PangoLayout used to display the entry.
The layout is useful to e.g. convert text positions to
pixel positions, in combination with gtkEntryGetLayoutOffsets.gtkEntryGetLayout(object)objectGtkEntryPangoLayout] the PangoLayout for this entry. [ transfer none ]gtkEntryLayoutIndexToTextIndex and
gtkEntryTextIndexToLayoutIndex are needed to convert byte
indices in the layout to byte indices in the entry contents.