tree.tcl

是TCL的另外一个编译（解释）器

                            set index  [lsearch $data($parent) $node]
                            set xli    [expr {$xi-[Widget::getoption $path -deltax]-5}]
                        }
                        set yl $ys
                    } else {
                        # position is before $node
                        # drop position is before $node in children of parent of $node
                        set parent [lindex $data($node) 0]
                        set index  [expr {[lsearch $data($parent) $node] - 1}]
                        set xli    [expr {$xi-[Widget::getoption $path -deltax]-5}]
                        set yl     $yi
                    }
                    lappend target [list $parent $index]
                    set vmode  [expr {$vmode | 2}]
                } else {
                    lappend target {}
                }

                if { ($vmode & 3) == 3 } {
                    # result have both node and position
                    # we compute what is the preferred method
                    if { $yc-$yi <= 3 || $ys-$yc <= 3 } {
                        lappend target "position"
                    } else {
                        lappend target "node"
                    }
                }
            }
        }

    if { $vmode && [set cmd [Widget::getoption $path -dropovercmd]] != "" } {
        # user-defined dropover command
        set res     [uplevel \#0 $cmd [list $path $source $target $op $type $dnddata]]
        set code    [lindex $res 0]
        set newmode 0
        if { $code & 1 } {
            # update vmode
            set mode [lindex $res 1]
            if { ($vmode & 1) && ![string compare $mode "node"] } {
                set newmode 1
            } elseif { ($vmode & 2) && ![string compare $mode "position"] } {
                set newmode 2
            } elseif { ($vmode & 4) && ![string compare $mode "widget"] } {
                set newmode 4
            }
        }
        set vmode $newmode
    } else {
        if { ($vmode & 3) == 3 } {
            # result have both item and position
            # we choose the preferred method
            if { ![string compare [lindex $target 3] "position"] } {
                set vmode [expr {$vmode & ~1}]
            } else {
                set vmode [expr {$vmode & ~2}]
            }
        }

        if { $data(dnd,mode) == 4 || $data(dnd,mode) == 0 } {
            # dropovermode is widget or empty - recall is not necessary
            set code 1
        } else {
            set code 3
        }
    }

    if {!$data(dnd,empty)} {
	# draw dnd visual following vmode
	if { $vmode & 1 } {
	    set data(dnd,node) [list "node" [lindex $target 1]]
	    $path.c create rectangle $xi $yi $xs $ys -tags drop
	} elseif { $vmode & 2 } {
	    set data(dnd,node) [concat "position" [lindex $target 2]]
	    $path.c create line $xli [expr {$yl-$dy/2}] $xli $yl $xs $yl -tags drop
	} elseif { $vmode & 4 } {
	    set data(dnd,node) [list "widget"]
	} else {
	    set code [expr {$code & 2}]
	}
    }

    if { $code & 1 } {
        DropSite::setcursor based_arrow_down
    } else {
        DropSite::setcursor dot
    }
    return $code
}


# ----------------------------------------------------------------------------
#  Command Tree::_auto_scroll
# ----------------------------------------------------------------------------
proc Tree::_auto_scroll { path x y } {
    variable $path
    upvar 0  $path data

    set xmax   [winfo width  $path]
    set ymax   [winfo height $path]
    set scroll {}
    if { $y <= 6 } {
        if { [lindex [$path.c yview] 0] > 0 } {
            set scroll [list yview -1]
            DropSite::setcursor sb_up_arrow
        }
    } elseif { $y >= $ymax-6 } {
        if { [lindex [$path.c yview] 1] < 1 } {
            set scroll [list yview 1]
            DropSite::setcursor sb_down_arrow
        }
    } elseif { $x <= 6 } {
        if { [lindex [$path.c xview] 0] > 0 } {
            set scroll [list xview -1]
            DropSite::setcursor sb_left_arrow
        }
    } elseif { $x >= $xmax-6 } {
        if { [lindex [$path.c xview] 1] < 1 } {
            set scroll [list xview 1]
            DropSite::setcursor sb_right_arrow
        }
    }

    if { [string length $data(dnd,afterid)] && [string compare $data(dnd,scroll) $scroll] } {
        after cancel $data(dnd,afterid)
        set data(dnd,afterid) ""
    }

    set data(dnd,scroll) $scroll
    if { [string length $scroll] && ![string length $data(dnd,afterid)] } {
        set data(dnd,afterid) [after 200 Tree::_scroll $path $scroll]
    }
    return $data(dnd,afterid)
}


# ----------------------------------------------------------------------------
#  Command Tree::_scroll
# ----------------------------------------------------------------------------
proc Tree::_scroll { path cmd dir } {
    variable $path
    upvar 0  $path data

    if { ($dir == -1 && [lindex [$path.c $cmd] 0] > 0) ||
         ($dir == 1  && [lindex [$path.c $cmd] 1] < 1) } {
        $path.c $cmd scroll $dir units
        set data(dnd,afterid) [after 100 Tree::_scroll $path $cmd $dir]
    } else {
        set data(dnd,afterid) ""
        DropSite::setcursor dot
    }
}

# Tree::_keynav --
#
#	Handle navigational keypresses on the tree.
#
# Arguments:
#	which      tag indicating the direction of motion:
#                  up         move to the node graphically above current
#                  down       move to the node graphically below current
#                  left       close current if open, else move to parent
#                  right      open current if closed, else move to child
#                  open       open current if closed, close current if open
#       win        name of the tree widget
#
# Results:
#	None.

proc Tree::_keynav {which win} {
    # Keyboard navigation is riddled with special cases.  In order to avoid
    # the complex logic, we will instead make a list of all the visible,
    # selectable nodes, then do a simple next or previous operation.

