I have created the Ui screen named HomeScreen.ui in Qt. This screen have no of different widget like QPushButton, QLabel etc. I want change the default navigation, for that I was trying to capture the keyEvents using keyPressedEvent function
void HomeScreen::keyPressEvent(QKeyEvent *event )
{
int keyCode = event->key();
qDebug() << keyCode;
}
but this is captuting event only when the focus is on homescreen, if the focus is on any child widget like push button keyPressEvent is not getting called. I want to capture event on child widgets so that i can write the navigation for them.
Can anybody tell me how to do that?
Related
I'm running a Qt 5.9.4 app with QWebView on a touch linux device displaying HTML webpages.
When users pinch their fingers on the screen, they zoom into the webpage. I want to disable that behaviour, because all the webpages should be 100% fullscreen.
I could temporarily disable it in the webpages (since I own their code) by adding user-scalable=no to the viewport, but that wont work in the long run because not every webpage will have that.
I tried to use eventFilter on different elements of my app, but couldn't get any Gesture or even Mouse event to catch.
This is how I create my webview (in a QDialog):
void Dialog::createWebView() {
view = new QWebEngineView(this);
profile = new QWebEngineProfile();
page = new QWeEnginePage(profile);
view->setPage(page);
view->setUrl(QUrl(path));
}
This is my eventFilter class:
EvFilter::EvFilter(QObject *parent) : QObject(parent)
{
}
bool EvFilter::eventFilter(QObject *obj, QEvent *event)
{
qDebug() << event->type() << "\n";
return QObject::eventFilter(obj, event);
}
I have tried doing
EvFilter* evf = new EvFilter();
view->installEventFilter(evf);
And also on every other element (profile, page, dialog) but couldn't seem to get any events corresponding to mouse or gesture.
What am I doing wrong? How could I prevent that behaviour in the entire webview?
After adding the event listener to the QApplication object, I can detect TouchBegin, TouchUpdate, TouchCancel and TouchEnd events, but nothing else (no Gesture event). I dont know how could I detect if the touchevent is the zoom gesture.
I think you could use this on the Dialog (didn't test it). I had some other widget showing a QML QtWebView and what I did to prevent the widget's children to get Pinch Gestures is:
this->grabGesture(Qt::PinchGesture, Qt::DontStartGestureOnChildren);
This prevents the underlying widget from receiving the PinchGesture, so that you can handle it yourself.
I want hide a QWidget when mouse clicks out of that widget just like it have a popup flag:
auto widget = new QWidget(this);
widget->setWindowFlag(Qt::Popup); // this widget will hide, when mouse click out of that widget.
For some reason, I can't set these flags and must implement some thing myself which behaves like this.
Or can I get a mouse event out of that widget?
Solution:
As I said, I can't use Qt flags and have to implement the similar behavior myself.My solution is installEventFilter to QApplication, in the override method eventFilter,I filter the QMouseEvent and send a signal.
Yes, you can get a mouse event out of the widget.
Make a custom widget and reimplement mousePressEvent, which will catch the last click (the ouside-the-widget click that hides the "popup"). But be careful to add the call to QWidget::mousePressEvent(event) in the end, otherwise the last click will be lost and your widget will remain onscreen.
CustomWidget::CutomWidget(QWidget *parent) : QWidget(parent)
{
setWindowFlags(Qt::Popup);
}
void CustomWidget::mousePressEvent(QMouseEvent *event)
{
if (!this->underMouse()) {
//if the click is not on the widget, i.e. if it's the click that hides it,
// you caught it, do what you want to do here.
}
QWidget::mousePressEvent(event);
}
Hope it helps.
I want to have a line edit field in a popup menu I've got. I'm basically letting the user pick from one of several common sizes for something, but I want them to be able to enter a custom size as the last entry in the menu.
So I've got something like this (snipped from larger code, new_menu is the menu of interest):
QWidget *widget = new QWidget(new_menu);
QHBoxLayout *layout = new QHBoxLayout;
QLineEdit* le = new QLineEdit;
le->setPlaceholderText("Custom");
le->setFixedWidth(100);
ayout->addWidget(le);
widget->setLayout(layout);
QWidgetAction* wa = new QWidgetAction(new_menu);
wa->setActionGroup(group);
wa->setDefaultWidget(widget);
new_menu->addAction(wa);
connect(le, SIGNAL(returnPressed()), this, SLOT(leslot()));
Which works great, the LineEdit shows up nice and centered in the menu, it's got the placeholder text, I can click it and edit, everything. However, when I hit enter on the textBox, it emits the returnPressed signal and the menu emits a triggered signal with one of the other actions on the list, so at best I'm changing my configuration twice and at worst things break.
Additionally, when I click off the edge of the LineEdit (still in the menu though, but not in the editable area), the menu emits a triggered signal with the QWidgetAction associated with it, which isn't what I want.
