Merge lp:~vanvugt/compiz-core/fix-alt-bugs into lp:compiz-core

[Daniel van Vugt]

Don't keep an active keyboard grab the whole time a shortcut key is held
down. Doing so was causing multiple bugs with Unity 5, which binds to
the Alt key. Instead use some simple heurisitics to decide if a key has
been "tapped" or not. (LP: #943194) (LP: #943851) (LP: #945373)

Yes, it is a compromise to go back to detecting taps based on timing.
However it is the only existing solution to all of these bugs related to
the Alt key.

[Alan Griffiths (alan-griffiths)]

Looks sane, seems to work (not entirely sure about reproducing 943194, but it doesn't seems worse.)

review: Approve

[Alan Griffiths (alan-griffiths)]

seems to fix https://bugs.launchpad.net/unity/+bug/944979 for me.

=== modified file 'metadata/core.xml.in'
--- metadata/core.xml.in	2010-06-12 07:43:36 +0000
+++ metadata/core.xml.in	2012-03-07 10:06:17 +0000
@@ -31,6 +31,13 @@
 		<min>0</min>
 		<max>10000</max>
 	    </option>
+	    <option name="tap_time" type="int">
+		<_short>Key Tap Time</_short>
+		<_long>Maximim amount of time (milliseconds) a key may be held down and still be reported as a "tap".</_long>
+		<default>150</default>
+		<min>0</min>
+		<max>10000</max>
+	    </option>
 	    <option name="ping_delay" type="int">
 		<_short>Ping Delay</_short>
 		<_long>Interval between ping messages</_long>
 
=== modified file 'src/event.cpp'
--- src/event.cpp	2012-03-06 11:05:05 +0000
+++ src/event.cpp	2012-03-07 10:06:17 +0000
@@ -143,13 +143,20 @@
 
     if (state == CompAction::StateInitKey && grabs.empty ())
     {
-        possibleTap = action;
+        int pressTime = arguments[7].value ().i ();
         int err = XGrabKeyboard (dpy, grabWindow, True,
-                                 GrabModeAsync, GrabModeSync, arguments[7].value ().i ());
+                                 GrabModeAsync, GrabModeAsync, pressTime);
+        /*
+         * We don't actually need this active grab for anything other than
+         * to test if it fails (AlreadyGrabbed). So we know if some other
+         * app has an active grab like a virtual machine or lock screen.
+         * (LP: #806255)
+         */
         if (err == GrabSuccess)
         {
-	    XAllowEvents (dpy, SyncKeyboard, CurrentTime);
-            tapGrab = true;
+            XUngrabKeyboard (dpy, pressTime);
+            possibleTap = action;
+            tapStart = pressTime;
         }
         else
         {
@@ -183,7 +190,10 @@
 {
     if (action == possibleTap)
     {
-        state |= CompAction::StateTermTapped;
+        int releaseTime = arguments[7].value ().i ();
+        int tapDuration = releaseTime - tapStart;
+        if (tapDuration < optionGetTapTime ())
+            state |= CompAction::StateTermTapped;
         possibleTap = NULL;
     }
 
@@ -964,6 +974,8 @@
 		o[3].value ().set ((int) xkbEvent->time);
 		o[4].reset ();
 		o[5].reset ();
+		o[6].reset ();
+		o[7].value ().set ((int) xkbEvent->time);
 
 		if (stateEvent->event_type == KeyPress)
 		    possibleTap = NULL;
@@ -1076,7 +1088,6 @@
     if (priv->grabs.empty () && event->type == KeyPress)
     {
 	XUngrabKeyboard (priv->dpy, event->xkey.time);
-	priv->tapGrab = false;
     }
 }
 
@@ -1905,6 +1916,14 @@
 	break;
     case FocusIn:
     {
+	/* When a menu etc gets a grab, it's safe to say we're not tapping
+	   any key right now. e.g. Detecting taps of "Alt" and cancelling
+	   when a menu is opened */
+	if (event->xfocus.mode == NotifyGrab &&
+	    event->xfocus.window != priv->root &&
+	    event->xfocus.window != priv->grabWindow)
+	    priv->possibleTap = NULL;
+
 	if (!XGetWindowAttributes (priv->dpy, event->xfocus.window, &wa))
 	    priv->setDefaultWindowAttributes (&wa);
 
 
=== modified file 'src/privatescreen.h'
--- src/privatescreen.h	2012-03-05 09:04:16 +0000
+++ src/privatescreen.h	2012-03-07 10:06:17 +0000
@@ -559,6 +559,7 @@
 	CompOption::Value plugin;
 	bool	          dirtyPluginList;
 	void *possibleTap;
+	Time  tapStart;
 };
 
 class EventManager :
@@ -607,8 +608,6 @@
 
 	CompIcon *defaultIcon;
 
-	bool  tapGrab;
-
     private:
 	virtual bool initDisplay (const char *name);
 };
 
=== modified file 'src/screen.cpp'
--- src/screen.cpp	2012-03-05 09:04:16 +0000
+++ src/screen.cpp	2012-03-07 10:06:17 +0000
@@ -2950,8 +2950,6 @@
 		XUngrabPointer (priv->dpy, CurrentTime);
 		return NULL;
 	    }
-	    else
-	        priv->tapGrab = false;
 	}
 	else
 	    return NULL;
@@ -3014,7 +3012,6 @@
 
 	XUngrabPointer (priv->dpy, CurrentTime);
 	XUngrabKeyboard (priv->dpy, CurrentTime);
-	priv->tapGrab = false;
     }
 }
 
@@ -3591,7 +3588,6 @@
 
     XUngrabPointer (priv->dpy, CurrentTime);
     XUngrabKeyboard (priv->dpy, CurrentTime);
-    priv->tapGrab = false;
 
     XSendEvent (priv->dpy, priv->root, false,
 		StructureNotifyMask, &ev);
@@ -5033,7 +5029,8 @@
     CoreOptions (false),
     plugin (),
     dirtyPluginList (true),
-    possibleTap (NULL)
+    possibleTap (NULL),
+    tapStart (0)
 {
 }
 
@@ -5049,8 +5046,7 @@
     edgeDelayTimer (),
     desktopWindowCount (0),
     mapNum (1),
-    defaultIcon (0),
-    tapGrab (false)
+    defaultIcon (0)
 {
     ValueHolder::SetDefault (static_cast<ValueHolder *> (this));
     TimeoutHandler *dTimeoutHandler = new TimeoutHandler ();