I'm having a hard time figuring out how to get the position(column and row) and the content in the QLineEdit. I'm using a eventFilter to get the signal but from there i'm stuck. any advice? Thank you
ui->tableWidget->setRowCount(5);
ui->tableWidget->setColumnCount(5);
QStringList wordList;
wordList << "alpha" << "omega" << "omega2" << "omega3" <<"omicron" << "zeta";
for(int i = 0; i<5;i++)
{
QLineEdit *lineEdit = new QLineEdit;
QCompleter *completer = new QCompleter(wordList);
completer->setCaseSensitivity(Qt::CaseInsensitive);
lineEdit->installEventFilter(this);
lineEdit->setCompleter(completer);
ui->tableWidget->setCellWidget(i,i,lineEdit);
}
....
bool MainWindow::eventFilter(QObject * object, QEvent *event)
{
}
I would like to get the position when I finish editing. I would like to pick a word from the list either through up and down key or left mouse click. Once a word is picked that word would populate the QLineEdit. Then i would want to know the position. Now, if the user writes a text different from the content of the list then no position should be returned. I'm only interested on whats in the "wordList". Thank you
As you indicate in your comments, you only want to obtain the text when an element that is set in the QCompleter is selected, for this we must use the void QCompleter::activated(const QString & text) signal.
To do this, a slot is created and the connection is made:
*.h
private slots:
void onActivated(const QString &text);
*.cpp
QCompleter *completer = new QCompleter(wordList);
...
connect(completer, qOverload<const QString &>(&QCompleter::activated), this, &MainWindow::onActivated);
There are 2 possible solutions:
The first to use the position of the QLineEdit that we obtain through the widget() method of the QCompleter, and the QCompleter we obtain it through sender() which is the object that emits the signal and pos(). then we get the QModelIndex with indexAt(), and this has the information of the row and column:
void MainWindow::onActivated(const QString &text)
{
QCompleter *completer = static_cast<QCompleter *>(sender());
QModelIndex ix = ui->tableWidget->indexAt(completer->widget()->pos());
if(ix.isValid()){
qDebug()<<ix.row()<<ix.column()<<text;
}
}
Or the row and column is saved as a property:
QCompleter *completer = new QCompleter(wordList);
...
completer->setProperty("row", i);
completer->setProperty("column", i);
void MainWindow::onActivated(const QString &text)
{
QCompleter *completer = static_cast<QCompleter *>(sender());
qDebug()<< completer->property("row").toInt()<<completer->property("column").toInt()<<text;
}
In the following link you can find both complete examples
Related
I'm making a Qt5.7 application where I am populating a QListView after reading stuff from a file. Here's the exact code of it.
QStringListModel *model;
model = new QStringListModel(this);
model->setStringList(stringList); //stringList has a list of strings
ui->listView->setModel(model);
ui->listView->setEditTriggers(QAbstractItemView::NoEditTriggers); //To disable editing
Now this displays the list just fine in a QListView that I have set up. What I need to do now is to get the string that has been double clicked and use that value elsewhere. How do I achieve that?
What I tried doing was to attach a listener to the QListView this way
... // the rest of the code
connect(ui->listView, SIGNAL(doubleClicked(QModelIndex)), this, SLOT(fetch()));
...
And then I have the function fetch
void Window::fetch () {
qDebug() << "Something was clicked!";
QObject *s = sender();
qDebug() << s->objectName();
}
However the objectName() function returns "listView" and not the listView item or the index.
The signal already provides you with a QModelIndex which was clicked.
So you should change your slot to this:
void Window::fetch (QModelIndex index)
{
....
QModelIndex has now a column and a row property. Because a list has no columns you are interessted in the row. This is the index of the item clicked.
//get model and cast to QStringListModel
QStringListModel* listModel= qobject_cast<QStringListModel*>(ui->listView->model());
//get value at row()
QString value = listModel->stringList().at(index.row());
You should add the index as parameter of your slot. You can use that index to access the list
Your code should be some thing like this.
void Window::fetch (QModelIndex index) {
/* Do some thing you want to do*/
}
I want to create an editable QComboBox which filters results according to the search query and updates the dropdown entries accordingly.
After reading How do I Filter the PyQt QCombobox Items based on the text input? I tried to implement something similar in C++.
But I can't store anything inside the QComboBox now. Even after adding new entries through addItem() the total count remains 0.
What is the reason for this and how do I insert entries inside the QComboBox with QSortFilterProxyModel?
