analytics/webcontent/ags/AccessibilityHandler.js

/********************************************************************************************************************************
* Licensed Materials - Property of IBM                                                                                          *
*                                                                                                                               *
* IBM Cognos Products: AGS                                                                                                      *
*                                                                                                                               *
* (C) Copyright IBM Corp. 2005, 2014                                                                                            *
*                                                                                                                               *
* US Government Users Restricted Rights - Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. *
*********************************************************************************************************************************/

/*-----------------------------------------------------------------------------------------------------

Class :			AccessibilityHandler

Description :	

-----------------------------------------------------------------------------------------------------*/

// Switch for keyboard support: true-turn on, false-turn off
var m_bSupportAccessibility = false;

// supported key code Tab-Enter-Esc-Space-Left-Up-Right-Down
var m_aSupportedKeycode = [9, 13, 27, 32, 37, 38, 39, 40];

var m_aTabMenuItems;
var m_aSummaryBarItems;
var m_oMetadataTree;
var m_oSourceTab;

var AccessibilityHandler = {};

AccessibilityHandler.isEnabled = function () {
	// check if user enable accessibility
	this.checkCookie();
	if(m_bSupportAccessibility && !document.all)
		return true;
	return false;
}

AccessibilityHandler.checkCookie = function () {
	var accessibility_cookie = getCookie("AGS_ACCESSIBILITY_ENABLED");
	if (accessibility_cookie != null && accessibility_cookie == "true") {
		m_bSupportAccessibility = true;
	}
}

AccessibilityHandler.enableAccessibility = function () {
	var cf = window.parent.getConfigFrame();
	var b_confirm = confirm(cf.enableAccessibility_string);
	if (b_confirm) {
		setCookie("AGS_ACCESSIBILITY_ENABLED","true");
	}
}

AccessibilityHandler.disableAccessibility = function () {
	var cf = window.parent.getConfigFrame();
	var b_confirm = confirm(cf.disableAccessibility_string);
	if (b_confirm) {
		setCookie("AGS_ACCESSIBILITY_ENABLED","false");
	}
}

AccessibilityHandler.initKeyboard = function () {
	if(this.isEnabled()) {
		this.initTaskMenu();
		this.initTabMenu();
		// register key down handler for CTRL key press
		document.body.onkeydown = this.onkeydown;
	}
}

AccessibilityHandler.initTaskMenu = function () {
	var taskMenuHTML = document.getElementById("taskContents_tableID");
	var taskMenuData = new CMenuExtractor(taskMenuHTML,"tr");
	taskMenuData.initTaskMenuItem();
}

AccessibilityHandler.initTabMenu = function () {
	var tabMenuHTML = document.getElementById("menuTabs_and_Props");
	var tabMenuData = new CMenuExtractor(tabMenuHTML,"img");
	m_aTabMenuItems = tabMenuData.getTabMenuItems();
	for (var i=0; i<m_aTabMenuItems.length; i++) {
		for (var j=0; j<m_aTabMenuItems[i].length; j++) {
			m_aTabMenuItems[i][j].onkeypress = this.tabMenuKeypress;
			m_aTabMenuItems[i][j].onfocus = this.tabMenuOnfocus;
			m_aTabMenuItems[i][j].onblur = this.tabMenuOnblur;
		}
	}
}

AccessibilityHandler.initSummaryBar = function () {
	var summaryBarHTML = document.getElementById("SummaryBarScrollpane");
	var summaryBarData = new CMenuExtractor(summaryBarHTML,"table");
	m_aSummaryBarItems = summaryBarData.getSummaryBarItems();
	for (var i=0; i<m_aSummaryBarItems.length; i++) {
		m_aSummaryBarItems[i].onkeypress = this.summaryBarKeypress;
	}
	// enable summary bar event condition item tabindex value
	m_aSummaryBarItems[0].setAttribute("tabindex", "0");
}

AccessibilityHandler.refreshCtrlTabItems = function() {
	// get metadata tree root element  
	m_oMetadataTree = document.getElementById("metadataTreelabelText");
	for (var i=0; i< m_aTabMenuItems.length; i++) {
		if (isVisible(m_aTabMenuItems[i][0])) {
			m_oSourceTab = m_aTabMenuItems[i][0];
			break;
		}
	}
}

