl, ProgressBarUpdater *> registry; // add this
// in UpdaterDialog
void UpdaterDialog::doDownload(const QModelIndex &index)
{
QUrl downloadURL = getDownloadUrl(index);
if (!validateURL(downloadURL)) return;
QNetworkRequest request(downloadURL);
downloadManager.get(request); // QueueMode is Parallel by default
ProgressBarUpdater *progressBar = new ProgressBarUpdater(this, index.row());
progressBar->setObjectName("ProgressBar_in_Row_" + QString::number(index.row()) );
// remove the connection - source of the bug, instead register the updater
downloadManager.registry[downloadURL] = progressBar;
QMetaObject::invokeMethod(&downloadManager, "checkForAllDone", Qt::QueuedConnection);
}
That's pretty much it, the progress updater is associated with the URL, and in DownloadManager::downloadProgress instead of emitting the progress to all progress updaters, you simply lookup the one which actually corresponds to the particular download, and only update its progress. It is somewhat clumsy, but as I said, if your design is proper, it would not be needed and you wouldn't have the problem in the first place.
There are other solutions as well:
change the DownloadManager's signal to void signalProgress(TransferItem *), and the body of downloadProgress toemit signalProgress(item); , change to void ProgressBarUpdater::updateProgress(TransferItem *), and in the body compare the transfer item's request's url to the one in the model at the currentIndexRow, and only model-setData() if it is the same. This solution is not very efficient, since it will emit to all progress updaters just to modify one.
cut out the middleman, what I've been suggesting from the start, make DownloadManager ::get() return a pointer to the DownloadItem/TransferItem created in its body, then in UpdaterDialog::doDownload() you can connect the transfer item directly to the appropriate progress updater, so you will no longer need DownloadManager::downloadProgress() and the signalProgress signal, you only need to change the signature of the signal in TransferItem to void downloadProgress(QMap<QString, QVariant>); and emit the progress rather than the item. This is actually the most efficient solution, as it involves nothing extra, jsut the removal of unnecessary stuff.
Related
I have a TreeModel which has some data loaded in it. There is a radio button in my application, which when clicked should update the TreeModel with a new data.
I have tried the following things on switching the radio button and none is working:
emit layoutChanged
emit layoutChanged();
emit dataChanged
emit dataChanged(QModelIndex(), QModelIndex());
Referenced from:
What does 'bottomRight' mean when using dataChanged() with a QTreeView in Qt?
Recursively visiting each node in the tree and emitting dataChanged
void TreeView::getLastExpandedState(const QModelIndex& parent)
{
bool isExpand = isExpanded(parent);
if (!isExpand) {
return;
}
int rows = model()->rowCount(parent);
for (int rowNum = 0; rowNum < rows ; ++rowNum) {
QModelIndex childIndex = model()->index(rowNum, 0, parent);
model->emitChange(parent,childIndex);
getLastExpandedState(childIndex);
}
}
void TreeModel::emitChange(const QModelIndex& parent,const QModelIndex& childIndex) {
emit dataChanged(parent,childIndex);
}
How to solve that?
The answer you reference is at best confusing and probably wrong.
Your model code needs to emit a dataChanged signal for any rectangle of cells where the data returned by the model data method has changed. See, for example, this question and answer, which goes into some detail.
Note that the parameters in the dataChanged signal should not be parent and child - they should be "topLeft" and "bottomRight". They need to have the same parent and also to be different. So you don't need to iterate over the rows and emit the signal for each row. You can send a combined signal for all the rows that have changed.
But you do need to send a signal for each parent (where data has changed) that signals the top left cell and bottom right cell for that parent. So you might end up creating an index for the top left cell for that parent at (0, 0, parent) and another for the bottom right cell at (rows, cols, parent) and then sending the signal for that pair of indices.
I didn't find a proper solution to this problem, so I hope somebody can give me an answer to my problem:
I am using a normal QTreeWidget, but as items I use an own subclass of QTreeWidgetItem (because I needed to store some other information in the item). Now I want to use the itemClicked() signal by the QTreeWidget, but I think my slot doesn't get any signal and I think it has to do with the signature of itemClicked(), since it sends a QTreeWidgetItem and of course not my own subclass.
Is it possible that QTreeWidget doesn't detect a click on my own subclass items?
