From 4952833028026f74476dd607a1d572187c75a4ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= <l.lunak@kde.org>
Date: Mon, 24 May 2004 08:54:04 +0000
Subject: [PATCH] Fix updateXTime() to make sure the X timestamp doesn't get
 newer than timestamp of events still in the X events queue. CCMAIL:
 81693-done@bugs.kde.org

svn path=/trunk/kdebase/kwin/; revision=314035
---
 events.cpp |  2 +-
 utils.cpp  | 77 ++++++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 64 insertions(+), 15 deletions(-)

diff --git a/events.cpp b/events.cpp
index cde8d737c8..9978f9eb81 100644
--- a/events.cpp
+++ b/events.cpp
@@ -435,7 +435,7 @@ bool Workspace::workspaceEvent( XEvent * e )
                 XGetInputFocus( qt_xdisplay(), &focus, &revert );
                 if( focus == None || focus == PointerRoot )
                     {
-                    kdWarning( 1212 ) << "X focus set to None/PointerRoot, reseting focus" << endl;
+                    //kdWarning( 1212 ) << "X focus set to None/PointerRoot, reseting focus" << endl;
                     if( mostRecentlyActivatedClient() != NULL )
                         requestFocus( mostRecentlyActivatedClient(), true );
                     else
diff --git a/utils.cpp b/utils.cpp
index 102c7f355c..5edec173b6 100644
--- a/utils.cpp
+++ b/utils.cpp
@@ -213,23 +213,72 @@ QCString getStringProperty(WId w, Atom prop, char separator)
     return result;
     }
 
-/*!
-  Updates qt_x_time by receiving a current timestamp from the server.
+static Time next_x_time;
+static Bool update_x_time_predicate( Display*, XEvent* event, XPointer )
+{
+    if( next_x_time != CurrentTime )
+        return False;
+    // from qapplication_x11.cpp
+    switch ( event->type ) {
+    case ButtonPress:
+	// fallthrough intended
+    case ButtonRelease:
+	next_x_time = event->xbutton.time;
+	break;
+    case MotionNotify:
+	next_x_time = event->xmotion.time;
+	break;
+    case KeyPress:
+	// fallthrough intended
+    case KeyRelease:
+	next_x_time = event->xkey.time;
+	break;
+    case PropertyNotify:
+	next_x_time = event->xproperty.time;
+	break;
+    case EnterNotify:
+    case LeaveNotify:
+	next_x_time = event->xcrossing.time;
+	break;
+    case SelectionClear:
+	next_x_time = event->xselectionclear.time;
+	break;
+    default:
+	break;
+    }
+    return False;
+}
 
-  Use this function only when really necessary. Keep in mind that it's
-  a roundtrip to the X-Server.
- */
+static Time nextXTime()
+    {
+    next_x_time = CurrentTime;
+    XEvent dummy;
+    XCheckIfEvent( qt_xdisplay(), &dummy, update_x_time_predicate, NULL );
+    return next_x_time;
+    }
+
+/*
+ Updates qt_x_time. This used to simply fetch current timestamp from the server,
+ but that can cause qt_x_time to be newer than timestamp of events that are
+ still in our events queue, thus e.g. making XSetInputFocus() caused by such
+ event to be ignored. Therefore first events queue is searched for first
+ event with timestamp.
+*/
 void updateXTime()
     {
-    static QWidget* w = 0;
-    if ( !w )
-        w = new QWidget;
-    long data = 1;
-    XChangeProperty(qt_xdisplay(), w->winId(), atoms->kwin_running, atoms->kwin_running, 32,
-                    PropModeAppend, (unsigned char*) &data, 1);
-    XEvent ev;
-    XWindowEvent( qt_xdisplay(), w->winId(), PropertyChangeMask, &ev );
-    qt_x_time = ev.xproperty.time;
+    qt_x_time = nextXTime();
+    if( qt_x_time == CurrentTime )
+        {
+        static QWidget* w = 0;
+        if ( !w )
+            w = new QWidget;
+        long data = 1;
+        XChangeProperty(qt_xdisplay(), w->winId(), atoms->kwin_running, atoms->kwin_running, 32,
+                        PropModeAppend, (unsigned char*) &data, 1);
+        XEvent ev;
+        XWindowEvent( qt_xdisplay(), w->winId(), PropertyChangeMask, &ev );
+        qt_x_time = ev.xproperty.time;
+        }
     }
 
 static int server_grab_count = 0;