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   1  YUI.add('moodle-core-actionmenu', function (Y, NAME) {
   2  
   3  /**
   4   * Provides drop down menus for list of action links.
   5   *
   6   * @module moodle-core-actionmenu
   7   */
   8  
   9  var BODY = Y.one(Y.config.doc.body),
  10      CSS = {
  11          MENUSHOWN: 'action-menu-shown'
  12      },
  13      SELECTOR = {
  14          CAN_RECEIVE_FOCUS_SELECTOR: 'input:not([type="hidden"]), a[href], button, textarea, select, [tabindex]',
  15          MENU: '.moodle-actionmenu[data-enhance=moodle-core-actionmenu]',
  16          MENUBAR: '[role="menubar"]',
  17          MENUITEM: '[role="menuitem"]',
  18          MENUCONTENT: '.menu[data-rel=menu-content]',
  19          MENUCONTENTCHILD: 'li a',
  20          MENUCHILD: '.menu li a',
  21          TOGGLE: '.toggle-display',
  22          KEEPOPEN: '[data-keepopen="1"]',
  23          MENUBARITEMS: [
  24              '[role="menubar"] > [role="menuitem"]',
  25              '[role="menubar"] > [role="presentation"] > [role="menuitem"]'
  26          ],
  27          MENUITEMS: [
  28              '> [role="menuitem"]',
  29              '> [role="presentation"] > [role="menuitem"]'
  30          ]
  31      },
  32      ACTIONMENU,
  33      ALIGN = {
  34          TL: 'tl',
  35          TR: 'tr',
  36          BL: 'bl',
  37          BR: 'br'
  38      };
  39  
  40  /**
  41   * Action menu support.
  42   * This converts a generic list of links into a drop down menu opened by hovering or clicking
  43   * on a menu icon.
  44   *
  45   * @namespace M.core.actionmenu
  46   * @class ActionMenu
  47   * @constructor
  48   * @extends Base
  49   */
  50  ACTIONMENU = function() {
  51      ACTIONMENU.superclass.constructor.apply(this, arguments);
  52  };
  53  ACTIONMENU.prototype = {
  54  
  55      /**
  56       * The dialogue used for all action menu displays.
  57       * @property type
  58       * @type M.core.dialogue
  59       * @protected
  60       */
  61      dialogue: null,
  62  
  63      /**
  64       * An array of events attached during the display of the dialogue.
  65       * @property events
  66       * @type Object
  67       * @protected
  68       */
  69      events: [],
  70  
  71      /**
  72       * The node that owns the currently displayed menu.
  73       *
  74       * @property owner
  75       * @type Node
  76       * @default null
  77       */
  78      owner: null,
  79  
  80      /**
  81       * The menu button that toggles this open.
  82       *
  83       * @property menulink
  84       * @type Node
  85       * @protected
  86       */
  87      menulink: null,
  88  
  89      /**
  90       * The set of menu nodes.
  91       *
  92       * @property menuChildren
  93       * @type NodeList
  94       * @protected
  95       */
  96      menuChildren: null,
  97  
  98      /**
  99       * The first menu item.
 100       *
 101       * @property firstMenuChild
 102       * @type Node
 103       * @protected
 104       */
 105      firstMenuChild: null,
 106  
 107      /**
 108       * The last menu item.
 109       *
 110       * @property lastMenuChild
 111       * @type Node
 112       * @protected
 113       */
 114      lastMenuChild: null,
 115  
 116      /**
 117       * Called during the initialisation process of the object.
 118       *
 119       * @method initializer
 120       */
 121      initializer: function() {
 122          Y.all(SELECTOR.MENU).each(this.enhance, this);
 123          BODY.delegate('key', this.moveMenuItem, 'down:37,39', SELECTOR.MENUBARITEMS.join(','), this);
 124  
 125          BODY.delegate('click', this.toggleMenu, SELECTOR.MENU + ' ' + SELECTOR.TOGGLE, this);
 126          BODY.delegate('key', this.showIfHidden, 'down:enter,38,40', SELECTOR.MENU + ' ' + SELECTOR.TOGGLE, this);
 127  
 128          // Ensure that we toggle on menuitems when the spacebar is pressed.
