Introduce post Workspace init phase

Workspace emits a signal when the initialization finished and
interested parties can connect to this signal to perform post
init actions. That is everything that does not have to be
performed to have a completely working Window Manager.

As an example loading the scripts is moved into this post init
phase.

REVIEW: 104580

scripting/scripting.cpp

@@ -252,6 +252,7 @@ KWin::Scripting::Scripting(QObject *parent)
     QDBusConnection::sessionBus().registerObject("/Scripting", this, QDBusConnection::ExportScriptableContents | QDBusConnection::ExportScriptableInvokables);
     QDBusConnection::sessionBus().registerService("org.kde.kwin.Scripting");
     connect(Workspace::self(), SIGNAL(configChanged()), SLOT(start()));
+    connect(Workspace::self(), SIGNAL(workspaceInitialized()), SLOT(start()));
 }
 
 void KWin::Scripting::start()

workspace.cpp

@@ -487,7 +487,6 @@ void Workspace::init()
 
 #ifdef KWIN_BUILD_SCRIPTING
     m_scripting = new Scripting(this);
-    m_scripting->start();
 #endif
 
     // SELI TODO: This won't work with unreasonable focus policies,
@@ -495,6 +494,9 @@ void Workspace::init()
     // want focus
     workspaceInit = false;
 
+    // broadcast that Workspace is ready, but first process all events.
+    QMetaObject::invokeMethod(this, "workspaceInitialized", Qt::QueuedConnection);
+
     // TODO: ungrabXServer()
 }
 

workspace.h

@@ -667,6 +667,11 @@ protected:
 
 Q_SIGNALS:
     Q_SCRIPTABLE void compositingToggled(bool active);
+    /**
+     * Emitted after the Workspace has setup the complete initialization process.
+     * This can be used to connect to for performing post-workspace initialization.
+     **/
+    void workspaceInitialized();
 
     //Signals required for the scripting interface
 signals: