I have just installed Ubuntu 19.04 and I'm using the Qt distribution it provides in the apt-get repo. I'm seeing that the QSytemTrayIcon signals do not emit upon mouse click. I'm aware of the issues with "activated" signal so I also connected a slot to listen to the "aboutToShow" signal from the QSystemTrayIcon's context menu which also should emit on mouse click. Neither of these signals are going out.
Here's my code for the QSystemTrayIcon:
// Create tray and setup tray icon
void MyClass::createTrayIcon()
{
m_pTrayIconMenu = new QMenu(this);
m_pTrayImage = new QPixmap(IMG_SMALL_NOT_CONNECTED);
m_pTrayIcon = new QSystemTrayIcon(this);
m_pTrayIcon->setContextMenu(m_pTrayIconMenu);
QIcon icon(*m_pTrayImage);
m_pTrayIcon->setIcon(icon);
setWindowIcon(icon);
m_pTrayIcon->show();
connect(m_pTrayIconMenu, SIGNAL(aboutToShow()),
this, SLOT(onActivated()));
connect(m_pTrayIcon, SIGNAL(activated(QSystemTrayIcon::ActivationReason)),
this, SLOT(onActivated(QSystemTrayIcon::ActivationReason)));
}
// Slot to handle context menu aboutToShow signal
void MyClass::onActivated()
{
if (!this->isVisible())
{
this->show();
}
else
{
this->hide();
}
}
// Slot to handle tray icon activated signal
void MyClass::onActivated(QSystemTrayIcon::ActivationReason r)
{
if (r == QSystemTrayIcon::Trigger)
{
if (!this->isVisible())
{
this->show();
}
else
{
this->hide();
}
}
}
In Ubuntu 18.04, the signals all emitted and everything was working fine. In Ubuntu 19.04 the signals do not emit.
Related
I'm working on a way of creating QWidgets that respond to touch, running as a plugin to a proprietary Qt 5.2 application. The application provides touch and gesture events (QTouchEvent, QGestureEvent), but no mouse events.
I have no control over the application itself, apart from what can be done at runtime, and I'm trying to be as minimally invasive as I can.
EDIT: To clarify the above paragraph, my code is being loaded automatically by Qt as a 'fake' image plugin. The host application appears to not have set Qt::AA_SynthesizeMouseForUnhandledTouchEvents, and when I tried to do it... things did not go well. The application has it's own set of touch and gesture handlers and Widgets it uses.
One option is to subclass each QWidget type and add custom event handling for touch events. I would rather not do this, however, as it would be tedious, and I don't really need advanced touch/gesture functionality for the most part.
Another option, which I've been trialing is to install an eventFilter on the widgets, which creates mouse events from the touch events, and sends the mouse event to the widget instead. This is working quite well for many simpler widgets, and even complex widgets like QFileDialog mostly work.
My problem comes with certain widget types (I've come across two so far), which either partially work, or don't work at all, and I'm not sure where I'm going wrong.
An example of a partially working widget with the eventFilter technique is the QComboBox. The combo box itself responds to the touch, and opens the dropdown list. However, the dropdown list itself just doesn't seem to work with the touch.
QDialogButtonBox is the most recent widget I've discovered that doesn't work. The eventFilter seems to trigger on the QDialogButtonBox itself, but not the button(s) for some reason.
