I need to have several shortcuts for one push button. For example Ctrl+W and Enter and Return (Enter and Return are different in Qt), any of them would cause a click on the button. How to do this? If the button was QAction, I would call setShortcuts() ( See Two shortcuts for one action which is NOT a duplicate. It is different, relates to QAction not QPushButton. ) but QPushButton has only setShortcut() (singular), which seems to not allow this. What solution or hack wold you suggest?
OK, I have got a solution which is not that hacky. I can create a QPushButton and a QAction, then set multiple shortcuts for QAction using QAction::setShortcuts() and connect this action to QPushButton::animateClick(). At first this solution did not work because I called connect(action, &QAction::triggered, button, &QPushButton::animateClick);. The problem was with invisible default arguments. QAction::triggered sends true/false indicating whether the action is checked. But QPushButton::animatedClick expects number of milliseconds to remain visually 'pressed'. Therefore it remained 'pressed' only for 0 or 1 millisecond, which is not enough to notice it (the default value of the argument is 100 milliseconds). This can be solved using lambda, hence:
// 'this' refers to a parent widget
auto action = new QAction(this);
action->setShortcuts({ tr("Ctrl+W"), tr("Return"), tr("Enter") });
this->addAction(action);
auto button = new QPushButton(tr("Hey, click me!"));
connect(action, &QAction::triggered, [button](){ button->animateClick(); });
And that's it.
Related
I'm creating my first C++ wxWidgets application. I'm trying to create some kind of split button where the options are displayed in a grid. I have a custom button class which, when right-clicked on, opens a custom wxPopupTransientWindow that contains other buttons.
When I click on the buttons in the popup, I want to simulate a left click on the main button. I'm trying to achieve this through events, but I'm kinda confused.
void expandButton::mouseReleased(wxMouseEvent& evt)
{
if (pressed) {
pressed = false;
paintNow();
wxWindow* mBtn = this->GetGrandParent();
mBtn->SetLabel(this->GetLabel());
mBtn->Refresh();
wxCommandEvent event(wxEVT_BUTTON);
event.SetId(GetId());
event.SetEventObject(mBtn);
mBtn-> //make it process the event somehow?
wxPopupTransientWindow* popup = wxDynamicCast(this->GetParent(), wxPopupTransientWindow);
popup->Dismiss();
}
}
What is the best way to do this?
You should do mBtn->ProcessWindowEvent() which is a shorter synonym for mBtn->GetEventHandler()->ProcessEvent() already mentioned in the comments.
Note that, generally speaking, you're not supposed to create wxEVT_BUTTON events from your own code. In this particular case and with current (and all past) version(s) of wxWidgets it will work, but a cleaner, and guaranteed to also work with the future versions, solution would be define your own custom event and generate it instead.
I'm using QT Creator to create a simple Application that has two textEdit fields next to each oteher. I want both fields to be linked when it comes to scrolling so that when one field scrolls up or down, the other one will as well automatically and vice versa. For this, I need a callback function that is triggered whenever the user moves the slideBar of one of the fields. Unfortunately, when I right click the textEdit fields and press "Go to slots" I can not find an event for the movement of the slideBar.
How can I achieve this?
QTextEdit does not have a signal for when the sliderbar in it changes, since it is not a scrollbar. However QScrollBar has the sliderMoved(int value) signal which is emitted when the slider moves. QScrollBar also has a way to set its scroll value via slots (with setValue(int value))
We can therefore tie two scrollbars together using signals and slots very easily.
For example:
...
// Get easy pointers to the scrollbars
QScrollBar* textbx_slider_1 = ui->textbx1->verticalScrollBar();
QScrollBar* textbx_slider_2 = ui->textbx2->verticalScrollBar();
// Connect them too each other
connect(textbx_slider_1, &QScrollBar::sliderMoved, textbx_slider_2, &QScrollBar::setValue); // Connect the first scrollbar to the second
connect(textbx_slider_2, &QScrollBar::sliderMoved, textbx_slider_1, &QScrollBar::setValue); // Connect the second scrollbar to the first
...
(This assumes that your QTextEdit widgets have ids' of textbx1 and textbx2)
Edit:
It is worth mentioning that sliderMoved will not be emitted when using the scroll wheel on the text box. To detect those inputs you must use something like QScrollBar::valueChanged. You have to be careful with this however since setValue emits valueChanged, meaning you will get an infinite feedback loop if you simply modify the above code.
To prevent this you could use a lambda, something like this:
...
int old_pos = textbx_slider_1->value()
std::function<void(int, QScrollBar*)> f = [old_pos](int new_pos, QScrollBar* slider){
if (new_pos != old_pos) {
// Only trigger if the value has changed
slider->setValue(new_pos);
old_pos = new_pos;
};
connect(textbx_slider_1, &QScrollBar::sliderMoved, std::bind(f, std::placeholders::_1, textbx_slider_2)); // Connect the first scrollbar to the second
connect(textbx_slider_2, &QScrollBar::sliderMoved, std::bind(f, std::placeholders::_1, textbx_slider_1)); // Connect the second scrollbar to the first
...
