Treeitem.prototype.handleKeydown = function()

in src/studies/apg/treeview/treeview-1/js/treeitem.js [104:219]
84 lines of code
23 McCabe index (conditional complexity)

Treeitem.prototype.handleKeydown = function (event) {

  var tgt = event.currentTarget,
    flag = false,
    char = event.key,
    clickEvent;

  function isPrintableCharacter (str) {
    return str.length === 1 && str.match(/\S/);
  }

  function printableCharacter (item) {
    if (char == '*') {
      item.tree.expandAllSiblingItems(item);
      flag = true;
    }
    else {
      if (isPrintableCharacter(char)) {
        item.tree.setFocusByFirstCharacter(item, char);
        flag = true;
      }
    }
  }

  if (event.altKey || event.ctrlKey || event.metaKey) {
    return;
  }

  if (event.shift) {
    if (isPrintableCharacter(char)) {
      printableCharacter(this);
    }
  }
  else {
    switch (event.keyCode) {
      case this.keyCode.SPACE:
      case this.keyCode.RETURN:
        // Create simulated mouse event to mimic the behavior of ATs
        // and let the event handler handleClick do the housekeeping.
        try {
          clickEvent = new MouseEvent('click', {
            'view': window,
            'bubbles': true,
            'cancelable': true
          });
        }
        catch (err) {
          if (document.createEvent) {
            // DOM Level 3 for IE 9+
            clickEvent = document.createEvent('MouseEvents');
            clickEvent.initEvent('click', true, true);
          }
        }
        tgt.dispatchEvent(clickEvent);
        flag = true;
        break;

      case this.keyCode.UP:
        this.tree.setFocusToPreviousItem(this);
        flag = true;
        break;

      case this.keyCode.DOWN:
        this.tree.setFocusToNextItem(this);
        flag = true;
        break;

      case this.keyCode.RIGHT:
        if (this.isExpandable) {
          if (this.isExpanded()) {
            this.tree.setFocusToNextItem(this);
          }
          else {
            this.tree.expandTreeitem(this);
          }
        }
        flag = true;
        break;

      case this.keyCode.LEFT:
        if (this.isExpandable && this.isExpanded()) {
          this.tree.collapseTreeitem(this);
          flag = true;
        }
        else {
          if (this.inGroup) {
            this.tree.setFocusToParentItem(this);
            flag = true;
          }
        }
        break;

      case this.keyCode.HOME:
        this.tree.setFocusToFirstItem();
        flag = true;
        break;

      case this.keyCode.END:
        this.tree.setFocusToLastItem();
        flag = true;
        break;

      default:
        if (isPrintableCharacter(char)) {
          printableCharacter(this);
        }
        break;
    }

  }

  if (flag) {
    event.stopPropagation();
    event.preventDefault();
  }
};