From b9d8f6ce349be7e932b2a4d5ccb2355cc97fd9d0 Mon Sep 17 00:00:00 2001
From: sgf <sgf.dma@gmail.com>
Date: Wed, 23 Sep 2015 22:50:23 +0300
Subject: [PATCH] X.A.Submap: establish pointer grab to avoid freezing X.

Establish active asynchronous pointer grab before entering infinity cycle.
Because xmonad already has passive synchronous pointer grab, this overwrites
it temporary and avoids freezing X, when button press occurs after submap key
press.

Also, terminate submap at button press in the same way, as we do for wrong key
press.
---
 CHANGES.md               |  6 ++++++
 XMonad/Actions/Submap.hs | 18 ++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index f2ea3df0..a5aa3731 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -42,6 +42,12 @@
     EWMH taskbars and pagers. Useful for `NamedScratchpad` windows, since
     you will usually be taken to the `NSP` workspace by them.
 
+  * `XMonad.Actions.Submap`
+
+    Establish pointer grab to avoid freezing X, when button press occurs after
+    submap key press.  And terminate submap at button press in the same way,
+    as we do for wrong key press.
+
 ### Minor Changes
 
   * `XMonad.Layout.LayoutBuilder`
diff --git a/XMonad/Actions/Submap.hs b/XMonad/Actions/Submap.hs
index cd85880a..d4caa26c 100644
--- a/XMonad/Actions/Submap.hs
+++ b/XMonad/Actions/Submap.hs
@@ -75,17 +75,23 @@ submapDefaultWithKey defAction keys = do
     XConf { theRoot = root, display = d } <- ask
 
     io $ grabKeyboard d root False grabModeAsync grabModeAsync currentTime
+    io $ grabPointer d root False buttonPressMask grabModeAsync grabModeAsync
+                     none none currentTime
 
     (m, s) <- io $ allocaXEvent $ \p -> fix $ \nextkey -> do
-        maskEvent d keyPressMask p
-        KeyEvent { ev_keycode = code, ev_state = m } <- getEvent p
-        keysym <- keycodeToKeysym d code 0
-        if isModifierKey keysym
-            then nextkey
-            else return (m, keysym)
+        maskEvent d (keyPressMask .|. buttonPressMask) p
+        ev <- getEvent p
+        case ev of
+          KeyEvent { ev_keycode = code, ev_state = m } -> do
+            keysym <- keycodeToKeysym d code 0
+            if isModifierKey keysym
+                then nextkey
+                else return (m, keysym)
+          _ -> return (0, 0)
     -- Remove num lock mask and Xkb group state bits
     m' <- cleanMask $ m .&. ((1 `shiftL` 12) - 1)
 
+    io $ ungrabPointer d currentTime
     io $ ungrabKeyboard d currentTime
 
     fromMaybe (defAction (m', s)) (M.lookup (m', s) keys)