 129          BODY.delegate('key', function(e) {
 130              e.currentTarget.simulate('click');
 131              e.preventDefault();
 132          }, 'down:32', SELECTOR.MENUBARITEMS.join(','));
 133      },
 134  
 135      /**
 136       * Enhances a menu adding aria attributes and flagging it as functional.
 137       *
 138       * @method enhance
 139       * @param {Node} menu
 140       * @return boolean
 141       */
 142      enhance: function(menu) {
 143          var menucontent = menu.one(SELECTOR.MENUCONTENT),
 144              align;
 145          if (!menucontent) {
 146              return false;
 147          }
 148          align = menucontent.getData('align') || this.get('align').join('-');
 149          menu.one(SELECTOR.TOGGLE).set('aria-haspopup', true);
 150          menucontent.set('aria-hidden', true);
 151          if (!menucontent.hasClass('align-' + align)) {
 152              menucontent.addClass('align-' + align);
 153          }
 154          if (menucontent.hasChildNodes()) {
 155              menu.setAttribute('data-enhanced', '1');
 156          }
 157      },
 158  
 159      /**
 160       * Handle movement between menu items in a menubar.
 161       *
 162       * @method moveMenuItem
 163       * @param {EventFacade} e The event generating the move request
 164       * @chainable
 165       */
 166      moveMenuItem: function(e) {
 167          var nextFocus,
 168              menuitem = e.target.ancestor(SELECTOR.MENUITEM, true);
 169  
 170          if (e.keyCode === 37) {
 171              nextFocus = this.getMenuItem(menuitem, true);
 172          } else if (e.keyCode === 39) {
 173              nextFocus = this.getMenuItem(menuitem);
 174          }
 175  
 176          if (nextFocus) {
 177              nextFocus.focus();
 178          }
 179          return this;
 180      },
 181  
 182      /**
 183       * Get the next menuitem in a menubar.
 184       *
 185       * @method getMenuItem
 186       * @param {Node} currentItem The currently focused item in the menubar
 187       * @param {Boolean} [previous=false] Move backwards in the menubar instead of forwards
 188       * @return {Node|null} The next item, or null if none was found
 189       */
 190      getMenuItem: function(currentItem, previous) {
 191          var menubar = currentItem.ancestor(SELECTOR.MENUBAR),
 192              menuitems,
 193              next;
 194  
 195          if (!menubar) {
 196              return null;
 197          }
 198  
 199          menuitems = menubar.all(SELECTOR.MENUITEMS.join(','));
 200  
 201          if (!menuitems) {
 202              return null;
 203          }
 204  
 205          var childCount = menuitems.size();
 206  
 207          if (childCount === 1) {
 208              // Only one item, exit now because we should already be on it.
 209              return null;
 210          }
 211  
 212          // Determine the next child.
 213          var index = 0,
 214              direction = 1,
 215              checkCount = 0;
 216  
 217          // Work out the index of the currently selected item.
 218          for (index = 0; index < childCount; index++) {
 219              if (menuitems.item(index) === currentItem) {
 220                  break;
 221              }
 222          }
 223  
 224          // Check that the menu item was found - otherwise return null.
 225          if (menuitems.item(index) !== currentItem) {
 226              return null;
 227          }
 228  
 229          // Reverse the direction if we want the previous item.
 230          if (previous) {
 231              direction = -1;
 232          }
 233  
 234          do {
 235              // Update the index in the direction of travel.
 236              index += direction;
 237  
 238              next = menuitems.item(index);
 239  
 240              // Check that we don't loop multiple times.
 241              checkCount++;
 242          } while (next && next.hasAttribute('hidden'));
 243  
 244          return next;
 245      },
 246  
 247      /**
 248       * Hides the menu if it is visible.
 249       * @param {EventFacade} e
 250       * @method hideMenu
 251       */
 252      hideMenu: function(e) {
 253          if (this.dialogue) {
 254              this.dialogue.removeClass('show');
 255              this.dialogue.one(SELECTOR.MENUCONTENT).set('aria-hidden', true);
 256              this.dialogue = null;
 257          }
 258          for (var i in this.events) {
 259              if (this.events[i].detach) {
 260                  this.events[i].detach();
 261              }
 262          }
 263          this.events = [];
 264          if (this.owner) {
 265              this.owner.removeClass(CSS.MENUSHOWN);
 266              this.owner = null;
 267          }
 268  
 269          if (this.menulink) {
 270              if (e.type != 'click') {
 271                  this.menulink.focus();
 272              }
 273              this.menulink = null;
 274          }
 275      },
 276  
 277      showIfHidden: function(e) {
 278          var menu = e.target.ancestor(SELECTOR.MENU),
 279              menuvisible = (menu.hasClass('show'));
 280  
 281          if (!menuvisible) {
 282              e.preventDefault();
 283              this.showMenu(e, menu);
 284          }
 285          return this;
 286      },
 287  
 288      /**
 289       * Toggles the display of the menu.