Here are the relevant bits of the current (very) WIP experimental code:
From NDBWidgets.h
void setTouchFilter(QWidget *w);
class TouchFilter : public QObject
{
Q_OBJECT
public:
TouchFilter(QWidget* parent = nullptr);
protected:
bool eventFilter(QObject *obj, QEvent *event) override;
};
And from NDBWidgets.cc
static void installTouchFilter(QWidget *w)
{
if (!w->property(touchFilterSet).isValid()) {
w->setProperty(touchFilterSet, QVariant(true));
w->setAttribute(Qt::WA_AcceptTouchEvents);
auto ef = new TouchFilter(w);
w->installEventFilter(ef);
}
}
void setTouchFilter(QWidget *w)
{
if (!w) {
return;
}
auto children = w->children();
nh_log("installing eventFilter on the following children:");
for (int i = 0; i < children.size(); ++i) {
if (auto wi = qobject_cast<QWidget*>(children.at(i))) {
nh_log(" Class: %s Name: %s", children.at(i)->metaObject()->className(), children.at(i)->objectName().toUtf8().constData());
installTouchFilter(wi);
// if (auto cb = qobject_cast<QComboBox*>(wi)) {
// setTouchFilter(cb->view());
// }
}
}
installTouchFilter(w);
}
TouchFilter::TouchFilter(QWidget *parent) : QObject(parent) {}
bool TouchFilter::eventFilter(QObject *obj, QEvent *event)
{
// Only care about widgets...
auto widget = qobject_cast<QWidget*>(obj);
if (!widget) {
return false;
}
auto type = event->type();
if (type == QEvent::TouchBegin || type == QEvent::TouchUpdate || type == QEvent::TouchEnd) {
event->accept();
auto tp = static_cast<QTouchEvent*>(event)->touchPoints().at(0);
nh_log("eventFilter triggered for class: %s name: %s", widget->metaObject()->className(), widget->objectName().toUtf8().constData());
if (type == QEvent::TouchBegin) {
nh_log("event TouchBegin captured");
QMouseEvent md(QEvent::MouseButtonPress, tp.pos(), tp.screenPos(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
QCoreApplication::sendEvent(widget, &md);
} else if (type == QEvent::TouchUpdate) {
nh_log("event TouchUpdate captured");
QMouseEvent mm(QEvent::MouseMove, tp.pos(), tp.screenPos(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
QCoreApplication::sendEvent(widget, &mm);
} else if (type == QEvent::TouchEnd) {
nh_log("event TouchEnd captured");
QMouseEvent mu(QEvent::MouseButtonRelease, tp.pos(), tp.screenPos(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
QCoreApplication::sendEvent(widget, &mu);
}
return true;
}
return false;
}
An example usage:
void NDBDbus::dlgComboBox() {
NDB_DBUS_USB_ASSERT((void) 0);
auto d = new QDialog();
d->setAttribute(Qt::WA_DeleteOnClose);
auto vl = new QVBoxLayout();
auto cb = new QComboBox(d);
cb->addItem("Item 1", QVariant(1));
cb->addItem("Item 2", QVariant(2));
vl->addWidget(cb);
auto bb = new QDialogButtonBox(QDialogButtonBox::Close, d);
connect(bb, &QDialogButtonBox::rejected, d, &QDialog::reject);
vl->addWidget(bb);
d->setLayout(vl);
setTouchFilter(d);
d->open();
}
I'm still very new to Qt event handling, and eventFilters, and I've gotten to the point where I'm rather stumped, so if anyone has any suggestions or ideas, I would very much appreciate them!
So, TLDR, and the final question: Is it possible to transform touch events to mouse events inside an eventFilter for widgets such as QComboBox or QDialogButtonBox? And if so, how?
I have been trying to hide a stand alone dialog application when the user hits the typical close button (The one with the X in the corner usually next to the minimize button) I cam across this post:
Qt: How do I handle the event of the user pressing the 'X' (close) button?
which I thought would have my solution, but I get strange behavior when I implement it.
void MyDialog::reject()
{
this->hide()
}
When I hit the X Button the whole application closes (the process disappears) which is not what I want. Since my gui spawns with a command line, I setup a test system where I can tell my dialog to hide via a text command where I call the same 'this->hide()' instruction, and everything works fine. The dialog hides and then shows back up when I tell it to show.
Any ideas why the reject method is closing my app completely even when I don't explicitly tell it to?
Override the virtual function "virtual void closeEvent(QCloseEvent * e)" in your dialog class. The code comment will explain in detail.
