Version 22 of tiled image

[...]

What is a tiled image? A tiled image is the behavior of a widget to display one or more repetitions of an image. The number of repetitions depends on the size of the widget and the size of the image.

When would I use a tiled image? If one wanted a background that had a textured feel to it, a small image , tiled, can provide that sort of optical illusion.

BLT (?) and Xbit support tiled images. With the latter,

    set tiled_image [image create gimg tiledImage -file image_file_name -tile 1]

can be used anywhere that a conventional Tk image is valid (true?).

Saverio Castellano offers,

    proc SetTiledBackground {cv img} {
      set h [image height $img]
      set w [image width $img]
      set width [$cv cget -width]
      set height [$cv cget -height]
      set row [expr $h/2]
      set col [expr $w/2]

      while {$row<$height} {
        set col [expr $w/2]
        while {$col<$width} {
           $cv create image $col $row -image $img
           incr col $w
        }
        incr row $h
      }
    }

Bryan Oakley (09 July 2003) provides a different variation that can be bound to the widget's <Configure> event so it will be retiled as the widget grows.

        # usage: tile canvasWidget ?image?
        proc tile {canvas args} {

                set oldImage [$canvas itemcget tile -image]

                switch -exact [llength $args] {
                        0 {set image $oldImage}
                        1 {set image [lindex $args 0]}
                        default {
                                return -code error "usage: tile path ?image?"
                        }
                }

                if {$image != $oldImage 
                    || [string length $image] == 0} {
                        $canvas delete all
                }

                if {[string length $image] == 0} return

                set imageHeight [image height $image]
                set imageWidth [image width $image]

                set width [winfo width $canvas]
                set height [winfo height $canvas]

                set x 0
                while {$x < $width} {
                        set y 0
                        while {$y < $height} {
                                # see if there's already a tile here
                                set tags [$canvas gettags $x/$y]
                                if {$tags == ""} {
                                        $canvas create image $x $y \
                                            -image $image \
                                            -anchor nw \
                                            -tags [list tile $x/$y] \
                                    }
                                incr y $imageHeight
                        }
                        incr x $imageWidth
                }

        }

Here's some code to test it:

        image create photo question -data {
                R0lGODlhFgAWAIUAAPwCBAQCBCQuNBwiJAwiLAwaJAwSHAwSFIy+3ERynCw2
                PCQuPAwmPCxOZCxWdJzG3FSazBwmNAQKDAQGBDRmhBQyTDxujDR2rIy21AwW
                JDyGxCxmjAwmNDRihAQOFDxmhCxunBQWFAwaLCRahDR6rESGvDQ2PCRWdDRu
                nDSGvCRSdAwWHCwuLDSOzHSmxDyKxBxCZBwqNHSu1DyOzAQSHAAAAAAAAAAA
                AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAAAAALAAAAAAWABYAAAah
                QIBwCAgIBAPCoGAgOoeBAyKhWCwYDUf0CX1AIhLiJEGpBLiAAaRxdgYsl7Yb
                k8igBZoN5xmAdDxoanp8HyANISF8EBsiXBMjJBolBEQmGHFoRScbKHIKDykq
                K5lFAZRCnyknTaROLA8tq61OChgtKqyzQgEYEJi6UC4vI3LAASkbMBPARAEB
                dszR0sACEaPSMTIQM8W6KzNl3bo0NOJDdEEAIf5oQ3JlYXRlZCBieSBCTVBU
                b0dJRiBQcm8gdmVyc2lvbiAyLjUNCqkgRGV2ZWxDb3IgMTk5NywxOTk4LiBB
                bGwgcmlnaHRzIHJlc2VydmVkLg0KaHR0cDovL3d3dy5kZXZlbGNvci5jb20A
                Ow==
        }
        canvas .c
        tile .c question
        bind .c <Configure> [list tile %W]
        pack .c -side top -fill both -expand y

DKF: I prefer to create a single pre-tiled image of the required size when the canvas isn't too large; the memory consumption is more, but the script is much shorter...

 image create photo foo -data {...}
 $canvas create image 0 0 -anchor nw -image [image create photo foo-tiled]
 foo-tiled copy foo -to 0 0 [winfo width $canvas] [winfo height $canvas]
 # Yes, that's all it takes folks!  photo image copying tiles for you!

(Bryan Oakley sez: very impressive! Nice job, Donal)

Apparently a variation on all this is the "tile extension" [L1 ], maintained as a subproject of tktable. It "is a testing ground for an improved version of the Tk styling engine." (no, the tile extension isn't "apparently a variation on all this"; they are completely unrelated).

It apparently give the ability to create applications with native GTK looks. Is the texturing all that people mean when they talk about GTK's appearance?

Will the tile extension make it into 8.5?

ABU: Here is my little contribution.

tcanvas is a pure-tcl widget written using Snit.

Here is a sample