How to trigger a hotkey to a QWindow using a QButton?

[fabriciokash]

@Pl45m4 said in How to trigger a hotkey to a QWindow using a QButton?:

@fabriciokash

Send the event to your widget, not to your window.
Maybe QShortCut works for you or simply create a QAction and assign the key shortcut.

https://doc.qt.io/qt-5/qshortcut.html

But QShortCut is not used when the user types the key? When the user click on a button, the program should simulate a hotkey "ctrl+a" to another widget. The user will not type it.

[Pl45m4]

@fabriciokash

You can trigger QShortCut or QActions without typing the actual keys and send it to the destination widget.

Or you can create a QKeyEvent and send to to your widget

https://doc.qt.io/qt-5/qkeyevent.html

[fabriciokash]

@Pl45m4

I have some really noob questions... Im trying to use QKeyEvent and what I need is to sendo a pair of keys, like ctrl+a, ctrl+v, etc. The question is about the constructor's parameters...

I have here

QKeyEvent *keyEvent = new QKeyEvent(QEvent::KeyPress, Qt::Key_Control, Qt::NoModifier)

Whats difference between KeyPress and KeyRelease?

And if the constructor accept only one Key, how I will use a pair of keys? like ctrl+A

[SGaist]

Hi,

@fabriciokash said in How to trigger a hotkey to a QWindow using a QButton?:

Whats difference between KeyPress and KeyRelease?

The first when you press a key on the keyboard.
The second when you release the key from the keyboard.

@fabriciokash said in How to trigger a hotkey to a QWindow using a QButton?:

And if the constructor accept only one Key, how I will use a pair of keys? like ctrl+A

A is the key, Ctrl is the modifier.

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Hi,

@fabriciokash said in How to trigger a hotkey to a QWindow using a QButton?:

Whats difference between KeyPress and KeyRelease?

The first when you press a key on the keyboard.
The second when you release the key from the keyboard.

@fabriciokash said in How to trigger a hotkey to a QWindow using a QButton?:

And if the constructor accept only one Key, how I will use a pair of keys? like ctrl+A

A is the key, Ctrl is the modifier.

Aaah got it. I understood the key and modifier

About press and release a key… it means i need two event objects? One for press and another for release to send to a widget?

[SGaist]

Yes you do.

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Yes you do.

I tried this code: two events inside a button clicked event

void Simulate::on_selectAllBtn_clicked()
{
    QKeyEvent *eventPress = new QKeyEvent(QEvent::KeyPress, Qt::Key_A, Qt::ControlModifier);
    QKeyEvent *eventRealease = new QKeyEvent(QEvent::KeyRelease, Qt::Key_A, Qt::ControlModifier);
    QCoreApplication::postEvent(targetWidget, eventPress);
    QCoreApplication::postEvent(targetWidget, eventRealease);
}

But I got a error on "KeyPress" and "KeyRelease": excepted unqualified-id before numeric constant

Can you help me with that?

[SGaist]

Can you show the compiler error message please ?

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Can you show the compiler error message please ?

Yes, sure.

Compile Output in Qt Creator

Detail: Changed button's name to exportBtn_2 and targetWidget to simulationWidget, but the error persists

[SGaist]

Did you include QEvent ?

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Did you include QEvent ?

Yes, i do.

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Did you include QEvent ?

I got the solution. I was doing #include <xdotool-master/xdo.h> and i think this file was causing some type of conflict. I just commented this line.

I gonna back to the event's problem

[fabriciokash]

void Simulate::on_selectAllBtn_clicked()
{
    QKeyEvent *eventPress = new QKeyEvent(QEvent::KeyPress, Qt::Key_A, Qt::ControlModifier);
    QKeyEvent *eventRealease = new QKeyEvent(QEvent::KeyRelease, Qt::Key_A, Qt::ControlModifier);
    QCoreApplication::postEvent(targetWidget, eventPress);
    QCoreApplication::postEvent(targetWidget, eventRealease);
}

This solution doesnt work. Is this code correct? As I commented, I created a QWindow from a window ID of a external program (in case, a gedit text editor) and put it on a QWidget. I dont know if this approach is for my case. I tried too use QApplication::setActiveWIndow and targetWidget->setFocus() before, but without success. Tried send the event to QWindow too, without success.

[SGaist]

You are trying to send these events to an external application ?
Which is it ?

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

You are trying to send these events to an external application ?
Which is it ?

Kind of it. I have a gedit text editor (external application) embed to a QWindow (intern application). And a QWidget is created from this QWindow, using QWidget *widget = QWidget::createWindowContainer(window);

In addition to that widget, i have too, on GUI, a QButton, called "Select All". When user click on this button, the system should select all text in text editor. So Im trying to send a Ctrl+A under the covers.

But I dont know if Im on right way to do this using that code.

[SGaist]

Which OS are you on ?

Sending key events through Qt's event loop like that won't work AFAIK. The application while embedded is still an external application.

[fabriciokash]

@SGaist said in How to trigger a hotkey to a QWindow using a QButton?:

Which OS are you on ?
Sending key events through Qt's event loop like that won't work AFAIK. The application while embedded is still an external application.

Im using Ubuntu 18.04.

There is a way to send the key event through OS?