git/lib/blame.tcl

# git-gui blame viewer
# Copyright (C) 2006, 2007 Shawn Pearce

class blame {

image create photo ::blame::img_back_arrow -data {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}

field commit    ; # input commit to blame
field path      ; # input filename to view in $commit
field history {}; # viewer history: {commit path}

field w          ; # top window in this viewer
field w_back     ; # our back button
field w_path     ; # label showing the current file path
field w_line     ; # text column: all line numbers
field w_cgrp     ; # text column: abbreviated commit SHA-1s
field w_load     ; # text column: loaded indicator
field w_file     ; # text column: actual file data
field w_cmit     ; # pane showing commit message
field status     ; # text variable bound to status bar
field old_height ; # last known height of $w.file_pane

field current_fd       {} ; # background process running
field highlight_line   -1 ; # current line selected
field highlight_commit {} ; # sha1 of commit selected

field total_lines       0  ; # total length of file
field blame_lines       0  ; # number of lines computed
field commit_count      0  ; # number of commits in $commit_list
field commit_list      {}  ; # list of commit sha1 in receipt order
field order                ; # array commit -> receipt order
field header               ; # array commit,key -> header field
field line_commit          ; # array line -> sha1 commit
field line_file            ; # array line -> file name

field r_commit      ; # commit currently being parsed
field r_orig_line   ; # original line number
field r_final_line  ; # final line number
field r_line_count  ; # lines in this region

field tooltip_wm     {} ; # Current tooltip toplevel, if open
field tooltip_timer  {} ; # Current timer event for our tooltip
field tooltip_commit {} ; # Commit in tooltip
field tooltip_text   {} ; # Text in current tooltip

variable active_color #98e1a0
variable group_colors {
	#cbcbcb
	#e1e1e1
}

constructor new {i_commit i_path} {
	variable active_color
	global cursor_ptr

	set commit $i_commit
	set path   $i_path

	make_toplevel top w
	wm title $top "[appname] ([reponame]): File Viewer"

	frame $w.header -background orange
	label $w.header.commit_l \
		-text {Commit:} \
		-background orange \
		-anchor w \
		-justify left
	set w_back $w.header.commit_b
	label $w_back \
		-image ::blame::img_back_arrow \
		-borderwidth 0 \
		-relief flat \
		-state disabled \
		-background orange \
		-activebackground orange
	bind $w_back <Button-1> "
		if {\[$w_back cget -state\] eq {normal}} {
			[cb _history_menu]
		}
		"
	label $w.header.commit \
		-textvariable @commit \
		-background orange \
		-anchor w \
		-justify left
	label $w.header.path_l \
		-text {File:} \
		-background orange \
		-anchor w \
		-justify left
	set w_path $w.header.path
	label $w_path \
		-background orange \
		-anchor w \
		-justify left
	pack $w.header.commit_l -side left
	pack $w_back -side left
	pack $w.header.commit -side left
	pack $w_path -fill x -side right
	pack $w.header.path_l -side right

	panedwindow $w.file_pane -orient vertical
	frame $w.file_pane.out
	frame $w.file_pane.cm
	$w.file_pane add $w.file_pane.out \
		-sticky nsew \
		-minsize 100 \
		-height 100 \
		-width 100
	$w.file_pane add $w.file_pane.cm \
		-sticky nsew \
		-minsize 25 \
		-height 25 \
		-width 100

	set w_load $w.file_pane.out.loaded_t
	text $w_load \
		-background white -borderwidth 0 \
		-state disabled \
		-wrap none \
		-height 40 \
		-width 1 \
		-font font_diff
	$w_load tag conf annotated -background grey

	set w_line $w.file_pane.out.linenumber_t
	text $w_line \
		-background white -borderwidth 0 \
		-state disabled \
		-wrap none \
		-height 40 \
		-width 5 \
		-font font_diff
	$w_line tag conf linenumber -justify right

	set w_cgrp $w.file_pane.out.commit_t
	text $w_cgrp \
		-background white -borderwidth 0 \
		-state disabled \
		-wrap none \
		-height 40 \
		-width 4 \
		-font font_diff
	$w_cgrp tag conf curr_commit
	$w_cgrp tag conf prior_commit \
		-foreground blue \
		-underline 1
	$w_cgrp tag bind prior_commit \
		<Button-1> \
		"[cb _load_commit @%x,%y];break"

