Unsolved QAbstractTableModel + QML TableView: How to call setData?
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@raven-worx Hi, thanks for answer. yes, I do re implement it. Its used in order for the
data
to work. Your answer is similar to this: https://stackoverflow.com/questions/56441036/call-qabstracttablemodel-setdata-method-from-qml?noredirect=1#comment99475440_56441036 But I simply cannot get ahead of it without an example. Doing:onEditingFinished: { theLoader.visible = false; theCellText.visible = true; tableModel.roleName = text; // or model.roleName = text; }
Doesnt work.
So far I have utilized the following hack: I added asetData
overload method:/** * @brief A wrapper for actual \ref setData method subclassed from * QAbstractTableModel class. It is needed whenever a QModelIndex is * not available (ie. QML side). * @param row: cell row number. * @param column: cell column number. * @param value: value to assign. * @return Non zero on success. */ bool CVarTableModel::setData(const int row, const int column, const QVariant& value) { return setData(index(row, column), value); }
And I call it like this on QML side:
onEditingFinished: { theLoader.visible = false; theCellText.visible = true; tableModel.setData(styleData.row, styleData.column, text); }
It does work, but now, for some reason, after the
dataChanged
is emited inside the actualsetData
override, the cell on QML side does not update... -
Starting from this example: https://wiki.qt.io/How_to_Use_a_Custom_Class_in_C%2B%2B_Model_and_QML_View
Changing the delegate to something like:
delegate: TextInput { text: edit.name onEditingFinished: { edit.name = text } }
is enough.
Regarding how it works, see the very last paragraph of the wiki -
@VRonin Hi, Thanks for answer. I have no idea where does 'edit` id come from, even after reviewing your link...
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From https://wiki.qt.io/How_to_Use_a_Custom_Class_in_C%2B%2B_Model_and_QML_View
accessing our data is very easy we just use the
roleName.propertyName
syntax. Since we saved our data inQt::EditRole
we usededit
as role name (a list of the default role names is In QAbstractItemModel's documentation)basically
edit
is the name of the role as returned byQAbstractItemModel::roleNames()
. The example doesn't overload it so the default name coresponding toQt::EditRole
is used -
@VRonin Thanks for clarification, this gets complicated. My override looks as follows:
/** * @brief Obtains the role names needed on the QML side. * @return A hash of role names. */ QHash<int, QByteArray> CVarTableModel::roleNames() const { QHash<int, QByteArray> roles; const int colCount = columnCount(); for (int col = 0; col < colCount; col++) roles[Qt::UserRole + col] = role(col).toByteArray(); return roles; }
And the
role
method is:/** * @brief Obtains the role name string assiociated to the provided \p column * @param column: Column number/ index. * @return Role name string (as Qvariant) in case \p column is valid. */ QVariant CVarTableModel::role(const int column) const { if (!isColumnValid(column)) return QString(); return QVariant::fromValue(static_cast<Columns>(column)); }
Columns
is a simple enum:/** * @brief An enumeration class providing the columns and the amount of * columns as well (use ZCOUNT as always last member). */ enum class Columns { Name = 0, Unit, Value, ZCOUNT, }; Q_ENUM(Columns)
So my role names would be
Name
,Unit
andValue
. How would this be consistent with theedit
way if its custom?
I would appreciate further help. -
So my role names would be Name, Unit and Value. How would this be consistent with the edit way if its custom?
easy, replace
edit
withName
,Unit
orValue
. For example, if theName
role will contain aQString
you can use:delegate: TextInput { text: Name onEditingFinished: { Name = text } }
My override looks as follows:
This is a very convoluted way to go about it. You can just use
QMetaEnum::fromType<Derived::Columns>().valueToKeys(col);
for (int col = 0; col < colCount; col++)
Looks like columns and roles are the same thing here but since 1 year ago they are now 2 distinct things (as they are in QtWidgets): https://blog.qt.io/blog/2018/08/29/tableview/
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@VRonin Thank you for follow-up. As for the method optimization, I will get back to that. But for the main problem, I did:
Component { id: theInputComp; TextInput { id: textInputId; anchors.fill: parent; onEditingFinished: { theLoader.visible = false; theCellText.visible = true; //tableModel.setData(styleData.row, //styleData.column, text); Name = text; } } }
And received:
qrc:/UBasicTable.qml:109: Error: Invalid write to global property "Name"
Am I missing something? -
Name
might be a reserved word. Try changingName = 0,
tocolName = 0,
and usetext: colName
andcolName = text
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@VRonin Doesnt matter how I call it:
qrc:/UBasicTable.qml:109: Error: Invalid write to global property "colName" qrc:/UBasicTable.qml:109: Error: Invalid write to global property "colName1" // this doesnt exist
Any other hints :/?
