git-gui: Display commit/tag/remote info in tooltip of revision picker

Our revision chooser mega-widget now sets up tooltips for itself so
that it displays details about a commit (or a tag and the commit
it refers to) when the user mouses over that line in the filtered
ref list.  If the item is from a remote tracking branch then we also
show the remote url and what branch on that remote we fetch from, so
the user has a clear concept of where that revision data originated.

To help the merge dialog I've also added a new constructor that
makes the dialog only offer unmerged revisions (those not in HEAD),
as this allows users to avoid performing merges only to get "Already
up to date" messages back from core Git.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

1 files changed, 230 insertions, 6 deletions

diff --git a/lib/choose_rev.tcl b/lib/choose_rev.tcl
index 6c4c3188f..bb6966eb9 100644
--- a/lib/choose_rev.tcl
+++ b/lib/choose_rev.tcl
@@ -16,8 +16,21 @@ field cur_specs [list]; # list of specs for $revtype
 field spec_head       ; # list of all head specs
 field spec_trck       ; # list of all tracking branch specs
 field spec_tag        ; # list of all tag specs
+field tip_data        ; # array of tip commit info by refname
 
-constructor new {path {title {}}} {
+field tooltip_wm        {} ; # Current tooltip toplevel, if open
+field tooltip_t         {} ; # Text widget in $tooltip_wm
+field tooltip_timer     {} ; # Current timer event for our tooltip
+
+proc new {path {title {}}} {
+	return [_new $path 0 $title]
+}
+
+proc new_unmerged {path {title {}}} {
+	return [_new $path 1 $title]
+}
+
+constructor _new {path unmerged_only title} {
 	global current_branch is_detached
 
 	set w $path
@@ -93,6 +106,10 @@ constructor new {path {title {}}} {
 		-yscrollcommand [cb _sb_set $w.list.sby v]
 	pack $w_list -fill both -expand 1
 	grid $w.list -sticky nswe -padx {20 5} -columnspan 2
+	bind $w_list <Any-Motion>  [cb _show_tooltip @%x,%y]
+	bind $w_list <Any-Enter>   [cb _hide_tooltip]
+	bind $w_list <Any-Leave>   [cb _hide_tooltip]
+	bind $w_list <Destroy>     [cb _hide_tooltip]
 
 	grid columnconfigure $w 1 -weight 1
 	if {$is_detached} {
@@ -105,21 +122,89 @@ constructor new {path {title {}}} {
 	bind $w_filter <Key-Return> [list focus $w_list]\;break
 	bind $w_filter <Key-Down>   [list focus $w_list]
 
+	set fmt list
+	append fmt { %(refname)}
+	append fmt { [list}
+	append fmt { %(objecttype)}
+	append fmt { %(objectname)}
+	append fmt { [concat %(taggername) %(authorname)]}
+	append fmt { [concat %(taggerdate) %(authordate)]}
+	append fmt { %(subject)}
+	append fmt {] [list}
+	append fmt { %(*objecttype)}
+	append fmt { %(*objectname)}
+	append fmt { %(*authorname)}
+	append fmt { %(*authordate)}
+	append fmt { %(*subject)}
+	append fmt {]}
+	set all_refn [list]
+	set fr_fd [git_read for-each-ref \
+		--tcl \
+		--sort=-taggerdate \
+		--format=$fmt \
+		refs/heads \
+		refs/remotes \
+		refs/tags \
+		]
+	fconfigure $fr_fd -translation lf -encoding utf-8
+	while {[gets $fr_fd line] > 0} {
+		set line [eval $line]
+		if {[lindex $line 1 0] eq {tag}} {
+			if {[lindex $line 2 0] eq {commit}} {
+				set sha1 [lindex $line 2 1]
+			} else {
+				continue
+			}
+		} elseif {[lindex $line 1 0] eq {commit}} {
+			set sha1 [lindex $line 1 1]
+		} else {
+			continue
+		}
+		set refn [lindex $line 0]
+		set tip_data($refn) [lrange $line 1 end]
+		lappend cmt_refn($sha1) $refn
+		lappend all_refn $refn
+	}
+	close $fr_fd
+
+	if {$unmerged_only} {
+		set fr_fd [git_read rev-list --all ^$::HEAD]
+		while {[gets $fr_fd sha1] > 0} {
+			if {[catch {set rlst $cmt_refn($sha1)}]} continue
+			foreach refn $rlst {
+				set inc($refn) 1
+			}
+		}
+		close $fr_fd
+	} else {
+		foreach refn $all_refn {
+			set inc($refn) 1
+		}
+	}
+
 	set spec_head [list]
 	foreach name [load_all_heads] {
-		lappend spec_head [list $name refs/heads/$name]
+		set refn refs/heads/$name
+		if {[info exists inc($refn)]} {
+			lappend spec_head [list $name $refn]
+		}
 	}
 
 	set spec_trck [list]
 	foreach spec [all_tracking_branches] {
-		set name [lindex $spec 0]
-		regsub ^refs/(heads|remotes)/ $name {} name
-		lappend spec_trck [concat $name $spec]
+		set refn [lindex $spec 0]
+		if {[info exists inc($refn)]} {
+			regsub ^refs/(heads|remotes)/ $refn {} name
+			lappend spec_trck [concat $name $spec]
+		}
 	}
 
 	set spec_tag [list]
 	foreach name [load_all_tags] {
-		lappend spec_tag [list $name refs/tags/$name]
+		set refn refs/tags/$name
+		if {[info exists inc($refn)]} {
+			lappend spec_tag [list $name $refn]
+		}
 	}
 
 		  if {$is_detached}             { set revtype HEAD
@@ -364,4 +449,143 @@ method _sb_set {sb orient first last} {
 	$sb set $first $last
 }
 
