I have a QSqlQueryModel table. The user can see and access this. I want to know which row/rows that the user selects.
I have looked through a lot of other posts and documentations from qt-centre and I think the closest I believe is to somehow use QModelIndex, as shown here:
// for QSqlQueryModel or subclasses:
QSqlQueryModel *qmod = qobject_cast<QSqlQueryModel*>(md);
if(!qmod) return false;
QSqlRecord rec = qmod->record(curr.row()); // you have data inside the "rec" object
taken from http://www.qtcentre.org/archive/index.php/t-3104.html.
However this doesn't work for me. I don't want to use Qtableview as I want to work with only sqlQueryModel.
How do I detect user selections?
Thanks!
QTableView has a selection model. You can use the currentRowChanged signal of that selection model:
YourWidget : public QWidget
{
Q_OBJECT
public:
YourWidget(QWidget *parent = 0);
private slots:
void onRowChanged(QModelIndex index);
}
YourWidget::YourWidget (QWidget *parent) :
QWidget(paret)
{
...
QTableView *view = new QTableView;
view->setModel(yourModel);
connect(view->selectionModel(),
SIGNAL(currentRowChanged(QModelIndex, QModelIndex)),
this,
SLOT(onRowChanged(QModelIndex)));
...
}
void YourWidget::onRowChanged(QModelIndex index)
{
int row = index.row();
QSqlRecord rec = yourModel->record(row);
...
}
Related
I am new to qt and I want to know how to make a dynamic menu.
I did get it to make new submenus but I don't know how I can implement the "triggered() function" of these dynamic made submenus, so that I have access to what happens if I want to click on such a new submenu.
Here what I have so far (with: vector<QString> = vec; and some .ui Window named "New_Window")
in mainwindow.cpp
in some function:
QMenu *menu = this->menuBar()->addMenu("Chat Members");
for (int i = 0; i < vec.size(); ++i){
QString name = vec.at(i);
QAction *act = menu->addAction(name);
New_Window* new_window = new New_Window;
QObject::connect(act,SIGNAL(triggered()),
new_window,SLOT(actionReaction()));
}
here is an example of how a signal slot with a dynamic interface works ,
class A is created after starting the program, then the user clicks on a button from class A, for example, a class A is created many times and we need to determine from what object we get a signal to press the button, so
class A : public QMainWindow
{
Q_OBJECT
public:
A(QWidget *parent = nullptr);
~A();
void setID(const int id);
void getId() const;
signals:
void onButtonPress(int ID);
private:
int mID;
};
here we create a new class A and store it in the vector in such a way,
QVector<A*> mCreatingClassA;
void createNewClassA
{
QVector<A*> mCreatingClassA;
....
A* a = new A();
int id = // create your unique ID
a->setId(id);
connect(a,SIGNAL(onButtonPress(int)),this,SLOT(onyourSlot(int)));
mCreatingClassA.push_back(a);
....
}
detect the object from which the signal was received)
void onyourSlot(int ID)
{
for (int i = 0; i < mCreatingClassA.size(); ++i) {
if(mCreatingClassA[i]->getId()==ID)
{
mCreatingClassA[i] // received a signal from this object
}
}
}
I am trying to use QTest to test UI interactions with a QListWidget.
Interactions made from a simple click work fine (QTest::mouseClick()) but interactions from a double click do not (QTest::mouseDClick()).
Here is simplified code sample to reproduce the issue :
Dialog.h
class UILIBSHARED_EXPORT Dialog : public QDialog
{
Q_OBJECT
public:
explicit Dialog(QWidget *parent = 0);
~Dialog();
int doubleClickCount = 0;
QString lastItemClicked = "";
QListWidget* GetListW();
private slots:
void on_listWidget_doubleClicked(const QModelIndex &index);
public:
Ui::Dialog *ui;
};
Dialog.cpp
QListWidget*Dialog::GetListW()
{
return ui->listWidget;
}
void Dialog::on_listWidget_doubleClicked(const QModelIndex &index)
{
lastItemClicked = ui->listWidget->item(index.row())->text();
++doubleClickCount;
}
And the test class :
class DoubleClickTest : public QObject
{
Q_OBJECT
public:
DoubleClickTest();
private Q_SLOTS:
void testDoubleClick();
};
void DoubleClickTest::testDoubleClick()
{
Dialog dialog;
dialog.show();
QListWidgetItem* item = dialog.GetListW()->item(1);
QRect rect = dialog.GetListW()->visualItemRect(item);
QTest::mouseDClick(dialog.GetListW()->viewport(), Qt::LeftButton, Qt::KeyboardModifiers(), rect.center());
QCOMPARE(dialog.doubleClickCount, 1);
}
I checked the dialog manually and the slot is called as expected.
