gridlayout.cpp Example File

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 #include "gridlayout.h"

 #include <QGraphicsWidget>
 #include <QDebug>

 GridLayoutAttached::GridLayoutAttached(QObject *parent)
 : QObject(parent), m_row(-1), m_column(-1), m_rowspan(1), m_colspan(1), m_alignment(-1), m_rowStretch(-1),
     m_colStretch(-1), m_rowSpacing(-1), m_colSpacing(-1), m_rowPrefHeight(-1), m_rowMaxHeight(-1), m_rowMinHeight(-1),
     m_rowFixHeight(-1), m_colPrefwidth(-1), m_colMaxwidth(-1), m_colMinwidth(-1), m_colFixwidth(-1)
 {
 }

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

 QHash<QGraphicsLayoutItem*, GridLayoutAttached*> GraphicsGridLayoutObject::attachedProperties;

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

 GraphicsGridLayoutObject::~GraphicsGridLayoutObject()
 {
 }

 void GraphicsGridLayoutObject::addWidget(QGraphicsWidget *widget)
 {
     //use attached properties
     if (QObject *obj = attachedProperties.value(qobject_cast<QGraphicsLayoutItem*>(widget))) {
         int row = static_cast<GridLayoutAttached *>(obj)->row();
         int column = static_cast<GridLayoutAttached *>(obj)->column();
         int rowSpan = static_cast<GridLayoutAttached *>(obj)->rowSpan();
         int columnSpan = static_cast<GridLayoutAttached *>(obj)->columnSpan();
         if (row == -1 || column == -1) {
             qWarning() << "Must set row and column for an item in a grid layout";
             return;
         }
         addItem(widget, row, column, rowSpan, columnSpan);
     }
 }

 void GraphicsGridLayoutObject::addLayoutItem(QGraphicsLayoutItem *item)
 {
     //use attached properties
     if (GridLayoutAttached *obj = attachedProperties.value(item)) {
         int row = obj->row();
         int column = obj->column();
         int rowSpan = obj->rowSpan();
         int columnSpan = obj->columnSpan();
         Qt::Alignment alignment = obj->alignment();

         if (row == -1 || column == -1) {
             qWarning() << "Must set row and column for an item in a grid layout";
             return;
         }

         if (obj->rowSpacing() != -1)
             setRowSpacing(row, obj->rowSpacing());
         if (obj->columnSpacing() != -1)
             setColumnSpacing(column, obj->columnSpacing());
         if (obj->rowStretchFactor() != -1)
             setRowStretchFactor(row, obj->rowStretchFactor());
         if (obj->columnStretchFactor() != -1)
             setColumnStretchFactor(column, obj->columnStretchFactor());
         if (obj->rowPreferredHeight() != -1)
             setRowPreferredHeight(row, obj->rowPreferredHeight());
         if (obj->rowMaximumHeight() != -1)
             setRowMaximumHeight(row, obj->rowMaximumHeight());
         if (obj->rowMinimumHeight() != -1)
             setRowMinimumHeight(row, obj->rowMinimumHeight());
         if (obj->rowFixedHeight() != -1)
             setRowFixedHeight(row, obj->rowFixedHeight());
         if (obj->columnPreferredWidth() != -1)
             setColumnPreferredWidth(row, obj->columnPreferredWidth());
         if (obj->columnMaximumWidth() != -1)
             setColumnMaximumWidth(row, obj->columnMaximumWidth());
         if (obj->columnMinimumWidth() != -1)
             setColumnMinimumWidth(row, obj->columnMinimumWidth());
         if (obj->columnFixedWidth() != -1)
             setColumnFixedWidth(row, obj->columnFixedWidth());

         addItem(item, row, column, rowSpan, columnSpan);

         if (alignment != -1)
             setAlignment(item, alignment);
         QObject::connect(obj, SIGNAL(alignmentChanged(QGraphicsLayoutItem*, Qt::Alignment)),
                          this, SLOT(updateAlignment(QGraphicsLayoutItem*, Qt::Alignment)));
     }
 }

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

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

 qreal GraphicsGridLayoutObject::spacing() const
 {
     if (verticalSpacing() == horizontalSpacing())
         return verticalSpacing();
     return -1;
 }

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

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

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

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