computeLineMetrics method Null safety
Returns the full list of LineMetrics that describe in detail the various
metrics of each laid out line.
The LineMetrics list is presented in the order of the lines they represent.
For example, the first line is in the zeroth index.
LineMetrics contains measurements such as ascent, descent, baseline, and
width for the line as a whole, and may be useful for aligning additional
widgets to a particular line.
Valid only after layout has been called.
Implementation
List<ui.LineMetrics> computeLineMetrics() {
assert(_debugAssertTextLayoutIsValid);
return _lineMetricsCache ??= _paragraph!.computeLineMetrics();
}