I know this is an old topic but I have encountered the same behaviour with a QTreeView and have passed some hours to find a workaround, so I think it can be useful for someone else.
Using QTest, the signal doubleClicked is never emitted due to a part of code in sources of Qt I do not understand (qtreeview.cpp, line 1934 with Qt 5.12.1, or for others, in qabstractitemview.cpp line 1952). I don't know if it is a bug or not.
To avoid this strange code, I just added a call to QTest::mouseClick before the call to QTest::mouseDClick with the same parameters.
It worked for me because my QTreeView do nothing particular on a simple click, but it can distort tests in another case.
If anyone has a better solution I take it !
I have a bunch of QTreeWidgetItems that have embedded widgets in them that i set using the setItemWidget() function in the QTreeWidgetItem class.
Problem is anytime I move QTreeWidgetItem using drag/drop or any other means the embedded widget I set before disappears. I've seen around various forums that others have had this same problem (see link below)
http://www.qtcentre.org/threads/40500-QTreeWidget-setItemWidget%28%29-item-disappears-after-moving-item
Any possible solutions?
The problem is caused by QTreeWidget's implementation. When items are moved within the model, it deletes items at old positions and recreates them at new positions. We need to ensure 3 thinngs:
Rescue embedded widget from being deleted when its item is deleted.
Attach some information to items so we can track them and choose which widget belongs to an item.
Re-insert widget after item is moved.
Here is proof-of-concept implementation. Tree_widget_keeper_wrapper ensures 1st objective, setItemWidget's reimplementation ensures the 2nd one, and rows_inserted slot ensures the 3rd one. I tested that it works but it should be improved before using in real projects. Qt::UserRole should be changed to a configurable role. We should use role that is not used by the model itself. I put all implementation to class declaration to make it more readable but you should separate them in real code.
class Tree_widget_keeper_wrapper : public QWidget {
Q_OBJECT
public:
Tree_widget_keeper_wrapper(QWidget* child) {
_child = child;
QVBoxLayout* layout1 = new QVBoxLayout(this);
layout1->setContentsMargins(0, 0, 0, 0);
layout1->addWidget(_child);
}
~Tree_widget_keeper_wrapper() {
if (_child->parent() == this) {
_child->hide();
_child->setParent(0);
}
}
private:
QWidget* _child;
};
class Fixed_tree_widget : public QTreeWidget {
Q_OBJECT
public:
Fixed_tree_widget(QWidget* parent) : QTreeWidget(parent) {
connect(model(), SIGNAL(rowsInserted(QModelIndex,int,int)),
this, SLOT(rows_inserted(QModelIndex,int,int)));
}
void setItemWidget(QTreeWidgetItem* item, int column, QWidget* widget) {
QTreeWidget::setItemWidget(item, column, new Tree_widget_keeper_wrapper(widget));
item->setData(column, Qt::UserRole, all_widgets.count());
all_widgets << widget;
}
private:
QWidgetList all_widgets;
private slots:
void rows_inserted(QModelIndex parent, int start, int end) {
for(int column = 0; column < model()->columnCount(parent); column++) {
for(int row = start; row <= end; row++) {
QModelIndex index = model()->index(row, column, parent);
QVariant data = model()->data(index, Qt::UserRole);
if (data.type() == QVariant::Int) {
int i = data.toInt();
QTreeWidgetItem* item = itemFromIndex(index);
if (item && i >= 0 && i < all_widgets.count()) {
setItemWidget(item, column, all_widgets[i]);
all_widgets[i]->show();
}
}
}
}
}
};
I tested it against InternalMove mode and dragging items with mouse. Maybe in some other cases you will need to listen to other model's signals.
I have a QTableView to display a bunch of data, which is stored in a QAbstractTableModel. I also want to edit the data sometime, so I use a QStyledItemDelegate to create an editor (of QTextEdit type) when I double click on the cell. However, I want to handle the key Press event myself, but I never catch Key_Escape pressing in the Text Edit editor (Other keys such as Enter and Ascii can be captured). I checked the code, and found that Escape is directly connected to QTableView's closeEditor() function, which is a virtual method and is automatically invoked. As far as I know, key press event is the bottom layer of event handling, but it is not true with such case.
I do need to capture the Escape key press event so that I can handle it myself, can anyone tell me how to do this? Thanks!
I got the answer, and I think would help others:
Override QStyledItemDelegate::eventFilter() method:
MyItemDelegate::eventFilter(QObject* editor, QEvent* event)
{
if(event->type()==QEvent::KeyPress)
return false;
return QStyledItemDelegate::eventFilter(editor, event);
}
According to Qt's documentation, QStyledItemDelegate::eventFilter() returns true if the given editor is a valid QWidget and the given event is handled; otherwise returns false. Tab, Backtab, Enter, Return and Ecs are handled by default. So, if you want to handle the key press event yourself, you must let eventFilter return false when KeyPress event occurs. So that the editor's keyPressEvent() method will be invoked instead.
