Utilities

/**
 * Positions element relative to another element with collision detection
 * @param {PositionOptions} options - Position configuration
 * @returns {jQuery} Positioned element for chaining
 */
$(element).position(options);

/**
 * Gets browser scrollbar width
 * @returns {number} Scrollbar width in pixels
 */
$.position.scrollbarWidth();

interface PositionOptions {
  my?: string;                       // Position of element to align (default: "center")
  at?: string;                       // Position of target to align to (default: "center")
  of?: string | Element | Event;     // Target element or position
  collision?: string;                // Collision handling: "flip", "fit", "flipfit", "none"
  using?: (position: {top: number, left: number}, feedback: object) => void; // Custom positioning function
  within?: string | Element;         // Constraining element (default: window)
}

// Collision handlers available
$.ui.position.fit.left;              // Fit collision handler for left edge
$.ui.position.fit.right;             // Fit collision handler for right edge  
$.ui.position.fit.top;               // Fit collision handler for top edge
$.ui.position.fit.bottom;            // Fit collision handler for bottom edge

$.ui.position.flip.left;             // Flip collision handler for left edge
$.ui.position.flip.right;            // Flip collision handler for right edge
$.ui.position.flip.top;              // Flip collision handler for top edge
$.ui.position.flip.bottom;           // Flip collision handler for bottom edge

// Center dialog in window
$('#dialog').position({
  my: "center",
  at: "center",
  of: window
});

// Position tooltip above element
$('#tooltip').position({
  my: "center bottom",
  at: "center top",
  of: "#trigger",
  collision: "flip"
});

// Position with custom logic
$('#menu').position({
  my: "left top",
  at: "left bottom",
  of: "#button",
  using: function(position, feedback) {
    $(this).css(position);
    $(this).addClass(feedback.horizontal + " " + feedback.vertical);
  }
});

// Key code constants
$.ui.keyCode.BACKSPACE;              // 8
$.ui.keyCode.COMMA;                  // 188
$.ui.keyCode.DELETE;                 // 46
$.ui.keyCode.DOWN;                   // 40
$.ui.keyCode.END;                    // 35
$.ui.keyCode.ENTER;                  // 13
$.ui.keyCode.ESCAPE;                 // 27
$.ui.keyCode.HOME;                   // 36
$.ui.keyCode.LEFT;                   // 37
$.ui.keyCode.PAGE_DOWN;              // 34
$.ui.keyCode.PAGE_UP;                // 33
$.ui.keyCode.PERIOD;                 // 190
$.ui.keyCode.RIGHT;                  // 39
$.ui.keyCode.SPACE;                  // 32
$.ui.keyCode.TAB;                    // 9
$.ui.keyCode.UP;                     // 38

$(document).keydown(function(event) {
  switch(event.keyCode) {
    case $.ui.keyCode.ESCAPE:
      closeDialog();
      break;
    case $.ui.keyCode.ENTER:
      submitForm();
      break;
    case $.ui.keyCode.TAB:
      // Handle tab navigation
      break;
  }
});

/**
 * Determines if element can receive focus
 * @param {Element} element - Element to test
 * @param {boolean} hasTabindex - Whether element has explicit tabindex
 * @returns {boolean} True if element is focusable
 */
$.ui.focusable(element, hasTabindex);

/**
 * Determines if element can be tabbed to
 * @param {Element} element - Element to test
 * @returns {boolean} True if element is tabbable
 */
$.ui.tabbable(element);

/**
 * Custom selectors for focusable elements
 */
$(':focusable');                     // Selects all focusable elements
$(':tabbable');                      // Selects all tabbable elements

// Find all focusable elements in container
var focusableElements = $('#container').find(':focusable');

// Check if specific element can receive focus
if ($.ui.focusable($('#my-element')[0])) {
  $('#my-element').focus();
}

// Trap focus within dialog
$('#dialog').on('keydown', function(event) {
  if (event.keyCode === $.ui.keyCode.TAB) {
    var tabbableElements = $(this).find(':tabbable');
    // Handle tab navigation within dialog
  }
});

/**
 * Safely gets document.activeElement avoiding IE errors
 * @param {Document} document - Document to check
 * @returns {Element} Active element or body if error
 */
$.ui.safeActiveElement(document);

/**
 * Safely blurs an element without errors
 * @param {Element} element - Element to blur
 */
$.ui.safeBlur(element);

// Get currently focused element safely
var activeElement = $.ui.safeActiveElement(document);

