button.htm

网上商城的设计与实现

// ************************************************************************<BR>
// Microsoft Script Library<BR>
// Visual InterDev 6.0 Button Object for DHTML<BR>
// Copyright 1998 Microsoft Corporation. All Rights Reserved.<BR>
// <B>Do not modify in design view. Switch to source view.</B><BR>
// ************************************************************************<BR>
// <SCRIPT>
function CreateButton(strName,funcInit,objParentElem)
{
	if (typeof(strName) != 'string' || strName == '')
		return null;
	
	var strTag = '<SPAN id="' + strName + '_SPAN">';
	strTag = strTag + '<input type=button name="' + strName + '" id="' + strName + '">';
	strTag = strTag + '</SPAN>'	

	if ((typeof(objParentElem) == 'object') && (objParentElem != null))
		objParentElem.insertAdjacentHTML('BeforeEnd',strTag);
	else
		document.write(strTag);

	//append public members
	var objButton = _BTN__createMembers(strName);
	if ((typeof(objButton) != 'object') || (objButton == null))
		return null;

	// events
	BTN_ONCLICK = 'onclick';
	// constants
	BTN_TEXT = 0;
	BTN_IMAGE = 1;

	//private members
	objButton._objEventManager = null;
	objButton._nStyle = BTN_TEXT;

	// advise for default eventhandlers
	objButton._objEventManager = CreateEventManager();
	objButton._fireEvent('_BTN__onbeforefuncinit(' + objButton.id + ')');
	objButton._fireEvent(funcInit);
	return objButton;
}

function _BTN__createMembers(strName)
{
	var objParentSpan = document.all[strName + '_SPAN'];
	var objButton = objParentSpan.children(0);
	if (typeof(objButton) != 'object')
		return null;

	// ensure strName is defined in global namespace
	var bDefineAsGlobal =	eval('typeof(' + strName + ') == "undefined"') ||
							typeof(objParentSpan._makeglobal) != 'undefined';
	if (bDefineAsGlobal)
	{	// scoped within a form, define in global namespace
		eval(strName + ' = objButton');
		objParentSpan._makeglobal = 1;
	}

	objButton.isVisible = _BTN_isVisible;
	objButton.show = _BTN_show;
	objButton.hide = _BTN_hide;
	objButton.setStyle = _BTN_setStyle;
	objButton.getStyle = _BTN_getStyle;
	objButton.advise = _BTN_advise;
	objButton.adviseDefaultHandler = _BTN_adviseDefaultHandler;
	objButton.unadvise = _BTN_unadvise;
	objButton.display = _BTN_display;
	objButton._fireEvent = _BTN__fireEvent;
	objButton._objSpan = eval(strName + '_SPAN');
	return objButton;
}

function _BTN_isVisible()
{	return (this.style.visibility != 'hidden');	}

function _BTN_show()
{	this.style.visibility = 'visible';	}

function _BTN_hide()
{	this.style.visibility = 'hidden';	}

function _BTN_setStyle(nStyle)
{
	if (!isNaN(parseInt(nStyle)) && nStyle != this._nStyle)
	{
		// type of tag needs to be changed
		// save current state
		var bVisible = this.isVisible();
		var bDisabled = this.disabled;
		var objEventManager = this._objEventManager;
		var strValue = '';
		var strSrc = '';
		var stralt = '';
		if ((this.value + '') != 'undefined')
			strValue = this.value;
		if ((this.src + '') != 'undefined')
			strSrc = this.src;
		if ((this.alt + '') != 'undefined')
			stralt = this.alt;
			
		// replace previous tag with new tag
		var strTag = '<input type=';
		if (nStyle == 0)
			strTag += 'button ';
		else
			strTag += 'image alt="' + stralt + '" ';		
		strTag += 'name="' + this.name + '" id="' + this.id + '" style="visibility:hidden">';
		this._objSpan.innerHTML = strTag;

		//append public members
		var objButton = _BTN__createMembers(this.name);
		if ((typeof(objButton) != 'object') || (objButton == null))
			return null;

		objButton.value = strValue;
		objButton.src = strSrc;
		objButton.alt = stralt;
		objButton.disabled = bDisabled;
		if (bVisible)	objButton.show();
		objButton._objEventManager = objEventManager;
		if (objEventManager != null)
		{	//re-attach all event handlers
			var nEvents = objEventManager.getEventCount();
			for (var i=0; i < nEvents; i++)
				eval('objButton.' + objEventManager.getEvent(i) + ' = _BTN__fireEvent;');
		}

		objButton._nStyle = nStyle;			
		return true;
	}
	return false;
}

function _BTN_getStyle(nStyle)
{	return this._nStyle;	}
	
function _BTN_advise(strEvent,funcToCall)
{
    var nAdviseID = this._objEventManager.advise(strEvent,funcToCall);
    if (nAdviseID != -1)
        eval('this.' + strEvent + ' = _BTN__fireEvent;');
    return nAdviseID;
}

function _BTN_adviseDefaultHandler(strName,strEvent)
{
    var nAdviseID = this._objEventManager.adviseDefaultHandler(strName,strEvent);
    if (nAdviseID != -1)
        eval('this.' + strEvent + ' = _BTN__fireEvent;');
}

function _BTN_unadvise(strEvent, nAdviseID)
{
    return this._objEventManager.unadvise(strEvent,nAdviseID);
}

function _BTN_display()
{	}

function _BTN__fireEvent(funcToFire)
{
    if (typeof(funcToFire) == 'undefined')
    {
        if (this._objEventManager != null)
            this._objEventManager.fireEvent('on' + window.event.type);
        if (this._nStyle == 0)
            return true;
        else
            return false;
    }
    else
        _EM__fireEvent(funcToFire);
}

function _BTN__onbeforefuncinit(objButton)
{	objButton.adviseDefaultHandler(objButton.id, BTN_ONCLICK);	}