In `QuillEditor` we display paragraphs using `RichText`. The height of a
`RichText` is calculated using a `TextPainter`, basically like this:
```dart
const textSpan = TextSpan(
children: [
TextSpan(text: 'Foo '),
TextSpan(text: 'Bar', style: TextStyle(fontSize: 20, height: 1)),
],
style: TextStyle(color: Colors.black, fontSize: 16),
);
final textPainter = TextPainter(text: textSpan, textDirection: TextDirection.ltr)..layout();
print('Height of textspan: ${textPainter.height}');
// Height of textspan: 20
```
Our code looks basically like this for an empty line:
```dart
const textSpan = TextSpan(
children: [TextSpan(text: '', style: TextStyle(color: Colors.black, fontSize: 20))],
style: null,
);
final textPainter = TextPainter(text: textSpan, textDirection: TextDirection.ltr)..layout();
print('Height of textspan: ${textPainter.height}');
// Height of textspan: 16
```
Now the line wrongly has the height 16 instead of 20, which cuts off the bottom
(see issue #133) from the text. To fix this, I moved the inner `TextSpan` one
layer higher.
Now the problem occurred that a line with several heights has the size of the
strut, because we enforce this size. I couldn't figure out why the strut size
is enforced, so I removed the behavior and a line with multiple sizes is now
displayed correctly.
Closes#133.
Till Friebe
5ac3a0b425