Basically PosRelativeToAnchor/Anchor does not seem to work if you are anchoring more than one component that is already anchored.
No. You can!
Here my hints:
[please, update LAMW from github]
You can get some device information using "jForm" methods
and handling jForm "OnJNIPrompt event":
Self.GetScreenSize() //"XLARGE" or "LARGE" or "NORMAL" or "SMALL"
Self.GetScreenDensity() //"XXHIGH" or "XHIGH" or "HIGH" or "MEDIUM" or "LOW"
and property:
Self.ScreenWH.Width
Self.ScreenWH.Height
And then change the components position and layout
[According to your need]
jTextView1.PosRelativeToParent:= [rpTop, rpLeft];
jTextView1.ResetAllRules();
jTextView1.UpdateLayout();
jButton1.LayoutParamWidth:= lpHalfOfParent;
jButton1.PosRelativeToParent:= [rpCenterHorizontal];
jButton1.PosRelativeToAnchor:= [raBelow];
jButton1.ResetAllRules();
jButton1.UpdateLayout();