@Override
				public Dimension getPreferredSize() {
					// rendering HTML the label can expand larger than the screen; keep it reasonable
					Dimension size = super.getPreferredSize();
					size.width = 300;
					return size;
				}
This spacer addresses the optical impression that the message panel changes size when showing details
Ghidra/Framework/Docking/src/main/java/docking/ErrLogExpandableDialog.java