linearlayout.h Example File

 /****************************************************************************
 **
 ** Copyright (C) 2015 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
 ** 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:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of The Qt Company Ltd nor the names of its
 **     contributors may be used to endorse or promote products derived
 **     from this software without specific prior written permission.
 **
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #ifndef LINEARLAYOUT_H
 #define LINEARLAYOUT_H

 #include <qdeclarative.h>

 #include <QGraphicsLinearLayout>
 #include <QGraphicsLayoutItem>

 class GraphicsLinearLayoutStretchItemObject : public QObject, public QGraphicsLayoutItem
 {
     Q_OBJECT
     Q_INTERFACES(QGraphicsLayoutItem)
 public:
     GraphicsLinearLayoutStretchItemObject(QObject *parent = 0);

     virtual QSizeF sizeHint(Qt::SizeHint, const QSizeF &) const;
 };

 class LinearLayoutAttached;
 class GraphicsLinearLayoutObject : public QObject, public QGraphicsLinearLayout
 {
     Q_OBJECT
     Q_INTERFACES(QGraphicsLayout QGraphicsLayoutItem)

     Q_PROPERTY(QDeclarativeListProperty<QGraphicsLayoutItem> children READ children)
     Q_PROPERTY(Qt::Orientation orientation READ orientation WRITE setOrientation)
     Q_PROPERTY(qreal spacing READ spacing WRITE setSpacing)
     Q_PROPERTY(qreal contentsMargin READ contentsMargin WRITE setContentsMargin)
     Q_CLASSINFO("DefaultProperty", "children")
 public:
     GraphicsLinearLayoutObject(QObject * = 0);
     ~GraphicsLinearLayoutObject();

     QDeclarativeListProperty<QGraphicsLayoutItem> children() { return QDeclarativeListProperty<QGraphicsLayoutItem>(this, 0, children_append, children_count, children_at, children_clear); }

     qreal contentsMargin() const;
     void setContentsMargin(qreal);

     void removeAt(int index);

     static LinearLayoutAttached *qmlAttachedProperties(QObject *);

 private slots:
     void updateStretch(QGraphicsLayoutItem*,int);
     void updateSpacing(QGraphicsLayoutItem*,int);
     void updateAlignment(QGraphicsLayoutItem*,Qt::Alignment);

 private:
     friend class LinearLayoutAttached;

     void clearChildren();
     void insertLayoutItem(int, QGraphicsLayoutItem *);

     static void children_append(QDeclarativeListProperty<QGraphicsLayoutItem> *prop, QGraphicsLayoutItem *item) {
         static_cast<GraphicsLinearLayoutObject*>(prop->object)->insertLayoutItem(-1, item);
     }

     static void children_clear(QDeclarativeListProperty<QGraphicsLayoutItem> *prop) {
         static_cast<GraphicsLinearLayoutObject*>(prop->object)->clearChildren();
     }

     static int children_count(QDeclarativeListProperty<QGraphicsLayoutItem> *prop) {
         return static_cast<GraphicsLinearLayoutObject*>(prop->object)->count();
     }

     static QGraphicsLayoutItem *children_at(QDeclarativeListProperty<QGraphicsLayoutItem> *prop, int index) {
         return static_cast<GraphicsLinearLayoutObject*>(prop->object)->itemAt(index);
     }

     static QHash<QGraphicsLayoutItem*, LinearLayoutAttached*> attachedProperties;
 };

 class LinearLayoutAttached : public QObject
 {
     Q_OBJECT

     Q_PROPERTY(int stretchFactor READ stretchFactor WRITE setStretchFactor NOTIFY stretchChanged)
     Q_PROPERTY(Qt::Alignment alignment READ alignment WRITE setAlignment NOTIFY alignmentChanged)
     Q_PROPERTY(int spacing READ spacing WRITE setSpacing NOTIFY spacingChanged)

 public:
     LinearLayoutAttached(QObject *parent);

     int stretchFactor() const { return m_stretch; }
     void setStretchFactor(int f);
     Qt::Alignment alignment() const { return m_alignment; }
     void setAlignment(Qt::Alignment a);
     int spacing() const { return m_spacing; }
     void setSpacing(int s);

 signals:
     void stretchChanged(QGraphicsLayoutItem*, int);
     void alignmentChanged(QGraphicsLayoutItem*, Qt::Alignment);
     void spacingChanged(QGraphicsLayoutItem*, int);

 private:
     int m_stretch;
     Qt::Alignment m_alignment;
     int m_spacing;
 };

 QML_DECLARE_INTERFACE(QGraphicsLayoutItem)
 QML_DECLARE_INTERFACE(QGraphicsLayout)
 QML_DECLARE_TYPE(GraphicsLinearLayoutStretchItemObject)
 QML_DECLARE_TYPE(GraphicsLinearLayoutObject)
 QML_DECLARE_TYPEINFO(GraphicsLinearLayoutObject, QML_HAS_ATTACHED_PROPERTIES)

 #endif