ss_new_ui_skin_and_page/ss/pizhu/pizhu-cursor.js

console.info("cursor");
// 为div保存range
var _range = null;
function displayAreaFocusAndBlur() {
	// 如果有保存的焦点则重新获取到该焦点，如果没有保存的焦点则以文本最后为该焦点
	$('#displayArea').on('focus', function(ev) {
		var selection = window.getSelection();
		if (selection && _range) {
			selection.removeAllRanges();
			selection.addRange(_range); // 添加焦点
		} else {
			var displayArea = document.getElementById('displayArea');
			cursorManager.setEndOfContenteditable(displayArea);
		}
	});
	// 保存焦点到_range
	$('#displayArea').on('blur', function() {
		var selection = window.getSelection();
		if (selection && selection.rangeCount > 0) {
			_range = selection.getRangeAt(0).cloneRange();
		}
	});
}

// 保证focus时，光标定位到元素的最后面
// Namespace management idea from
// http://enterprisejquery.com/2010/10/how-good-c-habits-can-encourage-bad-javascript-habits-part-1/
function cursorManage(cursorManager) {
	// From: http://www.w3.org/TR/html-markup/syntax.html#syntax-elements
	var voidNodeTags = [ 'AREA', 'BASE', 'BR', 'COL', 'EMBED', 'HR', 'IMG',
			'INPUT', 'KEYGEN', 'LINK', 'MENUITEM', 'META', 'PARAM', 'SOURCE',
			'TRACK', 'WBR', 'BASEFONT', 'BGSOUND', 'FRAME', 'ISINDEX' ];
	// From:
	// http://stackoverflow.com/questions/237104/array-containsobj-in-javascript
	Array.prototype.contains = function(obj) {
		var i = this.length;
		while (i--) {
			if (this[i] === obj) {
				return true;
			}
		}
		return false;
	}
	// Basic idea from:
	// http://stackoverflow.com/questions/19790442/test-if-an-element-can-contain-text
	function canContainText(node) {
		if (node.nodeType == 1) { // is an element node
			return !voidNodeTags.contains(node.nodeName);
		} else { // is not an element node
			return false;
		}
	}
	function getLastChildElement(el) {
		var lc = el.lastChild;
		while (lc && lc.nodeType != 1) {
			if (lc.previousSibling)
				lc = lc.previousSibling;
			else
				break;
		}
		return lc;
	}
	// Based on Nico Burns's answer
	cursorManager.setEndOfContenteditable = function(contentEditableElement) {
		while (getLastChildElement(contentEditableElement)
				&& canContainText(getLastChildElement(contentEditableElement))) {
			contentEditableElement = getLastChildElement(contentEditableElement);
		}
		var range, selection;
		if (document.createRange) // Firefox, Chrome, Opera, Safari, IE 9+
		{
			range = document.createRange(); // Create a range (a range is a like
			// the selection but invisible)
			range.selectNodeContents(contentEditableElement); // Select the
			// entire
			// contents of
			// the element
			// with the
			// range
			range.collapse(false); // collapse the range to the end point.
			// false means collapse to end rather than
			// the start
			selection = window.getSelection(); // get the selection object
			// (allows you to change
			// selection)
			selection.removeAllRanges(); // remove any selections already
			// made
			_range = range.cloneRange();
			selection.addRange(range); // make the range you have just created
			// the visible selection
		} else if (document.selection) // IE 8 and lower
		{
			range = document.body.createTextRange(); // Create a range (a
			// range is a like the
			// selection but
			// invisible)
			range.moveToElementText(contentEditableElement); // Select the
			// entire
			// contents of
			// the element
			// with the
			// range
			range.collapse(false); // collapse the range to the end point.
			// false means collapse to end rather than
			// the start
			range.select(); // Select the range (make it the visible selection
		}
	}
	cursorManager.setEndOfRange = function(range) {
		if (document.createRange) {
			range.collapse(false);
			selection = window.getSelection();
			selection.removeAllRanges();
			_range = range.cloneRange();
			selection.addRange(range);
		}
	}
}