Use DevicePresence events to tell the client about enabled/disabled devices.

Include the device id in the event sent to the client.

dix/devices.c

@@ -75,6 +75,7 @@ SOFTWARE.
 #include "swaprep.h"
 #include "dixevents.h"
 
+#include <X11/extensions/XI.h>
 #include <X11/extensions/XIproto.h>
 #include "exglobals.h"
 #include "exevents.h"
@@ -157,6 +158,8 @@ EnableDevice(DeviceIntPtr dev)
 {
     DeviceIntPtr *prev;
     int ret;
+    DeviceIntRec dummyDev;
+    devicePresenceNotify ev;
 
     for (prev = &inputInfo.off_devices;
 	 *prev && (*prev != dev);
@@ -175,6 +178,14 @@ EnableDevice(DeviceIntPtr dev)
     *prev = dev;
     dev->next = NULL;
 
+    ev.type = DevicePresenceNotify;
+    ev.time = currentTime.milliseconds;
+    ev.devchange = DeviceEnabled;
+    ev.deviceid = dev->id;
+    dummyDev.id = 0;
+    SendEventToAllWindows(&dummyDev, DevicePresenceNotifyMask,
+                          (xEvent *) &ev, 1);
+
     return TRUE;
 }
 
@@ -182,6 +193,8 @@ Bool
 DisableDevice(DeviceIntPtr dev)
 {
     DeviceIntPtr *prev;
+    DeviceIntRec dummyDev;
+    devicePresenceNotify ev;
 
     for (prev = &inputInfo.devices;
 	 *prev && (*prev != dev);
@@ -194,6 +207,15 @@ DisableDevice(DeviceIntPtr dev)
     *prev = dev->next;
     dev->next = inputInfo.off_devices;
     inputInfo.off_devices = dev;
+
+    ev.type = DevicePresenceNotify;
+    ev.time = currentTime.milliseconds;
+    ev.devchange = DeviceDisabled;
+    ev.deviceid = dev->id;
+    dummyDev.id = 0;
+    SendEventToAllWindows(&dummyDev, DevicePresenceNotifyMask,
+                          (xEvent *) &ev, 1);
+
     return TRUE;
 }
 
@@ -212,8 +234,8 @@ ActivateDevice(DeviceIntPtr dev)
     
     ev.type = DevicePresenceNotify;
     ev.time = currentTime.milliseconds;
-    ev.devchange = 0;
+    ev.devchange = DeviceAdded;
-    ev.deviceid = 0;
+    ev.deviceid = dev->id;
     dummyDev.id = 0;
     SendEventToAllWindows(&dummyDev, DevicePresenceNotifyMask,
                           (xEvent *) &ev, 1);
@@ -547,12 +569,15 @@ RemoveDevice(DeviceIntPtr dev)
     int ret = BadMatch;
     devicePresenceNotify ev;
     DeviceIntRec dummyDev;
+    int deviceid;
 
     DebugF("(dix) removing device %d\n", dev->id);
 
     if (!dev || dev == inputInfo.keyboard || dev == inputInfo.pointer)
         return BadImplementation;
 
+    deviceid = dev->id;
+
     prev = NULL;
     for (tmp = inputInfo.devices; tmp; (prev = tmp), (tmp = next)) {
 	next = tmp->next;
@@ -587,8 +612,8 @@ RemoveDevice(DeviceIntPtr dev)
         inputInfo.numDevices--;
         ev.type = DevicePresenceNotify;
         ev.time = currentTime.milliseconds;
-        ev.devchange = 0;
+        ev.devchange = DeviceRemoved;
-        ev.deviceid = 0;
+        ev.deviceid = deviceid;
         dummyDev.id = 0;
         SendEventToAllWindows(&dummyDev, DevicePresenceNotifyMask,
                               (xEvent *) &ev, 1);

hw/xfree86/common/xf86Xinput.c

@@ -764,4 +764,29 @@ xf86InitValuatorDefaults(DeviceIntPtr dev, int axnum)
     }
 }
 
+
+/**
+ * Deactivate a device. Call this function from the driver if you receive a
+ * read error or something else that spoils your day.
+ * Device will be moved to the off_devices list, but it will still be there
+ * until you really clean up after it.
+ * Notifies the client about an inactive device.
+ */
+_X_EXPORT void
+xf86DisableDevice(DeviceIntPtr dev)
+{
+    DisableDevice(dev);
+}
+
+/**
+ * Reactivate a device. Call this function from the driver if you just found
+ * out that the read error wasn't quite that bad after all.
+ * Device will be re-activated, and an event sent to the client. 
+ */
+_X_EXPORT void
+xf86EnableDevice(DeviceIntPtr dev)
+{
+    EnableDevice(dev);
+}
+
 /* end of xf86Xinput.c */

hw/xfree86/common/xf86Xinput.h

@@ -187,6 +187,8 @@ void xf86InitValuatorAxisStruct(DeviceIntPtr dev, int axnum, int minval,
 void xf86InitValuatorDefaults(DeviceIntPtr dev, int axnum);
 void xf86AddEnabledDevice(InputInfoPtr pInfo);
 void xf86RemoveEnabledDevice(InputInfoPtr pInfo);
+void xf86DisableDevice(DeviceIntPtr dev);
+void xf86EnableDevice(DeviceIntPtr dev);
 
 /* xf86Helper.c */
 void xf86AddInputDriver(InputDriverPtr driver, pointer module, int flags);
@@ -204,6 +206,7 @@ int xf86GetMotionEvents(DeviceIntPtr dev, xTimecoord *buff,
 void xf86CollectInputOptions(InputInfoPtr pInfo, const char **defaultOpts,
 			     pointer extraOpts);
 
+
 /* Legacy hatred */
 #define SendCoreEvents 59
 #define DontSendCoreEvents 60