TIP#171 implementation - sanity for <MouseWheel> event handling!

1 files changed, 18 insertions, 7 deletions

diff --git a/win/tkWinX.c b/win/tkWinX.c
index 160e141..4609a94 100644
--- a/win/tkWinX.c
+++ b/win/tkWinX.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tkWinX.c,v 1.59 2008/12/10 05:02:52 das Exp $
+ * RCS: @(#) $Id: tkWinX.c,v 1.60 2008/12/28 22:59:47 dkf Exp $
  */
 
 /*
@@ -1006,10 +1006,26 @@ GenerateXEvent(
     LPARAM lParam)
 {
     XEvent event;
-    TkWindow *winPtr = (TkWindow *)Tk_HWNDToWindow(hwnd);
+    TkWindow *winPtr;
     ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
 	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
+    if (message == WM_MOUSEWHEEL) {
+	POINTS rootPoint = MAKEPOINTS(lParam);
+	POINT pos;
+
+	/*
+	 * Redirect mousewheel events to the window containing the cursor.
+	 * That feels much less strange to users, and is how all the other
+	 * platforms work.
+	 */
+
+	pos.x = rootPoint.x;
+	pos.y = rootPoint.y;
+	hwnd = WindowFromPoint(pos);
+    }
+
+    winPtr = (TkWindow *) Tk_HWNDToWindow(hwnd);
     if (!winPtr || winPtr->window == None) {
 	return;
     }
@@ -1107,11 +1123,6 @@ GenerateXEvent(
 	break;
 
     case WM_MOUSEWHEEL:
-	/*
-	 * The mouse wheel event is closer to a key event than a mouse event
-	 * in that the message is sent to the window that has focus.
-	 */
-
     case WM_CHAR:
     case WM_UNICHAR:
     case WM_SYSKEYDOWN: