tk_chooseColor

tk_chooseColor, a Tk command, provides a color picker.

Documentation edit

official reference

Synopsis edit

: tk_chooseColor ?option value ...?

Description edit

The following option-value pairs are possible as command line arguments:

: -initialcolor color

Specifies the color to display in the color dialog when it pops up. Color must be in a form acceptable to the Tk_GetColor function.

: -parent window

Makes window the logical parent of the color dialog. The color dialog is displayed on top of its parent window.

: -title titleString

Specifies a string to display as the title of the dialog box. If this option is not specified, then a default title will be displayed.

tk_chooseColor returns the name of the color selected by the user, in a form acceptable to Tk_GetColor. If the user cancels the operation, the command returns the empty string.

Examples edit

button .b -bg [tk_chooseColor -initialcolor gray -title "Choose color"]

A minimal example:

button .b_fg -text "Set Foreground Color" -command {fg_color}
button .b_bg -text "Set Background Color" -command {bg_color}
label .l -text "Foreground Color on Background Color"

grid .b_fg .b_bg -sticky ew
grid .l -row 1 -columnspan 2 -sticky ew

proc fg_color { } {
    set color [tk_chooseColor]
    .l configure -fg $color
}

proc bg_color { } {
    set color [tk_chooseColor]
    .l configure -bg $color
}

wm title . {tk_chooseColor Example}

RS: A style note - no doubt this works as planned, but for more reusable (and also more compact) code, why not pass in the target widget, and the target attribute as well?

button .b_fg -text "Set Foreground Color" -command {color .l -fg}
button .b_bg -text "Set Background Color" -command {color .l -bg}
label .l -text "Foreground Color on Background Color"

grid .b_fg .b_bg -sticky ew
grid .l -row 1 -columnspan 2 -sticky ew

proc color {w what} {
    set color [tk_chooseColor]
    $w configure $what $color
}

For a tiny bit more safety, CL recommends instead

proc color {w what} {
    set color [tk_chooseColor]
        # "Cancel" means, "do nothing".
    if {$color eq {}} return
    $w configure $what $color
}

Michael Schlenker contributed the following example of the use of this function over on comp.lang.tcl:

# set color variable to color value returned from tk_chooseColor
set color [tk_chooseColor]
# be .c an canvas with some objects in it , sets the -fill color of all
# items to $color
.c itemconfigure all -fill $color

Robert Heller also answered in the same comp.lang.tcl thread with this code fragment:

canvas .thecanvas
pack .thecanvas
.thecanvas create oval 0 0 50 50 -fill red -outline blue -tag theOval
.thecanvas itemconfigure theOval -fill [
    tk_chooseColor -initialcolor [.thecanvas itemcget theOval -fill]]
.thecanvas itemconfigure theOval -outline [
    tk_chooseColor -initialcolor [.thecanvas itemcget theOval -outline]]

Arts and Crafts of Tcl-Tk Programming