[PATCH v3 0/5] Add horizontal mouse scroll support

[PATCH v3 0/5] Add horizontal mouse scroll support

[Dmitry Petrov]

This patchset adds implements passing horizontal scroll
events from the host system to guest systems via ps/2
mouse device.

This is useful during testing horizontal scroll behaviour
in guest operating systems as well as using it in case it
provides any benefits for a particular application.

The patch is based on the previous work by Brad Jorsch done
in 2010 but never merged, see
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=579968

Changes from V1 to V2:
  - Patch is split into a sequence
  - Value is clamped to 31 for horizontal scroll in the device code

Changes from V2 to V3:
  - Cover letter
  - Removed unnecessary log line

 hw/input/ps2.c    | 57 ++++++++++++++++++++++++++++++++++++++++-------
 qapi/ui.json      |  2 +-
 ui/cocoa.m        | 18 ++++++++++-----
 ui/gtk.c          | 54 ++++++++++++++++++++++++++++++++++----------
 ui/input-legacy.c | 15 +++++++++++++
 ui/sdl2.c         |  5 +++++
 6 files changed, 124 insertions(+), 27 deletions(-)

--
2.32.0

[PATCH v3 1/5] ps2: Initial horizontal scroll support

[Dmitry Petrov]

This change adds support for horizontal scroll to ps/2 mouse device
code. The code is implemented to match the logic of linux kernel
which is used as a reference.

Signed-off-by: Dmitry Petrov <dpetroff@gmail.com>
---
 hw/input/ps2.c | 57 +++++++++++++++++++++++++++++++++++++++++++-------
 qapi/ui.json   |  2 +-
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 9376a8f4ce..6236711e1b 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -123,6 +123,7 @@ typedef struct {
     int mouse_dx; /* current values, needed for 'poll' mode */
     int mouse_dy;
     int mouse_dz;
+    int mouse_dw;
     uint8_t mouse_buttons;
 } PS2MouseState;
 
@@ -715,7 +716,7 @@ static int ps2_mouse_send_packet(PS2MouseState *s)
     /* IMPS/2 and IMEX send 4 bytes, PS2 sends 3 bytes */
     const int needed = s->mouse_type ? 4 : 3;
     unsigned int b;
-    int dx1, dy1, dz1;
+    int dx1, dy1, dz1, dw1;
 
     if (PS2_QUEUE_SIZE - s->common.queue.count < needed) {
         return 0;
@@ -724,6 +725,7 @@ static int ps2_mouse_send_packet(PS2MouseState *s)
     dx1 = s->mouse_dx;
     dy1 = s->mouse_dy;
     dz1 = s->mouse_dz;
+    dw1 = s->mouse_dw;
     /* XXX: increase range to 8 bits ? */
     if (dx1 > 127)
         dx1 = 127;
@@ -740,6 +742,9 @@ static int ps2_mouse_send_packet(PS2MouseState *s)
     /* extra byte for IMPS/2 or IMEX */
     switch(s->mouse_type) {
     default:
+        /* Just ignore the wheels if not supported */
+        s->mouse_dz = 0;
+        s->mouse_dw = 0;
         break;
     case 3:
         if (dz1 > 127)
@@ -747,13 +752,41 @@ static int ps2_mouse_send_packet(PS2MouseState *s)
         else if (dz1 < -127)
                 dz1 = -127;
         ps2_queue_noirq(&s->common, dz1 & 0xff);
+        s->mouse_dz -= dz1;
+        s->mouse_dw = 0;
         break;
     case 4:
-        if (dz1 > 7)
-            dz1 = 7;
-        else if (dz1 < -7)
-            dz1 = -7;
-        b = (dz1 & 0x0f) | ((s->mouse_buttons & 0x18) << 1);
+        /*
+         * This matches what the Linux kernel expects for exps/2 in
+         * drivers/input/mouse/psmouse-base.c. Note, if you happen to
+         * press/release the 4th or 5th buttons at the same moment as a
+         * horizontal wheel scroll, those button presses will get lost. I'm not
+         * sure what to do about that, since by this point we don't know
+         * whether those buttons actually changed state.
+         */
+        if (dw1 != 0) {
+            if (dw1 > 31) {
+                dw1 = 31;
+            } else if (dw1 < -31) {
+                dw1 = -31;
+            }
+
+            /*
+             * linux kernel expects first 6 bits to represent the value
+             * for horizontal scroll
+             */
+            b = (dw1 & 0x3f) | 0x40;
+            s->mouse_dw -= dw1;
+        } else {
+            if (dz1 > 7) {
+                dz1 = 7;
+            } else if (dz1 < -7) {
+                dz1 = -7;
+            }
+
+            b = (dz1 & 0x0f) | ((s->mouse_buttons & 0x18) << 1);
+            s->mouse_dz -= dz1;
+        }
         ps2_queue_noirq(&s->common, b);
         break;
     }
@@ -764,7 +797,6 @@ static int ps2_mouse_send_packet(PS2MouseState *s)
     /* update deltas */
     s->mouse_dx -= dx1;
     s->mouse_dy -= dy1;
-    s->mouse_dz -= dz1;
 