QStyledItemDelegate::eventFilter is not a possibility beacuse is virtual protected
In order to get the events you should subclass your own QEditLine and override ::keyPressEvent there. Take notice of the code. I pass actual row and colum of my QTableWidget cell in order to know what we are editing in the overrided QLineEditor.
//.h
class MyStyledItemDelegate : public QStyledItemDelegate
{
public:
MyStyledItemDelegate(QObject *parent = 0);
QWidget* createEditor(QWidget* parent,const QStyleOptionViewItem &option,const QModelIndex &index) const;
};
//.cpp
#include "mylineedit.h"
MyStyledItemDelegate::MyStyledItemDelegate(QObject *parent)
:QStyledItemDelegate(parent)
{
}
QWidget* MyStyledItemDelegate::createEditor(QWidget* parent,const QStyleOptionViewItem &option,const QModelIndex &index) const
{
MyLineEdit* editor = new MyLineEdit(parent,index.row(),index.column());
return editor;
}
/////////////////////////////////////////////////////////////
//My own QLineEdit
/////////////////////////////////////////////////////////////
//.h
class MyLineEdit : public QLineEdit
{
Q_OBJECT
public:
int _nRow;
int _nCol;
public:
MyLineEdit(QWidget *parent = 0,int nRow=-1, int nCol=-1);
virtual void keyPressEvent(QKeyEvent* event);
signals:
void mySignal(const QVector<QVariant> &);
public slots:
};
//.cpp
MyLineEdit::MyLineEdit(QWidget *parent, int nRow,int nCol):
QLineEdit(parent)
{
_nRow=nRow;
_nCol=nCol;
}
/////////////////////////////////////////////////////////////////////////
void MyLineEdit::keyPressEvent(QKeyEvent* event)
{
qDebug() << "MyLineEdit::OnKeyPressEvent:"<<event->text()<< " row="<<_nRow<<" col=" <<_nCol;
///SET YOUR CODE HERE
QLineEdit::keyPressEvent(event);
}
I am developing an application that updates the data in QTableView from apache server once per second. The server sends data as XML table. Number of columns is constant, but the number of rows changes each time. The data in the rows may also vary.
To convert the XML into the data, I created a class TxTableData, which is used in TxTableModel (child of QAbstractTableModel). Also TxTableModel uses QTimer to update data from the server.
The problem is that if the number of lines decreases - QTableview did not react to it. When the number of rows increases - it's all right.
I need remove all rows from QTableView and fill it with new data, but QTableView does not do this. Can you
class TxTableModel : public QAbstractTableModel
{
Q_OBJECT
public:
TxTableModel(QObject *parent = 0);
void refreshData();
void parseXml(const QByteArray &xml);
public slots:
void httpDone(bool error);
void timerDone();
protected:
HttpConnect http;
TxTableData m_Data;
QTimer * timer;
};
TxTableModel::TxTableModel(QObject *parent) :
QAbstractTableModel(parent)
{
timer = new QTimer(this);
connect(&http, SIGNAL(done(bool)), this, SLOT(httpDone(bool)));
connect(timer, SIGNAL(timeout()), this, SLOT(timerDone()));
timer->start(1000);
}
void TxTableModel::refreshData()
{
TxRequest request;
request.setObject("order");
request.setMethod("getlist");
request.addParam("begin_time", 60*60*4);
request.addParam("end_time", 60*4);
http.queryAsync(request);
}
void TxTableModel::parseXml(const QByteArray &xml)
{
//qDebug() << xml;
int count = m_Data.getRowCount();
QXmlInputSource inputSource;
QXmlSimpleReader reader;
TxSaxTableHandler handler(&m_Data, false);
inputSource.setData(xml);
reader.setContentHandler(&handler);
reader.setErrorHandler(&handler);
beginResetModel();
reader.parse(inputSource);
endResetModel();
}
void TxTableModel::httpDone(bool error)
{
if (error) {
qDebug() << http.errorString();
} else {
parseXml(http.readAll());
}
}
void TxTableModel::timerDone()
{
refreshData();
}
It looks like you're not providing the full source of TxTableModel model, as it's missing implementation of rowCount, columnCount, data, setData, etc methods.
As for the problem, my guess would be:
As it was already suggested you can try cleaning the model before reloading it by calling removeRows(0, rowCount());
in your removeRows implementation, you should call beginRemoveRows before updating the rows collection and endRemoveRows after you're done. This should notify views about the model content change.
There is an example on how to implement the QAbstractTableModel here: Address Book Example
hope this helps, regards