PreferredHeight
virtual float PreferredHeight();
virtual float PreferredHeight() = 0;
virtual float PreferredHeight();
virtual float PreferredHeight() const;
height = max_c(height, fEditorView->PreferredHeight());
float PreferredHeight() const;
height += item->PreferredHeight() + 1.0;
float height = item->PreferredHeight();
BSize(B_SIZE_UNLIMITED, PreferredHeight()));
minSize.height = PreferredHeight();