git-gui: add search history to searchbar

Use the up/down keys to browse the history.
Signed-off-by: NBert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: NPat Thoyts <patthoyts@users.sourceforge.net>

lib/search.tcl

@@ -13,6 +13,9 @@ field casesensitive
 field default_casesensitive
 field searchdirn     -forwards
 
+field history
+field history_index
+
 field smarktop
 field smarkbot
 
@@ -28,6 +31,8 @@ constructor new {i_w i_text args} {
 		set default_casesensitive 1
 	}
 
+	set history [list]
+
 	${NS}::frame  $w
 	${NS}::label  $w.l       -text [mc Find:]
 	entry  $w.ent -textvariable ${__this}::searchstring -background lightgreen
@@ -50,6 +55,8 @@ constructor new {i_w i_text args} {
 	trace add variable searchstring write [cb _incrsearch_cb]
 	bind $w.ent <Return> [cb find_next]
 	bind $w.ent <Shift-Return> [cb find_prev]
+	bind $w.ent <Key-Up>   [cb _prev_search]
+	bind $w.ent <Key-Down> [cb _next_search]
 	
 	bind $w <Destroy> [list delete_this $this]
 	return $this
@@ -58,8 +65,10 @@ constructor new {i_w i_text args} {
 method show {} {
 	if {![visible $this]} {
 		grid $w
+		$w.ent delete 0 end
 		set regexpsearch  $default_regexpsearch
 		set casesensitive $default_casesensitive
+		set history_index [llength $history]
 	}
 	focus -force $w.ent
 }
@@ -68,6 +77,7 @@ method hide {} {
 	if {[visible $this]} {
 		focus $ctext
 		grid remove $w
+		_save_search $this
 	}
 }
 
@@ -160,6 +170,55 @@ method _incrsearch {} {
 	}
 }
 
+method _save_search {} {
+	if {$searchstring eq {}} {
+		return
+	}
+	if {[llength $history] > 0} {
+		foreach {s_regexp s_case s_expr} [lindex $history end] break
+	} else {
+		set s_regexp $regexpsearch
+		set s_case   $casesensitive
+		set s_expr   ""
+	}
+	if {$searchstring eq $s_expr} {
+		# update modes
+		set history [lreplace $history end end \
+				[list $regexpsearch $casesensitive $searchstring]]
+	} else {
+		lappend history [list $regexpsearch $casesensitive $searchstring]
+	}
+	set history_index [llength $history]
+}
+
+method _prev_search {} {
+	if {$history_index > 0} {
+		incr history_index -1
+		foreach {s_regexp s_case s_expr} [lindex $history $history_index] break
+		$w.ent delete 0 end
+		$w.ent insert 0 $s_expr
+		set regexpsearch $s_regexp
+		set casesensitive $s_case
+	}
+}
+
+method _next_search {} {
+	if {$history_index < [llength $history]} {
+		incr history_index
+	}
+	if {$history_index < [llength $history]} {
+		foreach {s_regexp s_case s_expr} [lindex $history $history_index] break
+	} else {
+		set s_regexp $default_regexpsearch
+		set s_case   $default_casesensitive
+		set s_expr   ""
+	}
+	$w.ent delete 0 end
+	$w.ent insert 0 $s_expr
+	set regexpsearch $s_regexp
+	set casesensitive $s_case
+}
+
 method find_prev {} {
 	find_next $this -backwards
 }
@@ -170,6 +229,7 @@ method find_next {{dir -forwards}} {
 	set searchdirn $dir
 	$ctext mark unset anchor
 	if {$searchstring ne {}} {
+		_save_search $this
 		set start [_get_new_anchor $this]
 		if {$dir eq "-forwards"} {
 			set start "$start + 1c"