     return 1;
 }
@@ -806,6 +838,12 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,
             } else if (btn->button == INPUT_BUTTON_WHEEL_DOWN) {
                 s->mouse_dz++;
             }
+
+            if (btn->button == INPUT_BUTTON_WHEEL_RIGHT) {
+                s->mouse_dw--;
+            } else if (btn->button == INPUT_BUTTON_WHEEL_LEFT) {
+                s->mouse_dw++;
+            }
         } else {
             s->mouse_buttons &= ~bmap[btn->button];
         }
@@ -833,8 +871,10 @@ static void ps2_mouse_sync(DeviceState *dev)
         /* if not remote, send event. Multiple events are sent if
            too big deltas */
         while (ps2_mouse_send_packet(s)) {
-            if (s->mouse_dx == 0 && s->mouse_dy == 0 && s->mouse_dz == 0)
+            if (s->mouse_dx == 0 && s->mouse_dy == 0
+                    && s->mouse_dz == 0 && s->mouse_dw == 0) {
                 break;
+            }
         }
     }
 }
@@ -1036,6 +1076,7 @@ static void ps2_mouse_reset(void *opaque)
     s->mouse_dx = 0;
     s->mouse_dy = 0;
     s->mouse_dz = 0;
+    s->mouse_dw = 0;
     s->mouse_buttons = 0;
 }
 
diff --git a/qapi/ui.json b/qapi/ui.json
index 2b4371da37..9354f4c467 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -905,7 +905,7 @@
 ##
 { 'enum'  : 'InputButton',
   'data'  : [ 'left', 'middle', 'right', 'wheel-up', 'wheel-down', 'side',
-  'extra' ] }
+  'extra', 'wheel-left', 'wheel-right' ] }
 
 ##
 # @InputAxis:
-- 
2.32.0

[PATCH v3 2/5] ui/cocoa: pass horizontal scroll information to the device code

[Dmitry Petrov]

Signed-off-by: Dmitry Petrov <dpetroff@gmail.com>
---
 ui/cocoa.m | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/ui/cocoa.m b/ui/cocoa.m
index 69745c483b..ac18e14ce0 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -970,21 +970,27 @@ QemuCocoaView *cocoaView;
              */
 
             /*
-             * When deltaY is zero, it means that this scrolling event was
-             * either horizontal, or so fine that it only appears in
-             * scrollingDeltaY. So we drop the event.
+             * We shouldn't have got a scroll event when deltaY and delta Y
+             * are zero, hence no harm in dropping the event
              */
-            if ([event deltaY] != 0) {
+            if ([event deltaY] != 0 || [event deltaX] != 0) {
             /* Determine if this is a scroll up or scroll down event */
-                buttons = ([event deltaY] > 0) ?
+                if ([event deltaY] != 0) {
+                  buttons = ([event deltaY] > 0) ?
                     INPUT_BUTTON_WHEEL_UP : INPUT_BUTTON_WHEEL_DOWN;
+                } else if ([event deltaX] != 0) {
+                  buttons = ([event deltaX] > 0) ?
+                    INPUT_BUTTON_WHEEL_LEFT : INPUT_BUTTON_WHEEL_RIGHT;
+                }
+
                 qemu_input_queue_btn(dcl.con, buttons, true);
                 qemu_input_event_sync();
                 qemu_input_queue_btn(dcl.con, buttons, false);
                 qemu_input_event_sync();
             }
+
             /*
-             * Since deltaY also reports scroll wheel events we prevent mouse
+             * Since deltaX/deltaY also report scroll wheel events we prevent mouse
              * movement code from executing.
              */
             mouse_event = false;
-- 
2.32.0

[PATCH v3 3/5] ui/gtk: pass horizontal scroll information to the device code

[Dmitry Petrov]

Signed-off-by: Dmitry Petrov <dpetroff@gmail.com>
---
 ui/gtk.c | 54 ++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 12 deletions(-)

diff --git a/ui/gtk.c b/ui/gtk.c
index 6a1f65d518..a8567b9ddc 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -968,33 +968,63 @@ static gboolean gd_scroll_event(GtkWidget *widget, GdkEventScroll *scroll,
                                 void *opaque)
 {
     VirtualConsole *vc = opaque;
-    InputButton btn;
+    InputButton btn_vertical;
+    InputButton btn_horizontal;
+    bool has_vertical = false;
+    bool has_horizontal = false;
 