    # One easy way to get all of the visible nodes is to query the canvas
    # object for all the items with the "node" tag; since the tree is always
    # completely redrawn, this list will be in vertical order.
    set nodes {}
    foreach nodeItem [$win.c find withtag node] {
	set node [Tree::_get_node_name $win $nodeItem 2]
	if { [Widget::cget $win.$node -selectable] } {
	    lappend nodes $node
	}
    }
	
    # Keyboard navigation is all relative to the current node
    # surles: Get the current node for single or multiple selection schemas.
    set node [_get_current_node $win]

    switch -exact -- $which {
	"up" {
	    # Up goes to the node that is vertically above the current node
	    # (NOT necessarily the current node's parent)
	    if { [string equal $node ""] } {
		return
	    }
	    set index [lsearch $nodes $node]
	    incr index -1
	    if { $index >= 0 } {
		$win selection set [lindex $nodes $index]
		_set_current_node $win [lindex $nodes $index]
		$win see [lindex $nodes $index]
		return
	    }
	}
	"down" {
	    # Down goes to the node that is vertically below the current node
	    if { [string equal $node ""] } {
		$win selection set [lindex $nodes 0]
		_set_current_node $win [lindex $nodes 0]
		$win see [lindex $nodes 0]
		return
	    }

	    set index [lsearch $nodes $node]
	    incr index
	    if { $index < [llength $nodes] } {
		$win selection set [lindex $nodes $index]
		_set_current_node $win [lindex $nodes $index]
		$win see [lindex $nodes $index]
		return
	    }
	}
	"right" {
	    # On a right arrow, if the current node is closed, open it.
	    # If the current node is open, go to its first child
	    if { [string equal $node ""] } {
		return
	    }
	    set open [$win itemcget $node -open]
            if { $open } {
                if { [llength [$win nodes $node]] } {
		    set index [lsearch $nodes $node]
		    incr index
		    if { $index < [llength $nodes] } {
			$win selection set [lindex $nodes $index]
			_set_current_node $win [lindex $nodes $index]
			$win see [lindex $nodes $index]
			return
		    }
                }
            } else {
                $win itemconfigure $node -open 1
                if { [set cmd [Widget::getoption $win -opencmd]] != "" } {
                    uplevel \#0 $cmd $node
                }
                return
            }
	}
	"left" {
	    # On a left arrow, if the current node is open, close it.
	    # If the current node is closed, go to its parent.
	    if { [string equal $node ""] } {
		return
	    }
	    set open [$win itemcget $node -open]
	    if { $open } {
		$win itemconfigure $node -open 0
                if { [set cmd [Widget::getoption $win -closecmd]] != "" } {
                    uplevel \#0 $cmd $node
                }
		return
	    } else {
		set parent [$win parent $node]
	        if { [string equal $parent "root"] } {
		    set parent $node
                } else {
                    while { ![$win itemcget $parent -selectable] } {
		        set parent [$win parent $parent]
		        if { [string equal $parent "root"] } {
			    set parent $node
			    break
		        }
                    }
		}
		$win selection set $parent
		_set_current_node $win $parent
		$win see $parent
		return
	    }
	}
	"space" {
	    if { [string equal $node ""] } {
		return
	    }
	    set open [$win itemcget $node -open]
	    if { [llength [$win nodes $node]] } {

		# Toggle the open status of the chosen node.

		$win itemconfigure $node -open [expr {$open?0:1}]

		if {$open} {
		    # Node was open, is now closed. Call the close-cmd

		    if { [set cmd [Widget::getoption $win -closecmd]] != "" } {
			uplevel \#0 $cmd $node
		    }
		} else {
		    # Node was closed, is now open. Call the open-cmd

		    if { [set cmd [Widget::getoption $win -opencmd]] != "" } {
			uplevel \#0 $cmd $node
		    }
                }
	    }
	}
    }
    return
}

# Tree::_get_current_node --
#
#	Get the current node for either single or multiple
#	node selection trees.  If the tree allows for 
#	multiple selection, return the cursor node.  Otherwise,
#	if there is a selection, return the first node in the
#	list.  If there is no selection, return the root node.
#
# arguments:
#       win        name of the tree widget
#
# Results:
#	The current node.

proc Tree::_get_current_node {win} {
    if {[info exists selectTree::selectCursor($win)]} {
	set result $selectTree::selectCursor($win)
    } elseif {[set selList [$win selection get]] != {}} {
	set result [lindex $selList 0]
    } else {
	set result ""
    }
    return $result
}

# Tree::_set_current_node --
#
#	Set the current node for either single or multiple
#	node selection trees.
#
# arguments:
#       win        Name of the tree widget
#	node	   The current node.
#
# Results:
#	None.

proc Tree::_set_current_node {win node} {
    if {[info exists selectTree::selectCursor($win)]} {
	set selectTree::selectCursor($win) $node
    }
    return
}

# Tree::_get_node_name --
#
#	Given a canvas item, get the name of the tree node represented by that
#	item.
#
# Arguments:
#	path		tree to query
#	item		Optional canvas item to examine; if omitted, 
#			defaults to "current"
#	tagindex	Optional tag index, since the n:nodename tag is not
#			in the same spot for all canvas items.  If omitted,
#			defaults to "end-1", so it works with "current" item.
#
# Results:
#	node	name of the tree node.

proc Tree::_get_node_name {path {item current} {tagindex end-1}} {
    return [string range [lindex [$path.c gettags $item] $tagindex] 2 end]
}