dropsite.tcl

The BWidget Toolkit is a high-level Widget Set for Tcl/Tk built using native Tcl/Tk 8.x namespaces.

# ------------------------------------------------------------------------------
#  dropsite.tcl
#  This file is part of Unifix BWidget Toolkit
#  $Id: dropsite.tcl,v 1.7 2003/10/20 21:23:52 damonc Exp $
# ------------------------------------------------------------------------------
#  Index of commands:
#     - DropSite::include
#     - DropSite::setdrop
#     - DropSite::register
#     - DropSite::setcursor
#     - DropSite::setoperation
#     - DropSite::_update_operation
#     - DropSite::_compute_operation
#     - DropSite::_draw_operation
#     - DropSite::_init_drag
#     - DropSite::_motion
#     - DropSite::_release
# ----------------------------------------------------------------------------


namespace eval DropSite {
    Widget::define DropSite dropsite -classonly

    Widget::declare DropSite [list \
	    [list -dropovercmd String "" 0] \
	    [list -dropcmd     String "" 0] \
	    [list -droptypes   String "" 0] \
	    ]

    proc use {} {}

    variable _top  ".drag"
    variable _opw  ".drag.\#op"
    variable _target  ""
    variable _status  0
    variable _tabops
    variable _defops
    variable _source
    variable _type
    variable _data
    variable _evt
    # key       win    unix
    # shift       1   |   1    ->  1
    # control     4   |   4    ->  4
    # alt         8   |  16    -> 24
    # meta            |  64    -> 88

    array set _tabops {
        mod,none    0
        mod,shift   1
        mod,control 4
        mod,alt     24
        ops,copy    1
        ops,move    1
        ops,link    1
    }

    if { $tcl_platform(platform) == "unix" } {
        set _tabops(mod,alt) 8
    } else {
        set _tabops(mod,alt) 16
    }
    array set _defops \
        [list \
             copy,mod  shift   \
             move,mod  control \
             link,mod  alt     \
             copy,img  @[file join $::BWIDGET::LIBRARY "images" "opcopy.xbm"] \
             move,img  @[file join $::BWIDGET::LIBRARY "images" "opmove.xbm"] \
             link,img  @[file join $::BWIDGET::LIBRARY "images" "oplink.xbm"]]

    bind DragTop <KeyPress-Shift_L>     {DropSite::_update_operation [expr %s | 1]}
    bind DragTop <KeyPress-Shift_R>     {DropSite::_update_operation [expr %s | 1]}
    bind DragTop <KeyPress-Control_L>   {DropSite::_update_operation [expr %s | 4]}
    bind DragTop <KeyPress-Control_R>   {DropSite::_update_operation [expr %s | 4]}
    if { $tcl_platform(platform) == "unix" } {
        bind DragTop <KeyPress-Alt_L>       {DropSite::_update_operation [expr %s | 8]}
        bind DragTop <KeyPress-Alt_R>       {DropSite::_update_operation [expr %s | 8]}
    } else {
        bind DragTop <KeyPress-Alt_L>       {DropSite::_update_operation [expr %s | 16]}
        bind DragTop <KeyPress-Alt_R>       {DropSite::_update_operation [expr %s | 16]}
    }

    bind DragTop <KeyRelease-Shift_L>   {DropSite::_update_operation [expr %s & ~1]}
    bind DragTop <KeyRelease-Shift_R>   {DropSite::_update_operation [expr %s & ~1]}
    bind DragTop <KeyRelease-Control_L> {DropSite::_update_operation [expr %s & ~4]}
    bind DragTop <KeyRelease-Control_R> {DropSite::_update_operation [expr %s & ~4]}
    if { $tcl_platform(platform) == "unix" } {
        bind DragTop <KeyRelease-Alt_L>     {DropSite::_update_operation [expr %s & ~8]}
        bind DragTop <KeyRelease-Alt_R>     {DropSite::_update_operation [expr %s & ~8]}
    } else {
        bind DragTop <KeyRelease-Alt_L>     {DropSite::_update_operation [expr %s & ~16]}
        bind DragTop <KeyRelease-Alt_R>     {DropSite::_update_operation [expr %s & ~16]}
    }
}


