[kdecorations] Drop initialParentWidget()

No longer needed for creating the preview and not set in our main
bridge. Thus it can go and we just use NULL as the parent widget.

bridge.cpp

@@ -180,11 +180,6 @@ int Bridge::currentDesktop() const
     return VirtualDesktopManager::self()->current();
 }
 
-QWidget* Bridge::initialParentWidget() const
-{
-    return NULL;
-}
-
 Qt::WindowFlags Bridge::initialWFlags() const
 {
     return Qt::WindowDoesNotAcceptFocus;

bridge.h

@@ -74,7 +74,6 @@ public:
     virtual void setKeepAbove(bool) override;
     virtual void setKeepBelow(bool) override;
     virtual int currentDesktop() const override;
-    virtual QWidget* initialParentWidget() const override;
     virtual Qt::WindowFlags initialWFlags() const override;
     virtual void grabXServer(bool grab) override;
 

kcmkwin/kwindecoration/preview.cpp

@@ -184,11 +184,6 @@ KDecorationPreviewBridge::KDecorationPreviewBridge(KDecorationPreview* p, bool a
 {
 }
 
-QWidget* KDecorationPreviewBridge::initialParentWidget() const
-{
-    return preview;
-}
-
 Qt::WindowFlags KDecorationPreviewBridge::initialWFlags() const
 {
     return 0;

kcmkwin/kwindecoration/preview.h

@@ -106,7 +106,6 @@ public:
     virtual void setKeepAbove(bool) override;
     virtual void setKeepBelow(bool) override;
     virtual int currentDesktop() const override;
-    virtual QWidget* initialParentWidget() const override;
     virtual Qt::WindowFlags initialWFlags() const override;
     virtual void grabXServer(bool grab) override;
 

libkdecorations/kcommondecoration.cpp

@@ -1323,10 +1323,6 @@ void KCommonDecoration::createMainWidget(Qt::WindowFlags flags)
 {
     return d->wrapper->createMainWidget(flags);
 }
-QWidget* KCommonDecoration::initialParentWidget() const
-{
-    return d->wrapper->initialParentWidget();
-}
 Qt::WindowFlags KCommonDecoration::initialWFlags() const
 {
     return d->wrapper->initialWFlags();

libkdecorations/kcommondecoration.h

@@ -354,7 +354,6 @@ Q_SIGNALS:
 public:
     void setMainWidget(QWidget*);
     void createMainWidget(Qt::WindowFlags flags = 0);
-    QWidget* initialParentWidget() const;
     Qt::WindowFlags initialWFlags() const;
     QWidget* widget();
     const QWidget* widget() const;

libkdecorations/kdecoration.cpp

@@ -91,7 +91,7 @@ const KDecorationOptions* KDecoration::options()
 void KDecoration::createMainWidget(Qt::WindowFlags flags)
 {
     // FRAME check flags?
-    QWidget *w = new QWidget(initialParentWidget(), initialWFlags() | flags);
+    QWidget *w = new QWidget(nullptr, initialWFlags() | flags);
     w->setObjectName(QLatin1String("decoration widget"));
     if (options()->showTooltips())
         w->setAttribute(Qt::WA_AlwaysShowToolTips);
@@ -106,11 +106,6 @@ void KDecoration::setMainWidget(QWidget* w)
     widget()->resize(geometry().size());
 }
 
-QWidget* KDecoration::initialParentWidget() const
-{
-    return d->bridge->initialParentWidget();
-}
-
 Qt::WindowFlags KDecoration::initialWFlags() const
 {
     return d->bridge->initialWFlags();

libkdecorations/kdecoration.h

@@ -982,10 +982,6 @@ public:
      *              like WX11BypassWM or WStyle_NoBorder are forbidden.
      */
     void createMainWidget(Qt::WindowFlags flags = 0);
-    /**
-     * The parent widget that should be used for the main widget.
-     */
-    QWidget* initialParentWidget() const;
     /**
      * The flags that should be used when creating the main widget.
      * It is possible to add more flags when creating the main widget, but only flags

libkdecorations/kdecorationbridge.h

@@ -81,7 +81,6 @@ public:
     virtual void setKeepBelow(bool) = 0;
     // not part of public API
     virtual int currentDesktop() const = 0;
-    virtual QWidget* initialParentWidget() const = 0;
     virtual Qt::WindowFlags initialWFlags() const = 0;
     virtual void grabXServer(bool grab) = 0;