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Just BTW... Figured out why doesnt the
dataChanged
signal fire the table update. I was calling it like this:emit dataChanged(index, index, {role});
and
role
was alwaysQt::EditRole
. Now I call it without roles parameter:emit dataChanged(index, index);
And the TableView cells are being updated! Thanks for the help @VRonin, it led me to the right place for this one.
I still havent figured out how to automatically callsetData
from the QML though (using the presented workaround). If you have any more ideas please let me know. -
Are you sure you are inside
delegate:
?
This is a minimal working example:#include <QGuiApplication> #include <QQmlContext> #include <QQmlApplicationEngine> #include <QStringListModel> #include <QDebug> class MyModel : public QStringListModel{ public: MyModel(QObject *parent = nullptr) : QStringListModel(parent) {} QHash<int, QByteArray> roleNames() const override { QHash<int, QByteArray> roles; roles[Qt::EditRole] = QByteArrayLiteral("TestRole"); roles[Qt::DisplayRole] = QByteArrayLiteral("AnotherRole"); return roles; } }; int main(int argc, char *argv[]) { #if defined(Q_OS_WIN) QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling); #endif QGuiApplication app(argc, argv); QQmlApplicationEngine engine; MyModel model; QObject::connect(&model,&MyModel::dataChanged,[](const QModelIndex& idx){ qDebug() << "Changed: " << idx.row() << " " << idx.data().toString(); }); model.setStringList(QStringList{"aaa","bbb","ccc"}); engine.rootContext()->setContextProperty("mymodel", &model); engine.load(QUrl(QStringLiteral("qrc:/main.qml"))); if (engine.rootObjects().isEmpty()) return -1; return app.exec(); }
import QtQml 2.2 import QtQuick 2.7 import QtQuick.Window 2.2 import QtQuick.Controls 2.3 Window { visible: true width: 640 height: 480 title: qsTr("Test Edit") ListView { anchors.fill: parent; width: 200; height: 250 model: mymodel delegate: TextInput { text: TestRole onEditingFinished: { TestRole = text } } } }
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@VRonin Hmmm... Here is the thing- I am inside
itemDelegate
notdelegate
.delegate
is available in differentQtQuick.Controls
version. If I switch to it, I will no longer have my other components available, iePopup
. IsntitemDelegate
anddelegate
the same thing?Look at the docs,
TableView
has nodelegate
member: https://doc.qt.io/qt-5/qml-qtquick-controls-tableview.html#rowDelegate-prop -
Looks like you are still using Qt Quick controls 1.
Qt Quick controls 2 is already 3 years old.If I switch to it, I will no longer have my other components available, ie Popup
Qt Quick Controls 2 has https://doc.qt.io/qt-5/qml-qtquick-controls2-popup.html
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@VRonin
QtQuick.Controls 2.5
do havedelegate
but dont haveTableViewColumn
which I am using for columns setting. Is there a better way now? -
@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:
Is there a better way now?
@VRonin said in QAbstractTableModel + QML TableView: How to call setData?:
Looks like columns and roles are the same thing here but since 1 year ago they are now 2 distinct things (as they are in QtWidgets): https://blog.qt.io/blog/2018/08/29/tableview/
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@VRonin Ok... So now everything I got ahead of with
styleData
is no longer working. This time I am really confused. Those links threat about animations the most and what I need for now is to be able to send/ receive data from the C++ model. Is there any example for that? -
@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:
So now everything I got ahead of with
styleData
is no longer working.What is
styleData
? -
@VRonin It was available in
itemDelegate
: https://doc.qt.io/qt-5/qml-qtquick-controls-tableview.html#itemDelegate-prop
One could use it to locate itself in the table as well as read model data. -
@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:
One could use it to locate itself in the table as well as read model data.
now you don't need it anymore. you just access role names directly to read data and you can use
index
,row
andcolumn
directly to locate yourself within the modelBtw, this doesnt call setData:
Yes it does. If the
dataChanged
signal is not enough to convince you you can add the below toMyModel
bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override{ qDebug() << "Called setData"; return QStringListModel::setData(index,value,role); }
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@VRonin Ok, you are right! Thanks.
It feels like we are really close this time. So this is the components now:TableView { anchors.fill: parent; model: tableModel; delegate: TextInput { text: Name; onEditingFinished: { Name = text } } }
My columns and roles are still mixed together because of the obsolete behavior- this needs to be disconnected. In this case, what should the
roleNames
override method return actually?