src/declarative/graphicsitems/qdeclarativerepeater.cpp
changeset 30 5dc02b23752f
child 33 3e2da88830cd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/declarative/graphicsitems/qdeclarativerepeater.cpp	Tue Jul 06 15:10:48 2010 +0300
@@ -0,0 +1,389 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "private/qdeclarativerepeater_p.h"
+#include "private/qdeclarativerepeater_p_p.h"
+
+#include "private/qdeclarativevisualitemmodel_p.h"
+#include <private/qdeclarativeglobal_p.h>
+#include <qdeclarativelistaccessor_p.h>
+
+#include <qlistmodelinterface_p.h>
+
+QT_BEGIN_NAMESPACE
+QDeclarativeRepeaterPrivate::QDeclarativeRepeaterPrivate()
+: model(0), ownModel(false)
+{
+}
+
+QDeclarativeRepeaterPrivate::~QDeclarativeRepeaterPrivate()
+{
+    if (ownModel)
+        delete model;
+}
+
+/*!
+    \qmlclass Repeater QDeclarativeRepeater
+    \since 4.7
+    \inherits Item
+
+    \brief The Repeater item allows you to repeat an Item-based component using a model.
+
+    The Repeater item is used to create a large number of
+    similar items.  For each entry in the model, an item is instantiated
+    in a context seeded with data from the model.  If the repeater will
+    be instantiating a large number of instances, it may be more efficient to
+    use one of Qt Declarative's \l {xmlViews}{view items}.
+
+    The model may be either an object list, a string list, a number or a Qt model.
+    In each case, the data element and the index is exposed to each instantiated
+    component.  
+    
+    The index is always exposed as an accessible \c index property.
+    In the case of an object or string list, the data element (of type string
+    or object) is available as the \c modelData property.  In the case of a Qt model,
+    all roles are available as named properties just like in the view classes. The
+    following example shows how to use the index property inside the instantiated
+    items.
+
+    \snippet doc/src/snippets/declarative/repeater-index.qml 0
+
+    \image repeater-index.png
+
+    Items instantiated by the Repeater are inserted, in order, as
+    children of the Repeater's parent.  The insertion starts immediately after
+    the repeater's position in its parent stacking list.  This is to allow
+    you to use a Repeater inside a layout.  The following QML example shows how
+    the instantiated items would visually appear stacked between the red and
+    blue rectangles.
+
+    \snippet doc/src/snippets/declarative/repeater.qml 0
+
+    \image repeater.png
+
+    The repeater instance continues to own all items it instantiates, even
+    if they are otherwise manipulated.  It is illegal to manually remove an item
+    created by the Repeater.
+
+    \note Repeater is Item-based, and cannot be used to repeat non-Item-derived objects.
+    For example, it cannot be used to repeat QtObjects.
+    \badcode
+    Item {
+        //XXX illegal. Can't repeat QtObject as it doesn't derive from Item.
+        Repeater {
+            model: 10
+            QtObject {}
+        }
+    }
+    \endcode
+ */
+
+/*!
+    \internal
+    \class QDeclarativeRepeater
+    \qmlclass Repeater
+ */
+
+/*!
+    Create a new QDeclarativeRepeater instance.
+ */
+QDeclarativeRepeater::QDeclarativeRepeater(QDeclarativeItem *parent)
+  : QDeclarativeItem(*(new QDeclarativeRepeaterPrivate), parent)
+{
+}
+
+/*!
+    Destroy the repeater instance.  All items it instantiated are also
+    destroyed.
+ */
+QDeclarativeRepeater::~QDeclarativeRepeater()
+{
+}
+
+/*!
+    \qmlproperty any Repeater::model
+
+    The model providing data for the repeater.
+
+    The model may be either an object list, a string list, a number or a Qt model.
+    In each case, the data element and the index is exposed to each instantiated
+    component.  The index is always exposed as an accessible \c index property.
+    In the case of an object or string list, the data element (of type string
+    or object) is available as the \c modelData property.  In the case of a Qt model,
+    all roles are available as named properties just like in the view classes.
+
+    As a special case the model can also be merely a number. In this case it will
+    create that many instances of the component. They will also be assigned an index
+    based on the order they are created.
+
+    Models can also be created directly in QML, using a \l{ListModel} or \l{XmlListModel}.
+
+    \sa {qmlmodels}{Data Models}
+*/
+QVariant QDeclarativeRepeater::model() const
+{
+    Q_D(const QDeclarativeRepeater);
+    return d->dataSource;
+}
+
+void QDeclarativeRepeater::setModel(const QVariant &model)
+{
+    Q_D(QDeclarativeRepeater);
+    if (d->dataSource == model)
+        return;
+
+    clear();
+    if (d->model) {
+        disconnect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int)));
+        disconnect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int)));
+        disconnect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int)));
+        disconnect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset()));
+        /*
+        disconnect(d->model, SIGNAL(createdItem(int, QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*)));
+        disconnect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*)));
+    */
+    }
+    d->dataSource = model;
+    emit modelChanged();
+    QObject *object = qvariant_cast<QObject*>(model);
+    QDeclarativeVisualModel *vim = 0;
+    if (object && (vim = qobject_cast<QDeclarativeVisualModel *>(object))) {
+        if (d->ownModel) {
+            delete d->model;
+            d->ownModel = false;
+        }
+        d->model = vim;
+    } else {
+        if (!d->ownModel) {
+            d->model = new QDeclarativeVisualDataModel(qmlContext(this), this);
+            d->ownModel = true;
+        }
+        if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model))
+            dataModel->setModel(model);
+    }
+    if (d->model) {
+        connect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int)));
+        connect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int)));
+        connect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int)));
+        connect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset()));
+        /*
+        connect(d->model, SIGNAL(createdItem(int, QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*)));
+        connect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*)));
+        */
+        regenerate();
+        emit countChanged();
+    }
+}
+
+/*!
