Broken VirtualTree theme item

[goldim]

Looks like VirtualTree somehow broken. I see now picture of folder by default.
ville.Fluent theme:

classic.Theme:

My code:

qx.Class.define("scada.signalmonitor.tree.Item", {
    extend: qx.ui.tree.VirtualTreeItem,

    properties: {
        checked: {
            check : "Boolean",
            event: "changeChecked",
            nullable : true
        },

        image: {
            check : "String",
            event: "changeImage",
            nullable : true
        },

        count: {
            check : "String",
            event: "changeCount",
            nullable : true
        }
    },

    members: {
        __checkbox : null,
        __image : null,
        __count : null,

        _addWidgets(){
            this.addSpacer();
            this.addOpenButton();

            this.addIcon();
            this.bind("image", this, "icon");

            this.__checkbox = this.__createCheckBox();
            this.addWidget(this.__checkbox);
            this.addLabel();

            this.addListener("click", function(e) {
                if (e.getTarget() !== this.getChildControl("open")){
                    this.__checkbox.execute();
                }
            }, this);

            this.__checkbox.addListener("click", function(e) {
                e.stopPropagation();
            }, this);

            // All else should be right justified
            this.addWidget(new qx.ui.core.Spacer(), {flex: 1});
        },

        __createCheckBox(){
            const checkbox = new qx.ui.form.CheckBox().set({
                focusable: false,
                triState: true,
                marginRight: 4
            });
            this.bind("checked", checkbox, "value");
            checkbox.bind("value", this, "checked");
            return checkbox;
        }
    }
});

[sqville]

@goldim I hunted all around demos and it looks like that's the default behavior when the tree-folder is included in the theme. I'll keep testing to see what I can find out. Leaving this item open and unlabeled for now.

[goldim]

Ok, if I have a little spare time I will check it out myself.