 290       * @method toggleMenu
 291       * @param {EventFacade} e
 292       */
 293      toggleMenu: function(e) {
 294          var menu = e.target.ancestor(SELECTOR.MENU),
 295              menuvisible = (menu.hasClass('show'));
 296  
 297          // Prevent event propagation as it will trigger the hideIfOutside event handler in certain situations.
 298          e.halt(true);
 299          this.hideMenu(e);
 300          if (menuvisible) {
 301              // The menu was visible and the user has clicked to toggle it again.
 302              return;
 303          }
 304          this.showMenu(e, menu);
 305      },
 306  
 307      /**
 308       * Handle keyboard events when the menu is open. We respond to:
 309       * * escape (exit)
 310       * * tab (move to next menu item)
 311       * * up/down (move to previous/next menu item)
 312       *
 313       * @method handleKeyboardEvent
 314       * @param {EventFacade} e The key event
 315       */
 316      handleKeyboardEvent: function(e) {
 317          var next;
 318          var markEventHandled = function(e) {
 319              e.preventDefault();
 320              e.stopPropagation();
 321          };
 322  
 323          // Handle when the menu is still selected.
 324          if (e.currentTarget.ancestor(SELECTOR.TOGGLE, true)) {
 325              if ((e.keyCode === 40 || (e.keyCode === 9 && !e.shiftKey)) && this.firstMenuChild) {
 326                  this.firstMenuChild.focus();
 327                  markEventHandled(e);
 328              } else if (e.keyCode === 38 && this.lastMenuChild) {
 329                  this.lastMenuChild.focus();
 330                  markEventHandled(e);
 331              } else if (e.keyCode === 9 && e.shiftKey) {
 332                  this.hideMenu(e);
 333                  markEventHandled(e);
 334              }
 335              return this;
 336          }
 337  
 338          if (e.keyCode === 27) {
 339              // The escape key was pressed so close the menu.
 340              this.hideMenu(e);
 341              markEventHandled(e);
 342  
 343          } else if (e.keyCode === 32) {
 344              // The space bar was pressed. Trigger a click.
 345              markEventHandled(e);
 346              e.currentTarget.simulate('click');
 347          } else if (e.keyCode === 9) {
 348              // The tab key was pressed. Tab moves forwards, Shift + Tab moves backwards through the menu options.
 349              // We only override the Shift + Tab on the first option, and Tab on the last option to change where the
 350              // focus is moved to.
 351              if (e.target === this.firstMenuChild && e.shiftKey) {
 352                  this.hideMenu(e);
 353                  markEventHandled(e);
 354              } else if (e.target === this.lastMenuChild && !e.shiftKey) {
 355                  if (this.hideMenu(e)) {
 356                      // Determine the next selector and focus on it.
 357                      next = this.menulink.next(SELECTOR.CAN_RECEIVE_FOCUS_SELECTOR);
 358                      if (next) {
 359                          next.focus();
 360                          markEventHandled(e);
 361                      }
 362                  }
 363              }
 364  
 365          } else if (e.keyCode === 38 || e.keyCode === 40) {
 366              // The up (38) or down (40) key was pushed.
 367              // On cursor moves we loops through the menu rather than exiting it as in the tab behaviour.
 368              var found = false,
 369                  index = 0,
 370                  direction = 1,
 371                  checkCount = 0;
 372  
 373              // Determine which menu item is currently selected.
 374              while (!found && index < this.menuChildren.size()) {
 375                  if (this.menuChildren.item(index) === e.currentTarget) {
 376                      found = true;
 377                  } else {
 378                      index++;
 379                  }
 380              }
 381  
 382              if (!found) {
 383                  return;
 384              }
 385  
 386              if (e.keyCode === 38) {
 387                  // Moving up so reverse the direction.
