# ----------------------------------------------------------------------
#  COMPONENT: FileChoiceEntry - widget for entering a choice of strings
#
#  This widget represents a <choice> entry on a control panel.
#  It is used to choose one of several mutually-exclusive strings.
# ======================================================================
#  AUTHOR:  Michael McLennan, Purdue University
#  Copyright (c) 2004-2005  Purdue Research Foundation
#
#  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::FileChoiceEntry {
    inherit itk::Widget

    itk_option define -state state State "normal"
    
    private variable _rebuildPending 0

    constructor {owner path args} { 
	# defined below 
    }
    destructor { 
	# defined below 
    }
    public method value {args}

    public method label {}
    public method tooltip {}

    protected method _rebuild {}
    protected method _newValue {}
    protected method _tooltip {}
    protected method _whenidle {}

    private variable _owner ""    ;# thing managing this control
    private variable _path ""     ;# path in XML to this number
    private variable _str2val     ;# maps option label => option value
}


itk::usual FileChoiceEntry {
    keep -cursor -font
    keep -foreground -background
    keep -textforeground -textbackground
    keep -selectbackground -selectforeground -selectborderwidth
}

# ----------------------------------------------------------------------
# CONSTRUCTOR
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::constructor {owner path args} {
    if {[catch {$owner isa Rappture::ControlOwner} valid] != 0 || !$valid} {
	error "bad object \"$owner\": should be Rappture::ControlOwner"
    }
    set _owner $owner
    set _path $path

    #
    # Create the widget and configure it properly based on other
    # hints in the XML.
    #
    itk_component add choice {
	Rappture::Combobox $itk_interior.choice -editable no
    }
    pack $itk_component(choice) -expand yes -fill both
    bind $itk_component(choice) <<Value>> [itcl::code $this _newValue]

    # First time, parse the <pattern> elements to generate notify callbacks
    # for each template found. 
    foreach cname [$_owner xml children -type pattern $_path] {
	set glob [string trim [$_owner xml get $_path.$cname]]
	# Successively replace each template with its value.
	while { [regexp -indices {@@[^@]*@@} $glob range] } {
	    foreach {first last} $range break
	    set i1 [expr $first + 2]
	    set i2 [expr $last  - 2]
	    set path [string range $glob $i1 $i2]
	    set value [$_owner xml get $_path.$cname]
	    set value [$_owner xml get $path]
	    set glob [string replace $glob $first $last $value]
	    $_owner notify add $this $path [itcl::code $this _whenidle]
	}
    }
    $_owner notify sync
    eval itk_initialize $args
    _rebuild
}

# ----------------------------------------------------------------------
# DESTRUCTOR
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::destructor {} {
    $_owner notify remove $this
}

# ----------------------------------------------------------------------
# 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::FileChoiceEntry::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 $args] == 1} {
	if {$onlycheck} {
	    # someday we may add validation...
	    return
	}
	set newval [lindex $args 0]
	if {[info exists _str2val($newval)]} {
	    # this is a label -- use it directly
	    $itk_component(choice) value $newval
	    set newval $_str2val($newval)  ;# report the actual value
	} else {
	    # this is a value -- search for corresponding label
	    foreach str [array names _str2val] {
		if {$_str2val($str) == $newval} {
		    $itk_component(choice) value $str
		    break
		}
	    }
	}
	return $newval

    } elseif {[llength $args] != 0} {
	error "wrong # args: should be \"value ?-check? ?newval?\""
    }

    #
    # Query the value and return.
    #
    set str [$itk_component(choice) value]
    if {[info exists _str2val($str)]} {
	return $_str2val($str)
    }
    return $str
}

# ----------------------------------------------------------------------
# USAGE: label
#
# Clients use this to query the label associated with this widget.
# Reaches into the XML and pulls out the appropriate label string.
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::label {} {
    set label [$_owner xml get $_path.about.label]
    if {"" == $label} {
	set label "Choice"
    }
    return $label
}

# ----------------------------------------------------------------------
# USAGE: tooltip
#
# Clients use this to query the tooltip associated with this widget.
# Reaches into the XML and pulls out the appropriate description
# string.  Returns the string that should be used with the
# Rappture::Tooltip facility.
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::tooltip {} {
    # query tooltip on-demand based on current choice
    return "@[itcl::code $this _tooltip]"
}

# ----------------------------------------------------------------------
# USAGE: _rebuild
#
# Used internally to rebuild the contents of this choice widget
# whenever something that it depends on changes.  Scans through the
# information in the XML spec and builds a list of choices for the
# widget.
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::_rebuild {} {
    puts stderr "filechoiceentry rebuild"
    set _rebuildPending 0
    # get rid of any existing choices
    $itk_component(choice) choices delete 0 end
    array unset _str2val
    #
    # Plug in the various options for the choice.
    #
    set max 10
    $_owner notify sync
    set allfiles {}
    foreach cname [$_owner xml children -type pattern $_path] {
	set glob [string trim [$_owner xml get $_path.$cname]]
	# Successively replace each template with its value.
	puts stderr "before glob=$glob"
	while { [regexp -indices {@@[^@]*@@} $glob range] } {
	    foreach {first last} $range break
	    set i1 [expr $first + 2]
	    set i2 [expr $last  - 2]
	    set path [string range $glob $i1 $i2]
	    set value [$_owner xml get $path.current]
	    puts stderr "$path.current: value=$value"
	    if { $value == "" } {
		set value [$_owner xml get $path.default]
		puts stderr "$path.default: value=$value"
	    }
	    set glob [string replace $glob $first $last $value]
	}
	puts stderr "after glob=$glob"
	# Replace the template with the substituted value.
	set files [glob -nocomplain $glob]
	puts stderr "files=$files"
	set allfiles [concat $allfiles $files]
    }
    set first ""
    foreach file $allfiles {
	set tail [file tail $file]
	if { $first == "" } {
	    set first $tail
	}
	$itk_component(choice) choices insert end $file $tail
	set _str2val($file) $tail
	set len [string length $tail]
	if {$len > $max} { set max $len }
    }
    $itk_component(choice) configure -width $max
    $itk_component(choice) value $tail
}

# ----------------------------------------------------------------------
# USAGE: _newValue
#
# Invoked automatically whenever the value in the choice changes.
# Sends a <<Value>> event to notify clients of the change.
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::_newValue {} {
    event generate $itk_component(hull) <<Value>>
}

# ----------------------------------------------------------------------
# USAGE: _tooltip
#
# Returns the tooltip for this widget, given the current choice in
# the selector.  This is normally called by the Rappture::Tooltip
# facility whenever it is about to pop up a tooltip for this widget.
# ----------------------------------------------------------------------
itcl::body Rappture::FileChoiceEntry::_tooltip {} {
    set tip [string trim [$_owner xml get $_path.about.description]]

    # get the description for the current choice, if there is one
    set str [$itk_component(choice) value]
    set path [$itk_component(choice) translate $str]
    set desc ""
    if {$path != ""} {
	set desc [$_owner xml get $path.about.description]
    }

    if {[string length $str] > 0 && [string length $desc] > 0} {
	append tip "\n\n$str:\n$desc"
    }
    return $tip
}

# ----------------------------------------------------------------------
# CONFIGURATION OPTION: -state
# ----------------------------------------------------------------------
itcl::configbody Rappture::FileChoiceEntry::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(choice) configure -state $itk_option(-state)
}

itcl::body Rappture::FileChoiceEntry::_whenidle {} {
    if { !$_rebuildPending } {
	after 10 [itcl::code $this _rebuild]
	set _rebuildPending 1
    }
}