How do you correctly retrieve the in use color of the text of a Label VisualElement?

Unity Engine
, ,
1

I have a CustomLabel:

[UxmlElement]
public partial class CustomLabel : Label
{
  [UxmlAttribute]
  public Color HighlightColor { get; set; } = Color.yellow;

  private Color m_prior_color;
  private bool  m_enabled_highlight;
 
  //=================================
  public bool EnableHighlight
  {
    get {  return m_enabled_highlight; }
    set {
      m_enabled_highlight = value;
      if (m_enabled_highlight) {
        m_prior_color = style.color.value;
        style.color = HighlightColor;
      } else {
        style.color = m_prior_color;
      }
    }
  }
}

UXML builder properly shows HighlightColor as a field and I can set it’s color value.
When I use code to set EnableHighlight = true, the color of the Label’s text changes correctly.
When I set EnableHighlight = false, the color of the Label’s text get’s set to RGBA(0,0,0,0) which is NOT what the original color was. The original color was white, as the color is actually unset/undefined.
When I explicitly set the color to something specific, I can properly see the new color, and change it to the HighlightColor, but again when I turn Highlight back off, it gets set to RGBA(0,0,0,0), and not the correct prior color.
When stepping through the code The value held by style.color.keyword has a value of “Null” and has the default RGBA(0,0,0,0) as the value retrieved from style.color.value. (explaining why it gets set to that via the above code)

From where do I read the correct original color value so I can save and restore it later? (Or is this a bug?)

Please do not suggest uss action themes like :hover, :active, :focus, etc. This is not my intent, I explicitly need to dynamically swap colors via code independently of those kind of trigger actions.

2

VisualElement.style is the styles you assign via code.

VisualElement.resolvedStyle is the current state of all styles after style sheets and code styles have been applied.

3

Thank you, that mostly worked. Mostly because I enable the highlight when a different control receives focus and I am setting the focus immediately when the uxml document is displayed. Apparently, styles are not fully resolved yet? I get a RGB(0,0,0,1) instead of its correct color. It does work on other controls that I trigger afterwards through various user interactions. I suspect I’ll need to delay a frame before assigning the focus which is the initial cause of the highlight trigger.

Edit: Confirmed, have to wait a frame for styles to resolve before triggering code that is going to read from resolvedStyle.