+    \qmlproperty Component Repeater::delegate
+    \default
+
+    The delegate provides a template defining each item instantiated by the repeater.
+    The index is exposed as an accessible \c index property.  Properties of the
+    model are also available depending upon the type of \l {qmlmodels}{Data Model}.
+ */
+QDeclarativeComponent *QDeclarativeRepeater::delegate() const
+{
+    Q_D(const QDeclarativeRepeater);
+    if (d->model) {
+        if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model))
+            return dataModel->delegate();
+    }
+
+    return 0;
+}
+
+void QDeclarativeRepeater::setDelegate(QDeclarativeComponent *delegate)
+{
+    Q_D(QDeclarativeRepeater);
+    if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model))
+       if (delegate == dataModel->delegate())
+           return;
+
+    if (!d->ownModel) {
+        d->model = new QDeclarativeVisualDataModel(qmlContext(this));
+        d->ownModel = true;
+    }
+    if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) {
+        dataModel->setDelegate(delegate);
+        regenerate();
+        emit delegateChanged();
+    }
+}
+
+/*!
+    \qmlproperty int Repeater::count
+
+    This property holds the number of items in the repeater.
+*/
+int QDeclarativeRepeater::count() const
+{
+    Q_D(const QDeclarativeRepeater);
+    if (d->model)
+        return d->model->count();
+    return 0;
+}
+
+
+/*!
+    \internal
+ */
+void QDeclarativeRepeater::componentComplete()
+{
+    QDeclarativeItem::componentComplete();
+    regenerate();
+}
+
+/*!
+    \internal
+ */
+QVariant QDeclarativeRepeater::itemChange(GraphicsItemChange change,
+                                       const QVariant &value)
+{
+    QVariant rv = QDeclarativeItem::itemChange(change, value);
+    if (change == ItemParentHasChanged) {
+        regenerate();
+    }
+
+    return rv;
+}
+
+void QDeclarativeRepeater::clear()
+{
+    Q_D(QDeclarativeRepeater);
+    if (d->model) {
+        foreach (QDeclarativeItem *item, d->deletables) {
+            d->model->release(item);
+        }
+    }
+    d->deletables.clear();
+}
+
+/*!
+    \internal
+ */
+void QDeclarativeRepeater::regenerate()
+{
+    Q_D(QDeclarativeRepeater);
+    if (!isComponentComplete())
+        return;
+
+    clear();
+
+    if (!d->model || !d->model->count() || !d->model->isValid() || !parentItem() || !isComponentComplete())
+        return;
+
+    for (int ii = 0; ii < count(); ++ii) {
+        QDeclarativeItem *item = d->model->item(ii);
+        if (item) {
+            QDeclarative_setParent_noEvent(item, parentItem());
+            item->setParentItem(parentItem());
+            item->stackBefore(this);
+            d->deletables << item;
+        }
+    }
+}
+
+void QDeclarativeRepeater::itemsInserted(int index, int count)
+{
+    Q_D(QDeclarativeRepeater);
+    if (!isComponentComplete())
+        return;
+    for (int i = 0; i < count; ++i) {
+        int modelIndex = index + i;
+        QDeclarativeItem *item = d->model->item(modelIndex);
+        if (item) {
+            QDeclarative_setParent_noEvent(item, parentItem());
+            item->setParentItem(parentItem());
+            if (modelIndex < d->deletables.count())
+                item->stackBefore(d->deletables.at(modelIndex));
+            else
+                item->stackBefore(this);
+            d->deletables.insert(modelIndex, item);
+        }
+    }
+}
+
+void QDeclarativeRepeater::itemsRemoved(int index, int count)
+{
+    Q_D(QDeclarativeRepeater);
+    if (!isComponentComplete() || count <= 0)
+        return;
+    while (count--) {
+        QDeclarativeItem *item = d->deletables.takeAt(index);
+        if (item)
+            d->model->release(item);
+        else
+            break;
+    }
+}
+
+void QDeclarativeRepeater::itemsMoved(int from, int to, int count)
+{
+    Q_D(QDeclarativeRepeater);
+    if (!isComponentComplete() || count <= 0)
+        return;
+    if (from + count > d->deletables.count()) {
+        regenerate();
+        return;
+    }
+    QList<QDeclarativeItem*> removed;
+    int removedCount = count;
+    while (removedCount--)
+        removed << d->deletables.takeAt(from);
+    for (int i = 0; i < count; ++i)
+        d->deletables.insert(to + i, removed.at(i));
+    d->deletables.last()->stackBefore(this);
+    for (int i = d->model->count()-1; i > 0; --i) {
+        QDeclarativeItem *item = d->deletables.at(i-1);
+        item->stackBefore(d->deletables.at(i));
+    }
+}
+
+void QDeclarativeRepeater::modelReset()
+{
+    if (!isComponentComplete())
+        return;
+    regenerate();
+}
+
+QT_END_NAMESPACE