Labeling ParentNode - Protovis Treemap_问答_开发者

I'm trying to label the parent node's of the treemap, but so far have only been able to successfully access the individual leaves of the treemap. Right now it does print the names of the parent nodes, but i want it to center on the parentnode, not the individual leaf as I have it now.

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Sprint","id":237884,"score":86},{"brand":"Samsung Digital Imaging","id":263317,"score":85},{"brand":"Time Warner","id":266908,"score":84},{"brand":"Microsoft Tag","id":277494,"score":84},{"brand":"Samsung Televisions","id":288921,"score":79},{"brand":"Microsoft Visual Studio","id":234168,"score":72},{"brand":"NBC Olympics","id":266564,"score":71},{"brand":"Samsung Mobile USA","id":294087,"score":71},{"brand":"Sony Electronics","id":263313,"score":66},{"brand":"Samsung USA","id":263316,"score":65},{"brand":"Samsung Service","id":288922,"score":63},{"brand":"LG USA Mobile","id":289167,"score":61},{"brand":"Sony PlayStation","id":236075,"score":60},{"brand":"LG Electronics USA","id":288915,"score":58},{"brand":"Microsoft Publisher","id":277505,"score":57},{"brand":"NBC","id":266563,"score":57},{"brand":"Microsoft Office","id":234169,"score":56},{"brand":"Samsung Galaxy Tab","id":294086,"score":56},{"brand":"Microsoft PowerPoint","id":277497,"score":54},{"brand":"Time Warner Cable","id":266909,"score":50},{"brand":"Samsung Notebook","id":289021,"score":48},{"brand":"Dell Spot","id":236265,"score":47},{"brand":"Microsoft Web Platform","id":277504,"score":46},{"brand":"Canon","id":299953,"score":45},{"brand":"Samsung Apps","id":289022,"score":44},{"brand":"Dell Go Green","id":236267,"score":36},{"brand":"Samsung Galaxy S","id":294883,"score":32},{"brand":"Microsoft Access","id":277500,"score":32},{"brand":"Microsoft Visio","id":277498,"score":26},{"brand":"Microsoft Excel","id":277506,"score":25},{"brand":"BlackBerry for AT&T","id":237824,"score":24},{"brand":"IBM Research","id":292838,"score":23},{"brand":"LG-Ericsson USA","id":288916,"score":20},{"brand":"Sony","id":263312,"score":20},{"brand":"Microsoft Word","id":277496,"score":17},{"brand":"Microsoft Learning","id":277503,"score":14},{"brand":"Microsoft Windows Server","开发者_开发百科id":277501,"score":11},{"brand":"Microsoft Lync","id":277502,"score":11},{"brand":"Dell Deals","id":236268,"score":7},{"brand":"HP","id":292840,"score":2},{"brand":"Dell Outlet","id":236270,"score":0}]}]};

var tree = json.sectors;
var ids = json.ids;
arr=[];
sRank={};
function active(d, v) {
            d.active = v; 
            if (d.parentNode) {
                active(d.parentNode, v);
                }
}

// used for alpha
sRank={};
for(var i in json.eranks)
{
    var sector = json.eranks[i].sector;
    sRank[sector]=[];
    for(var p in json.eranks[i].pages){
        sRank[sector].push(json.eranks[i].pages[p].brand)
    }
}
        var nodes = pv.dom(tree).root("tree").nodes();
        color = pv.Colors.category20().by(function (d) { return d.parentNode.nodeName });


        var vis = new pv.Panel()
                 .width(660)
                 .height(900);

        var treemap = vis.add(pv.Layout.Treemap)
                 .nodes(nodes);



        treemap.leaf.add(pv.Panel)
                 .fillStyle(function (d) { return color(d).alpha(1-sRank[d.parentNode.nodeName].indexOf(d.nodeName)/sRank[d.parentNode.nodeName].length) })
                 .strokeStyle("#fff")
                 .lineWidth(1)
                 .antialias(false)
                 .cursor("pointer")                  
                 .title(function(d) { return d.nodeName})
                 .event("click", function (d) {alert(d.parentNode.nodeName); });


       treemap.leaf.add(pv.Label)
            .font("20px sans-serif")
            .textBaseline("bottom")
            .text(function(d) { middle=Math.round(sRank[d.parentNode.nodeName].length/2)-1; 
            if(sRank[d.parentNode.nodeName].indexOf(d.nodeName) == middle) 
                {return d.parentNode.nodeName}}
            );

        vis.render();

The best option here is to use treemap.label, which is automatically centered for each node. By default, treemap.label has the .visible property set like this:

.visible(function(n) { return !n.firstChild; })

which only shows the label for leaf nodes. However, you can set the .visible property yourself once you've added a treemap, and change it to show only parent nodes (you have to make sure they have a parent node as well, or you get an extra, unwanted label for the root node):

treemap.label
    .visible(function(d) { return d.firstChild && d.parentNode });

In your example, you can chain this to your label, so the full snippet would look like:

treemap.label
    .visible(function(d) { return d.firstChild && d.parentNode })
  .add(pv.Label)
    .font("20px sans-serif")
    .textBaseline("bottom")
    .text(function(d) {
        return d.nodeName
    });

Working jsFiddle here: http://jsfiddle.net/nrabinowitz/T3fnT/1/