So two questions:
1) Can I get the return to work the way I want. It's fine if the menu closes when it's hit, but it can't emit another action too.
2) Can I get it to not emit an action at all when the lineEdit is clicked?
Here's what I ended up doing for anyone that follows. I subclassed QLineEdit thusly:
class EnterLineEdit : public QLineEdit {
Q_OBJECT
public:
void keyPressEvent(QKeyEvent *evt) {
if (evt->key() == Qt::Key_Enter || evt->key() == Qt::Key_Return) {
emit returnPressed();
} else {
QLineEdit::keyPressEvent(evt);
}
}
};
This lets me manually emit the returnPressed signal when enter/return is hit and not pass it up the widget hierarchy, so the menu never sees it when enter is hit over the lineedit. I connected the returnPressed signal to the hide() slot of the menu so that the menu will still close, but without triggering an action.
I looked around and it seems that the problem is present not only for tree widget but also for other widgets. But in my case, I found a solution, although an incomplete one. I am adding actions to my tree widget, so that when you right click on it, a popup with these actions appears. However, when I add items to my tree widget and I right click on them, the same popup appears.
What I would like to do is that when you right click on the tree widget, a tree widget popup menu appears and when you right click on items, another corresponding popup menu appears. Does anybody knows how to do this?
First,config QTreeWidget to response(emit signal) right mouse click:
treeWidget->setContextMenuPolicy(Qt::CustomContextMenu);
Second,connect the signal with your slot "MainWindow::prepareMenu":
connect(treeWidget,&QTreeWidget::customContextMenuRequested,this,&MainWindow::prepareMenu);
Third,create context menu in the slot:
void MainWindow::prepareMenu( const QPoint & pos )
{
QTreeWidget *tree = treeWid;
QTreeWidgetItem *nd = tree->itemAt( pos );
qDebug()<<pos<<nd->text(0);
QAction *newAct = new QAction(QIcon(":/Resource/warning32.ico"), tr("&New"), this);
newAct->setStatusTip(tr("new sth"));
connect(newAct, SIGNAL(triggered()), this, SLOT(newDev()));
QMenu menu(this);
menu.addAction(newAct);
QPoint pt(pos);
menu.exec( tree->mapToGlobal(pos) );
}
First you should set the context menu policy to CustomContextMenu:
treeView->setContextMenuPolicy(Qt::CustomContextMenu);
Then you can connect to the QWidget::customContextMenuRequested(const QPoint&) signal and show your context menu.
For those who prefer to use designer more, here is another way to do it:
1) Set context menu policy to custom context menu
Either by code:
ui->treeWidget->setContextMenuPolicy(Qt::CustomContextMenu);
or using graphical designer, click on the tree widget and set it using Property Editor:
2) Create Handler function
In designer, right click on the treeWidget and select "Go to Slot..." option. A window similar to this will appear:
Click on the "CustomContextMenuRequested(QPoint)" option. Handler function will be defined, declared, and it will be connected automatically.
void MainWindow::on_treeWidget_customContextMenuRequested(const QPoint &pos)
{
// this function will be called on right click
}
This step can also be done by defining and connecting the slot function yourself.
3) Create the options on the context menu.
Go to action editor tab (Usually docked at the bottom of designer). Add actions you want to have on context menu by clicking new button on top left. You will encounter such an interface :
You can (optionally) have a tooltip or icon for the action, or make it checkable. You can crate a shortcut like Ctrl+C for a copy action.
4) Create the menu and fire it
void MainWindow::on_treeWidget_customContextMenuRequested(const QPoint &pos)
{
QMenu menu(this); // add menu items
menu.addAction(ui->actionDelete);
menu.addEdit(ui->actionDelete);
...
ui->actionDelete->setData(QVariant(pos)); // if you will need the position data save it to the action
menu.exec( ui->treeWidget->mapToGlobal(pos) );
}
5) Create handler functions for each action
Like in step 2, either create slot function and connect it manually, or right-click on on an action, click the "Go to slots..." option and select triggered() slot.
6) Lastly, apply your logic in the slot function
void MainWindow::on_actionEdit_triggered()
{
QTreeWidgetItem *clickedItem = ui->treeWidget->itemAt(ui->actionDelete->data().toPoint());
// your logic
}
Take a look at overloading QAbstractItemModel and providing your own OnContextMenuRequested. Via this function you can have different items create different context menus.
