Listen for events from multiple buttons

You can listen for events from several buttons in one listener. Even in the same function. Each callback function receives a reference to ObjectButton instance, from which it can tell, which button was triggered.

Button ID

Each ObjectButton instance has a button ID, which corresponds to input pin number used by the button.

To get ID of a button, call ObjectButton#getId() function:

int input_pin = 13;
ObjectButton button = ObjectButton(input_pin);

// buttonId == input_pin
int buttonId = button.getId();

Listener with two distinct buttons

Let's create an example of a listener receiving events from two distinct buttons.

#include <ObjectButton.h>
#include <interfaces/IOnClickListener.h>

constexpr static byte INPUT_PIN_BUTTON1 = 13;
constexpr static byte INPUT_PIN_BUTTON2 = 14;

class OnClickListener : private virtual IOnClickListener {
public:
    OnClickListener() = default;

    void init();

    void update();

private:
    void onClick(ObjectButton &button) override;

    // Create two button instances, each bound to different input pin
    ObjectButton button1 = ObjectButton(INPUT_PIN_BUTTON1);
    ObjectButton button2 = ObjectButton(INPUT_PIN_BUTTON2);
};

void OnClickListener::onClick(ObjectButton &button) {
    // Which button was triggered?
    switch (button.getId()) {
        case INPUT_PIN_BUTTON1:
            // Button 1 clicked!
            break;
        case INPUT_PIN_BUTTON2:
            // Button 2 clicked!
            break;
    }
}

void OnClickListener::init() {
    // Initialize the listener
    button1.setDebounceTicks(10);
    button1.setOnClickListener(this);

    button2.setOnClickListener(this);
}

void OnClickListener::update() {
    button1.tick();
    button2.tick();
}

OnClickListener listener = OnClickListener();

void setup() {
    listener.init();
}

void loop() {
    listener.update();
}

Notice how we check in onClick() function, by which button it was triggered.