Here is my connection:
connect(treeWidget, SIGNAL(itemClicked(QTreeWidgetItem *)), this, SLOT(displayTransformData(QTreeWidgetItem*)));
And here is my slot:
void GUI::displayTransformData(QTreeWidgetItem* item) {
cout << "test" endl;
Q_actorTreeWidgetItem* actor_item = dynamic_cast<Q_actorTreeWidgetItem*>(item);
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor = actor_item->getActorReference();
double* position = new double[3];
position = actor->GetOrigin();
x_loc->setText(QString(std::to_string( position[0]).c_str() ));
}
I'm already trying to cast the item that I could get from the signal into my own subclass, but the slot function is never called, because the test from my cout line doesn't appear in the console.
I'm very grateful for every help!
The problem is your incorrect SIGNAL specification,
SIGNAL(itemClicked(QTreeWidgetItem *))
You should probably see a warning message at the console along the lines of:
QObject::connect: No such signal
tree_widget::itemClicked(QTreeWidgetItem *) in ...
From the documentation the actual signal spec is
void QTreeWidget::itemClicked(QTreeWidgetItem *item, int column)
So, using the old Qt4 syntax you need
connect(treeWidget, SIGNAL(itemClicked(QTreeWidgetItem *, int)),
this, SLOT(displayTransformData(QTreeWidgetItem*)));
If possible, however, you should make use of the newer Qt5 signal/slot syntax
connect(treeWidget, &QTreeWidget::itemClicked, this, &GUI::displayTransformData);
I have a QTableView with a custom QSortFilterProxyModel for searching and sorting and a QSqlQueryModel for populating the table.
void ProxyModel::searchTable(QString name, QString type, QString date, QString time ){
if(name_ != name)
name_ = name;
if(type_ != type)
type_ = type;
if(date_ != date)
date_ = date;
if(time_ != time)
time_ = time;
invalidateFilter();
}
bool ProxyModel::filterAcceptsRow(int source_row,
const QModelIndex &source_parent) const{
QModelIndex indName = sourceModel()->index(source_row,
0, source_parent);
QModelIndex indType= sourceModel()->index(source_row,
4, source_parent);
QModelIndex indDate = sourceModel()->index(source_row,
2, source_parent);
QModelIndex indTime = sourceModel()->index(source_row,
3, source_parent);
if(
sourceModel()->data(indName).toString().toLower().contains(name_.toLower())
&&sourceModel()->data(indType).toString().toLower().contains(type_.toLower())
&&sourceModel()->data(indDate).toString().toLower().contains(date_.toLower())
&&sourceModel()->data(indTime).toString().toLower().contains(time_.toLower())
)
{
emit adjust();
return true;
}
return false;
}
After a successful search, I emit a signal from my proxy model to a slot where it adjusts the table height to fit the size of the rows.
connect(proxyModel, SIGNAL(adjust()), this, SLOT(dataChanged()));
And when the search button is clicked
connect(ui->searchBtn, &QToolButton::clicked, this, &AllVisitedPlaces::getSearchOptions);
I call the proxy model searchTable method with search parameters
void AllVisitedPlaces::getSearchOptions()
{
proxyModel->searchTable(ui->nameLineEdit->text(),
ui->typeLineEdit->text(),
ui->dateLineEdit->text(),
ui->timeLineEdit->text());
adjustTableSize();
}
void AllVisitedPlaces::dataChanged()
{
adjustTableSize();
this->verticalHeader->setSectionResizeMode(QHeaderView::ResizeToContents);
}
void AllVisitedPlaces::adjustTableSize()
{
QRect rect = ui->table->geometry();
int height = 0;
for (int i =0; i < proxyModel->rowCount() ; i++)
height+= ui->table->rowHeight(i);
rect.setHeight(18 + ui->table->horizontalHeader()->height() + height);
ui->table->setGeometry(rect);
verticalHeader->setSectionResizeMode(QHeaderView::Stretch);
}
The problem is, when the table re-sizes , I lose scrolling.
How can I fix that ?
Before re-sizing :
After re-sizing :
Why would you expect scrolling when you've resized the table to fit its contents?
The likely problem is that your Ui is broken in other ways and the table is obscured: it has been resized, but you can't see that because whatever widget the table view sits in doesn't manage the table widget properly. But we can't tell for sure because you didn't minimize your code to provide a complete compileable example of what you're doing. We're talking about <100 lines of code in all - surely it wouldn't be a big deal to just paste such a main.cpp in your question. See e.g. example 1 or example 2.
This is a bad design anyway since you're presuming that the table will fit on screen. Yet it won't: once the resizing works, you'll end up with a vertically huge window that cannot be used as some of its corners will extend past the screen, with no way to reach them to see the contents or to resize the window.
