How do I fix this potential bug with the ComboBox Component in Flash ?

Question

When I add a ComboBox component into a Sprite, the height of the container is larger than it should.

Here's what I mean:

import fl.controls.ComboBox;
//add combo box inside a container sprite
var combo:ComboBox = new ComboBox();
var container:Sprite = new Sprite();
addChild(container);
container.addChild(combo);
//draw the outline of the container sprite
container.graphics.lineStyle(1,0x009900);
container.graphics.drawRect(0,0,container.width,container.height);
//I don't get this:
trace(combo.height);//outputs 22
trace(container.height);//outputs 101

Note: You will need the ComboBox component in your Library. I'm using Flash CS3 for this.

If I invalidate/redraw, like this:

combo.invalidate(InvalidationType.ALL,true);
combo.drawNow();

the height changes from 101 to 104.

Any solutions ?

UPDATE: I've overwritten the configUI method in a ComboBox subclass, but the measurements are correct all the time. Why does the container height change to 100 ?

Answer 1

So - I guess the displayed height of ComboBox is the actual height - id est, if it is opened, then the height WITH the drop down box, if not then WITHOUT. However - the items are STILL there, although with .visible set to false, which still expands the container, even if you can't see that... Therefore - I would say to do:

container.graphics.drawRect(0, 0, combo.width, combo.height);

That is the way to usually do it as well...

Answer 2

can you setup manually before this code:

container.width=100;

container.height=100;

container.graphics.drawRect(0,0,container.width,container.height);

Answer 3

"if it is opened, then the height WITH the drop down box"

Hmm, I think when the list is added to the displayList below the button its actually added has a popup. So the height is supposed to remain the button height, since the sprite will never actually contain the drop-down list.

A possible reason the Container height could be wrong before it goes through any invalidation could be due to the children it contains. Maybe the combobox skin (could be a movieClip of 102px height) or a combobox sub-component that always start at 102px height or with weird height (TextField in a Button is known to be sometime wrong).

A simple solution would be to wait until a creationComplete/added event and see what is the final height, then draw the border.