	set w_file $w.file_pane.out.file_t
	text $w_file \
		-background white -borderwidth 0 \
		-state disabled \
		-wrap none \
		-height 40 \
		-width 80 \
		-xscrollcommand [list $w.file_pane.out.sbx set] \
		-font font_diff

	scrollbar $w.file_pane.out.sbx \
		-orient h \
		-command [list $w_file xview]
	scrollbar $w.file_pane.out.sby \
		-orient v \
		-command [list scrollbar2many [list \
		$w_load \
		$w_line \
		$w_cgrp \
		$w_file \
		] yview]
	grid \
		$w_cgrp \
		$w_line \
		$w_load \
		$w_file \
		$w.file_pane.out.sby \
		-sticky nsew
	grid conf $w.file_pane.out.sbx -column 3 -sticky we
	grid columnconfigure $w.file_pane.out 3 -weight 1
	grid rowconfigure $w.file_pane.out 0 -weight 1

	set w_cmit $w.file_pane.cm.t
	text $w_cmit \
		-background white -borderwidth 0 \
		-state disabled \
		-wrap none \
		-height 10 \
		-width 80 \
		-xscrollcommand [list $w.file_pane.cm.sbx set] \
		-yscrollcommand [list $w.file_pane.cm.sby set] \
		-font font_diff
	$w_cmit tag conf header_key \
		-tabs {3c} \
		-background $active_color \
		-font font_uibold
	$w_cmit tag conf header_val \
		-background $active_color \
		-font font_ui
	$w_cmit tag raise sel
	scrollbar $w.file_pane.cm.sbx \
		-orient h \
		-command [list $w_cmit xview]
	scrollbar $w.file_pane.cm.sby \
		-orient v \
		-command [list $w_cmit yview]
	pack $w.file_pane.cm.sby -side right -fill y
	pack $w.file_pane.cm.sbx -side bottom -fill x
	pack $w_cmit -expand 1 -fill both

	frame $w.status \
		-borderwidth 1 \
		-relief sunken
	label $w.status.l \
		-textvariable @status \
		-anchor w \
		-justify left
	pack $w.status.l -side left

	menu $w.ctxm -tearoff 0
	$w.ctxm add command \
		-label "Copy Commit" \
		-command [cb _copycommit]

	foreach i [list \
		$w_cgrp \
		$w_load \
		$w_line \
		$w_file] {
		$i conf -cursor $cursor_ptr
		$i conf -yscrollcommand \
			[list many2scrollbar [list \
			$w_cgrp \
			$w_load \
			$w_line \
			$w_file \
			] yview $w.file_pane.out.sby]
		bind $i <Button-1> "
			[cb _hide_tooltip]
			[cb _click $i @%x,%y]
			focus $i
		"
		bind $i <Any-Motion>  [cb _show_tooltip $i @%x,%y]
		bind $i <Any-Enter>   [cb _hide_tooltip]
		bind $i <Any-Leave>   [cb _hide_tooltip]
		bind_button3 $i "
			[cb _hide_tooltip]
			set cursorX %x
			set cursorY %y
			set cursorW %W
			tk_popup $w.ctxm %X %Y
		"
	}

	foreach i [list \
		$w_cgrp \
		$w_load \
		$w_line \
		$w_file \
		$w_cmit] {
		bind $i <Key-Up>        {catch {%W yview scroll -1 units};break}
		bind $i <Key-Down>      {catch {%W yview scroll  1 units};break}
		bind $i <Key-Left>      {catch {%W xview scroll -1 units};break}
		bind $i <Key-Right>     {catch {%W xview scroll  1 units};break}
		bind $i <Key-k>         {catch {%W yview scroll -1 units};break}
		bind $i <Key-j>         {catch {%W yview scroll  1 units};break}
		bind $i <Key-h>         {catch {%W xview scroll -1 units};break}
		bind $i <Key-l>         {catch {%W xview scroll  1 units};break}
		bind $i <Control-Key-b> {catch {%W yview scroll -1 pages};break}
		bind $i <Control-Key-f> {catch {%W yview scroll  1 pages};break}
	}

	bind $w_cmit <Button-1> [list focus $w_cmit]
	bind $top <Visibility> [list focus $top]
	bind $w_file <Destroy> [list delete_this $this]

	grid configure $w.header -sticky ew
	grid configure $w.file_pane -sticky nsew
	grid configure $w.status -sticky ew
	grid columnconfigure $top 0 -weight 1
	grid rowconfigure $top 0 -weight 0
	grid rowconfigure $top 1 -weight 1
	grid rowconfigure $top 2 -weight 0

	set req_w [winfo reqwidth  $top]
	set req_h [winfo reqheight $top]
	if {$req_w < 600} {set req_w 600}
	if {$req_h < 400} {set req_h 400}
	set g "${req_w}x${req_h}"
	wm geometry $top $g
	update

	set old_height [winfo height $w.file_pane]
	$w.file_pane sash place 0 \
		[lindex [$w.file_pane sash coord 0] 0] \
		[expr {int($old_height * 0.70)}]
	bind $w.file_pane <Configure> \
	"if {{$w.file_pane} eq {%W}} {[cb _resize %h]}"

