Doubleclick selection bugs

[Integral]

[obuchtala]

@Integral can u check if this still is a problem?
Can't reproduce it here.

[obuchtala]

Ah... now i could reproduce it.

1. Empty doc so that there is only one paragraph
2. Select the whole line via double-click/triple-click(osx)
3. The selection is mapped incorrectly (collapsed at position 0)

[obuchtala]

Fixed.

[obuchtala]

For the records: we need to be careful to which element a surface is attached.
In this case, it was attached to a too high-level element, leading to undesired possible cursor positions.
In future we might improve the implementation in SurfaceSelection, but now it is better to have the surface element as close to the node elements as possible.

[Integral]

Still here:

[obuchtala]

A better description:
When you triple-click 'between' two paragraphs the selection is expanded to the second paragraph after double click but reduced to the first paragraph after 3rd click.

[obuchtala]

It seems that expanding the selection to the second paragraph is a bug.
Particularly, as the amount the second one gets selected is exactly the length of the first paragraph.

[obuchtala]

If the first paragraph is longer than the second, the selection disappears after double-click.

[Integral]

Exactly, but it's happened with doubleckick.