Xi, dix: Add ability to change MD classes + send event when doing so.

Each time a different slave device sends through a master, an
DeviceClassesChangedEvent is enqueued. When this event is processed, all
classes of the matching master device are changed, and the event is sent to
the clients.

Next time the master is queried, it thus shows the evclasses of the last slave
device. The original classes are stored in the devPrivates.

TODO: if all slave devices are removed, the master's original classes need to
be restored.

1 files changed, 57 insertions, 0 deletions

diff --git a/Xi/exevents.c b/Xi/exevents.c
index 4c57fd017..617aef7b4 100644
--- a/Xi/exevents.c
+++ b/Xi/exevents.c
@@ -73,6 +73,7 @@ SOFTWARE.
 #include "dixevents.h"	/* DeliverFocusedEvent */
 #include "dixgrabs.h"	/* CreateGrab() */
 #include "scrnintstr.h"
+#include "listdev.h" /* for CopySwapXXXClass */
 
 #ifdef XKB
 #include "xkbsrv.h"
@@ -127,6 +128,62 @@ ProcessOtherEvent(xEventPtr xE, DeviceIntPtr device, int count)
     xEvent core;
     int coretype = 0;
 
+    /* This event is always the first we get, before the actual events with
+     * the data. However, the way how the DDX is set up, "device" will
+     * actually be the slave device that caused the event.
+     */
+    if (GEIsType(xE, IReqCode, XI_DeviceClassesChangedNotify))
+    {
+        deviceClassesChangedEvent* dcce = (deviceClassesChangedEvent*)xE;
+        DeviceIntPtr master = device->u.master;
+        char* classbuff;
+
+        if (device->isMaster)
+            return;
+
+        if (!master) /* if device was set floating between SIGIO and now */
+            return;
+
+        dcce->deviceid     = master->id;
+        dcce->num_classes  = 0;
+
+        master->key        = device->key;
+        master->valuator   = device->valuator;
+        master->button     = device->button;
+        master->focus      = device->focus;
+        master->proximity  = device->proximity;
+        master->absolute   = device->absolute;
+        master->kbdfeed    = device->kbdfeed;
+        master->ptrfeed    = device->ptrfeed;
+        master->intfeed    = device->intfeed;
+        master->stringfeed = device->stringfeed;
+        master->bell       = device->bell;
+        master->leds       = device->leds;
+
+        /* event is already correct size, see comment in GetPointerEvents */
+        classbuff = (char*)&xE[1];
+        if (master->key) 
+        {
+            /* we don't actually swap here, swapping is done later */
+            CopySwapKeyClass(NullClient, master->key, &classbuff);
+            dcce->num_classes++;
+        }
+        if (master->button) 
+        {
+            CopySwapButtonClass(NullClient, master->button, &classbuff);
+            dcce->num_classes++;
+        }
+        if (master->valuator)
+        {
+            CopySwapValuatorClass(NullClient, master->valuator, &classbuff);
+            dcce->num_classes++;
+        }
+
+        SendEventToAllWindows(master, XI_DeviceClassesChangedMask,
+                              xE, 1);
+        return;
+    }
+
     coretype = XItoCoreType(xE->u.u.type);
     if (device->isMaster && device->coreEvents && coretype)
         sendCore = TRUE;