Move loading of the TabBox Config XML into a thread

This should improve the KWin startup time as some IO is moved
into another thread. Till the config is loaded the TabBox blocks
all signals to activate the TabBox, but it is unlikely that alt+tab
is tried to be used before KWin is completely started.

tabbox.cpp

@@ -280,6 +280,7 @@ TabBox::TabBox(QObject *parent)
     , m_desktopGrab(false)
     , m_tabGrab(false)
     , m_forcedGlobalMouseGrab(false)
+    , m_ready(false)
 {
     m_isShown = false;
     m_defaultConfig = TabBoxConfig();
@@ -308,11 +309,9 @@ TabBox::TabBox(QObject *parent)
     m_desktopListConfig.setDesktopSwitchingMode(TabBoxConfig::StaticDesktopSwitching);
     m_desktopListConfig.setLayout(TabBoxConfig::VerticalLayout);
     m_tabBox = new TabBoxHandlerImpl(this);
-    m_tabBox->setConfig(m_defaultConfig);
-
+    connect(m_tabBox, SIGNAL(ready()), SLOT(handlerReady()));
 
     m_tabBoxMode = TabBoxDesktopMode; // init variables
-    reconfigure();
     connect(&m_delayedShowTimer, SIGNAL(timeout()), this, SLOT(show()));
 }
 
@@ -320,6 +319,13 @@ TabBox::~TabBox()
 {
 }
 
+void TabBox::handlerReady()
+{
+    m_tabBox->setConfig(m_defaultConfig);
+    reconfigure();
+    m_ready = true;
+}
+
 void TabBox::initShortcuts(KActionCollection* keys)
 {
     KAction *a = NULL;
@@ -752,26 +758,41 @@ void TabBox::navigatingThroughWindows(bool forward, const KShortcut& shortcut, T
 
 void TabBox::slotWalkThroughWindows()
 {
+    if (!m_ready){
+        return;
+    }
     navigatingThroughWindows(true, m_cutWalkThroughWindows, TabBoxWindowsMode);
 }
 
 void TabBox::slotWalkBackThroughWindows()
 {
+    if (!m_ready){
+        return;
+    }
     navigatingThroughWindows(false, m_cutWalkThroughWindowsReverse, TabBoxWindowsMode);
 }
 
 void TabBox::slotWalkThroughWindowsAlternative()
 {
+    if (!m_ready){
+        return;
+    }
     navigatingThroughWindows(true, m_cutWalkThroughWindowsAlternative, TabBoxWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkBackThroughWindowsAlternative()
 {
+    if (!m_ready){
+        return;
+    }
     navigatingThroughWindows(false, m_cutWalkThroughWindowsAlternativeReverse, TabBoxWindowsAlternativeMode);
 }
 
 void TabBox::slotWalkThroughDesktops()
 {
+    if (!m_ready){
+        return;
+    }
     if (isGrabbed())
         return;
     if (areModKeysDepressed(m_cutWalkThroughDesktops)) {
@@ -784,6 +805,9 @@ void TabBox::slotWalkThroughDesktops()
 
 void TabBox::slotWalkBackThroughDesktops()
 {
+    if (!m_ready){
+        return;
+    }
     if (isGrabbed())
         return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopsReverse)) {
@@ -796,6 +820,9 @@ void TabBox::slotWalkBackThroughDesktops()
 
 void TabBox::slotWalkThroughDesktopList()
 {
+    if (!m_ready){
+        return;
+    }
     if (isGrabbed())
         return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopList)) {
@@ -808,6 +835,9 @@ void TabBox::slotWalkThroughDesktopList()
 
 void TabBox::slotWalkBackThroughDesktopList()
 {
+    if (!m_ready){
+        return;
+    }
     if (isGrabbed())
         return;
     if (areModKeysDepressed(m_cutWalkThroughDesktopListReverse)) {

tabbox.h

@@ -188,6 +188,8 @@ public slots:
     void slotWalkThroughWindowsAlternativeKeyChanged(const QKeySequence& seq);
     void slotWalkBackThroughWindowsAlternativeKeyChanged(const QKeySequence& seq);
 
+    void handlerReady();
+
 signals:
     void tabBoxAdded(int);
     void tabBoxClosed();
@@ -239,6 +241,7 @@ private:
     KShortcut m_cutWalkThroughGroupWindows, m_cutWalkThroughGroupWindowsReverse;
     KShortcut m_cutWalkThroughWindowsAlternative, m_cutWalkThroughWindowsAlternativeReverse;
     bool m_forcedGlobalMouseGrab;
+    bool m_ready; // indicates whether the config is completely loaded
 };
 } // namespace TabBox
 } // namespace

tabbox/tabboxhandler.cpp

@@ -30,6 +30,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "tabboxview.h"
 // Qt
 #include <qdom.h>
+#include <QtCore/QtConcurrentRun>
+#include <QtCore/QFutureWatcher>
 #include <QFile>
 #include <QKeyEvent>
 #include <QModelIndex>
@@ -94,11 +96,10 @@ TabBoxHandlerPrivate::TabBoxHandlerPrivate(TabBoxHandler *q)
     view = new TabBoxView();
 
     // load the layouts
-    parseConfig(KStandardDirs::locate("data", "kwin/DefaultTabBoxLayouts.xml"));
-    view->clientDelegate()->setConfig(tabBoxLayouts.value("Default"));
-    view->additionalClientDelegate()->setConfig(tabBoxLayouts.value("Text"));
-    view->desktopDelegate()->setConfig(tabBoxLayouts.value("Desktop"));
-    view->desktopDelegate()->setLayouts(tabBoxLayouts);
+    QFuture< void> future = QtConcurrent::run(this, &TabBoxHandlerPrivate::parseConfig, KStandardDirs::locate("data", "kwin/DefaultTabBoxLayouts.xml"));
+    QFutureWatcher< void > *watcher = new QFutureWatcher< void >(q);
+    watcher->setFuture(future);
+    q->connect(watcher, SIGNAL(finished()), q, SIGNAL(ready()));
 }
 
 TabBoxHandlerPrivate::~TabBoxHandlerPrivate()
@@ -325,6 +326,10 @@ void TabBoxHandlerPrivate::parseConfig(const QString& fileName)
             tabBoxLayouts.insert(layoutName, currentLayout);
         }
     } // for loop layouts
+    view->clientDelegate()->setConfig(tabBoxLayouts.value("Default"));
+    view->additionalClientDelegate()->setConfig(tabBoxLayouts.value("Text"));
+    view->desktopDelegate()->setConfig(tabBoxLayouts.value("Desktop"));
+    view->desktopDelegate()->setLayouts(tabBoxLayouts);
 }
 
 /***********************************************

tabbox/tabboxhandler.h

@@ -339,6 +339,7 @@ signals:
     * @see setConfig
     */
     void configChanged();
+    void ready();
 
 private:
     friend class TabBoxHandlerPrivate;