	_load $this
}

method _load {} {
	_hide_tooltip $this

	if {$total_lines != 0 || $current_fd ne {}} {
		if {$current_fd ne {}} {
			catch {close $current_fd}
			set current_fd {}
		}

		set highlight_line -1
		set highlight_commit {}
		set total_lines 0
		set blame_lines 0
		set commit_count 0
		set commit_list {}
		array unset order
		array unset line_commit
		array unset line_file

		$w_load conf -state normal
		$w_cgrp conf -state normal
		$w_line conf -state normal
		$w_file conf -state normal

		$w_load delete 0.0 end
		$w_cgrp delete 0.0 end
		$w_line delete 0.0 end
		$w_file delete 0.0 end

		$w_load conf -state disabled
		$w_cgrp conf -state disabled
		$w_line conf -state disabled
		$w_file conf -state disabled
	}

	if {[winfo exists $w.status.c]} {
		$w.status.c coords bar 0 0 0 20
	} else {
		canvas $w.status.c \
			-width 100 \
			-height [expr {int([winfo reqheight $w.status.l] * 0.6)}] \
			-borderwidth 1 \
			-relief groove \
			-highlightt 0
		$w.status.c create rectangle 0 0 0 20 -tags bar -fill navy
		pack $w.status.c -side right
	}

	if {$history eq {}} {
		$w_back conf -state disabled
	} else {
		$w_back conf -state normal
	}
	lappend history [list $commit $path]

	set status "Loading $commit:[escape_path $path]..."
	$w_path conf -text [escape_path $path]
	if {$commit eq {}} {
		set fd [open $path r]
	} else {
		set cmd [list git cat-file blob "$commit:$path"]
		set fd [open "| $cmd" r]
	}
	fconfigure $fd -blocking 0 -translation lf -encoding binary
	fileevent $fd readable [cb _read_file $fd]
	set current_fd $fd
}

method _history_menu {} {
	set m $w.backmenu
	if {[winfo exists $m]} {
		$m delete 0 end
	} else {
		menu $m -tearoff 0
	}

	for {set i [expr {[llength $history] - 2}]
		} {$i >= 0} {incr i -1} {
		set e [lindex $history $i]
		set c [lindex $e 0]
		set f [lindex $e 1]

		if {[regexp {^[0-9a-f]{40}$} $c]} {
			set t [string range $c 0 8]...
		} else {
			set t $c
		}
		if {![catch {set summary $header($c,summary)}]} {
			append t " $summary"
			if {[string length $t] > 70} {
				set t [string range $t 0 66]...
			}
		}

		$m add command -label $t -command [cb _goback $i $c $f]
	}
	set X [winfo rootx $w_back]
	set Y [expr {[winfo rooty $w_back] + [winfo height $w_back]}]
	tk_popup $m $X $Y
}

method _goback {i c f} {
	set history [lrange $history 0 [expr {$i - 1}]]
	set commit $c
	set path $f
	_load $this
}

method _read_file {fd} {
	if {$fd ne $current_fd} {
		catch {close $fd}
		return
	}

	$w_load conf -state normal
	$w_cgrp conf -state normal
	$w_line conf -state normal
	$w_file conf -state normal
	while {[gets $fd line] >= 0} {
		regsub "\r\$" $line {} line
		incr total_lines

		if {$total_lines > 1} {
			$w_load insert end "\n"
			$w_cgrp insert end "\n"
			$w_line insert end "\n"
			$w_file insert end "\n"
		}

