source: branches/uiuc_vtk_viewers/gui/scripts/switch.tcl @ 5033

# -*- mode: tcl; indent-tabs-mode: nil -*- 
# ----------------------------------------------------------------------
#  COMPONENT: switch - on/off switch
#
#  This widget is used to control a (boolean) on/off value.  
# It is just a wrapper around a button.
# ======================================================================
#  AUTHOR:  Michael McLennan, Purdue University
#  Copyright (c) 2004-2012  HUBzero Foundation, LLC
#
#  See the file "license.terms" for information on usage and
#  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# ======================================================================
package require Itk

itcl::class Rappture::Switch {
    inherit itk::Widget

    itk_option define -oncolor onColor Color "#00cc00"
    itk_option define -state state State "normal"
    itk_option define -showimage showimage Showimage "true"
    itk_option define -showtext showtext Showtext "true"
    itk_option define -interactcommand interactCommand InteractCommand ""

    constructor {args} { # defined below }
    public method value {args}

    private method _updateText {}
    private method _toggle {args}
    private variable _value 0  ;# value for this widget
}

itk::usual Switch {
    keep -cursor -background
}

# ----------------------------------------------------------------------
# CONSTRUCTOR
# ----------------------------------------------------------------------
itcl::body Rappture::Switch::constructor {args} {

    itk_component add button {
        button $itk_interior.value -compound left \
            -overrelief flat -relief flat -padx 3 -pady 0 -bd 0 \
            -command [itcl::code $this _toggle]
    } {
        #rename -background -textbackground textBackground Background
    }
    pack $itk_component(button) -side left -expand yes -fill both
    eval itk_initialize $args 
}

# ----------------------------------------------------------------------
# USAGE: value ?-check? ?<newval>?
#
# Clients use this to query/set the value for this widget.  With
# no args, it returns the current value for the widget.  If the
# <newval> is specified, it sets the value of the widget and
# sends a <<Value>> event.  If the -check flag is included, the
# new value is not actually applied, but just checked for correctness.
# ----------------------------------------------------------------------
itcl::body Rappture::Switch::value {args} {
    set onlycheck 0
    set i [lsearch -exact $args -check]
    if {$i >= 0} {
        set onlycheck 1
        set args [lreplace $args $i $i]
    }
    if {[llength $args] == 1} {
        set newval [lindex $args 0]
        # I don't like the "string is" commands. They have too many quirks.
        # If we're calling "expr" anyways, just put a catch on it.
        if { [catch {expr {($newval) ? 1 : 0}} newval] != 0 } {
            error "$newval: should be a yes, no, on, off, true, false, 0, or 1."
        }
        if {$onlycheck} {
            return
        }
        set _value $newval
        event generate $itk_component(hull) <<Value>>
        _updateText
    } elseif {[llength $args] != 0} {
        error "wrong # args: should be \"value ?-check? ?newval?\""
    }
    return [expr {($_value) ? "yes" : "no"}]
}

# ----------------------------------------------------------------------
# _toggle
#
#        Use internally to convert the toggled button into the
#        proper boolean format.  Yes, right now it's hardcoded to 
#        yes/no.  But in the future it could be some other text.
#
#        Can't use old "value" method because _value is already set
#        be the widget and doesn't pass the value on the command line.
#
# ----------------------------------------------------------------------
itcl::body Rappture::Switch::_toggle {} {
    if {$_value} {
        value off
    } else {
        value on
    }
    if {[string length $itk_option(-interactcommand)] > 0} {
        uplevel #0 $itk_option(-interactcommand)
    }
}

itcl::body Rappture::Switch::_updateText {} {
    set image ""
    set text ""
    if { $_value } {
        if {$itk_option(-showimage)} {
            set image [Rappture::icon switch1]
        }
        if {$itk_option(-showtext)} {
            set text "yes"
        }
    } else {
        if {$itk_option(-showimage)} {
            set image [Rappture::icon switch0]
        }
        if {$itk_option(-showtext)} {
            set text "no"
        }
    }
    $itk_component(button) configure -text $text -image $image
}


# ----------------------------------------------------------------------
# CONFIGURATION OPTION: -oncolor
# ----------------------------------------------------------------------
itcl::configbody Rappture::Switch::oncolor {
    # does nothing now, but may come back soon
}

# ----------------------------------------------------------------------
# CONFIGURATION OPTION: -state
# ----------------------------------------------------------------------
itcl::configbody Rappture::Switch::state {
    set valid {normal disabled}
    if {[lsearch -exact $valid $itk_option(-state)] < 0} {
        error "bad value \"$itk_option(-state)\": should be [join $valid {, }]"
    }
    $itk_component(button) configure -state $itk_option(-state)
}

# ----------------------------------------------------------------------
# CONFIGURATION OPTION: -showimage
# ----------------------------------------------------------------------
itcl::configbody Rappture::Switch::showimage {
    if {[string is boolean $itk_option(-showimage)] != 1} {
        error "bad value \"$itk_option(-showimage)\": should be a boolean"
    }
    _updateText
}

# ----------------------------------------------------------------------
# CONFIGURATION OPTION: -showtext
# ----------------------------------------------------------------------
itcl::configbody Rappture::Switch::showtext {
    if {[string is boolean $itk_option(-showtext)] != 1} {
        error "bad value \"$itk_option(-showtext)\": should be a boolean"
    }
    _updateText
}