Re: [XForms] Is there some way of putting a semi transparent box on an xyplot?

[Jens Thoms Toerring]

hi bill,

On Mon, Apr 29, 2013 at 03:29:00PM -0700, Bill Unruh wrote:
> Is there some way of putting a semi transparent box on top of an xyplot? In
> many programs one can select a part of the polt image-- eg for purposes of
> exanding the axes so as to include only that part of the image. But I can find
> no way of doing that in xforms. Ie, I want to put the mouse on one part of the
> image, hold left button down and drag it across the image. This will then
> change the shading of that part of the image-- either in a box whose corner is
> the place where the mouse was first left clicked to the current location of
> the mouse, or even the whole y range with x values greyed from where the mouse
> was first clicked to where the left botton was release. But the only thing
> which seems to have a "transparent" colour behaviour seems to be the overlay
> postioner, which is not sufficient. Is there anything else in xforms which
> would allow this behaviour that I have missed? (even something like "Box A
> lies on top of box B but is semi transparent so you can see what is
> underneath". Under "Images" the semitranparent "glass" seems to do
> something like this but
> that would not seem to be applicable to other objects.
> 
> 
> Some sort of overlay would parhaps work, but I have no idea how to make the
> colour on the overlay a transparent colour.

I fear that I have to disapoint you, but to my knowledge there's
no support for any kind of transparency in XForms. As far as I
know X itself only started to support transparency a relatively
short time ago (via some extensions), and that was quite some
time after XForms was developed. I don't know what you're refer-
ring to with "Images" and "glass", so I can't comment on this.

That doesn't necessarily mean that it's impossible to do - perhaps
someone else here on the mailing list has some nice ideas.

                             Best regards, Jens
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