// Safely blur element before focusing another
$.ui.safeBlur(currentElement);
newElement.focus();

/**
 * Finds the nearest scrollable parent element
 * @param {boolean} includeHidden - Include elements with hidden overflow
 * @returns {jQuery} Scrollable parent element
 */
$(element).scrollParent(includeHidden);

// Find scrollable container for positioning
var scrollContainer = $('#element').scrollParent();

// Monitor scroll events on correct container
$('#element').scrollParent().on('scroll', function() {
  // Reposition element
});

/**
 * Generates unique ID for element if it doesn't have one
 * @returns {jQuery} Element for chaining
 */
$(element).uniqueId();

/**
 * Removes generated unique ID from element
 * @returns {jQuery} Element for chaining  
 */
$(element).removeUniqueId();

// Ensure element has ID for ARIA references
$('#form-field').uniqueId();
var fieldId = $('#form-field').attr('id');
$('#field-label').attr('for', fieldId);

// Clean up generated IDs
$('#form-field').removeUniqueId();

/**
 * Escapes CSS selector special characters
 * @param {string} selector - Selector string to escape
 * @returns {string} Escaped selector string
 */
$.ui.escapeSelector(selector);

// Safely use dynamic IDs as selectors
var elementId = 'item:1.2';
var escapedId = $.ui.escapeSelector(elementId);
$('#' + escapedId).addClass('selected');

// Escape user input for selector use
var userInput = $('.special[chars]');
var safeSelector = $.ui.escapeSelector(userInput);

/**
 * Disables text selection on element
 * @returns {jQuery} Element for chaining
 */
$(element).disableSelection();

/**
 * Enables text selection on element
 * @returns {jQuery} Element for chaining
 */
$(element).enableSelection();

// Prevent text selection during drag operations
$('#draggable').draggable({
  start: function() {
    $(this).disableSelection();
  },
  stop: function() {
    $(this).enableSelection();
  }
});

// Disable selection on UI controls
$('.ui-button, .ui-slider').disableSelection();

/**
 * jQuery UI version string
 */
$.ui.version;                        // "1.13.3"

/**
 * Widget-safe data storage (avoids conflicts)
 * @param {string} key - Data key
 * @param {any} value - Data value
 * @returns {any} Stored value when getting
 */
$(element).data(key, value);

// Store widget instance data
$('#element').data('ui-widget', widgetInstance);

// Check for existing widget instance
if ($('#element').data('ui-dialog')) {
  $('#element').dialog('open');
}

/**
 * Form reset mixin for widgets that need to respond to form resets
 */
$.ui.formResetMixin;

/**
 * Gets form element for input
 * @returns {jQuery} Form element or empty jQuery object
 */
$(input).form();

/**
 * Gets all labels associated with form element
 * @returns {jQuery} Associated label elements
 */
$(input).labels();

// Handle form reset in custom widget
$.widget('ui.customWidget', {
  _create: function() {
    this._on(this.element.form(), {
      reset: this.refresh
    });
  }
});

// Update labels when widget changes
var labels = $('#input').labels();
labels.addClass('widget-active');

// Position utility types
interface PositionOptions {
  my?: string;
  at?: string;
  of?: string | Element | Event | { pageX: number, pageY: number };
  collision?: string;
  using?: (position: { top: number, left: number }, feedback: PositionFeedback) => void;
  within?: string | Element;
}

interface PositionFeedback {
  element: {
    element: jQuery;
    left: number;
    top: number;
    width: number;
    height: number;
  };
  target: {
    element: jQuery;
    left: number;
    top: number;
    width: number;
    height: number;
  };
  horizontal: 'left' | 'center' | 'right';
  vertical: 'top' | 'middle' | 'bottom';
  important: 'horizontal' | 'vertical';
}

// Key code enumeration
interface KeyCodes {
  BACKSPACE: 8;
  COMMA: 188;
  DELETE: 46;
  DOWN: 40;
  END: 35;
  ENTER: 13;
  ESCAPE: 27;
  HOME: 36;
  LEFT: 37;
  PAGE_DOWN: 34;
  PAGE_UP: 33;
  PERIOD: 190;
  RIGHT: 39;
  SPACE: 32;
  TAB: 9;
  UP: 38;
}

// Utility function signatures
type FocusableTest = (element: Element, hasTabindex?: boolean) => boolean;
type TabbableTest = (element: Element) => boolean;
type SafeActiveElement = (document: Document) => Element;
type SafeBlur = (element: Element) => void;
type EscapeSelector = (selector: string) => string;