AccessibilityHandler.tabMenuOnfocus = function (evt) { 
	this.className = "selectedTabImage";
}

AccessibilityHandler.tabMenuOnblur = function (evt) { 
	this.className = "normalTabImage";
}

AccessibilityHandler.onkeydown = function (evt) {
	evt = (evt) ? evt : ((event) ? event : null);
	var keyCode = evt.keyCode || evt.which;

	// check for Ctrl + Tab key press
	if (keyCode == 9 && evt.ctrlKey) {
	
		AccessibilityHandler.refreshCtrlTabItems();
		// check if metadata tree is visible
		if (isVisible(m_oMetadataTree))
			m_oMetadataTree.focus();
		else
			m_oSourceTab.click();
	}
}

AccessibilityHandler.tabMenuKeypress = function (evt) {	
	evt = (evt) ? evt : ((event) ? event : null);
	var keyCode = evt.keyCode || evt.which;
	var currentTabMenu, index;

	for (var i=0; i<m_aTabMenuItems.length; i++) {
		if (AccessibilityHandler.contains(m_aTabMenuItems[i], this)) {
			currentTabMenu = m_aTabMenuItems[i];
			for (var j=0; j<currentTabMenu.length; j++) {
				if (this == currentTabMenu[j]) {
					index = j;
					break;
				}
			}
			break;
		}
	}
	AccessibilityHandler.toggleItem(this, currentTabMenu, index, keyCode);
}

AccessibilityHandler.summaryBarKeypress = function (evt) {	
	evt = (evt) ? evt : ((event) ? event : null);
	var keyCode = evt.keyCode || evt.which;
	var index;
	
	for (var i=0; i<m_aSummaryBarItems.length; i++) {
		if (this == m_aSummaryBarItems[i]) {
			index = i;
			break;
		}
	} 
	AccessibilityHandler.toggleItem(this, m_aSummaryBarItems, index, keyCode);
}

AccessibilityHandler.toggleItem = function (currentItem,currentMenu,index,keyCode) {
	// check for Right key press
	if (keyCode == 39) {
		if (index != currentMenu.length -1) {
			currentMenu[index + 1].focus();
		}
	}
	// check for Left key press
	else if (keyCode == 37) {
		if (index != 0) {
			currentMenu[index - 1].focus();
		}
	}
	// check for Enter key press
	else if (keyCode == 13) {
		currentItem.click();
	}
}

AccessibilityHandler.setTabMenuFocus = function (currentTab) {
	var tab_modelItem = document.getElementById("metadataTreelabelText");
	var tab_dataItem = document.getElementById("agentItemsTree0labelText");
	var tab_functionItem = document.getElementById("functionsTreelabelText");
	var tab_parameterItem = document.getElementById("agentParameterTree0labelText");
	var tab_historyItem = document.getElementById("historyTree0labelText");

	// if currentTab has items, focus on the first one, if not, focus on itself.
	switch (currentTab) {
		case TAB_MODEL:
			if (tab_modelItem != null)
				tab_modelItem.focus();
			else
				m_aTabMenuItems[0][0].focus();
			break;
		case TAB_DATAITEMS:
			if (tab_dataItem != null)
				tab_dataItem.focus();
			else
				m_aTabMenuItems[1][1].focus();
			break;
		case TAB_FUNCTIONS:
			if (tab_functionItem != null)
				tab_functionItem.focus();
			else
				m_aTabMenuItems[2][2].focus();
			break;
		case TAB_PARAMETERS:
			if (tab_parameterItem != null)
				tab_parameterItem.focus();
			else
				m_aTabMenuItems[3][3].focus();
			break;
		case TAB_HISTORY:
			if (tab_historyItem != null)
				tab_historyItem.focus();
			else
				m_aTabMenuItems[4][4].focus();
			break;
		case TAB_MEMBERS:
			m_aTabMenuItems[5][5].focus();
			break;
	}
}

