谷歌音乐搜索栏的提示功能

/**
 * 为搜索框添加提示功能
 * @param searchTip		提示信息
 * @param searchBoxId	搜索输入框 ID
 * @param hideBoxId		关键字隐藏框 ID
 */
m.hint.initHint = function(searchTip, searchBoxId, hideBoxId){
	var searchBox = document.getElementById(searchBoxId);
	var hideBox = null;
	if(searchBox){
		if(hideBoxId) {
			hideBox = document.getElementById(hideBoxId);
		}
		l.events.listen(searchBox, "blur", l.bind(m.hint.onInputBlur, null, searchBox, hideBox), false);
		l.events.listen(searchBox, "focus", l.bind(m.hint.onInputFocus, null, searchBox, hideBox), false);
		if(hideBox){
			l.events.listen(searchBox, "change", bind(m.hint.onInputChange, null, searchBox, hideBox), false);
			hideBox.value = m.hint.getInputValue(searchBox);
		}
 
		// 在这里将搜索提示赋给临时变量
		m.hint.Gh[searchBox] = searchTip;
		// 如果搜索框存在, 则为搜索框加上临时变量和灰色字的 class
		m.hint.onInputBlur(searchBox);
	}
};
 
m.hint.onInputBlur = function(searchBox, hideBox) {
	m.hint.fi(searchBox);
	hideBox && m.hint.onInputChange(searchBox, hideBox);
};
 
m.hint.fi = function(searchBox) {
	if(searchBox) {
		var searchTip = m.hint.Gh[searchBox];
		if(searchTip && (searchBox.value.trim()=="" || searchBox.value==searchTip)) {
			searchBox.setAttribute(m.hint.IS_HINT, "1");
			searchBox.className += " hint";
			searchBox.value = searchTip;
		}
	}
};