[PATCH] gitk: Do not select file list entries during diff loading

[Peter Oberndorfer <kumbayo84@arcor.de>]

Scrolling notification works by callingscrolltext{}
with with 2 values between 0 and 1
for the beginning and the end of the view relative to the total length.
When a long diff with several files is loaded,
the diff view length is updated several times
and causes executions of scrolltext{} even when
the current view never changed.

Every time scrolltext{} is executed,
a entry in the file list is selected and scrolled to.

This makes it impossible for a user to scroll the file list
while a long diff is still loading.

Signed-off-by: Peter Oberndorfer <kumbayo84@arcor.de>
---
Hi,

i used v3 of the Synchronize patch (+ the 2 fixes on top)
for some time now on mingw,
but i found a slight problem for my usage.

While the diff is loaded, the file list on the right side always scrolls up.
When a single revision touches hundreds of files [1] the loading takes
quite long.
During the diff loading i want to scroll down in the file list to the
relevant file i
am interested in. But the file list jumps up all the time.

Please review/test the patch carefully before applying,
since i do not often work with tcl/tk :-)
(Or suggest better ways to solve this problem)

Greetings Peter

[1] I imported history of a historic project. Each release is represented
by a single commit. Thus one commit contains a lot of files/big amount
of changes.
But most times i am interested in only a single file in the middle of
the file list.

 gitk-git/gitk | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/gitk-git/gitk b/gitk-git/gitk
index b294c9e..621db87 100755
--- a/gitk-git/gitk
+++ b/gitk-git/gitk
@@ -8004,7 +8004,7 @@ proc nextfile {} {

 proc clear_ctext {{first 1.0}} {
     global ctext smarktop smarkbot
-    global ctext_file_names ctext_file_lines
+    global ctext_file_names ctext_file_lines ctext_last_scroll_pos
     global pendinglinks

     set l [lindex [split $first .] 0]
@@ -8020,6 +8020,7 @@ proc clear_ctext {{first 1.0}} {
     }
     set ctext_file_names {}
     set ctext_file_lines {}
+    set ctext_last_scroll_pos -1
 }

 proc settabs {{firstab {}}} {
@@ -8162,21 +8163,24 @@ proc
suppress_highlighting_file_for_current_scrollpos {} {
 }

 proc scrolltext {f0 f1} {
-    global searchstring cmitmode ctext
+    global searchstring cmitmode ctext ctext_last_scroll_pos
     global suppress_highlighting_file_for_this_scrollpos

+    .bleft.bottom.sb set $f0 $f1
+    if {$searchstring ne {}} {
+	searchmarkvisible 0
+    }
+
     set topidx [$ctext index @0,0]
+    if {$topidx eq $ctext_last_scroll_pos} return
+    set ctext_last_scroll_pos $topidx
+
     if {![info exists suppress_highlighting_file_for_this_scrollpos]
 	|| $topidx ne $suppress_highlighting_file_for_this_scrollpos} {
 	highlightfile_for_scrollpos $topidx
     }

     catch {unset suppress_highlighting_file_for_this_scrollpos}
-
-    .bleft.bottom.sb set $f0 $f1
-    if {$searchstring ne {}} {
-	searchmarkvisible 0
-    }
 }

 proc setcoords {} {
@@ -11643,6 +11647,7 @@ set autoselect 1
 set autosellen 40
 set perfile_attrs 0
 set want_ttk 1
+set ctext_last_scroll_pos -1

 if {[tk windowingsystem] eq "aqua"} {
     set extdifftool "opendiff"
-- 
1.8.0.rc2.251.g3315d86