		$w_line insert end "$total_lines" linenumber
		$w_file insert end "$line"
	}
	$w_load conf -state disabled
	$w_cgrp conf -state disabled
	$w_line conf -state disabled
	$w_file conf -state disabled

	if {[eof $fd]} {
		close $fd
		_status $this
		set cmd {nice git blame -M -C --incremental}
		if {$commit eq {}} {
			lappend cmd --contents $path
		} else {
			lappend cmd $commit
		}
		lappend cmd -- $path
		set fd [open "| $cmd" r]
		fconfigure $fd -blocking 0 -translation lf -encoding binary
		fileevent $fd readable [cb _read_blame $fd]
		set current_fd $fd
	}
} ifdeleted { catch {close $fd} }

method _read_blame {fd} {
	variable group_colors

	if {$fd ne $current_fd} {
		catch {close $fd}
		return
	}

	$w_cgrp conf -state normal
	while {[gets $fd line] >= 0} {
		if {[regexp {^([a-z0-9]{40}) (\d+) (\d+) (\d+)$} $line line \
			cmit original_line final_line line_count]} {
			set r_commit     $cmit
			set r_orig_line  $original_line
			set r_final_line $final_line
			set r_line_count $line_count

			if {[catch {set g $order($cmit)}]} {
				set bg [lindex $group_colors 0]
				set group_colors [lrange $group_colors 1 end]
				lappend group_colors $bg

				$w_cgrp tag conf g$cmit -background $bg
				$w_line tag conf g$cmit -background $bg
				$w_file tag conf g$cmit -background $bg

				set order($cmit) $commit_count
				incr commit_count
				lappend commit_list $cmit
			}
		} elseif {[string match {filename *} $line]} {
			set file [string range $line 9 end]
			set n    $r_line_count
			set lno  $r_final_line
			set cmit $r_commit

			if {[regexp {^0{40}$} $cmit]} {
				set commit_abbr work
				set commit_type curr_commit
			} elseif {$cmit eq $commit} {
				set commit_abbr this
				set commit_type curr_commit
			} else {
				set commit_type prior_commit
				set commit_abbr [string range $cmit 0 4]
			}

			set author_abbr {}
			set a_name {}
			catch {set a_name $header($cmit,author)}
			while {$a_name ne {}} {
				if {![regexp {^([[:upper:]])} $a_name _a]} break
				append author_abbr $_a
				unset _a
				if {![regsub \
					{^[[:upper:]][^\s]*\s+} \
					$a_name {} a_name ]} break
			}
			if {$author_abbr eq {}} {
				set author_abbr { |}
			} else {
				set author_abbr [string range $author_abbr 0 3]
				while {[string length $author_abbr] < 4} {
					set author_abbr " $author_abbr"
				}
			}
			unset a_name

			set first_lno $lno
			while {
			   ![catch {set ncmit $line_commit([expr {$first_lno - 1}])}]
			&& ![catch {set nfile $line_file([expr {$first_lno - 1}])}]
			&& $ncmit eq $cmit
			&& $nfile eq $file
			} {
				incr first_lno -1
			}

			while {$n > 0} {
				set lno_e "$lno.0 lineend + 1c"
				if {[catch {set g g$line_commit($lno)}]} {
					$w_load tag add annotated $lno.0 $lno_e
				} else {
					$w_cgrp tag remove g$g $lno.0 $lno_e
					$w_line tag remove g$g $lno.0 $lno_e
					$w_file tag remove g$g $lno.0 $lno_e

					$w_cgrp tag remove a$g $lno.0 $lno_e
					$w_line tag remove a$g $lno.0 $lno_e
					$w_file tag remove a$g $lno.0 $lno_e
				}

				set line_commit($lno) $cmit
				set line_file($lno)   $file

				$w_cgrp delete $lno.0 "$lno.0 lineend"
				if {$lno == $first_lno} {
					$w_cgrp insert $lno.0 $commit_abbr $commit_type
				} elseif {$lno == [expr {$first_lno + 1}]} {
					$w_cgrp insert $lno.0 $author_abbr
				} else {
					$w_cgrp insert $lno.0 { |}
				}

				$w_cgrp tag add g$cmit $lno.0 $lno_e
				$w_line tag add g$cmit $lno.0 $lno_e
				$w_file tag add g$cmit $lno.0 $lno_e

				$w_cgrp tag add a$cmit $lno.0 $lno_e
				$w_line tag add a$cmit $lno.0 $lno_e
				$w_file tag add a$cmit $lno.0 $lno_e

				if {$highlight_line == -1} {
					if {[lindex [$w_file yview] 0] == 0} {
						$w_file see $lno.0
						_showcommit $this $lno
					}
				} elseif {$highlight_line == $lno} {
					_showcommit $this $lno
				}

				incr n -1
				incr lno
				incr blame_lines
			}

			while {
			   ![catch {set ncmit $line_commit($lno)}]
			&& ![catch {set nfile $line_file($lno)}]
			&& $ncmit eq $cmit
			&& $nfile eq $file
			} {
				$w_cgrp delete $lno.0 "$lno.0 lineend"

				if {$lno == $first_lno} {
					$w_cgrp insert $lno.0 $commit_abbr $commit_type
				} elseif {$lno == [expr {$first_lno + 1}]} {
					$w_cgrp insert $lno.0 $author_abbr
				} else {
					$w_cgrp insert $lno.0 { |}
				}
				incr lno
			}