Here's some shortened pseudo-ish code from one of my projects that may be helpful:
void MyModel::OnContextMenuRequested(const QModelIndex& index, const QPoint& globalPos)
{
// find 'node' corresponding to 'index'
vector<pair<string,BaseNode*> > actions = node->GetActions(true);
if(actions.size()==0) return;
// the ptr list helps us delete the actions
boost::ptr_list<QObject> actionPtrList;
QList<QAction*> qtActions;
for(unsigned int i=0;i<actions.size();i++)
{
QAction* act = new QAction(actions[i].first.c_str(),NULL);
act->setData(qVariantFromValue(actions[i].second));
actionPtrList.push_back(act);
qtActions.append(act);
}
// create and show the context menu
QMenu *menu = new QMenu("Item actions",NULL);
actionPtrList.push_back(menu);
QAction* act = menu->exec(qtActions,globalPos);
if(act==NULL) return;
// act on the resulting action 'act'
}
This is sort of a chicken and egg problem. I'd like my widget window to be closed when the mouse clicks outside. As I understand it, there will be no mouse events for my widget for a click occurring outside of it. There is a SetFocus slot, but where is its counterpart or focus loss? "focusOutEvent" doesn't get called for my class.
My widget window is a child window of a widget always shown on my main window and it's a "Qt::ToolTip", so I assume some problems could arise from that fact. Any way around that?
My Goal: I have a custom toolbar widget where buttons on it may have “drop down” widgets. These drop down widgets have no standard windows frame. I don’t want them to “steal” caption focus from the main window and I want them to disappear as soon as the user clicks ANYWHERE on the screen outside of their region. I have having serious difficulties finding a strategy that’s not compromise on Qt to get this done.
Am I missing something? (bet I am).
I used:
setWindowFlags(Qt::FramelessWindowHint | Qt::Popup);
This seems to work well on OSX and Windows. My window appears correctly, does not steal the focus from my main window's caption, and the focus loss event is called correctly as soon as I click outside of it.
If your widget could have focus, and 'steal' the caption focus of some of your other widgets, it would have been easier. Something like this could work:
class ToolBarWidget : public QWidget
{
Q_OBJECT
public:
explicit ToolBarWidget(QWidget * parent = 0)
{
setFocusPolicy(Qt::ClickFocus);
}
protected:
void focusOutEvent(QFocusEvent * event)
{
close();
}
}
And when you create any of your widgets you'd do:
ToolBarWidget * pWidget = new ToolBarWidget(this);
pWidget->show();
pWidget->setFocus();
Done! Well, I guess not quiet. first, you don't want the ToolBarWidget to get any focus in the first place. And second, you want for the user to be able to click anywhere and the ToolBarWidget to be hidden.
So, you may keep track of every ToolBarWidget that you create. For example, in a 'QList ttWidgets' member variable. Then, whenever you create a new ToolBarWidget, you'd do this:
ToolBarWidget * pWidget = new ToolBarWidget(this);
pWidget->installEventFilter(this);
pWidget->show();
and in your main widget class, implement the eventFilter() function. Something like:
bool MainWidget::eventFilter(QObject *obj, QEvent *event)
{
if (event->type() == QEvent::FocusOut ||
event->type() == QEvent::KeyPress ||
event->type() == QEvent::MouseButtonPress)
{
while (!ttWidgets.isEmpty()) {
ToolBarWidget * p = ttWidgets->takeFirst();
p->close();
p->deleteLater();
}
}
return MainWidget::eventFilter(obj, event);
}
And that will work. Because this way, even though your ToolTabWidgets aren't getting focus, some other widget in your main widget has focus. And once that changes (whether the user clicked out of your window, or on another control inside it, or in this case, a key or mouse button is pressed, the control will reach that eventFilter() function and close all your tab widgets.
BTW, in order to capture the MouseButtonPress, KeyPress etc. from the other widgets, you would either need to installEventFilter on them too, or just reimplement the QWidget::event(QEvent * event) function in your main widget, and look for those events there.
you can do this by using QDesktopWidget.h like this
void MainWindow::on_actionAbout_triggered()
{
AboutDialog aboutDialog;
//Set location of player in center of display
aboutDialog.move(QApplication::desktop()->screen()->rect().center() -aboutDialog.rect().center());
// Adding popup flags so that dialog closes when it losses focus
aboutDialog.setWindowFlags(Qt::Popup);
//finally opening dialog
aboutDialog.exec();
}
This is what worked for me in order to not steel the focus from the main application:
.h
bool eventFilter(QObject *obj, QEvent *event) override;
.cpp
bool Notification::eventFilter(QObject *obj, QEvent *event)
{
if(event->type() == QEvent::MouseButtonPress)
deleteLater();
return QObject::eventFilter(obj, event);
}
...
// somewhere else (i.e. constructor, main window,...)
qApp->installEventFilter(this);
OP's own answer is great for Qt versions below 4.8, but as they mention in their answer, it does not work for versions above that. The Qt::Popup widget will not disappear when the mouse is clicked outside of the widget, and it will sink all of the input that would normally close it.
Upon further investigation, this is only an issue for non-dialog widgets. A QDialog using Qt::Popup will properly close when the user clicks outside of it, but any other QWidget, like a QFrame, will not. So in order to work around this behavior change in Qt 4.8, all that is necessary is to wrap the widget in a QDialog.