[PATCH v2 4/4] xkb: push locked modifier state down to attached slave devices

[Peter Hutterer]

Whenever the master changes, push the locked modifier state to the attached
slave devices, then update the indicators. This way, when NumLock or CapsLock
are hit on any device, the LED will light up on all devices. Likewise, a new
keyboard attached to a master device will light up with the correct
indicators.

The indicators are handled per-keyboard, depending on the layout, i.e. if one
keyboard has grp_led:num set, the NumLock LED won't light up on that keyboard.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 dix/devices.c    |  3 +++
 include/xkbsrv.h |  4 ++++
 xkb/xkbActions.c | 20 ++++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/dix/devices.c b/dix/devices.c
index 1c86d52..ab923d5 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -416,6 +416,8 @@ EnableDevice(DeviceIntPtr dev, BOOL sendevent)
         XISendDeviceHierarchyEvent(flags);
     }
 
+    if (!IsMaster(dev))
+        XkbPushLockedStateToSlaves(GetMaster(dev, MASTER_KEYBOARD), 0, 0);
     RecalculateMasterButtons(dev);
 
     /* initialise an idle timer for this device*/
@@ -2649,6 +2651,7 @@ AttachDevice(ClientPtr client, DeviceIntPtr dev, DeviceIntPtr master)
         dev->spriteInfo->paired = master;
         dev->spriteInfo->spriteOwner = FALSE;
 
+        XkbPushLockedStateToSlaves(GetMaster(dev, MASTER_KEYBOARD), 0, 0);
         RecalculateMasterButtons(master);
     }
 
diff --git a/include/xkbsrv.h b/include/xkbsrv.h
index 0299327..5c5459f 100644
--- a/include/xkbsrv.h
+++ b/include/xkbsrv.h
@@ -638,6 +638,10 @@ extern _X_EXPORT void XkbHandleActions(DeviceIntPtr /* dev */ ,
                                        DeviceEvent *    /* event */
     );
 
+extern void XkbPushLockedStateToSlaves(DeviceIntPtr /* master */,
+                                       int /* evtype */,
+                                       int /* key */);
+
 extern _X_EXPORT Bool XkbEnableDisableControls(XkbSrvInfoPtr /* xkbi */ ,
                                                unsigned long /* change */ ,
                                                unsigned long /* newValues */ ,
diff --git a/xkb/xkbActions.c b/xkb/xkbActions.c
index 9a257f5..17f2807 100644
--- a/xkb/xkbActions.c
+++ b/xkb/xkbActions.c
@@ -1176,6 +1176,25 @@ _XkbApplyState(DeviceIntPtr dev, Bool genStateNotify, int evtype, int key)
 }
 
 void
+XkbPushLockedStateToSlaves(DeviceIntPtr master, int evtype, int key)
+{
+    DeviceIntPtr dev;
+    Bool genStateNotify;
+
+    nt_list_for_each_entry(dev, inputInfo.devices, next) {
+        if (!dev->key || GetMaster(dev, MASTER_KEYBOARD) != master)
+            continue;
+
+        genStateNotify = _XkbWantStateNotify(dev->key->xkbInfo);
+
+        dev->key->xkbInfo->state.locked_mods =
+            master->key->xkbInfo->state.locked_mods;
+
+        _XkbApplyState(dev, genStateNotify, evtype, key);
+    }
+}
+
+void
 XkbHandleActions(DeviceIntPtr dev, DeviceIntPtr kbd, DeviceEvent *event)
 {
     int key, bit, i;
@@ -1329,6 +1348,7 @@ XkbHandleActions(DeviceIntPtr dev, DeviceIntPtr kbd, DeviceEvent *event)
     }
 
     _XkbApplyState(dev, genStateNotify, event->type, key);
+    XkbPushLockedStateToSlaves(dev, event->type, key);
 }
 
 int
-- 
1.8.4.2