Finally, once you properly use layouts in your Ui design, the setGeometry() call on any widget below top-level is a no-op: it's the layout that controls the child widget geometry. The solution then is not to set the widget's geometry, but to set its minimum size instead.
You're facing an XY Problem: you're dead set on a solution, without telling us what it is that you're trying to achieve and making sure first that what you're after makes sense (as in: that it will actually lead to a usable Ui!).
I'm modifying the Qt 5 Terminal example and use a QTextEdit window as a terminal console. I've encountered several problems.
Qt does a strange interpretation of carriage return ('\r') in incoming strings. Ocassionally, efter 3-7 sends, it interprets ('\r') as new line ('\n'), most annoying. When I finally found out I choose to filter out all '\r' from the incoming data.
Is this behaviour due to some setting?
Getting the cursor interaction to work properly is a bit problematic. I want the console to have autoscroll selectable via a checkbox. I also want it to be possible to select text whenever the console is running, without losing the selection when new data is coming.
Here is my current prinout function, that is a slot connected to a signal emitted as soon as any data has arrived:
void MainWindow::printSerialString(QString& toPrint)
{
static int cursPos=0;
//Set the cursorpos to the position from last printout
QTextCursor c = ui->textEdit_console->textCursor();
c.setPosition(cursPos);
ui->textEdit_console->setTextCursor( c );
ui->textEdit_console->insertPlainText(toPrint);
qDebug()<<"Cursor: " << ui->textEdit_console->textCursor().position();
//Save the old cursorposition, so the user doesn't change it
cursPos= ui->textEdit_console->textCursor().position();
toPrint.clear();
}
I had the problem that if the user clicked around in the console, the cursor would change position and the following incoming data would end up in the wrong place. Issues:
If a section is marked by the user, the marking would get lost when new data is coming.
When "forcing" the pointer like this, it gets a rather ugly autoscroll behaviour that isn't possible to disable.
If the cursor is changed by another part of the program between to printouts, I also have to record that somehow.
The append function which sound like a more logical solution, works fine for appending a whole complete string but displays an erratic behaviour when printing just parts of an incoming string, putting characters and new lines everywhere.
I haven't found a single setting regarding this but there should be one? Setting QTextEdit to "readOnly" doesn't disable the cursor interaction.
3.An idea is to have two cursors in the console. One invisible that is used for printouts and that is not possible at all to manipulate for the user, and one visible which enables the user to select text. But how to do that beats me :) Any related example, FAQ or guide are very appreciated.
I've done a QTextEdit based terminal for SWI-Prolog, pqConsole, with some features, like ANSI coloring sequences (subset) decoding, command history management, multiple insertion points, completion, hinting...
It runs a nonblocking user interface while serving a modal REPL (Read/Eval/Print/Loop), the most common interface for interpreted languages, like Prolog is.
The code it's complicated by the threading issues (on user request, it's possible to have multiple consoles, or multiple threads interacting on the main), but the core it's rather simple. I just keep track of the insertion point(s), and allow the cursor moving around, disabling editing when in output area.
pqConsole it's a shared object (I like such kind of code reuse), but for deployment, a stand-alone program swipl-win is more handy.
Here some selected snippets, the status variables used to control output are promptPosition and fixedPosition.
/** display different cursor where editing available
*/
void ConsoleEdit::onCursorPositionChanged() {
QTextCursor c = textCursor();
set_cursor_tip(c);
if (fixedPosition > c.position()) {
viewport()->setCursor(Qt::OpenHandCursor);
set_editable(false);
clickable_message_line(c, true);
} else {
set_editable(true);
viewport()->setCursor(Qt::IBeamCursor);
}
if (pmatched.size()) {
pmatched.format_both(c);
pmatched = ParenMatching::range();
}
ParenMatching pm(c);
if (pm)
(pmatched = pm.positions).format_both(c, pmatched.bold());
}
/** strict control on keyboard events required
*/
void ConsoleEdit::keyPressEvent(QKeyEvent *event) {
using namespace Qt;
...
bool accept = true, ret = false, down = true, editable = (cp >= fixedPosition);
QString cmd;
switch (k) {
case Key_Space:
if (!on_completion && ctrl && editable) {
compinit2(c);
return;
}
accept = editable;
break;
case Key_Tab:
if (ctrl) {
event->ignore(); // otherwise tab control get lost !
return;
}
if (!on_completion && !ctrl && editable) {
compinit(c);
return;
}
break;
case Key_Backtab:
// otherwise tab control get lost !
event->ignore();
return;
case Key_Home:
if (!ctrl && cp > fixedPosition) {
c.setPosition(fixedPosition, (event->modifiers() & SHIFT) ? c.KeepAnchor : c.MoveAnchor);
setTextCursor(c);
return;
}
case Key_End:
case Key_Left:
case Key_Right:
case Key_PageUp:
case Key_PageDown:
break;
}
you can see that most complexity goes in keyboard management...
