Disable a function on focus of dropdown input

Question

I am using the function below to bind scroll events to a slider element, to trigger next/previous slides.

However in certain situations I'd like to disable that function, for instances when dropdowns are in focus, to allow the user to scroll through the dropdown list. And then when the dropdown element is out of focus, I'd like to re-activate my scroll function. How can this be achieved?

function debounce(func, wait, immediate) {
  var timeout;
  return function() {
    var context = this,
      args = arguments;
    var later = function() {
      timeout = null;
      if (!immediate) func.apply(context, args);
    };
    var callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait);
    if (callNow) func.apply(context, args);
  };
}

var onScroll = debounce(function(direction) {
  if (direction == false) {
    $(".slider-next").trigger('tap');
  } else {
    $(".slider-prev").trigger('tap');
  }
}, 100, true);

$('#slider').bind('wheel mousewheel', function(e) {
  e.preventDefault();
  var delta;
  if (typeof event != 'undefined' && event.wheelDelta) {
    delta = event.wheelDelta;
  } else {
    delta = -1 * e.originalEvent.deltaY;
  }
  onScroll(delta >= 0);
});

Answer 1

Here's how you can modify your current implementation to enable and disable the scroll event handling based on whether dropdowns are in focus:

Step 1: Define a Flag to Track Dropdown Focus

Create a flag that will indicate whether any dropdown is currently focused. This will determine whether to handle the scroll events for the slider.

var dropdownInFocus = false;

// Detect focus on any dropdown
$('select').on('focus', function() {
  dropdownInFocus = true;
});

// Detect blur on any dropdown
$('select').on('blur', function() {
  dropdownInFocus = false;
});

You can point to any element; dropdowns are typically select elements.

Step 2: Modify the Event Handler to Respect the Focus Flag

Update your existing scroll event handler to check the dropdownInFocus flag before deciding to trigger next/previous slides.

$('#slider').bind('wheel mousewheel', function(e) {
  if (!dropdownInFocus) {
    e.preventDefault();
    var delta;
    if (typeof event != 'undefined' && event.wheelDelta) {
      delta = event.wheelDelta;
    } else {
      delta = -1 * e.originalEvent.deltaY;
    }
    onScroll(delta >= 0);
  }
});

Explanation

This solution leverages a simple flag (dropdownInFocus) to track whether any dropdown is focused. When a dropdown receives focus, the flag is set to true, disabling the scroll binding for the slider. When the dropdown loses focus, the flag is reset to false, re-enabling the slider's scroll functionality. This allows users to scroll through dropdowns without triggering the slider's navigation unintentionally.