RE: Toolbar redraw causes unwanted selection

[Drew Adams]

I said:

> I currently estimate [tool-bar height] at 2 * frame-char-height *
> tool-bar-lines, and that works well. (I treat a nil value as 0.)

Before someone else jumps in to say that the tool-bar height is unrelated to
the frame-char-height: yes, I realize that. That formula works well for some
common character sizes, but it would perhaps be better to use a constant.

It would be great if there were a variable or frame parameter that reflected
the tool-bar height or the height of a single tool-bar line (so height would
be that times `tool-bar-lines'). I imagine that such a height could be
different for different toolkits etc.