     if (scroll->direction == GDK_SCROLL_UP) {
-        btn = INPUT_BUTTON_WHEEL_UP;
+        btn_vertical = INPUT_BUTTON_WHEEL_UP;
+        has_vertical = true;
     } else if (scroll->direction == GDK_SCROLL_DOWN) {
-        btn = INPUT_BUTTON_WHEEL_DOWN;
+        btn_vertical = INPUT_BUTTON_WHEEL_DOWN;
+        has_vertical = true;
+    } else if (scroll->direction == GDK_SCROLL_LEFT) {
+        btn_horizontal = INPUT_BUTTON_WHEEL_LEFT;
+        has_horizontal = true;
+    } else if (scroll->direction == GDK_SCROLL_RIGHT) {
+        btn_horizontal = INPUT_BUTTON_WHEEL_RIGHT;
+        has_horizontal = true;
     } else if (scroll->direction == GDK_SCROLL_SMOOTH) {
         gdouble delta_x, delta_y;
         if (!gdk_event_get_scroll_deltas((GdkEvent *)scroll,
                                          &delta_x, &delta_y)) {
             return TRUE;
         }
-        if (delta_y == 0) {
-            return TRUE;
-        } else if (delta_y > 0) {
-            btn = INPUT_BUTTON_WHEEL_DOWN;
+
+        if (delta_y > 0) {
+            btn_vertical = INPUT_BUTTON_WHEEL_DOWN;
+            has_vertical = true;
+        } else if (delta_y < 0) {
+            btn_vertical = INPUT_BUTTON_WHEEL_UP;
+            has_vertical = true;
+        } else if (delta_x > 0) {
+            btn_horizontal = INPUT_BUTTON_WHEEL_RIGHT;
+            has_horizontal = true;
+        } else if (delta_x < 0) {
+            btn_horizontal = INPUT_BUTTON_WHEEL_LEFT;
+            has_horizontal = true;
         } else {
-            btn = INPUT_BUTTON_WHEEL_UP;
+            return TRUE;
         }
     } else {
         return TRUE;
     }
 
-    qemu_input_queue_btn(vc->gfx.dcl.con, btn, true);
-    qemu_input_event_sync();
-    qemu_input_queue_btn(vc->gfx.dcl.con, btn, false);
-    qemu_input_event_sync();
+    if (has_vertical) {
+        qemu_input_queue_btn(vc->gfx.dcl.con, btn_vertical, true);
+        qemu_input_event_sync();
+        qemu_input_queue_btn(vc->gfx.dcl.con, btn_vertical, false);
+        qemu_input_event_sync();
+    }
+
+    if (has_horizontal) {
+        qemu_input_queue_btn(vc->gfx.dcl.con, btn_horizontal, true);
+        qemu_input_event_sync();
+        qemu_input_queue_btn(vc->gfx.dcl.con, btn_horizontal, false);
+        qemu_input_event_sync();
+    }
+
     return TRUE;
 }
 
-- 
2.32.0

[PATCH v3 4/5] ui/sdl2: pass horizontal scroll information to the device code

[Dmitry Petrov]

Signed-off-by: Dmitry Petrov <dpetroff@gmail.com>
---
 ui/sdl2.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ui/sdl2.c b/ui/sdl2.c
index 0bd30504cf..46a252d7d9 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -33,6 +33,7 @@
 #include "sysemu/runstate-action.h"
 #include "sysemu/sysemu.h"
 #include "ui/win32-kbd-hook.h"
+#include "qemu/log.h"
 
 static int sdl2_num_outputs;
 static struct sdl2_console *sdl2_console;
@@ -535,6 +536,10 @@ static void handle_mousewheel(SDL_Event *ev)
         btn = INPUT_BUTTON_WHEEL_UP;
     } else if (wev->y < 0) {
         btn = INPUT_BUTTON_WHEEL_DOWN;
+    } else if (wev->x < 0) {
+        btn = INPUT_BUTTON_WHEEL_RIGHT;
+    } else if (wev->x > 0) {
+        btn = INPUT_BUTTON_WHEEL_LEFT;
     } else {
         return;
     }
-- 
2.32.0

[PATCH v3 5/5] ui/input-legacy: pass horizontal scroll information

[Dmitry Petrov]

This code seems to be used by vmport hack, passing these values allows
to implement horizontal scroll support even when using vmport.
In case it's not supported horizontal scroll will act as a vertical one.

Signed-off-by: Dmitry Petrov <dpetroff@gmail.com>
---
 ui/input-legacy.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/ui/input-legacy.c b/ui/input-legacy.c
index 9fc78a639b..46ea74e44d 100644
--- a/ui/input-legacy.c
+++ b/ui/input-legacy.c
@@ -23,6 +23,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "qapi/qapi-commands-ui.h"
 #include "ui/console.h"
 #include "keymaps.h"
@@ -179,6 +180,20 @@ static void legacy_mouse_event(DeviceState *dev, QemuConsole *src,
                                     1,
                                     s->buttons);
         }
+        if (btn->down && btn->button == INPUT_BUTTON_WHEEL_RIGHT) {
+            s->qemu_put_mouse_event(s->qemu_put_mouse_event_opaque,
+                                    s->axis[INPUT_AXIS_X],
+                                    s->axis[INPUT_AXIS_Y],
+                                    -2,
+                                    s->buttons);
+        }
+        if (btn->down && btn->button == INPUT_BUTTON_WHEEL_LEFT) {
+            s->qemu_put_mouse_event(s->qemu_put_mouse_event_opaque,
+                                    s->axis[INPUT_AXIS_X],
+                                    s->axis[INPUT_AXIS_Y],
+                                    2,
+                                    s->buttons);
+        }
         break;
     case INPUT_EVENT_KIND_ABS:
         move = evt->u.abs.data;
-- 
2.32.0