(The weirdness with std::bind() is simply so we don't repeat virtually the same lambda twice)
Currently, I am working on an editor program. I want to assign three shortcut keys (QKeySequence::Cut), (QKeySequence::Copy) and (QKeySequence::Paste) to my customized functions. However, it does not work as my expectation.
For testing, I open the "Application Example" from QtCreator. Then, I try to disable all the shortcut keys as following:
//cutAct->setShortcuts(QKeySequence::Cut);
connect(cutAct, SIGNAL(triggered()), textEdit, SLOT(cut()));
copyAct = new QAction(QIcon(":/images/copy.png"), tr("&Copy"), this);
//copyAct->setShortcuts(QKeySequence::Copy);
connect(copyAct, SIGNAL(triggered()), textEdit, SLOT(copy()));
pasteAct = new QAction(QIcon(":/images/paste.png"), tr("&Paste"), this);
//pasteAct->setShortcuts(QKeySequence::Paste);
Surprisingly, the shortcut keys still working as before.
Another test is that:
connect all the actions to customized slots.
assign all the key sequences to the actions which have already connected to my customized slots.
Then, my result is
Click Cut, Copy, Paste on toolbar go to my customized slots.
The shortcut key works independently with my customized slots.
Any advice are welcome.
Thank you very much.
I have found the way to override the default shortcut, thanks to the code of Sigil.
I use the following code:
Delacre a new action in header:
QShortcut &m_Paste1;
Then, in the constructor of class:
m_Paste1(*(new QShortcut(QKeySequence(QKeySequence::Paste), this, 0, 0, Qt::WidgetShortcut))),
Finally, connect it to your own slot
connect(&m_Paste1, SIGNAL(activated()), this, SLOT(paste()));
I am populating a sytem tray icon menu (QMenu) from entries in an xml file which is read when my application starts up.
I am unsure of how to properly set up the SLOT end of the action:
QList<CMenuItem> menuItems = m_layout->getMenuItems();
QListIterator<CMenuItem> iter(menuItems);
while (iter.hasNext())
{
CMenuItem menuItem = iter.next();
QAction *action = new QAction(menuItem.qsTitle, this);
connect(action, SIGNAL(triggered()), this, SLOT(launchMenuItem()));
trayIconMenu->addAction(action);
}
How does my "launchMenuItem()" SLOT know which menu item was triggered? I can't make a SLOT for each menu item as I don't know how many items will exist until run time.
I can think of some ugly ways to do this, but I am looking for the RIGHT way.
What I usually do is to use QAction::setData(const QVariant&) to store whatever action ID I need. Then on slot side I retrieve ID with QAction::data() and behave accordingly.
Note that QVariant obviously accepts much more than basic int (which is what I use to identify actions), you can pass any QVariant-compatible info.
edit : oh! btw, this is somehow ugly because I make use of QObject::sender() to cast triggered action back. Sorry for that, but it works anyway.
I have a Qaction on a menu item for deleting selected items in one of my views. Here is how i create the action:
deleteAct = new QAction( tr("Delete Selected"), this);
deleteAct->setShortcut(QKeySequence::Delete);
connect(deleteAct, SIGNAL(triggered()), this, SLOT(deleteSelected()));
I setup a keyboard shortcut (Delete Key) which should trigger the delectAct action. It works most of the time but at some points it stops working... Does anyone know why the shortcut would stop working?
Note: the action still works if i trigger it from the menu item. Its just the shortcut that doesn't...
You need to add the action to a widget, since it's the widget that will be listening for key events.
Assuming "this" is a mainwindow, simply do
addAction(deleteAct);
Note that you can add the same action to multiple widgets (that's the whole point of the separated action concept). So it's fine to add it to the mainwindow and to a menu.
Try changing the shortcut context of the action, for example:
deleteAct->setShortcutContext(Qt::ApplicationShortcut);
The shortcut works depending on the focus of the application views.
I wanted to have shortcuts working on buttons.
In my application I changed the shortcut context of the action,
added the action to the widget
and finally to the subviews of the application.
Then the necessary signals and slots of widget an action must be connected.
const QAbstractButton*button = dynamic_cast<QAbstractButton*>(widget);
action->setShortcutContext(Qt::WidgetWithChildrenShortcut);
widget->addAction(action);
ui->textBrowser->addAction(action);
ui->treeSource->addAction(action);
if (button)
{
if (button->isCheckable())
{
action->setCheckable(true);
if (button->isChecked()) action->setChecked(true);
connect(action, SIGNAL(triggered(bool)), button, SLOT(setChecked(bool)));
connect(button, SIGNAL(clicked(bool)), action, SLOT(setChecked(bool)));
}
else
{
connect(action, SIGNAL(triggered()), button, SLOT(click()));
}
}
Without seeing the complete code, I'd hazard a guess that somewhere it gets enabled/disabled. Make sure that the shortcut is getting hit in the constructor and not 'disabled' somewhere else because of a setting perhaps.
You can use http://doc.qt.io/qt-5/qaction.html#shortcutVisibleInContextMenu-prop property since QT 5.10 for this:
deleteAct->setShortcutVisibleInContextMenu(true);