Change the style of nodes

Question

In my project I using gwt 2.5.1 and gxt 3.0.1. I create Tree.

    protected void createTree(TreeStore<ProjectExtended> treeStore) {

    ValueProvider<ProjectExtended, SafeHtml> provider = new ValueProvider<ProjectExtended, SafeHtml>() {

        @Override
        public void setValue(ProjectExtended object, SafeHtml value) {

        }

        @Override
        public SafeHtml getValue(ProjectExtended object) {

            if(object == null) return SafeHtmlUtils.EMPTY_SAFE_HTML;

            if (!object.getActive()) {
                return SafeHtmlUtils.fromTrustedString(
                        "<span class=\"projectNotActive\">" + object.getName() + 
                        "</span> " + "<span class=\"dictIdText\"> ( " + 
                        object.getId() + " / " + object.getParentId() + " ) </span>");
            } else {
                return SafeHtmlUtils.fromTrustedString(
                        object.getName() + "<span class=\"dictIdText\"> ( " +
                        object.getId() + " / " + object.getParentId() + " ) </span>");
            }
        }

        @Override
        public String getPath() {
            return "name";
        }
    };

    Tree<ProjectExtended, SafeHtml> tree = new Tree<ProjectExtended, SafeHtml>(treeStore, provider);
    tree.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);

    add(tree);
}

I try to change the style of nodes which aren't active. But I can't solve this problem, because browser displayes them wrong!

https://i.sstatic.net/0Jmdq.png

is there a way to solve this?

Answer 1

I solved the problem. The article which helped is here.

There’s a simple example of code.

1. You should create an inherited class AbstractCell and override the render method:

   public class SimpleAbstractCell extends AbstractCell<String> {
   
       @Override
       public void render(Context context, String value, SafeHtmlBuilder sb) {
           /*
           * Always do a null check on the value. Cell widgets can pass null to
           * cells if the underlying data contains a null, or if the data arrives
           * out of order.
           */
           if (value == null) {
               return;
           }
   
           SafeHtml safeValue = SafeHtmlUtils.fromTrustedString(value);
           sb.append(safeValue);
       }
   }
   

2. During creation a tree you should declare contentCell:

   protected void createTree(TreeStore<ProjectExtended> treeStore) {
   
       ValueProvider<ProjectExtended, String> provider = new ValueProvider<ProjectExtended, String>() {
   
           @Override
           public void setValue(ProjectExtended object, String value) {
   
           }
   
           @Override
           public String getValue(ProjectExtended object) {
   
               if(object == null) return "";
   
               if (!object.getActive()) {
                   return 
                       "<span class=\"projectNotActive\">" + object.getName() + 
                       "</span> " + "<span class=\"dictIdText\"> ( " + 
                       object.getId() + " / " + object.getParentId() + " ) </span>";
               } else {
                   return 
                       object.getName() + "<span class=\"dictIdText\"> ( " +
                       object.getId() + " / " + object.getParentId() + " ) </span>";
               }
           }
   
           @Override
           public String getPath() {
               return "name";
           }
       };
   
       Tree<ProjectExtended, String> tree = new Tree<ProjectExtended, String>(treeStore, provider);
       tree.setCell(new SimpleAbstractCell());
       tree.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
   
       add(tree);
   }
   

That’s all. I hope it’ll be useful for smb.