Checkbox Tree to Radio Tree

[Tim Hooper <Th...@woh.rr.com>]

I want to convert the Checkbox Tree control into a Radio button tree control.  
Seems like it shouldn't be that hard.  I've used the Click framework controls, 
but never made one myself.  Any pointers on how to get started?

Re: Checkbox Tree to Radio Tree

[Bob Schellink <sa...@gmail.com>]

Hi Tim,

Tim Hooper wrote:
> I want to convert the Checkbox Tree control into a Radio button tree control.  
> Seems like it shouldn't be that hard.  I've used the Click framework controls, 
> but never made one myself.  Any pointers on how to get started?


I just had a look at the CheckboxTree and its not as straightforward 
to change from checkbox to radio as it could be. Ideally Tree should 
expose a method such as #createControl which returns a Checkbox but 
could be overridden to return a Radio.

In the meantime you could create a custom RadioTree which extends 
CheckboxTree and specify a custom Decorator.

Below is some code which could help.

kind regards

bob


     class RadioTree extends CheckboxTree {
         public RadioTree(String name) {
             super(name);
             setDecorator(new RadioDecorator());
         }

         class RadioDecorator implements Decorator {
             public String render(Object object, Context context) {
                 TreeNode treeNode = (TreeNode) object;
                 HtmlStringBuffer buffer = new HtmlStringBuffer();

                 renderIcon(buffer, treeNode);

                 buffer.append("<input ");
                 buffer.append(" style=\"margin:0\" type=\"radio\"");
                 buffer.appendAttribute("name", SELECT_TREE_NODE_PARAM);
                 buffer.appendAttribute("value", treeNode.getId());

                 if (treeNode.isSelected()) {
                     buffer.appendAttribute("checked", "checked");
                 }

                 buffer.elementEnd();

                 buffer.elementStart("span");
                 if (treeNode.isSelected()) {
                     buffer.appendAttribute("class", "selected");
                 } else {
                     buffer.appendAttribute("class", "unselected");
                 }
                 buffer.closeTag();

                 renderValue(buffer, treeNode);
                 buffer.elementEnd("span");

                 return buffer.toString();
             }

             /**
              * Render the node's value.
              *
              * @param buffer string buffer containing the markup
              * @param treeNode treeNode to render
              */
             protected void renderValue(HtmlStringBuffer buffer, 
TreeNode treeNode) {

                 //just print normal value
                 if (treeNode.getValue() != null) {
                     buffer.append(treeNode.getValue());
                 }
                 buffer.append("\n");
             }
         }
     }