+method _show_tooltip {pos} {
+	if {$tooltip_wm ne {}} {
+		_open_tooltip $this
+	} elseif {$tooltip_timer eq {}} {
+		set tooltip_timer [after 1000 [cb _open_tooltip]]
+	}
+}
+
+method _open_tooltip {} {
+	global remote_url
+
+	set tooltip_timer {}
+	set pos_x [winfo pointerx $w_list]
+	set pos_y [winfo pointery $w_list]
+	if {[winfo containing $pos_x $pos_y] ne $w_list} {
+		_hide_tooltip $this
+		return
+	}
+
+	set pos @[join [list \
+		[expr {$pos_x - [winfo rootx $w_list]}] \
+		[expr {$pos_y - [winfo rooty $w_list]}]] ,]
+	set lno [$w_list index $pos]
+	if {$lno eq {}} {
+		_hide_tooltip $this
+		return
+	}
+
+	set spec [lindex $cur_specs $lno]
+	set refn [lindex $spec 1]
+	if {$refn eq {}} {
+		_hide_tooltip $this
+		return
+	}
+
+	if {$tooltip_wm eq {}} {
+		set tooltip_wm [toplevel $w_list.tooltip -borderwidth 1]
+		wm overrideredirect $tooltip_wm 1
+		wm transient $tooltip_wm [winfo toplevel $w_list]
+		set tooltip_t $tooltip_wm.label
+		text $tooltip_t \
+			-takefocus 0 \
+			-highlightthickness 0 \
+			-relief flat \
+			-borderwidth 0 \
+			-wrap none \
+			-background lightyellow \
+			-foreground black
+		$tooltip_t tag conf section_header -font font_uibold
+		bind $tooltip_wm <Escape> [cb _hide_tooltip]
+		pack $tooltip_t
+	} else {
+		$tooltip_t conf -state normal
+		$tooltip_t delete 0.0 end
+	}
+
+	set data $tip_data($refn)
+	if {[lindex $data 0 0] eq {tag}} {
+		set tag  [lindex $data 0]
+		if {[lindex $data 1 0] eq {commit}} {
+			set cmit [lindex $data 1]
+		} else {
+			set cmit {}
+		}
+	} elseif {[lindex $data 0 0] eq {commit}} {
+		set tag  {}
+		set cmit [lindex $data 0]
+	}
+
+	$tooltip_t insert end "[lindex $spec 0]\n"
+
+	if {$tag ne {}} {
+		$tooltip_t insert end "\n"
+		$tooltip_t insert end "tag" section_header
+		$tooltip_t insert end "  [lindex $tag 1]\n"
+		$tooltip_t insert end [lindex $tag 2]
+		$tooltip_t insert end " ([lindex $tag 3])\n"
+		$tooltip_t insert end [lindex $tag 4]
+		$tooltip_t insert end "\n"
+	}
+
+	if {$cmit ne {}} {
+		$tooltip_t insert end "\n"
+		$tooltip_t insert end "commit" section_header
+		$tooltip_t insert end "  [lindex $cmit 1]\n"
+		$tooltip_t insert end [lindex $cmit 2]
+		$tooltip_t insert end " ([lindex $cmit 3])\n"
+		$tooltip_t insert end [lindex $cmit 4]
+	}
+
+	if {[llength $spec] > 2} {
+		$tooltip_t insert end "\n"
+		$tooltip_t insert end "remote" section_header
+		$tooltip_t insert end "  [lindex $spec 2]\n"
+		$tooltip_t insert end "url"
+		$tooltip_t insert end " $remote_url([lindex $spec 2])\n"
+		$tooltip_t insert end "branch"
+		$tooltip_t insert end " [lindex $spec 3]"
+	}
+
+	$tooltip_t conf -state disabled
+	_position_tooltip $this
+}
+
+method _position_tooltip {} {
+	set max_h [lindex [split [$tooltip_t index end] .] 0]
+	set max_w 0
+	for {set i 1} {$i <= $max_h} {incr i} {
+		set c [lindex [split [$tooltip_t index "$i.0 lineend"] .] 1]
+		if {$c > $max_w} {set max_w $c}
+	}
+	$tooltip_t conf -width $max_w -height $max_h
+
+	set req_w [winfo reqwidth  $tooltip_t]
+	set req_h [winfo reqheight $tooltip_t]
+	set pos_x [expr {[winfo pointerx .] +  5}]
+	set pos_y [expr {[winfo pointery .] + 10}]
+
+	set g "${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 $tooltip_wm
+		set tooltip_wm {}
+	}
+	if {$tooltip_timer ne {}} {
+		after cancel $tooltip_timer
+		set tooltip_timer {}
+	}
+}
+
 }