Flex - Subclassing VBox in MXML to use as a base component, advice needed

Question

I'd like to extend VBox to add some "defaults" and a bit of boilerplate-ish code (let's call it "VBoxSub" here), the idea being that "pages" in the application would extend this VBox subclass.

This seems to work fine except that the final classes extending "VBoxSub" don't inherit the width/height settings set in VBoxSub when in Flash Builder's design mode. When switching to design mode with the component empty, all it shows is a tiny plain box instead of a larger 1000x700 working area with the default VBox css background color. What's going on here? (Yeah I've tried refreshing/restarting design view.)

I'd like to have each of these components all be exactly the same size so that when laying out the UI I know exactly how much space I have to work with - preferably without having to copy/paste the width and height attributes into every darn mxml file (and having to worry about updating each one if the w/h ever change!). (Using Flash Builder 4, SDK 4.1)

I've tried doing this to get it to work, but still no good in Design View:

override protected function measure():void {
    super.measure();

    measuredWidth=1000;
    measuredMinWidth=1000;
    measuredHeight=700;
    measuredMinHeight=700;
}

Do I really need to hard code width/height in every component "page" within the application?

SteAp SteAp · Accepted Answer · 2011-09-20T00:11:12

Flash Builder doesn't execute Actionscript in design mode. Since the AS code doesn't get executed, the VBox doesn't get measured in design mode.

You need to use declarative MXML in such a situation.

Flex - Subclassing VBox in MXML to use as a base component, advice needed

1 Answers