I Have Create Dynamic n*n LineEdit in Qt? - qt

i want create dynamic n*n with QLineEdit object. for example 3*3 or 17*17 QLineEdite.
How Make it?

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How to change the order of QTableView rows by dragging and store the changes to the model?

I want to know how to change the order of QTableView rows by dragging, and store the order changes to the model?
I use QTableView as view and QSqlTableModel as model. I am using Qt 5.15.
I set:
ui->table_view->setSelectionMode(QAbstractItemView::SingleSelection);
ui->table_view->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->table_view->setEditTriggers(QAbstractItemView::NoEditTriggers);
Methods I tried:
1.
ui->table_view->setSectionsMovable(true);
ui->table_view->setDragEnabled(true);
ui->table_view->setDragDropMode(QAbstractItemView::InternalMove);
ui->table_view->setAcceptDrops(true);
It doesn't take effect. The row cannot be dragged.
2.
ui->table_view->verticalHeader()->setSectionsMovable(true);
ui->table_view->verticalHeader()->setDragEnabled(true);
ui->table_view->verticalHeader()->setDragDropMode(QAbstractItemView::InternalMove);
ui->table_view->verticalHeader()->setAcceptDrops(true);
The row can be dragged by vertical header. But the order of changes will not affect the model.
As far as I know the QTableView does not call moveRows method of the model by itself. Instead drag and drop actions call *mimeData methods.
So, one option would be the following:
In your model you need to implement mimeData and dropMimeData functions. When you drag and drop a row the view will ask for mimeData() of the given row. If you are sure that you need only internal moves you can encode the selected row indices to QMimeData. Then in the dropMimeData() you decode the indices that were selected and use them to call your moveRows() implementation. Return false from this function to prevent removing of the moved out rows.
Another option can be to override the QTableView methods such as dropEvent() in a way, that it calls the model moveRows() method directly.

QT: QTableView read cell content

I'm writing a small program with QT creator (QT 5.2.1) under Windows 7 (32 bit) and I'm having problems reading the informations stored in a TableView. My application has 3 elements, a TableView to store text data, a TextBrowser to show info and a buttom.
I modified the TableView properties: when the user selects with the mouse a cell, the full row is selected and multiple row selection is not allowed.
The user select a row and when the buttom is pressed, I would like to read the content of a specific TableView cell and show it in a TextBrowser. In particular, I would like to know the row index of the selected row and read the content of the cell with that row index and a specific column index (example 2).
The pseudo-code is this:
void my_program::on_pushButton_clicked()
{
ui->textBrowser->append("button pressed");
QItemSelectionModel *select = ui->tableView->selectionModel();
int index_row = select->selectedRows();
int index_column = 2;
char cell_data[30] = ??[index_row][index_column]
ui->textBrowser->append(cell_data);
}
The main problem is that select->selectedRows() returns a QModelIndex that is a collection of indexs and I do not know how to convert it to int (since multiple selection are not allowed, it should have only one element).
I would be glad if someone can suggest me a way to proceed.
Thanks
Francesco
edit:
Hi Bogdan, thanks a lot!! I succeed to read the cell content by using
ui->textBrowser->append(ui->tableView->model()->data(ui->tableView->model()->index(2,5)).toString());
this give me the content of the cell in position 2,5.
not sure if this is the best way or not but it works !!.
Can you be a bit more precise about how to iterate the QModeIndexList ? thanks :)
selectedRows() returns QModelIndexList, thus you need to iterate over it and call QModelIndex::data() to get stored data.

How to split columns of the QtableWidget into subcolumns in Qt

I am using QtableWidget for my GUI application.
In my GUI , I have to display a table widget which has Rows and Columns and for each row , column is further divided into two sub columns.
Can any body please tell me how to divide columns into subcolumn for Qtable Widget? (I need to divide horizontal header view also into sub columns).
From the question it is unclear what/how you want to subdivide, but in general Qt has no concept of a subcolumn.
You can however control the display and editing of individual items using an item delegate. So I suggest you experiment with that.
http://doc.qt.io/qt-5/qabstractitemview.html#setIndexWidget
http://doc.qt.io/qt-5/qabstractitemview.html#setItemDelegate
http://doc.qt.io/qt-5/qabstractitemview.html#setItemDelegateForColumn
http://doc.qt.io/qt-5/qabstractitemview.html#setItemDelegateForRow

Programmatically adding a new row to a QAbstractListModel subclass

Within an already-instantiated QAbstractListModel subclass, how do I add a row with data in each column, and have the associated QListView display the new row?
It seems that the only way to do it is to reimplement insertRow and setData within my model, and then hack them together in some sort of sequence within another function to add a row. Must I do this? Surely Qt must make it easier to add a new row.
Thanks much!
--Dany.
Just change your model's data storage, in between beginInsertRows() and endInsertRows().
For instance, let's say you have a flat list model and your model stores the data internally in a QVector m_data. You want to prepend the list, i.e. insert a row at position 0:
beginInsertRows( QModelIndex(), 0, 0 ); //notify views and proxy models that a line will be inserted
m_data.prepend( somedata ); // do the modification to the model data
endInsertRows(); //finish insertion, notify views/models
I'm afraid you have to do it that way. From the docs:
Models that provide interfaces to resizable list-like data structures can provide implementations of insertRows() and removeRows().

One QStandardItemModel for different QTableView, Generic vs Specific Views

I really don't know if this makes sense but this is what I trying to do:
I'm doing my game's editor in QT. Currently I'm using a QStandardItemModel to store all my scene items. These items have names, position, Textures(vector of Texture which is a custom class), Animations (vector of Animation), etc.
I find it useful to have one item for row cause I can add or remove these items easily besides having them in a single place so changing this model should affect the entire app.
Now, I'm trying to do specific views for say the "Textures" of a certain item. This QTableView should show the texture's name, path etc. So, basically how can I grab the vector of Textures in the general model and fill another view without doing another model?
You will want to use a QSortFilterProxy Model. Set one up like this.
QTableView *tableView = new QTableView;
MyItemModel *sourceModel = new MyItemModel(this);
QSortFilterProxyModel *proxyModel = new QSortFilterProxyModel(this);
proxyModel->setSourceModel(sourceModel);
proxyModel->setFilterKeyColumn(column_#_to_filter_by);
proxyModel->setFilterRegExp(a_regex_that_matches_the_item_you_want_to_display);
tableView->setModel(proxyModel);
You should be able to use one model and different proxies to setup different views.

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