Add notifier for mouse mode changes

Right now, DisplayState clients rely on polling the mouse mode to determine
when the device is changed to an absolute device.  Use a notification list to
add an explicit notification.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

2 files changed, 39 insertions, 1 deletions

diff --git a/console.h b/console.h
index f3c619f0f8..6def1152e6 100644
--- a/console.h
+++ b/console.h
@@ -3,6 +3,7 @@
 
 #include "qemu-char.h"
 #include "qdict.h"
+#include "notify.h"
 
 /* keyboard/mouse support */
 
@@ -56,6 +57,8 @@ void kbd_mouse_event(int dx, int dy, int dz, int buttons_state);
 
 /* Does the current mouse generate absolute events */
 int kbd_mouse_is_absolute(void);
+void qemu_add_mouse_mode_change_notifier(Notifier *notify);
+void qemu_remove_mouse_mode_change_notifier(Notifier *notify);
 
 /* Of all the mice, is there one that generates absolute events */
 int kbd_mouse_has_absolute(void);
diff --git a/input.c b/input.c
index 8d5a14d2da..c956e06f77 100644
--- a/input.c
+++ b/input.c
@@ -28,12 +28,13 @@
 #include "console.h"
 #include "qjson.h"
 
-
 static QEMUPutKBDEvent *qemu_put_kbd_event;
 static void *qemu_put_kbd_event_opaque;
 static QTAILQ_HEAD(, QEMUPutLEDEntry) led_handlers = QTAILQ_HEAD_INITIALIZER(led_handlers);
 static QTAILQ_HEAD(, QEMUPutMouseEntry) mouse_handlers =
     QTAILQ_HEAD_INITIALIZER(mouse_handlers);
+static NotifierList mouse_mode_notifiers = 
+    NOTIFIER_LIST_INITIALIZER(mouse_mode_notifiers);
 
 void qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque)
 {
@@ -41,6 +42,24 @@ void qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque)
     qemu_put_kbd_event = func;
 }
 
+static void check_mode_change(void)
+{
+    static int current_is_absolute, current_has_absolute;
+    int is_absolute;
+    int has_absolute;
+
+    is_absolute = kbd_mouse_is_absolute();
+    has_absolute = kbd_mouse_has_absolute();
+
+    if (is_absolute != current_is_absolute ||
+        has_absolute != current_has_absolute) {
+        notifier_list_notify(&mouse_mode_notifiers);
+    }
+
+    current_is_absolute = is_absolute;
+    current_has_absolute = has_absolute;
+}
+
 QEMUPutMouseEntry *qemu_add_mouse_event_handler(QEMUPutMouseEvent *func,
                                                 void *opaque, int absolute,
                                                 const char *name)
@@ -58,6 +77,8 @@ QEMUPutMouseEntry *qemu_add_mouse_event_handler(QEMUPutMouseEvent *func,
 
     QTAILQ_INSERT_TAIL(&mouse_handlers, s, node);
 
+    check_mode_change();
+
     return s;
 }
 
@@ -75,6 +96,8 @@ void qemu_remove_mouse_event_handler(QEMUPutMouseEntry *entry)
 
     qemu_free(entry->qemu_put_mouse_event_name);
     qemu_free(entry);
+
+    check_mode_change();
 }
 
 QEMUPutLEDEntry *qemu_add_led_event_handler(QEMUPutLEDEvent *func,
@@ -256,4 +279,16 @@ void do_mouse_set(Monitor *mon, const QDict *qdict)
     if (!found) {
         monitor_printf(mon, "Mouse at given index not found\n");
     }
+
+    check_mode_change();
+}
+
+void qemu_add_mouse_mode_change_notifier(Notifier *notify)
+{
+    notifier_list_add(&mouse_mode_notifiers, notify);
+}
+
+void qemu_remove_mouse_mode_change_notifier(Notifier *notify)
+{
+    notifier_list_remove(&mouse_mode_notifiers, notify);
 }