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From: jmc on 26 Jul 2010 12:17
Hello,

On the console, I create an image, and after, try to verify this image
is actually created :

Here is a "copy and paste" for what I did :

(Images) 32 % image create photo testRawImage -data $rawData
testRawImage
(Images) 33 % info exists testRawImage
0


I believe "info exists" (Tcl) is not the right tool to make a check
for the result of a Tk command, but looking in the doc either for
"winfo" or "info" command, I can't find anything which suit my need.

Thanks in advance.


Jean-Marie
From: jmc on 26 Jul 2010 13:18
On 26 juil, 18:33, George Petasis <petas...(a)yahoo.gr> wrote:
> Στις 26/7/2010 7:17 μμ, ο/η jmc έγραψε:
>
>
>
> > Hello,
>
> > On the console, I create an image, and after, try to verify this image
> > is actually created :
>
> > Here is a "copy and paste" for what I did :
>
> > (Images) 32 % image create photo testRawImage -data $rawData
> > testRawImage
> > (Images) 33 % info exists testRawImage
> > 0
>
> > I believe "info exists" (Tcl) is not the right tool to make a check
> > for the result of a Tk command, but looking in the doc either for
> > "winfo" or "info" command, I can't find anything which suit my need.
>
> > Thanks in advance.
>
> > Jean-Marie
>
> There are several way to check:
>
> 1) image names returns a list of all images. You can check if the image
> is in the returned list.
>
> 2) Another way is to check commands, if you know the image command name:
>     llength [info commands image_name] == 1
>
> 3) Call the image command directly: <image_name> cget - height, around a
> catch statement.
>
> George

(I don't see my preceding reply posted - sorry for repetition)

Thanks George : "image names" suit my need

Jean-Marie
From: jmc on 26 Jul 2010 16:39
On 26 juil, 19:33, "Gerald W. Lester" <Gerald.Les...(a)KnG-
Consulting.net> wrote:
> jmc wrote:
> > Hello,
>
> > On the console, I create an image, and after, try to verify this image
> > is actually created :
>
> > Here is a "copy and paste" for what I did :
>
> > (Images) 32 % image create photo testRawImage -data $rawData
> > testRawImage
> > (Images) 33 % info exists testRawImage
> > 0
>
> > I believe "info exists" (Tcl) is not the right tool to make a check
> > for the result of a Tk command, but looking in the doc either for
> > "winfo" or "info" command, I can't find anything which suit my need.
>
> While George gave you a solution, I'd like to point out why [info exists]
> did not work -- it checks for the existence of a *variable* not a command..
> The [image create] command creates a new command, not a variable.
>
> --
> +------------------------------------------------------------------------+
> | Gerald W. Lester, President, KNG Consulting LLC                        |
> | Email: Gerald.Les...(a)kng-consulting.net                                |
> +------------------------------------------------------------------------+

Thanks Gerald for this precision. I read this in the doc and forget it
quite immediately because it is not clear to me :

a) on what does act this "command" (the name of an image for
instance) ?
b) It seems that this kind of user defined command in Tcl/Tk has not
the same meaning as others like "proc". I'm not sure but reading the
doc I would bet that "info command" doesn't output image names
(defined as command).

