How to create a push button that works with spacebar?

[jcsxdev]

I created a push button using GestureClick:

Here is a snippet of the code:

    // --snip--

    // Add an action when the button is pressed
    gesture_click.connect_pressed(
        clone! (@weak push_button => move |gesture, _n_press, _x, _y| {
            gesture.set_state(gtk::EventSequenceState::Claimed);
            push_button.set_label("Release me!");
            print!("Button pressed!  \r");
            let _ = std::io::stdout().flush();
        }),
    );

    // Add an action when the button is released
    gesture_click.connect_released(
        clone! (@weak push_button => move |gesture, _n_press, _x, _y| {
            gesture.set_state(gtk::EventSequenceState::Claimed);
            push_button.set_label("Press me!");
            print!("Button released!\r");
            let _ = std::io::stdout().flush();
        }),
    );

    // --snip--

But I can’t figure out how to get this to work with the space bar. Currently, this is what happens using the spacebar:

I also tried working with the spacebar using EventControllerKey, but I ran into the same situation as described here:

• rust - Detect that user presses spacebar GTK4 - Stack Overflow

[jf2048]

It should work if you simply use connect_clicked on the button itself.

Generally you do not want to use GestureClick or EventControllerKey unless you are implementing your own widget.

[jcsxdev]

Hi @jf2048,

Thank you for your reply and sorry for the late response.

It should work if you simply use connect_clicked on the button itself.

By simply using connect_clicked I can detect that the button was pressed, but I can't detect when it was released. As of now, there is no connect_released method in ButtonExt.

My goal is to keep the button pressed while the mouse button is pressed or while the space bar key is pressed. Can you please provide an example using button_clicked to detect these two button states?

In the meantime, I managed to make it work using GestureClick and EventControllerKey:

• Solution using GestureClick and EventControllerKey

But the following problem occurs when the space bar key is held down:

As demonstrated in the GIF, the button opacity is constantly toggled when the space bar key is pressed.

The problem does not occur when the mouse button is pressed:

---

Solution using GestureClick and EventControllerKey

Current solution:

    // --snip--

    // Create a GestureClick to handle mouse press and release events
    let gesture_click = gtk::GestureClick::new();

    // Add an action when the button is pressed
    gesture_click.connect_pressed(clone!(
        #[weak]
        push_button,
        move |gesture, _n_press, _x, _y| {
            gesture.set_state(gtk::EventSequenceState::Claimed);
            push_button.set_label("Release me!");
            print!("Button pressed!  \r");
            let _ = io::stdout().flush();
        }
    ));

    // Add an action when the button is released
    gesture_click.connect_released(clone!(
        #[weak]
        push_button,
        move |gesture, _n_press, _x, _y| {
            gesture.set_state(gtk::EventSequenceState::Claimed);
            push_button.set_label("Press me!");
            print!("Button released!\r");
            let _ = io::stdout().flush();
        }
    ));

    push_button.add_controller(gesture_click.upcast::<gtk::EventController>());

    // Create a EventControlKey to handle spacebar press and release events
    let controller_key = EventControllerKey::new();

    controller_key.connect_key_pressed(clone!(
        #[weak_allow_none]
        push_button,
        move |_controller, keyval, _keycode, _state| {
            if keyval == Key::space {
                push_button
                    .expect("Failed to unwrap Button")
                    .set_label("Release me!");
                print!("Button pressed!  \r");
                let _ = io::stdout().flush();
            }
            false.into()
        }
    ));

    controller_key.connect_key_released(clone!(
        #[weak]
        push_button,
        move |_controller, keyval, _keycode, _state| {
            if keyval == Key::space {
                push_button.set_label("Press me!");
                print!("Button released!\r");
                let _ = io::stdout().flush();
            }
        }
    ));

    push_button.add_controller(controller_key.upcast::<gtk::EventControllerKey>());

    // --snip--