[PATCH 1/2] gitk: Added support for OS X mouse wheel

[Jonathan del Strother <maillist@steelskies.com>]

From: Jonathan del Strother <jon.delStrother@bestbefore.tv>

(Väinö Järvelä supplied this patch a while ago for 1.5.2.  It no longer
applied cleanly, so I'm reposting it.)

MacBook doesn't seem to recognize MouseRelease-4 and -5 events, at all.
So i added a support for the MouseWheel event, which i limited to Tcl/tk
aqua, as i couldn't test it neither on Linux or Windows. Tcl/tk needs to
be updated from the version that is shipped with OS X 10.4 Tiger, for
this patch to work.

Signed-off-by: Jonathan del Strother <jon.delStrother@bestbefore.tv>
---
 gitk |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/gitk b/gitk
index 300fdce..ee2a6f5 100755
--- a/gitk
+++ b/gitk
@@ -843,6 +843,12 @@ proc makewindow {} {
     } else {
 	bindall <ButtonRelease-4> "allcanvs yview scroll -5 units"
 	bindall <ButtonRelease-5> "allcanvs yview scroll 5 units"
+        if {[tk windowingsystem] eq "aqua"} {
+            bindall <MouseWheel> {
+                set delta [expr {- (%D)}]
+                allcanvs yview scroll $delta units
+            }
+        }
     }
     bindall <2> "canvscan mark %W %x %y"
     bindall <B2-Motion> "canvscan dragto %W %x %y"
-- 
1.5.3.1