Here is the relevant snippet of the code:
SearchBox = new QComboBox(this);
SearchBox->setEditable(true);
// Try adding a few entries and check if they persist after changing the model
SearchBox->addItem(QString("hi"));
SearchBox->addItem(QString("bye"));
int count = SearchBox->count(); // count = 2
ProxyModel = new QSortFilterProxyModel;
ProxyModel->setSourceModel(SearchBox->model());
ProxyModel->setFilterCaseSensitivity(Qt::CaseSensitivity::CaseInsensitive);
SearchBox->setModel(ProxyModel);
// Check count again
count = SearchBox->count(); // count = 0 <- Why?
// Try adding new entries
SearchBox->addItem(QString("Hi again"));
count = SearchBox->count(); // count = 0 .. So new entries don't get stored
Completer = new QCompleter(ProxyModel,this);
Completer->setCompletionMode(QCompleter::UnfilteredPopupCompletion);
SearchBox->setCompleter(Completer);
QObject::connect(SearchBox->lineEdit(), SIGNAL(textChanged(const QString)), ProxyModel, SLOT(setFilterFixedString(const QString)));
QObject::connect(Completer, SIGNAL(activated(const QString &)), this, SLOT(onCompleterActivated(const QString &)));
Use QStringListModel to store items. Application crashes if proxy model have no items (if filter string filters out all items)(this needs further investigation - is this completer issue or combobox). This can be fixed by not applying such filter (onTextChanged(QString text) slot). Completer completes input if theres only one item (not sure if it's ok). And sometimes checkbox doubles all items (don't know why). If this issues is critical, I think you need to write custom ComboBox from scratch and this is serious work.
{
SearchBox = new QComboBox(this);
SearchBox->setEditable(true);
QStringList Items;
Items << "hi" << "bye";
StringListModel = new QStringListModel();
StringListModel->setStringList(Items);
ProxyModel = new QSortFilterProxyModel;
ProxyModel->setSourceModel(StringListModel);
ProxyModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
SearchBox->setModel(ProxyModel);
// Check count again
int count = SearchBox->count(); // count = 2
// Try adding new entries
QStringList Items_ = StringListModel->stringList();
Items_ << "hi again";
StringListModel->setStringList(Items_);
count = SearchBox->count(); // count = 3
Completer = new QCompleter(ProxyModel,this);
Completer->setCompletionMode(QCompleter::UnfilteredPopupCompletion);
SearchBox->setCompleter(Completer);
QObject::connect(SearchBox->lineEdit(), SIGNAL(textChanged(const QString)), this, SLOT(onTextChanged(QString)));
QObject::connect(Completer, SIGNAL(activated(const QString &)), this, SLOT(onCompleterActivated(const QString &)));
}
void MainWindow::onTextChanged(QString Text) {
QStringList Items = StringListModel->stringList();
QString Item;
foreach(Item,Items) {
if (Item.indexOf(Text) > -1) {
ProxyModel->setFilterFixedString(Text);
return;
}
}
}
I have a QListview where I have set a model. The model contains the QList. Now I want to get the contents of QListview on clicking the item. But I don't know how to do this? Through some tutorials I followed I am able to get two items appear in the QListview as follows. But I dont know how to make it work?? Please anyone help. The code which I am working as follows.
listviewmodel =new QListView;
listviewmodel->setModel( createModel() );
listviewmodel->setViewMode(QListView::IconMode);
listviewmodel->setIconSize(QSize(size().width()/8, size().height()/8));
connect(listviewmodel,SIGNAL(clicked(const QModelIndex)),this,SLOT(ItemClicked(QModelIndex)));
QAbstractItemModel *MainWindow::createModel()
{
QStandardItemModel *model = new QStandardItemModel();
QList<QStandardItem *> listItem;
QStandardItem *item2 = new QStandardItem();
item2->setIcon(QIcon(QPixmap::fromImage(qimages2)));
listItem << item2;
QStandardItem *item1 = new QStandardItem();
item1->setIcon(QIcon(QPixmap::fromImage(qimages1)));
listItem << item1;
model->appendColumn(listItem);
return model;
}
void MainWindow::ItemClicked (QModelIndex index )
{
textEdit->setText(index.data().toString());
}
I checked your code in QtCreator and it works as you described. So what is the problem? Are you getting some errors? Maybe did you not put declaration of ItemClicked(QModelIndex) below the public slots:? Are you sure that connect returns true? Try to check it:
bool success = connect(listviewmodel,SIGNAL(clicked(const QModelIndex)),this,SLOT(ItemClicked(QModelIndex)));
Q_ASSERT(success);
EDIT: If you want to display only icons at QListView and get some text informations after clicking on specified item, you can do it in the following way:
item2->setIcon(QIcon(QPixmap::fromImage(qimages2)));
item2->setData("informations about item2", Qt::UserRole);
(...)
void MainWindow::ItemClicked (QModelIndex index )
{
QString data = index.data(Qt::UserRole).value<QString>();
ui->textEdit->setText(data);
}
I have a QComboBox in one of the columns of a QTableView. How can I change the other columns depending on what I selected in the ComboBox? I am using the QComboBox as a delegate.
