Can the default line width sizes be changed?

[steve.ledger]

No, the mouse wheel does not do that. Soquili got it right.

I wonder why you would be so definate? Because it certianly does ol' bean..

In Xara's mousewheel implementation you can't still control the line width outside the strange default values,

Agreed, but certainly the one click'n'roll' method does work and produces a similar result as a spin-control would with the same parameters.

Of course when rolling the mouse wheel (and watching the line thickness change in real-time) the preset (your strange default values..?) thicknesses are chosen in sequence rather than the tiniest of possible increments. But this is hardly a major issue because I can customise this by entering the precise value if necesary. I am not constrained by or limited to the presets.

......and you need to click in the box and also click inside the document to free the focus from the field. Try this with a drawing tool selected.

Not sure I fully follow that sentence, but I was able to draw a squiggly line with the freehand (drawing) tool, click 'once' inside the line thickness control and spin the mouse wheel and watch the line thickness change in real-time, up and down with the direction I spun the wheel..
One click back to the document and I'm back drawing.
But seriously, in a vector program where creating/removing [many nodes] /adjusting/sizing/rotating and colouring objects many many many times over to get it just right is all part of the normal workflow routine - are we really going to be concerned about mouse clicks???

Is this not going down the 'I want everything to work my way' route which we see crop up all too often.
Customisation at any level is only ever going to be 'within allowable parameters'.

I'd prefer to buy just 6 rissoles, but the supermarket butcher only packs them in qtys of 9. Life goes on.