Another XP style panel bar for Web

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Introduction

Windows XP users are already familiar with a Panel Bar that appears on the left side in Windows Explorer. This article introduces another way to mimic this user interface in web applications. This article is inspired by another great article Windows XP Style Menu already available on CodeProject. However the idea presented in this article makes use of tables a lot to format the panel bar contents and also provides a way to alter stylesheets at run-time.

Panelbar Layout

The following figure shows the HTML layout of a single item in the panel bar. The exact same layout is followed by every other item in the panel bar.

• The entire panel bar is wrapped in a div tag.
• The actual panel bar is formed using two div tags. Mainly Header and Links.
• The header is rendered as a single row table.
• The item links are again rendered as table rows.

The entire panelbar HTML is generated at runtime using client side JavaScript. So you don't need to include any HTML as required by most of the other panel bars I have seen.

Driving script

The panel bar requires two JavaScript files. The Panelbar.js file houses the actual code for menu generation and ua.js houses the script used for browser detection. The page in which you want to show the panelbar needs to emit the following JavaScript code:

<script language="javascript">
  var objTmp;

  objTmp = createMenu("Community", "");
  createSubMenu(objTmp, "Site Map", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Add To Favorites", 
                        "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "CodeProject Stuff", 
                        "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Who's Who", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Tell a friend", "PanelBar.htm#", 
                        "", "", "", "WKSpace");
  createSubMenu(objTmp, "Industry Contacts", 
                        "PanelBar.htm#", "", "", "", "WKSpace");

  objTmp = createMenu(".NET", "");
  createSubMenu(objTmp, "ASP.NET", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Managed C++", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "SOAP & XML", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "VB.NET", "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "C++ Web Services", 
                        "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Compact Framework", 
                        "PanelBar.htm#", "", "", "", "WKSpace");
  createSubMenu(objTmp, "Cross Platform", "PanelBar.htm#", "", "", "", "WKSpace");

  setTheme("XPClassic.css", null, null)
  initialize(150);    
</script>

The createMenu function takes two parameters. The first one is the header text and the second is the tooltip text. Currently this parameter is ignored. In future, this can be used with the title attribute of the span tag and enclosing the header text within it.

The createSubMenu function takes the following six parameters:

1. The reference to the header object under which the link items are to be rendered.
2. The link text to be displayed.
3. The link URL.
4. The extra data to be passed to the link URL through the query string.
5. The tooltip text to be displayed for the link.
6. The name of the image file to be rendered before the link text.
7. Finally, the target window or frame name in which the link should be opened.

The setTheme basically allows menu customization. It takes the following three parameters:

1. The name of the custom CSS file.
2. The relative path and name of the folder containing the custom theme file. The default value is CSS.
3. The relative path and name of the folder containing the images used in the custom theme. The default value is IMAGES.

Finally, the initialize function which takes a single parameter and uses it to decide the width of the panelbar. This function is also responsible for generating the necessary HTML.

JavaScript structures

The panel bar is composed using the following JavaScript structures. The MenuBand structure contains information required to render the header portion. It also contains an array of sub items. The drawMenu member is responsible for rendering the header as well as the sub items.

/********************
 * Header structure *
 *******************/
function MenuBand(pstrDesc, pstrTip)
{
    // Properties

    this.id        = "";           //generated at runtime.

    this.label     = pstrDesc;     //Text to be displayed in header

    this.microHelp = pstrTip;      //Tooltip text

    this.isHeader  = true;
    this.open      = false;        //future use

    this.submenu   = new Array;    //array containing link items.

    this.smcount   = 0;            //count of sub items.


    //Methods

    this.addSubMenu = addSubMenu;  //function for item addition

    this.render     = drawMenu;    //function for rendering header

}

The SubMenu structure contains information required to render the individual sub item. Again it also has a drawMenu member which is responsible for rendering this sub item. This member is called from the drawMenu member of MenuBand.

/**********************
 * Sub item structure *
 *********************/
function SubMenu(pstrDesc, pstrLink, pstrLinkData, pstrTip, pstrImage, pstrTarget)
{
    // Properties

    this.parentId   = "";            //populated at runtime

    this.label      = pstrDesc;      //Item text to be displayed

    this.hlink      = pstrLink;      //Link url

    this.linkTarget = pstrTarget;    //Target window and or frame identifier

    this.linkData   = pstrLinkData;  //Exrta data to be passed through querystring.

    this.microHelp  = pstrTip;       //Tooltip text.

    this.isHeader   = false;
    this.isSelected = false;         //future use

    this.iconSrc    = pstrImage;     //Name of the image file.


    //Methods

    this.render     = drawSubMenu;   //function for rendering sub item.

}

Drawing functions

The two most important functions in the panel bar construction are drawMenu and drawSubMenu. As the name suggests, the drawMenu renders the header part and calls drawSubMenu on each sub item to render individual sub items.

