src/declarative/util/qdeclarativepackage.cpp

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  41
  42 #include "private/qdeclarativepackage_p.h"
  43
  44 #include <private/qobject_p.h>
  45 #include <private/qdeclarativeguard_p.h>
  46
  47 QT_BEGIN_NAMESPACE
  48
  49 /*!
  50     \qmlclass Package QDeclarativePackage
  51     \ingroup qml-working-with-data
  52     \brief Package provides a collection of named items.
  53
  54     The Package class is used in conjunction with
  55     VisualDataModel to enable delegates with a shared context
  56     to be provided to multiple views.
  57
  58     Any item within a Package may be assigned a name via the
  59     \l{Package::name}{Package.name} attached property.
  60
  61     The example below creates a Package containing two named items;
  62     \e list and \e grid.  The third element in the package (the \l Rectangle) is parented to whichever
  63     delegate it should appear in.  This allows an item to move
  64     between views.
  65
  66     \snippet examples/declarative/modelviews/package/Delegate.qml 0
  67
  68     These named items are used as the delegates by the two views who
  69     reference the special \l{VisualDataModel::parts} property to select
  70     a model which provides the chosen delegate.
  71
  72     \snippet examples/declarative/modelviews/package/view.qml 0
  73
  74     \sa {declarative/modelviews/package}{Package example}, {demos/declarative/photoviewer}{Photo Viewer demo}, QtDeclarative
  75 */
  76
  77 /*!
  78     \qmlattachedproperty string Package::name
  79     This attached property holds the name of an item within a Package.
  80 */
  81
  82
  83 class QDeclarativePackagePrivate : public QObjectPrivate
  84 {
  85 public:
  86     QDeclarativePackagePrivate() {}
  87
  88     struct DataGuard : public QDeclarativeGuard<QObject>
  89     {
  90         DataGuard(QObject *obj, QList<DataGuard> *l) : list(l) { (QDeclarativeGuard<QObject>&)*this = obj; }
  91         QList<DataGuard> *list;
  92         void objectDestroyed(QObject *) {
  93             // we assume priv will always be destroyed after objectDestroyed calls
  94             list->removeOne(*this);
  95         }
  96     };
  97
  98     QList<DataGuard> dataList;
  99     static void data_append(QDeclarativeListProperty<QObject> *prop, QObject *o) {
 100         QList<DataGuard> *list = static_cast<QList<DataGuard> *>(prop->data);
 101         list->append(DataGuard(o, list));
 102     }
 103     static void data_clear(QDeclarativeListProperty<QObject> *prop) {
 104         QList<DataGuard> *list = static_cast<QList<DataGuard> *>(prop->data);
 105         list->clear();
 106     }
 107     static QObject *data_at(QDeclarativeListProperty<QObject> *prop, int index) {
 108         QList<DataGuard> *list = static_cast<QList<DataGuard> *>(prop->data);
 109         return list->at(index);
 110     }
 111     static int data_count(QDeclarativeListProperty<QObject> *prop) {
 112         QList<DataGuard> *list = static_cast<QList<DataGuard> *>(prop->data);
 113         return list->count();
 114     }
 115 };
 116
 117 QHash<QObject *, QDeclarativePackageAttached *> QDeclarativePackageAttached::attached;
 118
 119 QDeclarativePackageAttached::QDeclarativePackageAttached(QObject *parent)
 120 : QObject(parent)
 121 {
 122     attached.insert(parent, this);
 123 }
 124
 125 QDeclarativePackageAttached::~QDeclarativePackageAttached()
 126 {
 127     attached.remove(parent());
 128 }
 129
 130 QString QDeclarativePackageAttached::name() const
 131 {
 132     return _name;
 133 }
 134
 135 void QDeclarativePackageAttached::setName(const QString &n)
 136 {
 137     _name = n;
 138 }
 139
 140 QDeclarativePackage::QDeclarativePackage(QObject *parent)
 141     : QObject(*(new QDeclarativePackagePrivate), parent)
 142 {
 143 }
 144
 145 QDeclarativePackage::~QDeclarativePackage()
 146 {
 147     Q_D(QDeclarativePackage);
 148     for (int ii = 0; ii < d->dataList.count(); ++ii) {
 149         QObject *obj = d->dataList.at(ii);
 150         obj->setParent(this);
 151     }
 152 }
 153
 154 QDeclarativeListProperty<QObject> QDeclarativePackage::data()
 155 {
 156     Q_D(QDeclarativePackage);
 157     return QDeclarativeListProperty<QObject>(this, &d->dataList, QDeclarativePackagePrivate::data_append,
 158                                                         QDeclarativePackagePrivate::data_count,
 159                                                         QDeclarativePackagePrivate::data_at,
 160                                                         QDeclarativePackagePrivate::data_clear);
 161 }
 162
 163 bool QDeclarativePackage::hasPart(const QString &name)
 164 {
 165     Q_D(QDeclarativePackage);
 166     for (int ii = 0; ii < d->dataList.count(); ++ii) {
 167         QObject *obj = d->dataList.at(ii);
 168         QDeclarativePackageAttached *a = QDeclarativePackageAttached::attached.value(obj);
 169         if (a && a->name() == name)
 170             return true;
 171     }
 172     return false;
 173 }
 174
 175 QObject *QDeclarativePackage::part(const QString &name)
 176 {
 177     Q_D(QDeclarativePackage);
 178     if (name.isEmpty() && !d->dataList.isEmpty())
 179         return d->dataList.at(0);
 180
 181     for (int ii = 0; ii < d->dataList.count(); ++ii) {
 182         QObject *obj = d->dataList.at(ii);
 183         QDeclarativePackageAttached *a = QDeclarativePackageAttached::attached.value(obj);
 184         if (a && a->name() == name)
 185             return obj;
 186     }
 187
 188     if (name == QLatin1String("default") && !d->dataList.isEmpty())
 189         return d->dataList.at(0);
 190
 191     return 0;
 192 }
 193
 194 QDeclarativePackageAttached *QDeclarativePackage::qmlAttachedProperties(QObject *o)
 195 {
 196     return new QDeclarativePackageAttached(o);
 197 }
 198
 199
 200
 201 QT_END_NAMESPACE