rm default font will be used.</li><li><code>fontSize</code>: The size of glyphs (in logical pixels) to use when painting the text.</li><li><code>letterSpacing</code>: The amount of space (in logical pixels) to add between each letter.</li><li><code>wordSpacing</code>: The amount of space (in logical pixels) to add at each sequence of white-space (i.e. between each word).</li><li><code>textBaseline</code>: The common baseline that should be aligned between this text span and its parent text span, or, for the