Re: [Qemu-devel] [PATCH] mouse click simple queue

[Stefano Stabellini]

Sorry for the format of the patch, this time I have generated it using 
diff -uNp.

Stefano Stabellini wrote:
> Hi all,
>
> qemu doesn't enqueue mouse events, just records the latest mouse state.
> This can cause some lost mouse double clicks if the events are not 
> processed fast enought.
> I am attaching a patch that implements a simple queue for left mouse 
> click events.
>
> Best Regards,
>
> Stefano Stabellini

Index: sdl.c
===================================================================
RCS file: /sources/qemu/qemu/sdl.c,v
retrieving revision 1.45
diff -u -p -r1.45 sdl.c
--- sdl.c       17 Nov 2007 17:14:38 -0000      1.45
+++ sdl.c       28 Jan 2008 11:57:05 -0000
@@ -290,11 +290,10 @@ static void sdl_grab_end(void)
     sdl_update_caption();
 }
 
-static void sdl_send_mouse_event(int dz)
+static void sdl_send_mouse_event(int dx, int dy, int dz, int state)
 {
-    int dx, dy, state, buttons;
-    state = SDL_GetRelativeMouseState(&dx, &dy);
-    buttons = 0;
+    int buttons = 0;
+    
     if (state & SDL_BUTTON(SDL_BUTTON_LEFT))
         buttons |= MOUSE_EVENT_LBUTTON;
     if (state & SDL_BUTTON(SDL_BUTTON_RIGHT))
@@ -311,7 +310,7 @@ static void sdl_send_mouse_event(int dz)
            absolute_enabled = 1;
        }
 
-       SDL_GetMouseState(&dx, &dy);
+        SDL_GetMouseState(&dx, &dy);
        dx = dx * 0x7FFF / width;
        dy = dy * 0x7FFF / height;
     } else if (absolute_enabled) {
@@ -474,11 +473,19 @@ static void sdl_refresh(DisplayState *ds
         case SDL_MOUSEMOTION:
             if (gui_grab || kbd_mouse_is_absolute() ||
                 absolute_enabled) {
-                sdl_send_mouse_event(0);
+                int dx, dy, state;
+                state = SDL_GetRelativeMouseState(&dx, &dy);
+                sdl_send_mouse_event(dx, dy, 0, state);
             }
             break;
-        case SDL_MOUSEBUTTONDOWN:
         case SDL_MOUSEBUTTONUP:
+            if (gui_grab || kbd_mouse_is_absolute()) {
+                int dx, dy, state;
+                state = SDL_GetRelativeMouseState(&dx, &dy);
+                sdl_send_mouse_event(dx, dy, 0, state);
+            }
+            break;
+        case SDL_MOUSEBUTTONDOWN:
             {
                 SDL_MouseButtonEvent *bev = &ev->button;
                 if (!gui_grab && !kbd_mouse_is_absolute()) {
@@ -488,16 +495,21 @@ static void sdl_refresh(DisplayState *ds
                         sdl_grab_start();
                     }
                 } else {
-                    int dz;
+                    int dx, dy, dz, state;
                     dz = 0;
+                    state = SDL_GetRelativeMouseState(&dx, &dy);
 #ifdef SDL_BUTTON_WHEELUP
-                    if (bev->button == SDL_BUTTON_WHEELUP && ev->type == 
SDL_MOUSEBUTTONDOWN) {
+                    if (bev->button == SDL_BUTTON_WHEELUP) {
                         dz = -1;
-                    } else if (bev->button == SDL_BUTTON_WHEELDOWN && ev->type 
== SDL_MOUSEBUTTONDOWN) {
+                    }
+                    else if (bev->button == SDL_BUTTON_WHEELDOWN) {
                         dz = 1;
                     }
+                    else {
+                        state = bev->button | state;
+                    }
 #endif
-                    sdl_send_mouse_event(dz);
+                    sdl_send_mouse_event(dx, dy, dz, state);
                 }
             }
             break;
Index: hw/usb-hid.c
===================================================================
RCS file: /sources/qemu/qemu/hw/usb-hid.c,v
retrieving revision 1.16
diff -u -p -r1.16 usb-hid.c
--- hw/usb-hid.c        14 Jan 2008 02:25:44 -0000      1.16
+++ hw/usb-hid.c        28 Jan 2008 11:57:06 -0000
@@ -384,17 +384,39 @@ static const uint8_t usb_hid_usage_keys[
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 };
 
