From fa8c6cba51219ab4ce86ee66725c52882b7403e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20L=C3=BCbking?= <thomas.luebking@gmail.com>
Date: Sun, 24 Apr 2011 22:21:58 +0200
Subject: [PATCH] forward port of a389a45ecaea2577f5162edd1485356c81263cce

prevent accidental desktop swaps

CCBUG: 220088
---
 effects/desktopgrid/desktopgrid.cpp | 5 ++++-
 effects/desktopgrid/desktopgrid.h   | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/effects/desktopgrid/desktopgrid.cpp b/effects/desktopgrid/desktopgrid.cpp
index 950303f8c2..79240f7ac6 100644
--- a/effects/desktopgrid/desktopgrid.cpp
+++ b/effects/desktopgrid/desktopgrid.cpp
@@ -54,6 +54,7 @@ DesktopGridEffect::DesktopGridEffect()
     , keyboardGrab(false)
     , wasWindowMove(false)
     , wasDesktopMove(false)
+    , isValidMove(false)
     , windowMove(NULL)
     , windowMoveDiff()
     , gridSize()
@@ -543,7 +544,7 @@ void DesktopGridEffect::windowInputMouseEvent(Window, QEvent* e)
             XDefineCursor(display(), input, QCursor(Qt::ClosedHandCursor).handle());
         }
         if (d != highlightedDesktop) { // Highlight desktop
-            if ((me->buttons() & Qt::LeftButton) && !wasWindowMove && d <= effects->numberOfDesktops()) {
+            if ((me->buttons() & Qt::LeftButton) && isValidMove && !wasWindowMove && d <= effects->numberOfDesktops()) {
                 EffectWindowList windows = effects->stackingOrder();
                 EffectWindowList stack;
                 foreach (EffectWindow * w, windows) {
@@ -580,6 +581,7 @@ void DesktopGridEffect::windowInputMouseEvent(Window, QEvent* e)
     }
     if (e->type() == QEvent::MouseButtonPress) {
         if (me->buttons() == Qt::LeftButton) {
+            isValidMove = true;
 //             QRect rect;
             dragStartPos = me->pos();
             bool isDesktop = (me->modifiers() & Qt::ControlModifier);
@@ -625,6 +627,7 @@ void DesktopGridEffect::windowInputMouseEvent(Window, QEvent* e)
         }
     }
     if (e->type() == QEvent::MouseButtonRelease && me->button() == Qt::LeftButton) {
+        isValidMove = false;
         if (!wasWindowMove && !wasDesktopMove) {
             setCurrentDesktop(posToDesktop(me->pos()));
             if (windowMove)
diff --git a/effects/desktopgrid/desktopgrid.h b/effects/desktopgrid/desktopgrid.h
index 2795b2a934..8a8ddabeb9 100644
--- a/effects/desktopgrid/desktopgrid.h
+++ b/effects/desktopgrid/desktopgrid.h
@@ -125,7 +125,7 @@ private:
     int highlightedDesktop;
     Window input;
     bool keyboardGrab;
-    bool wasWindowMove, wasDesktopMove;
+    bool wasWindowMove, wasDesktopMove, isValidMove;
     EffectWindow* windowMove;
     QPoint windowMoveDiff;
     QPoint dragStartPos;