dix: rework DeviceChangedEvents a bit.

DCEs are now processed when sent throught the master device, not when sent
through the slave device. This includes a removal of some un-used (or partly
used) fields in the DCE itself to something more self-explanatory.

TODO: if a device has events queued and its attachment is changed, the DCE
is silently dropped now. Instead, it should be generated as soon as the
first event after the attachment is sent.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

4 files changed, 30 insertions, 31 deletions

diff --git a/Xi/exevents.c b/Xi/exevents.c
index 22126492a..2377d054e 100644
--- a/Xi/exevents.c
+++ b/Xi/exevents.c
@@ -699,23 +699,31 @@ XISendDeviceChangedEvent(DeviceIntPtr device, DeviceIntPtr master, DeviceChanged
 static void
 ChangeMasterDeviceClasses(DeviceIntPtr device, DeviceChangedEvent *dce)
 {
-    DeviceIntPtr master = device->u.master;
+    DeviceIntPtr slave;
+    int rc;
 
-    if (IsMaster(device))
+    /* For now, we don't have devices that change physically. */
+    if (!IsMaster(device))
         return;
 
-    if (!master) /* if device was set floating between SIGIO and now */
-        return;
+    rc = dixLookupDevice(&slave, dce->sourceid, serverClient, DixReadAccess);
+
+    if (rc != Success)
+        return; /* Device has disappeared */
+
+    if (!slave->u.master)
+        return; /* set floating since the event */
 
+    if (slave->u.master->id != dce->masterid)
+        return; /* not our slave anymore, don't care */
 
-    master = GetMaster(device,
-             (dce->flags & DEVCHANGE_POINTER_EVENT) ? MASTER_POINTER : MASTER_KEYBOARD);
+    /* FIXME: we probably need to send a DCE for the new slave now */
 
-    master->public.devicePrivate = device->public.devicePrivate;
+    device->public.devicePrivate = slave->public.devicePrivate;
 
     /* FIXME: the classes may have changed since we generated the event. */
-    DeepCopyDeviceClasses(device, master, dce);
-    XISendDeviceChangedEvent(device, master, dce);
+    DeepCopyDeviceClasses(slave, device, dce);
+    XISendDeviceChangedEvent(slave, device, dce);
 }
 
 /**
diff --git a/dix/eventconvert.c b/dix/eventconvert.c
index f0c98eadc..07a8e5fb9 100644
--- a/dix/eventconvert.c
+++ b/dix/eventconvert.c
@@ -350,7 +350,7 @@ appendKeyInfo(DeviceChangedEvent *dce, xXIKeyInfo* info)
     info->type = XIKeyClass;
     info->num_keycodes = dce->keys.max_keycode - dce->keys.min_keycode + 1;
     info->length = sizeof(xXIKeyInfo)/4 + info->num_keycodes;
-    info->sourceid = dce->deviceid;
+    info->sourceid = dce->sourceid;
 
     kc = (uint32_t*)&info[1];
     for (i = 0; i < info->num_keycodes; i++)
@@ -371,7 +371,7 @@ appendButtonInfo(DeviceChangedEvent *dce, xXIButtonInfo *info)
     info->num_buttons = dce->buttons.num_buttons;
     info->length = bytes_to_int32(sizeof(xXIButtonInfo)) +
                    info->num_buttons + mask_len;
-    info->sourceid = dce->deviceid;
+    info->sourceid = dce->sourceid;
 
     bits = (unsigned char*)&info[1];
     memset(bits, 0, mask_len * 4);
@@ -399,7 +399,7 @@ appendValuatorInfo(DeviceChangedEvent *dce, xXIValuatorInfo *info, int axisnumbe
     info->resolution = dce->valuators[axisnumber].resolution;
     info->number = axisnumber;
     info->mode = dce->valuators[axisnumber].mode; /* Server doesn't have per-axis mode yet */
-    info->sourceid = dce->deviceid;
+    info->sourceid = dce->sourceid;
 
     return info->length * 4;
 }
@@ -441,7 +441,7 @@ eventToDeviceChanged(DeviceChangedEvent *dce, xEvent **xi)
     dcce->evtype       = XI_DeviceChanged;
     dcce->time         = dce->time;
     dcce->deviceid     = dce->deviceid;
-    dcce->sourceid     = dce->deviceid;
+    dcce->sourceid     = dce->sourceid;
     dcce->reason       = (dce->flags & DEVCHANGE_DEVICE_CHANGE) ? XIDeviceChange : XISlaveSwitch;
     dcce->num_classes  = 0;
     dcce->length = bytes_to_int32(len - sizeof(xEvent));
diff --git a/dix/getevents.c b/dix/getevents.c
index 5f0095430..2912c1e85 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -193,19 +193,15 @@ CreateClassesChangedEvent(EventList* event,
 
     dce = (DeviceChangedEvent*)event->event;
     memset(dce, 0, sizeof(DeviceChangedEvent));
-    dce->deviceid = master->id;
+    dce->deviceid = slave->id;
+    dce->masterid = master->id;
     dce->header = ET_Internal;
     dce->length = sizeof(DeviceChangedEvent);
     dce->type = ET_DeviceChanged;
     dce->time = ms;
     dce->flags = type;
-    if (master->last.slave)
-    {
-        dce->flags |= DEVCHANGE_HAS_OLD_SLAVE;
-        dce->old_slaveid = master->last.slave->id;
-    }
-    dce->flags |= DEVCHANGE_HAS_NEW_SLAVE;
-    dce->new_slaveid = slave->id;
+    dce->flags |= DEVCHANGE_SLAVE_SWITCH;
+    dce->sourceid = slave->id;
 
     if (slave->button)
     {
diff --git a/include/eventstr.h b/include/eventstr.h
index b7611a5b1..8dd98be5f 100644
--- a/include/eventstr.h
+++ b/include/eventstr.h
@@ -120,9 +120,8 @@ struct _DeviceEvent
 };
 
 
-/* Flags used in DeviceChangedEvent to signal if new/old slave is present. */
-#define DEVCHANGE_HAS_OLD_SLAVE 0x1
-#define DEVCHANGE_HAS_NEW_SLAVE 0x2
+/* Flags used in DeviceChangedEvent to signal if the slave has changed */
+#define DEVCHANGE_SLAVE_SWITCH 0x2
 /* Flags used in DeviceChangedEvent to signal whether the event was a
  * pointer event or a keyboard event */
 #define DEVCHANGE_POINTER_EVENT 0x4
@@ -140,14 +139,10 @@ struct _DeviceChangedEvent
     int length;           /**< Length in bytes */
     Time time;            /**< Time in ms */
     int deviceid;         /**< Device whose capabilities have changed */
-    int flags;            /**< Mask of ::HAS_OLD_SLAVE, ::HAS_NEW_SLAVE,
+    int flags;            /**< Mask of ::HAS_NEW_SLAVE,
                                ::POINTER_EVENT, ::KEYBOARD_EVENT */
-    /** If flags & HAS_OLD_SLAVE is set, old_slaveid specifies SD previously
-     * attached to this device. */
-    int old_slaveid;
-    /** If flags & HAS_NEW_SLAVE is set, new_slaveid specifies device now
-     * attached to this device. */
-    int new_slaveid;
+    int masterid;         /**< MD when event was generated */
+    int sourceid;         /**< The device that caused the change */
 
     struct {
         int num_buttons;        /**< Number of buttons */