AccessibilityHandler.getTabindex = function (item) {
	var parent = item.getParent();
	var current;
	if (parent.getParent() == null) {
		for (var i=0; i<parent.getNumItems(); i++) {
			if (item == parent.get(i)) {
				current = i;
				break;
			}
		}
	}
	if (current != 0)
		return -1;
	else
		return 0;
}

AccessibilityHandler.setTabindex = function (item) {
	if (this.isEnabled()) { 
		var parent = item.getParent();
		if (parent.getParent() == null) {
			for (var i=0; i<parent.getNumItems(); i++) {
				if (item == parent.get(i)) {
					parent.get(i).enableTabindex();
				}
				else {
					parent.get(i).disableTabindex();
				}
				// just ensure to close the menu when mouse interrupted
				if (parent.get(i).getMenu().isVisible()) {	
					parent.get(i).getMenu().remove(true);
				}
			}
		}
	}
}

AccessibilityHandler.setRolloverState = function (item) {
	if (this.isEnabled() && item.getMenuType() == "dropDown") {
		var htmlElement;
		var parent = item.getParent();
		for (var i=0; i<parent.getNumItems(); i++) {
			if (item != parent.get(i)) {
				htmlElement = parent.get(i).getHTMLElement();
				htmlElement.className = item.getStyle().getNormalState();
			}	
		}
	}
}

AccessibilityHandler.isSupportedKeycode = function (keycode) {
	if (this.contains(m_aSupportedKeycode, keycode))
		return true;
	return false;
}

AccessibilityHandler.contains = function (array, obj) {
	for (var i = 0; i < array.length; i++) {
		if (array[i] === obj) {
			return true;
		}
	}
	return false;
}

AccessibilityHandler.getNextItem = function (item,keyCode) {
	var current, next, first = 0;
	var parent = item.getParent();
	var last = parent.getNumItems()-1;
	var count = 0;
	for (var i=0; i<parent.getNumItems(); i++) {
		if (item == parent.get(i)) {
			current = i;
			break;
		}
	}
	
	// get next item for Right or Down key press
	if (keyCode == 39 || keyCode == 40) {
		next = current + 1;
		if (current == last) {
			next = first;
		}
		while(this.isNextAvailable(parent.get(next))) {
			count ++;
			if (next < last)	{
				next = next + 1;
			} else {
				next = first;
			}
			// only retrieve one circle
			if(count == last)
				break;
		}
	} 
	
	// get next item for Left or Up key press
	else if (keyCode == 37 || keyCode == 38) {
		next = current - 1;
		if (current == first) {
			next = last;
		}
		while(this.isNextAvailable(parent.get(next))) {
			count ++;
			if (next > first) {
				next = next - 1;
			} else {
				next = last;
			}
			// only retrieve one circle
			if(count == last)
				break;
		}
	} 
	return parent.get(next);
}

AccessibilityHandler.isNextAvailable = function (item) {
	if (item instanceof CToolbarButton) {
		return false;
	}
	else if (item instanceof CMenuItem && item.getMenuType() == "dynamic") {
		var style = item.getHTMLElement().getAttribute("style");
		if (style == null || style.indexOf("none") == -1) {
			return false;
		}
	} 
	else if (item instanceof CMenuItem && item.isVisible()) {
		return false;
	}
	return true;
}

function setCookie(c_name,value,expiredays) {
	var exdate = new Date();
	if (expiredays != null) {
		exdate.setDate(exdate.getDate()+expiredays);
	} else {
		exdate.setUTCFullYear(exdate.getUTCFullYear() + 1);
	}
	document.cookie = c_name+ "=" + escape(value) + ";expires=" + exdate.toGMTString();
}

function getCookie(c_name) {
	if (document.cookie.length>0) {
		c_start=document.cookie.indexOf(c_name + "=");
		if (c_start!=-1) { 
			c_start=c_start + c_name.length+1;
			c_end=document.cookie.indexOf(";",c_start);
			if (c_end==-1) {
				c_end=document.cookie.length;
			}
			return unescape(document.cookie.substring(c_start,c_end));
		} 
	}
	return "";
}

function isVisible(element) {
	var rect = element.getBoundingClientRect();
	return !!(rect.bottom - rect.top);
}