+static int currentbutton = 0;
+typedef struct _mouseclick {
+    int button_state;
+    struct _mouseclick *next;
+} mouseclick; 
+static mouseclick mousequeue[20];
+static mouseclick *head = mousequeue;
+static mouseclick *tail = mousequeue;
+
 static void usb_mouse_event(void *opaque,
                             int dx1, int dy1, int dz1, int buttons_state)
 {
     USBHIDState *hs = opaque;
     USBMouseState *s = &hs->ptr;
 
+    if (hs->changed == 1){
+        //A mouse event is lost
+        if (buttons_state != currentbutton && tail->next != head) {
+            //A left click event is lost: let's add it to the queue
+            //counter++;
+            tail->button_state = buttons_state;
+            tail = tail->next;
+        }
+    }
+    else {
+        s->buttons_state = buttons_state;
+    }
+
     s->dx += dx1;
     s->dy += dy1;
     s->dz += dz1;
-    s->buttons_state = buttons_state;
     hs->changed = 1;
+    currentbutton = buttons_state;
 }
 
 static void usb_tablet_event(void *opaque,
@@ -403,11 +425,24 @@ static void usb_tablet_event(void *opaqu
     USBHIDState *hs = opaque;
     USBMouseState *s = &hs->ptr;
 
+    if (hs->changed == 1){
+        //A mouse event is lost
+        if (buttons_state != currentbutton && tail->next != head) {
+            //A left click event is lost: let's add it to the queue
+            //counter++;
+            tail->button_state = buttons_state;
+            tail = tail->next;
+        }
+    }
+    else {
+        s->buttons_state = buttons_state;
+    }
+
     s->x = x;
     s->y = y;
     s->dz += dz;
-    s->buttons_state = buttons_state;
     hs->changed = 1;
+    currentbutton = buttons_state;
 }
 
 static void usb_keyboard_event(void *opaque, int keycode)
@@ -776,13 +811,26 @@ static int usb_hid_handle_data(USBDevice
             /* TODO: Implement finite idle delays.  */
             if (!(s->changed || s->idle))
                 return USB_RET_NAK;
-            s->changed = 0;
+
             if (s->kind == USB_MOUSE)
                 ret = usb_mouse_poll(s, p->data, p->len);
             else if (s->kind == USB_TABLET)
                 ret = usb_tablet_poll(s, p->data, p->len);
             else if (s->kind == USB_KEYBOARD)
                 ret = usb_keyboard_poll(&s->kbd, p->data, p->len);
+
+            if ((s->kind == USB_MOUSE || s->kind == USB_TABLET) && s->changed) 
{
+                USBMouseState *ms = &s->ptr;
+                if (head != tail) {
+                    ms->buttons_state = head->button_state;
+                    head = head->next;
+                }
+                else {
+                    s->changed = 0;
+                }
+            } else {
+                s->changed = 0;
+            }
         } else {
             goto fail;
         }
@@ -808,8 +856,16 @@ static void usb_hid_handle_destroy(USBDe
 
 USBDevice *usb_tablet_init(void)
 {
+    int i;
     USBHIDState *s;
 
+    for (i = 0; i < 19; i++) {
+        mousequeue[i].button_state = 0;
+        mousequeue[i].next = &(mousequeue[i + 1]);
+    }
+    mousequeue[i].button_state = 0;
+    mousequeue[i].next = mousequeue;
+
     s = qemu_mallocz(sizeof(USBHIDState));
     if (!s)
         return NULL;
@@ -831,8 +887,16 @@ USBDevice *usb_tablet_init(void)
 
 USBDevice *usb_mouse_init(void)
 {
+    int i;
     USBHIDState *s;
 
+    for (i = 0; i < 19; i++) {
+        mousequeue[i].button_state = 0;
+        mousequeue[i].next = &(mousequeue[i + 1]);
+    }
+    mousequeue[i].button_state = 0;
+    mousequeue[i].next = mousequeue;
+
     s = qemu_mallocz(sizeof(USBHIDState));
     if (!s)
         return NULL;