XQuartz: Add a scroll_in_device_direction preference

This preference allows users to override the related option in Mac OS X's
Mouse/Trackpad preferences.  This effectively lets the user determine
which "context" all of X11 fits into for context-based scrolling until
such API exists within X11 itself to pass along to X11 clients.

This is applicable to Mav OS X 10.7+

Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>

3 files changed, 36 insertions, 12 deletions

diff --git a/hw/xquartz/X11Application.h b/hw/xquartz/X11Application.h
index 619f32f7a..baee29d4c 100644
--- a/hw/xquartz/X11Application.h
+++ b/hw/xquartz/X11Application.h
@@ -104,6 +104,9 @@ void X11ApplicationMain(int argc, char **argv, char **envp);
 #define PREFS_FFM                   "wm_ffm"
 #define PREFS_FOCUS_ON_NEW_WINDOW   "wm_focus_on_new_window"
 
+#define PREFS_SCROLL_IN_DEV_DIRECTION "scroll_in_device_direction"
+extern Bool XQuartzScrollInDeviceDirection;
+
 #define PREFS_SYNC_PB                "sync_pasteboard"
 #define PREFS_SYNC_PB_TO_CLIPBOARD   "sync_pasteboard_to_clipboard"
 #define PREFS_SYNC_PB_TO_PRIMARY     "sync_pasteboard_to_primary"
diff --git a/hw/xquartz/X11Application.m b/hw/xquartz/X11Application.m
index 320bca179..8a03fbe29 100644
--- a/hw/xquartz/X11Application.m
+++ b/hw/xquartz/X11Application.m
@@ -79,6 +79,11 @@ static TISInputSourceRef last_key_layout;
 static KeyboardLayoutRef last_key_layout;
 #endif
 
+/* This preference is only tested on Lion or later as it's not relevant to
+ * earlier OS versions.
+ */
+Bool XQuartzScrollInDeviceDirection = FALSE;
+
 extern int darwinFakeButtons;
 
 /* Store the mouse location while in the background, and update X11's pointer
@@ -787,6 +792,9 @@ static NSMutableArray * cfarray_to_nsarray (CFArrayRef in) {
     
     noTestExtensions = ![self prefs_get_boolean:@PREFS_TEST_EXTENSIONS
                                         default:FALSE];
+    
+    XQuartzScrollInDeviceDirection = [self prefs_get_boolean:@PREFS_SCROLL_IN_DEV_DIRECTION
+                                                     default:XQuartzScrollInDeviceDirection];
 
 #if XQUARTZ_SPARKLE
     NSURL *url =  [self prefs_copy_url:@PREFS_UPDATE_FEED default:nil];
@@ -1339,20 +1347,30 @@ static const char *untrusted_str(NSEvent *e) {
             break;
             
 		case NSScrollWheel:
+            {
+                float deltaX = [e deltaX];
+                float deltaY = [e deltaY];
 #if !defined(XPLUGIN_VERSION) || XPLUGIN_VERSION == 0
-            /* If we're in the background, we need to send a MotionNotify event
-             * first, since we aren't getting them on background mouse motion
-             */
-            if(!XQuartzServerVisible && noTestExtensions) {
-                bgMouseLocationUpdated = FALSE;
-                DarwinSendPointerEvents(darwinPointer, MotionNotify, 0, location.x,
-                                        location.y, pressure, tilt.x, tilt.y);
-            }
+                /* If we're in the background, we need to send a MotionNotify event
+                * first, since we aren't getting them on background mouse motion
+                */
+                if(!XQuartzServerVisible && noTestExtensions) {
+                    bgMouseLocationUpdated = FALSE;
+                    DarwinSendPointerEvents(darwinPointer, MotionNotify, 0, location.x,
+                                            location.y, pressure, tilt.x, tilt.y);
+                }
 #endif
-			DarwinSendScrollEvents([e deltaX], [e deltaY], location.x, location.y,
-                                   pressure, tilt.x, tilt.y);
-            break;
-            
+#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
+                // TODO: Change 1117 to NSAppKitVersionNumber10_7 when it is defined
+                if(NSAppKitVersionNumber >= 1117 && XQuartzScrollInDeviceDirection && [e isDirectionInvertedFromDevice]) {
+                    deltaX *= -1;
+                    deltaY *= -1;
+                }
+#endif
+                DarwinSendScrollEvents(deltaX, deltaY, location.x, location.y,
+                                       pressure, tilt.x, tilt.y);
+                break;
+            }
         case NSKeyDown: case NSKeyUp:
             {
                 /* XKB clobbers our keymap at startup, so we need to force it on the first keypress.
diff --git a/hw/xquartz/man/Xquartz.man b/hw/xquartz/man/Xquartz.man
index aea56c943..0ea6e6eb8 100644
--- a/hw/xquartz/man/Xquartz.man
+++ b/hw/xquartz/man/Xquartz.man
@@ -83,6 +83,9 @@ This option defaults to false and is provided only "for experts."  It updates th
 .TP 8
 .B defaults write __bundle_id_prefix__.X11 enable_test_extensions -boolean true
 This option defaults to false and is only accessible through the command line.  Enable this option to turn on the DEC-XTRAP, RECORD, and XTEST extensions in the server.
+.TP 8
+.B defaults write __laucnd_id_prefix__.X11 scroll_in_device_direction -boolean true
+This option defaults to false.  Enable this option to ensure that X11 scroll events are always in the direction of the device.  This overrides the related option in the Mouse/Trackpad section of System Preferences.
 .SH OPTIONS
 .PP
 In addition to the normal server options described in the \fIXserver(1)\fP