Question

I’m trying to build a collapsible panel in Flex 4. I thought I’d use s/thing like this:

<s:Panel
    width="100%">

    <s:controlBarContent>

            <flexlib:WindowShade
                width="100% />

    </s:controlBarContent>

</s:Panel>

But that throws an error: Instantiation attempted on a non-constructor. I grabbed the flexlib zip for flex 4 but I’m still getting that error.

Is there another way to create a collapsible panel in a control bar?

Thank you for any tips!

Answer 1

You need to define the header renderer or header Class for the WindowShade component.
Looking at their code where this exception occurs
Exception is:

TypeError: Error #1007: Instantiation attempted on a non-constructor.
at flexlib.containers::WindowShade/createOrReplaceHeaderButton()[...\src\flexlib\containers\WindowShade.as:258]

The code that throws exception is this

        if(_headerRenderer) {
            _headerButton = _headerRenderer.newInstance() as Button;
        }
        else {
            var headerClass:Class = getStyle("headerClass");
           _headerButton = new headerClass();
        }

You need to define either a headerClass or a headerRenderer.
For testing purposes i used

    <s:Panel
    width="100%">

    <s:controlBarContent>

        <containers:WindowShade headerClass="mx.controls.Button"
            width="100%" />

    </s:controlBarContent>

</s:Panel>

and it works like a charm 🙂

Have fun and good luck.