Various fixes to mouse wheel scrolling:...

webkit/glue/webinputevent_mac.mm

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006-2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 101 matching lines @@
 
   layout_test_click_count = 0;
 }
 
 // WebMouseWheelEvent ---------------------------------------------------------
 
 WebMouseWheelEvent::WebMouseWheelEvent(NSEvent *event, NSView* view) {
   type = MOUSE_WHEEL;
   button = BUTTON_NONE;
 
-  NSPoint location = [NSEvent mouseLocation];  // global coordinates
-  global_x = location.x;
-  global_y = location.y;
-  
-  NSPoint windowLocal = [event locationInWindow];
-  location = [view convertPoint:windowLocal fromView:nil];
-  y = [view frame].size.height - location.y;  // flip y
-  x = location.x;
-
-  int wheel_delta = [event deltaY];
-  const int delta_lines = wheel_delta * kDefaultScrollLinesPerWheelDelta;
-
-  // Scroll horizontally if shift is held. WebKit's WebKit/win/WebView.cpp 
-  // does the equivalent.
-  // TODO(jackson): Support WM_MOUSEHWHEEL = 0x020E event as well. 
-  // (Need a mouse with horizontal scrolling capabilities to test it.)
-  if ([event modifierFlags] & NSShiftKeyMask) {
-    // Scrolling up should move left, scrolling down should move right
-    delta_x = -delta_lines;  
-    delta_y = 0;
-  } else {
-    delta_x = 0;
-    delta_y = delta_lines;
-  }
-
+  // Set modifiers based on key state.
   if ([event modifierFlags] & NSControlKeyMask)
     modifiers |= CTRL_KEY;
   if ([event modifierFlags] & NSShiftKeyMask)
     modifiers |= SHIFT_KEY;
   if ([event modifierFlags] & NSAlternateKeyMask)
     modifiers |= ALT_KEY;
+
+  // Set coordinates by translating event coordinates from screen to client.
+  NSPoint location = [NSEvent mouseLocation];  // global coordinates
+  global_x = location.x;
+  global_y = location.y;
+  NSPoint windowLocal = [event locationInWindow];
+  location = [view convertPoint:windowLocal fromView:nil];
+  x = location.x;
+  y = [view frame].size.height - location.y;  // flip y
+
+  // Convert wheel delta amount to a number of lines to scroll.
+  float wheel_delta = [event deltaY];
+  const float delta_lines = wheel_delta * kDefaultScrollLinesPerWheelDelta;
+
+  // Set scroll amount based on above calculations.
+  if ([event modifierFlags] & NSShiftKeyMask) {
+    // Scrolling up should move left, scrolling down should move right.  This is
+    // opposite Safari, but seems more consistent with vertical scrolling.

[Avi (use Gerrit), 2009/03/05 02:10:36]

Nonono. Safari's shift-scrolling matches Cocoa's, which matches everyone else on
the system. "Seems more consistent" is not a good excuse to do the opposite of
everyone.

+    delta_x = delta_lines;
+    delta_y = 0;
+  } else {
+    delta_x = 0;
+    delta_y = delta_lines;
+  }
+  scroll_by_page = false;
 }
 
 // WebKeyboardEvent -----------------------------------------------------------
 
 // ----------------------------------------------------------------------
 // Begin Apple code, copied from KeyEventMac.mm
 //
 // We can share some of this code if we factored it out of KeyEventMac, but
 // the main problem is that it relies on the NSString ctor on String for
 // conversions, and since we're building without PLATFORM(MAC), we don't have
@@ skipping 842 matching lines @@
       [unmodified_str length] < kTextLengthCap) {
     [text_str getCharacters:&text[0]];
     [unmodified_str getCharacters:&unmodified_text[0]];
   } else {
     LOG(ERROR) << "Event had text too long; dropped";
   }
   [identifier_str getCString:&key_identifier[0]
                    maxLength:kIdentifierLengthCap
                     encoding:NSASCIIStringEncoding];
 }