Dialog::Dialog(QWidget *parent) :QDialog(parent), ui(new Ui::Dialog){
ui->setupUi(this);
}
Dialog::~Dialog(){
delete ui;
}
//SLOT
void Dialog::fnShow(){
//Show the dialog
this->show();
}
void Dialog::closeEvent(QCloseEvent *e){
QMessageBox::StandardButton resBtn = QMessageBox::question( this, "APP_NAME",
tr("Are you sure?\n"),
QMessageBox::Cancel | QMessageBox::No | QMessageBox::Yes,
QMessageBox::Yes);
if (resBtn != QMessageBox::Yes){
//Hiding the dialog when the close button clicked
this->hide();
//event ignored
e->ignore();
//Testing. To show the dialog again after 2 seconds
QTimer *qtimer = new QTimer(this);
qtimer->singleShot(2000,this,SLOT(fnShow()));
qtimer->deleteLater();
}
//below code is for understanding
//as by default it is e->accept();
else{
//close forever
e->accept();
}
}
The dialog opens with two buttons, OK and Cancel. None of the buttons responds to user click. I have to press the X on the top right to cancel the dialog.
bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
if (obj == mTabWidget && event->type() == QEvent::MouseButtonDblClick)
{
// query and set tab(s) names
QTabWidget *tab = qobject_cast<QTabWidget *>(obj);
if(tab)
{
QDialog dlg;
QVBoxLayout la(&dlg);
QLineEdit ed;
la.addWidget(&ed);
QDialogButtonBox bb(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
la.addWidget(&bb);
dlg.setLayout(&la);
if(dlg.exec() == QDialog::Accepted)
{
tab->setTabText(0, ed.text());
return true;
}
}
}
// Standard event processing
return QObject::eventFilter(obj, event);
}
Am I missing any connect() line or signals? I tried to read the Qt documentation, but from what I understood, calling QDialogButtonBox::OK gets processed as Accepted.
UPDATE :
New Dialog Function
OK, i have created a new function that takes care of the Dialog box, i am calling it from the event function. it is still not responding, now on the terminal, i see an error that says, : no such slot MainWindow::accept() and another for reject. I know that i have no slots for these two in the .h file. i tried to find how to build the slots but i couldnt, any help would be great. thank you
void MainWindow::initializeBOX()
{
QDialog dlg;
QVBoxLayout la(&dlg);
QLineEdit ed;
la.addWidget(&ed);
//QDialogButtonBox bb(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
//btnbox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
connect(buttonBox, SIGNAL(accepted()), this, SLOT(accept()));
connect(buttonBox, SIGNAL(rejected()), this, SLOT(reject()));
la.addWidget(buttonBox);
dlg.setLayout(&la);
if(dlg.exec() == QDialog::Accepted)
{
mTabWidget->setTabText(0, ed.text());
}
}
Rather than launching the dialog from event filer you should trap QWidget::mouseDoubleClickEvent by overloading that virtual function in your code. And as long as it is a callback already you can do more stuff immediately from there including the dialog. Or maybe send the signal to slot that does the dialog (a bit cleaner). I would do the signal from mouseDoubleClickEvent event handler and make the parent QWidget::mouseDoubleClickEvent to consume the event to avoid possible complications especially when porting the code to other platform.
Event filters are for non-standard event processing. There is nothing non-standard in your case.
I have a Qt Application which i want to show in the System Tray.
My desired behavior is that if the user clicks the close button of the Application than that application hides in the system tray but does not exit.
My code in main.cpp is :
if (QSystemTrayIcon::isSystemTrayAvailable())
{
QObject *root = engine.rootObjects().at(0);
QQuickWindow *window = qobject_cast<QQuickWindow *>(root);
QAction *showAction = new QAction(QObject::tr("Show"), window);
window->connect(showAction, SIGNAL(triggered()), window, SLOT(show()));
QAction *hideAction = new QAction(QObject::tr("Hide"), window);
window->connect(hideAction, SIGNAL(triggered()), window, SLOT(hide()));
QAction *quitAction = new QAction(QObject::tr("&Quit"), window);
window->connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
QObject::connect(qApp,SIGNAL(aboutToQuit()),window,SLOT(hide()));
QMenu *trayIconMenu = new QMenu();
trayIconMenu->addAction(showAction);
trayIconMenu->addAction(hideAction);
trayIconMenu->addSeparator();
trayIconMenu->addAction(quitAction);
QSystemTrayIcon *trayIcon = new QSystemTrayIcon(window);
trayIcon->setContextMenu(trayIconMenu);
trayIcon->setToolTip("xxx");
trayIcon->setIcon(QIcon("xxx.png"));
trayIcon->show();
}
Now i am not able to connect the aboutToQuit signal and hide the application in the tray i.e
QObject::connect(qApp,SIGNAL(aboutToQuit()),window,SLOT(hide())); line is not correct but i am not getting any errors etc.
Apart from this everything is working correctly.Can someone please tell me what i am doing wrong and how can i achieve my desired behavior.
I would also like to know whether i have got the right signal to connect or whether i should try connecting to some other signal.
Thanks in advance.
You can use :
qApp()->setQuitOnLastWindowClosed(false);
quitOnLastWindowClosed property is true by default which causes your application to quit when the last window is closed. By setting it to false, your application does not terminate when you close the main window.
You can also reimplement closeEvent of your main widget, ignore the close event and just hide your window :
void MainWindow::closeEvent(QCloseEvent * e)
{
e->ignore();
this->hide();
}
I open QDialog window from QMainWindow. Now when I press the QDialog window
its not always closing in the first press - I need to press few times (3-4) to close it .
I have closeEvent slot that has simple event->accept(); inside it.
This is how I call the QDialog from the main window:
void MyManager::DialogContainerOpen(type t)
{
if(pMyDialogContainer == NULL)
{
pMyDialogContainer = new MyDialogContainer();
}
int returnVal = QDialog::Rejected;
if(!m_bContainer)
{
m_bContainer = true;
int returnVal = pMyDialogContainer->exec();
if(returnVal != QDialog::Accepted ) {
m_bContainer = false;
}
}
}
This is the first problem.
The second problem is how do i set the QDialog windows NOT to be allays on top? (I don’t want it to block the parent window.
UPDATE
well i found out that the function from the MainWindow that showing the contexMenu
and inside it has the connect single/slot is keeps to invoke so i just used the disconnect
i dont know if its the best sulotion but its working.
now i juat have the final problem .
here is the code i hope its ok
void MainWindowContainer::ShowContextMenu(const QPoint& pos) // this is a slot
{
QModelIndex modelIndx;
QPoint globalPos = ui.treeView_mainwindow->mapToGlobal(pos);
bool b1 = connect(OpenAction, SIGNAL(triggered()),m_SignalMapper, SLOT(map()) );
m_SignalMapper->setMapping(OpenAction,voidID);
bool b2 = connect(m_SignalMapper, SIGNAL(mapped(QString)), this, SLOT(OpenWin(QString)));
QAction* selectedItem = ContextMenu.exec(globalPos);
}
void MainWindowContainer::OpenWin(QString gid)
{
//disconnect(sender0, SIGNAL(overflow()),receiver1, SLOT(handleMathError()));
disconnect(m_SignalMapper, SIGNAL(mapped(QString)),this, SLOT(OpenWin(QString)));
disconnect(OpenAction,SIGNAL(triggered()),m_SignalMapper, SLOT(map()));
....
....
}
For your second question, the term you are looking for is modal vs modeless dialogs. The QDialog documentation tells exactly how you create non-modal dialogs:
Modeless dialogs are displayed using show(), which returns control to the caller immediately.
i.e. don't use exec() as that will make a modal dialog (which blocks the parent).
You should not connect the same signal/slot more than once unless you want the action run multiple times. All you need to do is to connect the QAction's signal to the slot once. This is usually done in the constructor (or a dedicated function called from the constructor) where you create the action.