Add helper functions to avoid multiple occurrences of hard-wired constants.

1 files changed, 24 insertions, 0 deletions

diff --git a/library/tk.tcl b/library/tk.tcl
index a6dc37c..74942cb 100644
--- a/library/tk.tcl
+++ b/library/tk.tcl
@@ -543,6 +543,30 @@ proc ::tk::CancelRepeat {} {
     set Priv(afterId) {}
 }
 
+
+# ::tk::IsHiResScroll $state --
+# Checks whether the HiResScrollMask bit is set in the state.
+
+proc ::tk::IsHiResScroll state {
+    if {[expr {$state & 512}]} {
+	return 1
+    } else {
+	return 0
+    }
+}
+
+# ::tk::ScrollDirection $state --
+# Checks if ShiftMask is set in the MouseWheelEvent state.
+# Returns h for a horizontal scroll, v for a vertical scroll
+
+proc ::tk::ScrollDirection state {
+    if {[expr {$state & 1}]} {
+	return "h"
+    } else {
+	return "v"
+    }
+}
+
 ## ::tk::MouseWheel $w $dir $amount $factor $units
 
 proc ::tk::MouseWheel {w dir amount {factor -120.0} {units units}} {