[PATCH] gitk: workaround Tcl/Tk Cmd-TAB behavior on OSX

[Tair Sabirgaliev <tair.sabirgaliev@bee.kz>]

On OSX Tcl/Tk application windows are created behind all
the applications down the stack of windows. This is very
annoying, because once a gitk window appears, it's the
downmost window and switching to it is pain.

The patch is trivial: if we are on OSX, emulate Cmd-Shift-TAB
key event, so that the gitk application window is brought
from bottom to top.

Signed-off-by: Tair Sabirgaliev <tair.sabirgaliev@gmail.com>
---
  gitk | 13 +++++++++++++
  1 file changed, 13 insertions(+)

diff --git a/gitk b/gitk
index 572f73f..60a87fc 100755
--- a/gitk
+++ b/gitk
@@ -11687,6 +11687,19 @@ if {[catch {package require Tk 8.4} err]} {
      exit 1
  }
  +# On OSX workaround the Tcl/Tk windows going down the stack of Cmd-TAB
+if {[tk windowingsystem] eq "aqua"} {
+    exec osascript -e {
+        tell application "System Events"
+            key down command
+            key down shift
+            keystroke tab
+            key up shift
+            key up command
+        end tell    +    }
+}
+
  # Unset GIT_TRACE var if set
  if { [info exists ::env(GIT_TRACE)] } {
      unset ::env(GIT_TRACE)
-- 
1.8.2