 388                  direction = -1;
 389              }
 390  
 391              // Try to find the next
 392              do {
 393                  index += direction;
 394                  if (index < 0) {
 395                      index = this.menuChildren.size() - 1;
 396                  } else if (index >= this.menuChildren.size()) {
 397                      // Handle wrapping.
 398                      index = 0;
 399                  }
 400                  next = this.menuChildren.item(index);
 401  
 402                  // Add a counter to ensure we don't get stuck in a loop if there's only one visible menu item.
 403                  checkCount++;
 404              } while (checkCount < this.menuChildren.size() && next !== e.currentTarget && next.hasClass('hidden'));
 405  
 406              if (next) {
 407                  next.focus();
 408                  markEventHandled(e);
 409              }
 410          }
 411      },
 412  
 413      /**
 414       * Hides the menu if the event happened outside the menu.
 415       *
 416       * @protected
 417       * @method hideIfOutside
 418       * @param {EventFacade} e
 419       */
 420      hideIfOutside: function(e) {
 421          if (!e.target.ancestor(SELECTOR.MENUCONTENT, true)) {
 422              this.hideMenu(e);
 423          }
 424      },
 425  
 426      /**
 427       * Displays the menu with the given content and alignment.
 428       *
 429       * @method showMenu
 430       * @param {EventFacade} e
 431       * @param {Node} menu
 432       * @return M.core.dialogue
 433       */
 434      showMenu: function(e, menu) {
 435          var ownerselector = menu.getData('owner'),
 436              menucontent = menu.one(SELECTOR.MENUCONTENT);
 437          this.owner = (ownerselector) ? menu.ancestor(ownerselector) : null;
 438          this.dialogue = menu;
 439          menu.addClass('show');
 440          if (this.owner) {
 441              this.owner.addClass(CSS.MENUSHOWN);
 442              this.menulink = this.owner.one(SELECTOR.TOGGLE);
 443          } else {
 444              this.menulink = e.target.ancestor(SELECTOR.TOGGLE, true);
 445          }
 446          this.constrain(menucontent.set('aria-hidden', false));
 447  
 448          this.menuChildren = this.dialogue.all(SELECTOR.MENUCHILD);
 449          if (this.menuChildren) {
 450              this.firstMenuChild = this.menuChildren.item(0);
 451              this.lastMenuChild = this.menuChildren.item(this.menuChildren.size() - 1);
 452  
 453              this.firstMenuChild.focus();
 454          }
 455  
 456          // Close the menu if the user presses escape.
 457          this.events.push(BODY.on('key', this.hideMenu, 'esc', this));
 458  
 459          // Close the menu if the user clicks outside the menu.
 460          this.events.push(BODY.on('click', this.hideIfOutside, this));
 461  
 462          // Close the menu if the user focuses outside the menu.
 463          this.events.push(BODY.delegate('focus', this.hideIfOutside, '*', this));
 464  
 465          // Check keyboard changes.
 466          this.events.push(
 467              menu.delegate('key', this.handleKeyboardEvent,
 468                            'down:9, 27, 38, 40, 32', SELECTOR.MENUCHILD + ', ' + SELECTOR.TOGGLE, this)
 469              );
 470  
 471          // Close the menu after a button was pushed.
 472          this.events.push(menu.delegate('click', function(e) {
 473              if (e.currentTarget.test(SELECTOR.KEEPOPEN)) {
 474                  return;
 475              }
 476              this.hideMenu(e);
 477          }, SELECTOR.MENUCHILD, this));
 478  
 479          return true;
 480      },
 481  
 482      /**
 483       * Constrains the node to its the page width.
 484       *
 485       * @method constrain
 486       * @param {Node} node
 487       */
 488      constrain: function(node) {
 489          var selector = node.getData('constraint'),
 490              nx = node.getX(),
 491              ny = node.getY(),
 492              nwidth = node.get('offsetWidth'),
 493              nheight = node.get('offsetHeight'),
 494              cx = 0,
 495              cy = 0,
 496              cwidth,
 497              cheight,
 498              coverflow = 'auto',
 499              newwidth = null,
 500              newheight = null,
 501              newleft = null,
 502              newtop = null,
 503              boxshadow = null;
 504  
 505          if (selector) {
 506              selector = node.ancestor(selector);
 507          }
 508          if (selector) {
 509              cwidth = selector.get('offsetWidth');
 510              cheight = selector.get('offsetHeight');
 511              cx = selector.getX();
 512              cy = selector.getY();
 513              coverflow = selector.getStyle('overflow') || 'auto';
 514          } else {
 515              cwidth = node.get('docWidth');
 516              cheight = node.get('docHeight');
 517          }
 518  
 519          // Constrain X.
