Disable Tree Item

Vaadin 6 / 7 / 8 Framework UI
1

Hi,
I want to disable items of tree, I use this:

Tree.setEnabled(false);

that disable all tree nodes and items.
but How can I disable just some items of tree component ?

2

There isn’t a built-in way to “disable” tree nodes. You can somewhat easily prevent selecting “disabled” items by reverting any disallowed selection to the previous selection. This requires that you set the tree in immediate mode though. You can also style tree nodes to look as “disabled”:

final Tree tree = new Tree("My Tree");
tree.setContainerDataSource(createTreeContent());
        
// Show all leaf nodes as disabled
tree.setItemStyleGenerator(new Tree.ItemStyleGenerator() {
    public String getStyle(Object itemId) {
        if (! tree.hasChildren(itemId))
            return "disabled";
        return null;
    }
});
        
// Disallow selecting "disabled" leaf nodes
tree.addListener(new Property.ValueChangeListener() {
    Object previous = null;

    public void valueChange(ValueChangeEvent event) {
        if (! tree.hasChildren(tree.getValue()))
            tree.setValue(previous);
        else
            previous = tree.getValue();
    }
});
tree.setImmediate(true);
        
layout.addComponent(tree);

And the CSS:

.v-tree-node-caption-disabled {
    color: graytext;
    font-style: italic;
}

See a
live example

3

Hi,
I use:

tree.setItemStyleGenerator(new Tree.ItemStyleGenerator() {
     public String getStyle(Object itemId) {
         if (! tree.hasChildren(itemId))
             return "disabled";
        return null;
   }
});

and it is very helpfull ! thanks

4

Nice trick. Note that end users may still tamper with the messages being sent from the client-side (browser) into server-side and actually select nodes that you expect not to be ever selected. If you are strict about logic / security, you might want to check that only correct values have been selected.

5

Hi,
I have a tree with items that get store after button click into the panel and i have a combobox with some four values if i select specific second value from ComboBox and press the Button then only it has to show the Tree item in the panel otherwise it should not show the item at all how i can achieve this can u please help me regarding this

6

Hey Ranjit,

Are you talking about filtering? Perhaps this might help:
https://vaadin.com/forum/#!/thread/264195/264194
.

Here’s an example:
https://dev.vaadin.com/svn/doc/book-examples/trunk/src/com/vaadin/book/examples/datamodel/ContainerFilterExample.java
.

7

Hi,

its been 5 years since last one replied here.

is there still the problem with disabling items on a Vaadin (8) Tree?
i mean beside the workaround Marko Grönroos mentioned.