Jean-Marie

From: jmc on 26 Jul 2010 18:36
On 26 juil, 23:12, "Gerald W. Lester" <Gerald.Les...(a)KnG-
Consulting.net> wrote:
> jmc wrote:
> > On 26 juil, 19:33, "Gerald W. Lester" <Gerald.Les...(a)KnG-
> > Consulting.net> wrote:
> >> jmc wrote:
> >>> Hello,
> >>> On the console, I create an image, and after, try to verify this image
> >>> is actually created :
> >>> Here is a "copy and paste" for what I did :
> >>> (Images) 32 % image create photo testRawImage -data $rawData
> >>> testRawImage
> >>> (Images) 33 % info exists testRawImage
> >>> 0
> >>> I believe "info exists" (Tcl) is not the right tool to make a check
> >>> for the result of a Tk command, but looking in the doc either for
> >>> "winfo" or "info" command, I can't find anything which suit my need.
> >> While George gave you a solution, I'd like to point out why [info exists]
> >> did not work -- it checks for the existence of a *variable* not a command.
> >> The [image create] command creates a new command, not a variable.
>
> > Thanks Gerald for this precision. I read this in the doc and forget it
> > quite immediately because it is not clear to me :
>
> > a) on what does act this "command" (the name of an image for
> > instance) ?
>
> It acts on the created image.  The particular subcommands depend on the type
> of image, photo or bitmap.  To see what subcommands are available look at
> the appropriate man/help page (photo or bitmap).
>
> > b) It seems that this kind of user defined command in Tcl/Tk has not
> > the same meaning as others like "proc". I'm not sure but reading the
> > doc I would bet that "info command" doesn't output image names
> > (defined as command).
>
> It indeed has the exact same meaning as other commands.  BTW, you lose your
> bet on the [info command] -- you owe me a bottle of good beer! :)
>
> Try:
>         image create photo testRawImage -data $rawData
>         info command *RawImage
>
> --
> +------------------------------------------------------------------------+
> | Gerald W. Lester, President, KNG Consulting LLC                        |
> | Email: Gerald.Les...(a)kng-consulting.net                                |
> +------------------------------------------------------------------------+

Just verified (should have done before...). And yes I can see now the
usefullness of patern matching for such command... Ok I loose my bet
and I owe you a really good beer! Thanks again for your explanation.

Jean-Marie
From: jmc on 26 Jul 2010 20:38
On 27 juil, 01:24, S...(a)ControlQ.com wrote:
> On Mon, 26 Jul 2010, jmc wrote:
> > Hello,
>
> > On the console, I create an image, and after, try to verify this image
> > is actually created :
>
> > Here is a "copy and paste" for what I did :
>
> > (Images) 32 % image create photo testRawImage -data $rawData
> > testRawImage
> > (Images) 33 % info exists testRawImage
> > 0
>
> > I believe "info exists" (Tcl) is not the right tool to make a check
> > for the result of a Tk command, but looking in the doc either for
> > "winfo" or "info" command, I can't find anything which suit my need.
>
> > Thanks in advance.
>
> > Jean-Marie
>
> Jean-Marie,
>
> I took the slightly different approach of creating the image when
> needed, and then caching it, so that you use a simple interface to
> reference ALL images ...
>
> namespace eval img {
>    array set pic {}
>
>    proc getImage { clr btn } {
>      set idx [format "%s_%s" $clr $btn]
>      set ix [lsearch [array names img::pic] $idx]
>      if { $ix < 0 } {
>        return [img::newImage $clr $btn]
>      }
>      return $img::pic($idx)
>    }
>
>    proc newImage { clr btn } {
>      set idx [format "%s_%s" $clr $btn]
>      set img::pic($idx) {}
>      if [file exists images/$clr/$btn.gif ] {
>        set img::pic($idx) [image create photo img_$idx]
>        $img::pic($idx) read images/$clr/$btn.gif
>      }
>      return $img::pic($idx)
>    }
>
> }
>
>    grid configure [ttk::button $btn -image [img::getImage $clr $b] -command doSomething ]
>         -row $r -column $c
>
> This uses namespaces, and creates an array indexed by the colour and name
> of the image file ... if the image exists, the pre-created reference is
> returned by getImage, and if not, getImage references newImage to create it,
> and saves the reference ... In my case it was convenient to index by colour
> and name, but this is entirely dependant upon your problem domain ... it is
> particularly useful for icons and button labels ...
>
> HTH, Cheers,
> Rob Sciuk.

Thanks Rob. Very interesting. I didn't realize it was possible to
store a command in an array. Cool !

Jean-Marie
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