Re: [TCLCORE] TIP #262: Background Images for Frames

[Eric T. <et...@ro...>]

At 08:15 AM 4/3/2006 -0700, Peter MacDonald wrote:

>Currently a bgimage can be implement in canvas at the script level, but it is 
>messy and there is no such option for text...

A number of good ideas have surfaced since the TIP was 
published.

-------- canvas approach 

I've been experimenting using canvases in place of frames, 
and I'm now wondering what, if anything, a canvas cannot do 
that a frame can do. I've experimented with nested canvases, 
just like nested frames and so far it all seems to work.

I've also seen some pure tcl code that will tile an image.

The one other idea that has surfaced, and for which I was 
about to modify the TIP, was to add an option for 
transparency. If a canvas's background image could be made 
transparent then perhaps there's no need to change frames.

I was also thinking that when implementing transparency, one 
would use

-transparent <float> 


where 0. was totally opaque, and 1. was totally transparent. 
This could potentially allow for semi-transparency. If a 
system couldn't implement this, it could just then round the 
value to 0/1 for opaque/transparent.

If this was a configurable option, then some cool fade in/out 
effects on images could be created by stepping the value 
between 0. .. 1. over a short timespan. 

-------  paved widgets 

It has also come to my attention that there's a package 
called Paved::widgets which does do tiling and also 
background images. It can transform an existing frame into a 
Paved::frame.

http://web.tiscali.it/irrational/tcl/paved1.1/doc/index.html


I have posted a question about transparency, and the only 
other issue might be that this also requires the snit 
package. I've often had difficulty with scripts that need 
lots of packages, as they then become much more difficult to 
deploy. But that's just my situation. 


Eric Taylor