There are at least 2 approaches.
Use natural for Qt's model itemChanged signal.
emit signal from your delegate and catch it inside your main window.
If your delegate is standard which means that inside setModelData() method you have something like:
QComboBox *line = static_cast<QComboBox*>(editor);
QString data = line->currentText();
//...
model->setData(index, data);
then I think you should use just natural way. For example:
connect(model,&QStandardItemModel::itemChanged,[=](QStandardItem * item) {
if(item->column() == NEEDED_COLUMN)
{
//you found, just get data and use it as you want
qDebug() << item->text();
}
});
I used here C++11 (CONFIG += c++11 to .pro file) and new syntax of signals and slots, but of course you can use old syntax if you want.
I already reproduced your code(delegate with combobox) and my solution works if I select something in combobox and confirm that by enter clicking for example. But if you want to get solution where data will be changed automatically, when you select another item in combobox(without pressing enter) then see next case:
Create special signal onside delegate:
signals:
void boxDataChanged(const QString & str);
Create connection inside createEditor() method:
QWidget *ItemDelegate::createEditor(QWidget *parent,
const QStyleOptionViewItem &option,
const QModelIndex &index) const
{
QComboBox *editor = new QComboBox(parent);
connect(editor,SIGNAL(currentIndexChanged(QString)),this,SIGNAL(boxDataChanged(QString)));
return editor;
}
And use it!
ItemDelegate *del = new ItemDelegate;
ui->tableView->setItemDelegate( del);
ui->tableView->setModel(model);
connect(del,&ItemDelegate::boxDataChanged,[=](const QString & str) {
//you found, just get data and use it as you want
qDebug() << str;
});
I have a bunch of QComboBoxes in a table. So that I know which one was triggered I remap the signal to encode the table cell location (as described in Selecting QComboBox in QTableWidget)
(Why Qt doesn't just send the cell activated signal first so you can use the same current row/column mechanism as any other cell edit I don't know.)
But this removes all knowledge of the original sender widget. Calling QComboBox* combo = (QComboBox* )sender() in the slot fails, presumably because sender() is now the QSignalMapper.
I can use the encoded row/column to lookup the QComboBox in the table widget but that seems wrong. Is there a more correct way to do it?
e.g.:
// in table creator
_signalMapper = new QSignalMapper(this);
// for each cell
QComboBox* combo = new QComboBox();
connect(combo, SIGNAL(currentIndexChanged(int)), _signalMapper, SLOT(map()));
_signalMapper->setMapping(combo, row);
// and finally
connect(_signalMapper, SIGNAL(mapped(int)),this, SLOT(changedType(int)));
// slot
void myDlg::changedType(int row)
{
QComboBox* combo = (QComboBox* )sender(); // this doesn't work !!
}
EDIT: Added for future search: there is a new book "Advanced Qt Programming" by Mark Summerfield that explains how to do this sort of thing.
Why not connect the QComboBox's signal straight to your slot?
QComboBox *combo = ...
connect(combo, SIGNAL(currentIndexChanged(int)), this, SLOT(changedType(int)));
And then in your slot you can use the sender() method to retrieve the QComboBox that was changed.
void myDlg::changedType(int row)
{
QComboBox *combo = qobject_cast<QComboBox *> sender();
if(combo != 0){
// rest of code
}
}
Alternatively, to use the QSignalMapper method you would just need to change your slot to use the mapping you set up:
void myDlg::changedType(int row)
{
QComboBox *combo = qobject_cast<QComboBox *>(_signalMapper->mapping(row));
if(combo != 0){
// rest of code
}
}
I don't know exact answer, but maybe you should use: QComboBox* combo = qobject_cast(sender()) instead of QComboBox* combo = (QComboBox* )sender(). Someting like this:
QObject* obj = sender();
QComboBox* combo = qobject_cast<QComboBox*>(obj);
if(combo)
{
doSomethingWithCombo(combo);
}
else
{
// obj is not QComboBox instance
}
But maybe QSignalMapper really substitutes itself instead of real sender...