/** \brief send text to output
*
* Decode ANSI terminal sequences, to output coloured text.
* Colours encoding are (approx) derived from swipl console.
*/
void ConsoleEdit::user_output(QString text) {
#if defined(Q_OS_WIN)
text.replace("\r\n", "\n");
#endif
QTextCursor c = textCursor();
if (status == wait_input)
c.setPosition(promptPosition);
else {
promptPosition = c.position(); // save for later
c.movePosition(QTextCursor::End);
}
auto instext = [&](QString text) {
c.insertText(text, output_text_fmt);
// Jan requested extension: put messages *above* the prompt location
if (status == wait_input) {
int ltext = text.length();
promptPosition += ltext;
fixedPosition += ltext;
ensureCursorVisible();
}
};
// filter and apply (some) ANSI sequence
int pos = text.indexOf('\x1B');
if (pos >= 0) {
int left = 0;
...
instext(text.mid(pos));
}
else
instext(text);
linkto_message_source();
}
I think you should not use a static variable (like that appearing in your code), but rely instead on QTextCursor interface and some status variable, like I do.
Generally, using a QTextEdit for a feature-rich terminal widget seems to be a bad idea. You'll need to properly handle escape sequences such as cursor movements and color mode settings, somehow stick the edit to the top-left corner of current terminal "page", etc. A better solution could be to inherit QScrollArea and implement all the needed painting–selection-scrolling features yourself.
As a temporary workaround for some of your problems I can suggest using ui->textEdit_console->append(toPrint) instead of insertPlainText(toPrint).
To automatically scroll the edit you can move the cursor to the end with QTextEdit::moveCursor() and call QTextEdit::ensureCursorVisible().
How should this be done by using the model->setData() method call?
I have derived a class called "MyStandardItemModel" from QStandardItemModel. I have made my third and fourth columns non-editable by overriding the protected virtual flags method. This is how it goes:
#define TX_PACKET_COLUMN (4u)
#define RX_PACKET_COLUMN (5u)
Qt::ItemFlags MyStandardItemModel::flags(const QModelIndex& index) const
{
if (index.column() == TX_PACKET_COLUMN || index.column() == RX_PACKET_COLUMN)
{
return (QStandardItemModel::flags(index) & ~Qt::ItemIsEditable);
}
else
{
return QStandardItemModel::flags(index);
}
}
...
//Set model
ui->testCaseTableView->setModel(model);
Having this done, I am not able to edit the cells in the third and fourth column.
Now, I want that when I double click on these cells, a pop-up dialog comes up. I will modify some data in the editable field of that dialog, and then copy it back to the non editable cells inside the code.
I tried to just write a doubleclick() handler for the QTreeView and just copy some data to the cells just to see if it is possible to copy data to the non-editable cells.
This operation is failing, and the data is not written into the non-editable cells.
Here you can find the double click handler:
void MainWindow::on_testCaseTableView_doubleClicked(const QModelIndex &index)
{
QVariant variant;
variant.toString() = "AA";
if((index.column() == TX_PACKET_COLUMN)||(index.column() == RX_PACKET_COLUMN))
{
model->setData(index, variant); // set new value
}
}
The setData(..) operation is clearing the already written data in the cells, but string "AA" is not getting written. Please suggest how to copy some data to non-editable cells inside the code.
QVariant set is empty. Nothing needs to be wrong in your model. Error is on this line:
variant.toString() = "AA";
change to:
QVariant variant("AA"); // just for testing anyway
As I indicated in my comment, you have to fix this first issue:
instead of:
QVariant variant;
variant.toString() = "AA";
you should write
QVariant variant = QLatin1String("AA");
In general, you would look into the setData(...) implementation for such cases whether you emit the data changed signal properly and so forth, but here you are entering a prior issue which can lead to problems, so let us fix that.
Note, you should use QLatin1String to avoid the unnecessary explicit conversion from raw char* to QString. This is a good practice in general, and this is available with Qt 4 as well as Qt 5.
Although, you could also use the QStringLiteral macro for creating a QString very efficiently with template magic out of your raw literal, but that requires C++11.