		} elseif {[regexp {^([a-z-]+) (.*)$} $line line key data]} {
			set header($r_commit,$key) $data
		}
	}
	$w_cgrp conf -state disabled

	if {[eof $fd]} {
		close $fd
		set current_fd {}
		set status {Annotation complete.}
		destroy $w.status.c
	} else {
		_status $this
	}
} ifdeleted { catch {close $fd} }

method _status {} {
	set have  $blame_lines
	set total $total_lines
	set pdone 0
	if {$total} {set pdone [expr {100 * $have / $total}]}

	set status [format \
		"Loading annotations... %i of %i lines annotated (%2i%%)" \
		$have $total $pdone]
	$w.status.c coords bar 0 0 $pdone 20
}

method _click {cur_w pos} {
	set lno [lindex [split [$cur_w index $pos] .] 0]
	if {$lno eq {}} return
	_showcommit $this $lno
}

method _load_commit {pos} {
	set lno [lindex [split [$w_cgrp index $pos] .] 0]
	if {[catch {set cmit $line_commit($lno)}]} return
	if {[catch {set file $line_file($lno)  }]} return

	set commit $cmit
	set path $file
	_load $this
}

method _showcommit {lno} {
	global repo_config
	variable active_color

	if {$highlight_commit ne {}} {
		set cmit $highlight_commit
		$w_cgrp tag conf a$cmit -background {}
		$w_line tag conf a$cmit -background {}
		$w_file tag conf a$cmit -background {}
	}

	$w_cmit conf -state normal
	$w_cmit delete 0.0 end
	if {[catch {set cmit $line_commit($lno)}]} {
		set cmit {}
		$w_cmit insert end "Loading annotation..."
	} else {
		$w_cgrp tag conf a$cmit -background $active_color
		$w_line tag conf a$cmit -background $active_color
		$w_file tag conf a$cmit -background $active_color

		set author_name {}
		set author_email {}
		set author_time {}
		catch {set author_name $header($cmit,author)}
		catch {set author_email $header($cmit,author-mail)}
		catch {set author_time [clock format \
			$header($cmit,author-time) \
			-format {%Y-%m-%d %H:%M:%S}
		]}

		set committer_name {}
		set committer_email {}
		set committer_time {}
		catch {set committer_name $header($cmit,committer)}
		catch {set committer_email $header($cmit,committer-mail)}
		catch {set committer_time [clock format \
			$header($cmit,committer-time) \
			-format {%Y-%m-%d %H:%M:%S}
		]}

		if {[catch {set msg $header($cmit,message)}]} {
			set msg {}
			catch {
				set fd [open "| git cat-file commit $cmit" r]
				fconfigure $fd -encoding binary -translation lf
				if {[catch {set enc $repo_config(i18n.commitencoding)}]} {
					set enc utf-8
				}
				while {[gets $fd line] > 0} {
					if {[string match {encoding *} $line]} {
						set enc [string tolower [string range $line 9 end]]
					}
				}
				set msg [encoding convertfrom $enc [read $fd]]
				set msg [string trim $msg]
				close $fd

				set author_name [encoding convertfrom $enc $author_name]
				set committer_name [encoding convertfrom $enc $committer_name]

				set header($cmit,author) $author_name
				set header($cmit,committer) $committer_name
			}
			set header($cmit,message) $msg
		}

		$w_cmit insert end "commit $cmit\n" header_key
		$w_cmit insert end "Author:\t" header_key
		$w_cmit insert end "$author_name $author_email" header_val
		$w_cmit insert end "$author_time\n" header_val

		$w_cmit insert end "Committer:\t" header_key
		$w_cmit insert end "$committer_name $committer_email" header_val
		$w_cmit insert end "$committer_time\n" header_val

		if {$line_file($lno) ne $path} {
			$w_cmit insert end "Original File:\t" header_key
			$w_cmit insert end "[escape_path $line_file($lno)]\n" header_val
		}

