Mouse Wheel Bug Fixes

include/uiohook.h

@@ -109,6 +109,7 @@ typedef struct _mouse_wheel_event_data {
     int16_t x;
     int16_t y;
     uint8_t type;
+    uint8_t amount;
     int16_t rotation;
     uint16_t delta;
     uint8_t direction;

src/darwin/post_event.c

@@ -238,7 +238,7 @@ static int post_mouse_wheel_event(uiohook_event * const event, CGEventSourceRef
 
     CGEventRef cg_event = CGEventCreateScrollWheelEvent(
         src,
-        kCGScrollEventUnitLine,
+        scroll_unit,
         // TODO Currently only support 1 wheel axis.
         (CGWheelCount) 1, // 1 for Y-only, 2 for Y-X, 3 for Y-X-Z
         event->data.wheel.rotation // TODO Is this value correct? Do we need PPL?

src/windows/dispatch_event.c

@@ -412,13 +412,15 @@ bool dispatch_mouse_wheel(uint64_t timestamp, MSLLHOOKSTRUCT *mshook, uint8_t di
 
             uio_event.data.wheel.type = WHEEL_BLOCK_SCROLL;
             uio_event.data.wheel.rotation *= 1;
+            uio_event.data.wheel.amount = 1;
         } else {
             /* If this number is 0, no scrolling should occur.
              * If the number of lines to scroll is greater than the number of lines viewable, the scroll operation
              * should also be interpreted as a page down or page up operation. */
 
             uio_event.data.wheel.type = WHEEL_UNIT_SCROLL;
             uio_event.data.wheel.rotation *= wheel_amount;
+            uio_event.data.wheel.amount = wheel_amount;
         }
 
         // Set the direction based on what event was received.

src/windows/post_event.c

@@ -166,7 +166,9 @@ static int map_mouse_event(uiohook_event * const event, INPUT * const input) {
         case EVENT_MOUSE_WHEEL:
             input->mi.dwFlags = MOUSEEVENTF_WHEEL;
 
-            // type, amount and rotation?
+            // TODO What are we going to do about delta=? We could normalize with rotation *= (120 / delta)
+            // TODO What are we going to do about type=WHEEL_BLOCK_SCROLL?
+            // TODO What are we going to do about amount=? Is this really a setting, not event property?
             input->mi.mouseData = event->data.wheel.rotation;
             break;
 

src/x11/dispatch_event.c

@@ -251,13 +251,14 @@ static bool dispatch_mouse_wheel_rotated(XButtonEvent * const x_event) {
     /* Some scroll wheel properties are available via the new XInput2 (XI2) extension. Unfortunately the extension is
      * not available on my development platform at this time. For the time being we will just use the Windows default
      * value of 3. */
+    uio_event.data.wheel.amount = WHEEL_AMOUNT;
     uio_event.data.wheel.delta = 100;
     if (x_event->button == WheelDown || x_event->button == WheelLeft) {
         // Wheel Rotated Up and Away.
-        uio_event.data.wheel.rotation = -3 * uio_event.data.wheel.delta;
+        uio_event.data.wheel.rotation = -1 * uio_event.data.wheel.delta;
     } else { // event.button == WheelUp || event.button == WheelRight
         // Wheel Rotated Down and Towards.
-        uio_event.data.wheel.rotation = 3 * uio_event.data.wheel.delta;
+        uio_event.data.wheel.rotation = uio_event.data.wheel.delta;
     }
 
     if (x_event->button == WheelUp || x_event->button == WheelDown) {

src/x11/input_helper.h

@@ -35,6 +35,9 @@
 #define XButton1    8
 #define XButton2    9
 
+// The static number of clicks for X11 because it is a non-configurable amount.
+#define WHEEL_AMOUNT 3
+
 // For this struct, refer to libxnee, requires Xlibint.h
 typedef union {
     unsigned char       type;

src/x11/post_event.c

@@ -119,40 +119,43 @@ static int post_mouse_button_event(uiohook_event * const event) {
 static int post_mouse_wheel_event(uiohook_event * const event) {
     int status = UIOHOOK_FAILURE;
 
-    XButtonEvent btn_event = {
-        .serial = 0,
-        .send_event = False,
-        .display = helper_disp,
+    if (event->data.wheel.delta > 0) {
+        XButtonEvent btn_event = {
+            .serial = 0,
+            .send_event = False,
+            .display = helper_disp,
 
-        .window = None,                                /* “event” window it is reported relative to */
-        .root = None,                                  /* root window that the event occurred on */
-        .subwindow = XDefaultRootWindow(helper_disp),  /* child window */
+            .window = None,                                /* “event” window it is reported relative to */
+            .root = None,                                  /* root window that the event occurred on */
+            .subwindow = XDefaultRootWindow(helper_disp),  /* child window */
 
-        .time = CurrentTime,
+            .time = CurrentTime,
 
-        .x = event->data.wheel.x,                      /* pointer x, y coordinates in event window */
-        .y = event->data.wheel.y,
+            .x = event->data.wheel.x,                      /* pointer x, y coordinates in event window */
+            .y = event->data.wheel.y,
 
-        .x_root = 0,                                   /* coordinates relative to root */
-        .y_root = 0,
+            .x_root = 0,                                   /* coordinates relative to root */
+            .y_root = 0,
 
-        .state = 0x00,                                 /* key or button mask */
-        .same_screen = True
-    };
+            .state = 0x00,                                 /* key or button mask */
+            .same_screen = True
+        };
 
-    // Wheel events should be the same as click events on X11.
-    // type, amount and rotation
-    unsigned int button = button_map_lookup(event->data.wheel.rotation < 0 ? WheelUp : WheelDown);
+        unsigned int button = button_map_lookup(event->data.wheel.rotation < 0 ? WheelUp : WheelDown);
 
-    if (XTestFakeButtonEvent(helper_disp, button, True, 0) != 0) {
+        // X11 does not support a rotation amount so we will emulate the number of rotations based on the static wheel amount.
+        // TODO What are we going to do about type=WHEEL_BLOCK_SCROLL?
+        // TODO What are we going to do about amount=? Is this really a setting, not event property?
         status = UIOHOOK_SUCCESS;
+        for (int i = abs(event->data.wheel.rotation) / (event->data.wheel.delta * event->data.wheel.amount); i > 0 && status == UIOHOOK_SUCCESS; i--) {
+            // Wheel events are be the same as click events on X11.
+            if (!XTestFakeButtonEvent(helper_disp, button, True, 0) || !XTestFakeButtonEvent(helper_disp, button, False, 0)) {
+                status = UIOHOOK_FAILURE;
+            }
+        }
     }
 
-    if (status == UIOHOOK_SUCCESS && XTestFakeButtonEvent(helper_disp, button, False, 0) == 0) {
-        status = UIOHOOK_FAILURE;
-    }
-
-    return UIOHOOK_SUCCESS;
+    return status;
 }
 
 static int post_mouse_motion_event(uiohook_event * const event) {