Qt 4.8: linearlayout.cpp Example File (declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp)

Qt Reference Documentation

# linearlayout.cpp Example File

declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp

     /****************************************************************************
     **
     ** 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 examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
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     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
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     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
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     **     the names of its contributors may be used to endorse or promote
     **     products derived from this software without specific prior written
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     #include "linearlayout.h"

     #include <QGraphicsWidget>
     #include <QGraphicsLayoutItem>

     LinearLayoutAttached::LinearLayoutAttached(QObject *parent)
     : QObject(parent), m_stretch(1), m_alignment(Qt::AlignTop), m_spacing(0)
     {
     }

     void LinearLayoutAttached::setStretchFactor(int f)
     {
         if (m_stretch != f) {
             m_stretch = f;
             emit stretchChanged(reinterpret_cast<QGraphicsLayoutItem*>(parent()), m_stretch);
         }
     }

     void LinearLayoutAttached::setSpacing(int s)
     {
         if (m_spacing != s) {
             m_spacing = s;
             emit spacingChanged(reinterpret_cast<QGraphicsLayoutItem*>(parent()), m_spacing);
         }
     }

     void LinearLayoutAttached::setAlignment(Qt::Alignment a)
     {
         if (m_alignment != a) {
             m_alignment = a;
             emit alignmentChanged(reinterpret_cast<QGraphicsLayoutItem*>(parent()), m_alignment);
         }
     }

     GraphicsLinearLayoutStretchItemObject::GraphicsLinearLayoutStretchItemObject(QObject *parent)
         : QObject(parent)
     {
     }

     QSizeF GraphicsLinearLayoutStretchItemObject::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
     {
         Q_UNUSED(which);
         Q_UNUSED(constraint);
         return QSizeF();
     }

     GraphicsLinearLayoutObject::GraphicsLinearLayoutObject(QObject *parent)
     : QObject(parent)
     {
     }

     GraphicsLinearLayoutObject::~GraphicsLinearLayoutObject()
     {
     }

     void GraphicsLinearLayoutObject::insertLayoutItem(int index, QGraphicsLayoutItem *item)
     {
         insertItem(index, item);

         if (LinearLayoutAttached *obj = attachedProperties.value(item)) {
             setStretchFactor(item, obj->stretchFactor());
             setAlignment(item, obj->alignment());
             updateSpacing(item, obj->spacing());
             QObject::connect(obj, SIGNAL(stretchChanged(QGraphicsLayoutItem*,int)),
                              this, SLOT(updateStretch(QGraphicsLayoutItem*,int)));
             QObject::connect(obj, SIGNAL(alignmentChanged(QGraphicsLayoutItem*,Qt::Alignment)),
                              this, SLOT(updateAlignment(QGraphicsLayoutItem*,Qt::Alignment)));
             QObject::connect(obj, SIGNAL(spacingChanged(QGraphicsLayoutItem*,int)),
                              this, SLOT(updateSpacing(QGraphicsLayoutItem*,int)));
         }
     }

     void GraphicsLinearLayoutObject::removeAt(int index)
     {
         QGraphicsLayoutItem *item = itemAt(index);
         if (item) {
             LinearLayoutAttached *obj = attachedProperties.value(item);
             obj->disconnect(this);
             attachedProperties.remove(item);
         }
         QGraphicsLinearLayout::removeAt(index);
     }

     void GraphicsLinearLayoutObject::clearChildren()
     {
         // do not delete the removed items; they will be deleted by the QML engine
         while (count() > 0)
             removeAt(count()-1);
     }

     qreal GraphicsLinearLayoutObject::contentsMargin() const
     {
         qreal a, b, c, d;
         getContentsMargins(&a, &b, &c, &d);
         if (a == b && a == c && a == d)
             return a;
         return -1;
     }

     void GraphicsLinearLayoutObject::setContentsMargin(qreal m)
     {
         setContentsMargins(m, m, m, m);
     }

     void GraphicsLinearLayoutObject::updateStretch(QGraphicsLayoutItem *item, int stretch)
     {
         QGraphicsLinearLayout::setStretchFactor(item, stretch);
     }

     void GraphicsLinearLayoutObject::updateSpacing(QGraphicsLayoutItem* item, int spacing)
     {
         for (int i=0; i < count(); i++){
             if (itemAt(i) == item) {
                 QGraphicsLinearLayout::setItemSpacing(i, spacing);
                 return;
             }
         }
     }

     void GraphicsLinearLayoutObject::updateAlignment(QGraphicsLayoutItem *item, Qt::Alignment alignment)
     {
         QGraphicsLinearLayout::setAlignment(item, alignment);
     }

     QHash<QGraphicsLayoutItem*, LinearLayoutAttached*> GraphicsLinearLayoutObject::attachedProperties;
     LinearLayoutAttached *GraphicsLinearLayoutObject::qmlAttachedProperties(QObject *obj)
     {
         LinearLayoutAttached *rv = new LinearLayoutAttached(obj);
         if (qobject_cast<QGraphicsLayoutItem*>(obj))
             attachedProperties.insert(qobject_cast<QGraphicsLayoutItem*>(obj), rv);
         return rv;
     }