/*************************************************************
 * Render header part and for each sub item invokes drawMenu.*
 ************************************************************/
function drawMenu()
{
    var iCntr = 0;
    var objMenu;
    var strId, strLbl;

    document.write("<div class=\"menuHeaderCollapsed\" id=\"" + this.id + "\"" + 
                    " onmouseover=\"mousehover(this)\"" + 
                    " onmouseout=\"mouseout(this)\"" +
                    "onclick=\"toggle(this)\">");
    document.write("<table border=\"0\" cellspacing=\"0\"" +
                    " cellpadding=\"4\" width=\"100%\">");
    document.write("<tr><td style=\"vertical-align: center;\">" + 
                   this.label + "</td></tr>");
    document.write("</table></div>");

    //start drawing sub menu

    document.write("<div style=\"display: none; visibility: hidden;\"" +
                    " class=\"menuItems\" id=\"" + this.id + "_child" + "\">");
    document.write("<table border=\"0\" cellspacing=\"0\"" +
                    " cellpadding=\"4\" width=\"100%\">");
    for (iCntr = 0; iCntr < this.smcount; iCntr++)
    {
        this.submenu[iCntr].render();
    }
    document.write("</table></div>");
}

/********************
 * Renders sub item.
 *******************/
function drawSubMenu()
{
    var strImg = "";

    document.write("<tr><td>");
    if (this.iconSrc)
        strImg = "<img src=\"" + _strCtxt + _imageFolder + "/" + 
                    this.iconSrc + " border=\"0\"\"> ";
    document.write("<a href=" + 
              getLink(this.linkTarget, (_strCtxt + this.hlink), this.linkData) + 
              "\">");
    document.write(strImg);
    document.write(this.label);
    document.write("</a>");
    document.write("</td></tr>");
}

Stylesheet

There is really nothing special about the stylesheet(s) used. The attached source contains four different stylesheets. The following stylesheet renders the Code Project panelbar:

body
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    font-weight: normal;
    background-color: #FC9A04;
}

#panelBar
{
    background-color: #FC9A04;
    height: 100%;
    width: 100%;
    vertical-align: top;
}

.menuHeaderExpanded
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    font-weight: bold;
    background-image: url('../Images/CPExpand.gif');
    background-position: right center;
    background-repeat: no-repeat;
    color: #FC9A04;
    height: 23px;
    cursor: hand;
    border-left: 1px solid #000000;
}

.menuHeaderExpandedOver
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    font-weight: bold;
    background-image: url('../Images/CPExpand.gif');
    background-position: right center;
    background-repeat: no-repeat;
    color: #FC9A04;
    height: 23px;
    cursor: hand;
    border-left: 1px solid #000000;
}

.menuHeaderExpanded td
{
    color: #FC9A04;
    font-size: 8pt;
    font-weight: normal;
}

.menuHeaderExpandedOver td
{
    color: #FC9A04;
    font-size: 8pt;
    font-weight: bold;
}

.menuHeaderCollapsed
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    font-weight: bold;
    background-image: url('../Images/CPCollapse.gif');
    background-position: right center;
    background-repeat: no-repeat;
    color: #FC9A04;
    height: 23px;
    cursor: hand;
    border-left: 1px solid #000000;
}

.menuHeaderCollapsedOver
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    font-weight: bold;
    background-image: url('../Images/CPCollapse.gif');
    background-position: right center;
    background-repeat: no-repeat;
    color: #FC9A04;
    height: 23px;
    cursor: hand;
    border-left: 1px solid #000000;
}

.menuHeaderCollapsed td
{
    color: #FC9A04;
    font-size: 8pt;
    font-weight: normal;
}

.menuHeaderCollapsedOver td
{
    color: #FC9A04;
    font-size: 8pt;
    font-weight: bold;;
}

.menuItems
{
    font-family: Verdana, Tahoma, Arial;
    font-size: 8pt;
    background-color: #FFCC99;
    color: #000000;
    position: relative;
}

.menuItems table
{
    font-family: Tahoma, Verdana, Arial;
    font-size: 8pt;
    background-color: #FFCC99;
    color: #000000;
    border-top: 1px solid #000000;
    border-left: 1px solid #000000;
    border-right: 1px solid #000000;
    border-bottom: 1px solid #000000;
}

.menuItems a
{
    color: #000000;
    text-decoration: none;
}

.menuItems a:hover
{
    color: #000000;
    font-weight: bold;
    text-decoration: none;
}

Possible Enhancements

• Support for browsers other than Internet Explorer 6.0 and FireFox 1.0.
• Support for header tooltips.
• Drawing box around sub item upon mouse hover.

Revision History

• Feb. 11, 2005

  First release.

• Feb. 17, 2005

  Fixed images and stylesheets to remove arrow direction bug.

• Apr. 13, 2005

  Fixed image not getting displayed bug for subitems.

• Aug 17, 2005
  1. Support for background images for individual panel.
  2. Support for multiple panel instances.