gwt - 改变节点的样式

Question

在我的项目中，我使用gwt 2.5.1和gxt 3.0.1。我创建树。

    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);
}

我尝试更改不活动节点的样式。但我无法解决这个问题，因为浏览器显示错误！

http://i.stack.imgur.com/0Jmdq.png

有没有办法解决这个问题？

Answer 1

我解决了这个问题。有帮助的文章在这里。

有一个简单的代码示例。

1. 您应该创建一个继承类 AbstractCell 并覆盖 render 方法：

   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. 在创建树期间，您应该声明 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);
   }
   

就这样。我希望它对 smb 有用。