# ----------------------------------------------------------------------------
#  Command DropSite::include
# ----------------------------------------------------------------------------
proc DropSite::include { class types } {
    set dropoptions [list \
	    [list	-dropenabled	Boolean	0	0] \
	    [list	-dropovercmd	String	""	0] \
	    [list	-dropcmd	String	""	0] \
	    [list	-droptypes	String	$types	0] \
	    ]
    Widget::declare $class $dropoptions
}


# ----------------------------------------------------------------------------
#  Command DropSite::setdrop
#  Widget interface to register
# ----------------------------------------------------------------------------
proc DropSite::setdrop { path subpath dropover drop {force 0}} {
    set cen    [Widget::hasChanged $path -dropenabled en]
    set ctypes [Widget::hasChanged $path -droptypes   types]
    if { $en } {
        if { $force || $cen || $ctypes } {
            register $subpath \
                -droptypes   $types \
                -dropcmd     $drop  \
                -dropovercmd $dropover
        }
    } else {
        register $subpath
    }
}


# ----------------------------------------------------------------------------
#  Command DropSite::register
# ----------------------------------------------------------------------------
proc DropSite::register { path args } {
    variable _tabops
    variable _defops
    upvar \#0 DropSite::$path drop

    Widget::init DropSite .drop$path $args
    if { [info exists drop] } {
        unset drop
    }
    set dropcmd [Widget::getMegawidgetOption .drop$path -dropcmd]
    set types   [Widget::getMegawidgetOption .drop$path -droptypes]
    set overcmd [Widget::getMegawidgetOption .drop$path -dropovercmd]
    Widget::destroy .drop$path
    if { $dropcmd != "" && $types != "" } {
        set drop(dropcmd) $dropcmd
        set drop(overcmd) $overcmd
        foreach {type ops} $types {
            set drop($type,ops) {}
            foreach {descop lmod} $ops {
                if { ![llength $descop] || [llength $descop] > 3 } {
                    return -code error "invalid operation description \"$descop\""
                }
                foreach {subop baseop imgop} $descop {
                    set subop [string trim $subop]
                    if { ![string length $subop] } {
                        return -code error "sub operation is empty"
                    }
                    if { ![string length $baseop] } {
                        set baseop $subop
                    }
                    if { [info exists drop($type,ops,$subop)] } {
                        return -code error "operation \"$subop\" already defined"
                    }
                    if { ![info exists _tabops(ops,$baseop)] } {
                        return -code error "invalid base operation \"$baseop\""
                    }
                    if { ![string equal $subop $baseop] &&
                         [info exists _tabops(ops,$subop)] } {
                        return -code error "sub operation \"$subop\" is a base operation"
                    }
                    if { ![string length $imgop] } {
                        set imgop $_defops($baseop,img)
                    }
                }
                if { [string equal $lmod "program"] } {
                    set drop($type,ops,$subop) $baseop
                    set drop($type,img,$subop) $imgop
                } else {
                    if { ![string length $lmod] } {
                        set lmod $_defops($baseop,mod)
                    }
                    set mask 0
                    foreach mod $lmod {
                        if { ![info exists _tabops(mod,$mod)] } {
                            return -code error "invalid modifier \"$mod\""
                        }
                        set mask [expr {$mask | $_tabops(mod,$mod)}]
                    }
                    if { ($mask == 0) != ([string equal $subop "default"]) } {
                        return -code error "sub operation default can only be used with modifier \"none\""
                    }
                    set drop($type,mod,$mask)  $subop
                    set drop($type,ops,$subop) $baseop
                    set drop($type,img,$subop) $imgop
                    lappend masklist $mask
                }
            }
            if { ![info exists drop($type,mod,0)] } {
                set drop($type,mod,0)       default
                set drop($type,ops,default) copy
                set drop($type,img,default) $_defops(copy,img)
                lappend masklist 0
            }
            set drop($type,ops,force) copy
            set drop($type,img,force) $_defops(copy,img)
            foreach mask [lsort -integer -decreasing $masklist] {
                lappend drop($type,ops) $mask $drop($type,mod,$mask)
            }
        }
    }
}


# ----------------------------------------------------------------------------
#  Command DropSite::setcursor
# ----------------------------------------------------------------------------
proc DropSite::setcursor { cursor } {
    catch {.drag configure -cursor $cursor}
}


# ----------------------------------------------------------------------------
#  Command DropSite::setoperation
# ----------------------------------------------------------------------------