text: /****************************************************************************
  **
  ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
  ** All rights reserved.
  ** Contact: Nokia Corporation (qt-info@nokia.com)
  **
  ** This file is part of the QtGui module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
  ** GNU Lesser General Public License Usage
  ** This file may be used under the terms of the GNU Lesser General Public
  ** License version 2.1 as published by the Free Software Foundation and
  ** appearing in the file LICENSE.LGPL included in the packaging of this
  ** file. Please review the following information to ensure the GNU Lesser
  ** General Public License version 2.1 requirements will be met:
  ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  **
  ** In addition, as a special exception, Nokia gives you certain additional
  ** rights. These rights are described in the Nokia Qt LGPL Exception
  ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU General
  ** Public License version 3.0 as published by the Free Software Foundation
  ** and appearing in the file LICENSE.GPL included in the packaging of this
  ** file. Please review the following information to ensure the GNU General
  ** Public License version 3.0 requirements will be met:
  ** http://www.gnu.org/copyleft/gpl.html.
  **
  ** Other Usage
  ** Alternatively, this file may be used in accordance with the terms and
  ** conditions contained in a signed written agreement between you and Nokia.
  **
  **
  **
  **
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/
  
  #include "qglobal.h"
  
  #ifndef QT_NO_GRAPHICSVIEW
  
  #include "qgraphicslayout_p.h"
  #include "qgraphicslayout.h"
  #include "qgraphicswidget.h"
  #include "qapplication.h"
  
  QT_BEGIN_NAMESPACE
  
  /*!
      \internal
  
      \a mw is the new parent. all items in the layout will be a child of \a mw.
   */
  void QGraphicsLayoutPrivate::reparentChildItems(QGraphicsItem *newParent)
  {
      Q_Q(QGraphicsLayout);
      int n =  q->count();
      //bool mwVisible = mw && mw->isVisible();
      for (int i = 0; i < n; ++i) {
          QGraphicsLayoutItem *layoutChild = q->itemAt(i);
          if (!layoutChild) {
              // Skip stretch items
              continue;
          }
          if (layoutChild->isLayout()) {
              QGraphicsLayout *l = static_cast<QGraphicsLayout*>(layoutChild);
              l->d_func()->reparentChildItems(newParent);
          } else if (QGraphicsItem *itemChild = layoutChild->graphicsItem()){
              QGraphicsItem *childParent = itemChild->parentItem();
  #ifdef QT_DEBUG
              if (childParent && childParent != newParent && itemChild->isWidget() && qt_graphicsLayoutDebug()) {
                  QGraphicsWidget *w = static_cast<QGraphicsWidget*>(layoutChild);
                  qWarning("QGraphicsLayout::addChildLayout: widget %s \"%s\" in wrong parent; moved to correct parent",
                           w->metaObject()->className(), w->objectName().toLocal8Bit().constData());
              }
  #endif
              if (childParent != newParent)
                  itemChild->setParentItem(newParent);
          }
      }
  }
  
  void QGraphicsLayoutPrivate::getMargin(qreal *result, qreal userMargin, QStyle::PixelMetric pm) const
  {
      if (!result)
          return;
      Q_Q(const QGraphicsLayout);
  
      QGraphicsLayoutItem *parent = q->parentLayoutItem();
      if (userMargin >= 0.0) {
          *result = userMargin;
      } else if (!parent) {
          *result = 0.0;
      } else if (parent->isLayout()) {    // sublayouts have 0 margin by default
          *result = 0.0;
      } else {
          *result = 0.0;
          if (QGraphicsItem *layoutParentItem = parentItem()) {
              if (layoutParentItem->isWidget())
                  *result = (qreal)static_cast<QGraphicsWidget*>(layoutParentItem)->style()->pixelMetric(pm, 0);
          }
      }
  }
  
  Qt::LayoutDirection QGraphicsLayoutPrivate::visualDirection() const
  {
      if (QGraphicsItem *maybeWidget = parentItem()) {
          if (maybeWidget->isWidget())
              return static_cast<QGraphicsWidget*>(maybeWidget)->layoutDirection();
      }
      return QApplication::layoutDirection();
  }
  
  static bool removeLayoutItemFromLayout(QGraphicsLayout *lay, QGraphicsLayoutItem *layoutItem)
  {
      if (!lay)
          return false;
  
      for (int i = lay->count() - 1; i >= 0; --i) {
          QGraphicsLayoutItem *child = lay->itemAt(i);
          if (child && child->isLayout()) {
              if (removeLayoutItemFromLayout(static_cast<QGraphicsLayout*>(child), layoutItem))
                  return true;
          } else if (child == layoutItem) {
              lay->removeAt(i);
              return true;
          }
      }
      return false;
  }
  
  /*!
      \internal
  
      This function is called from subclasses to add a layout item \a layoutItem
      to a layout.
  
      It takes care of automatically reparenting graphics items, if needed.
  
      If \a layoutItem is a  is already in a layout, it will remove it  from that layout.
  
  */
  void QGraphicsLayoutPrivate::addChildLayoutItem(QGraphicsLayoutItem *layoutItem)
  {
      Q_Q(QGraphicsLayout);
      if (QGraphicsLayoutItem *maybeLayout = layoutItem->parentLayoutItem()) {
          if (maybeLayout->isLayout())
              removeLayoutItemFromLayout(static_cast<QGraphicsLayout*>(maybeLayout), layoutItem);
      }
      layoutItem->setParentLayoutItem(q);
      if (layoutItem->isLayout()) {
          if (QGraphicsItem *parItem = parentItem()) {
              static_cast<QGraphicsLayout*>(layoutItem)->d_func()->reparentChildItems(parItem);
          }
      } else {
          if (QGraphicsItem *item = layoutItem->graphicsItem()) {
              QGraphicsItem *newParent = parentItem();
              QGraphicsItem *oldParent = item->parentItem();
              if (oldParent == newParent || !newParent)
                  return;
  
  #ifdef QT_DEBUG
              if (oldParent && item->isWidget()) {
                  QGraphicsWidget *w = static_cast<QGraphicsWidget*>(item);
                  qWarning("QGraphicsLayout::addChildLayoutItem: %s \"%s\" in wrong parent; moved to correct parent",
                      w->metaObject()->className(), w->objectName().toLocal8Bit().constData());
              }
  #endif
  
              item->setParentItem(newParent);
          }
      }
  }
  
  void QGraphicsLayoutPrivate::activateRecursive(QGraphicsLayoutItem *item)
  {
      if (item->isLayout()) {
          QGraphicsLayout *layout = static_cast<QGraphicsLayout *>(item);
          if (layout->d_func()->activated) {
              if (QGraphicsLayout::instantInvalidatePropagation()) {
                  return;
              } else {
                  layout->invalidate();   // ### LOOKS SUSPICIOUSLY WRONG!!???
              }
          }
  
          for (int i = layout->count() - 1; i >= 0; --i) {
              QGraphicsLayoutItem *childItem = layout->itemAt(i);
              if (childItem)
                  activateRecursive(childItem);
          }
          layout->d_func()->activated = true;
      }
  }
  
  
  QT_END_NAMESPACE
  
  #endif //QT_NO_GRAPHICSVIEW
  