		$w_cmit insert end "\n$msg"
	}
	$w_cmit conf -state disabled

	set highlight_line $lno
	set highlight_commit $cmit

	if {$highlight_commit eq $tooltip_commit} {
		_hide_tooltip $this
	}
}

method _copycommit {} {
	set pos @$::cursorX,$::cursorY
	set lno [lindex [split [$::cursorW index $pos] .] 0]
	if {![catch {set commit $line_commit($lno)}]} {
		clipboard clear
		clipboard append \
			-format STRING \
			-type STRING \
			-- $commit
	}
}

method _show_tooltip {cur_w pos} {
	set lno [lindex [split [$cur_w index $pos] .] 0]
	if {[catch {set cmit $line_commit($lno)}]} {
		_hide_tooltip $this
		return
	}

	if {$cmit eq $highlight_commit} {
		_hide_tooltip $this
		return
	}

	if {$cmit eq $tooltip_commit} {
		_position_tooltip $this
	} elseif {$tooltip_wm ne {}} {
		_open_tooltip $this $cur_w
	} elseif {$tooltip_timer eq {}} {
		set tooltip_timer [after 1000 [cb _open_tooltip $cur_w]]
	}
}

method _open_tooltip {cur_w} {
	set tooltip_timer {}
	set pos_x [winfo pointerx $cur_w]
	set pos_y [winfo pointery $cur_w]
	if {[winfo containing $pos_x $pos_y] ne $cur_w} {
		_hide_tooltip $this
		return
	}

	set pos @[join [list \
		[expr {$pos_x - [winfo rootx $cur_w]}] \
		[expr {$pos_y - [winfo rooty $cur_w]}]] ,]
	set lno [lindex [split [$cur_w index $pos] .] 0]
	set cmit $line_commit($lno)

	set author_name {}
	set author_email {}
	set author_time {}
	catch {set author_name $header($cmit,author)}
	catch {set author_email $header($cmit,author-mail)}
	catch {set author_time [clock format \
		$header($cmit,author-time) \
		-format {%Y-%m-%d %H:%M:%S}
	]}

	set committer_name {}
	set committer_email {}
	set committer_time {}
	catch {set committer_name $header($cmit,committer)}
	catch {set committer_email $header($cmit,committer-mail)}
	catch {set committer_time [clock format \
		$header($cmit,committer-time) \
		-format {%Y-%m-%d %H:%M:%S}
	]}

	set summary {}
	catch {set summary $header($cmit,summary)}

	set tooltip_commit $cmit
	set tooltip_text "commit $cmit
$author_name $author_email  $author_time
$summary"

	set file $line_file($lno)
	if {$file ne $path} {
		append tooltip_text "

Original File: $file"
	}

	if {$tooltip_wm ne "$cur_w.tooltip"} {
		_hide_tooltip $this

		set tooltip_wm [toplevel $cur_w.tooltip -borderwidth 1]
		wm overrideredirect $tooltip_wm 1
		wm transient $tooltip_wm [winfo toplevel $cur_w]
		pack [label $tooltip_wm.label \
			-background lightyellow \
			-foreground black \
			-textvariable @tooltip_text \
			-justify left]
	}
	_position_tooltip $this
}

method _position_tooltip {} {
	set req_w [winfo reqwidth  $tooltip_wm.label]
	set req_h [winfo reqheight $tooltip_wm.label]
	set pos_x [expr {[winfo pointerx .] +  5}]
	set pos_y [expr {[winfo pointery .] + 10}]

	set g "${req_w}x${req_h}"
	if {$pos_x >= 0} {append g +}
	append g $pos_x
	if {$pos_y >= 0} {append g +}
	append g $pos_y

	wm geometry $tooltip_wm $g
	raise $tooltip_wm
}

method _hide_tooltip {} {
	if {$tooltip_wm ne {}} {
		destroy $tooltip_wm
		set tooltip_wm {}
		set tooltip_commit {}
	}
	if {$tooltip_timer ne {}} {
		after cancel $tooltip_timer
		set tooltip_timer {}
	}
}

method _resize {new_height} {
	set diff [expr {$new_height - $old_height}]
	if {$diff == 0} return

	set my [expr {[winfo height $w.file_pane] - 25}]
	set o [$w.file_pane sash coord 0]
	set ox [lindex $o 0]
	set oy [expr {[lindex $o 1] + $diff}]
	if {$oy < 0}   {set oy 0}
	if {$oy > $my} {set oy $my}
	$w.file_pane sash place 0 $ox $oy

	set old_height $new_height
}

}