 520          // First up if the width is more than the constrain its easily full width + full height.
 521          if (nwidth > cwidth) {
 522              // The width of the constraint.
 523              newwidth = nwidth = cwidth;
 524              // The constraints xpoint.
 525              newleft = nx = cx;
 526          } else {
 527              if (nx < cx) {
 528                  // If nx is less than cx we need to move it right.
 529                  newleft = nx = cx;
 530              } else if (nx + nwidth >= cx + cwidth) {
 531                  // The top right of the node is outside of the constraint, move it in.
 532                  newleft = cx + cwidth - nwidth;
 533              }
 534          }
 535  
 536          // Constrain Y.
 537          if (nheight > cheight && coverflow.toLowerCase() === 'hidden') {
 538              // The node extends over the constrained area and would be clipped.
 539              // Reduce the height of the node and force its overflow to scroll.
 540              newheight = nheight = cheight;
 541              node.setStyle('overflow', 'auto');
 542          }
 543          // If the node is below the top of the constraint AND
 544          //    the node is longer than the constraint allows.
 545          if (ny >= cy && ny + nheight > cy + cheight) {
 546              // Move it up.
 547              newtop = cy + cheight - nheight;
 548              try {
 549                  boxshadow = node.getStyle('boxShadow').replace(/.*? (\d+)px \d+px$/, '$1');
 550                  if (new RegExp(/^\d+$/).test(boxshadow) && newtop - cy > boxshadow) {
 551                      newtop -= boxshadow;
 552                  }
 553              } catch (ex) {
 554              }
 555          }
 556  
 557          if (newleft !== null) {
 558              node.setX(newleft);
 559          }
 560          if (newtop !== null) {
 561              node.setY(newtop);
 562          }
 563          if (newwidth !== null) {
 564              node.setStyle('width', newwidth.toString() + 'px');
 565          }
 566          if (newheight !== null) {
 567              node.setStyle('height', newheight.toString() + 'px');
 568          }
 569      }
 570  };
 571  
 572  Y.extend(ACTIONMENU, Y.Base, ACTIONMENU.prototype, {
 573      NAME: 'moodle-core-actionmenu',
 574      ATTRS: {
 575          align: {
 576              value: [
 577                  ALIGN.TR, // The dialogue.
 578                  ALIGN.BR  // The button
 579              ]
 580          }
 581      }
 582  });
 583  
 584  M.core = M.core || {};
 585  M.core.actionmenu = M.core.actionmenu || {};
 586  
 587  /**
 588   *
 589   * @static
 590   * @property M.core.actionmenu.instance
 591   * @type {ACTIONMENU}
 592   */
 593  M.core.actionmenu.instance = null;
 594  
 595  /**
 596   * Init function - will only ever create one instance of the actionmenu class.
 597   *
 598   * @method M.core.actionmenu.init
 599   * @static
 600   * @param {Object} params
 601   */
 602  M.core.actionmenu.init = M.core.actionmenu.init || function(params) {
 603      M.core.actionmenu.instance = M.core.actionmenu.instance || new ACTIONMENU(params);
 604  };
 605  
 606  /**
 607   * Registers a new DOM node with the action menu causing it to be enhanced if required.
 608   *
 609   * @method M.core.actionmenu.newDOMNode
 610   * @param node
 611   * @return {boolean}
 612   */
 613  M.core.actionmenu.newDOMNode = function(node) {
 614      if (M.core.actionmenu.instance === null) {
 615          return true;
 616      }
 617      node.all(SELECTOR.MENU).each(M.core.actionmenu.instance.enhance, M.core.actionmenu.instance);
 618  };
 619  
 620  
 621  }, '@VERSION@', {"requires": ["base", "event", "node-event-simulate"]});