Don't set status to Ready until model has been created (currently this

is set as soon as XML data is downloaded, so there is no notification
when model is actually ready to be used).

This also fixes data() to not crash if it is called before the model
is ready.

Task-number: QTBUG-7835

2 files changed, 97 insertions, 53 deletions

diff --git a/src/declarative/util/qdeclarativexmllistmodel.cpp b/src/declarative/util/qdeclarativexmllistmodel.cpp
index 3e08854..efc614b 100644
--- a/src/declarative/util/qdeclarativexmllistmodel.cpp
+++ b/src/declarative/util/qdeclarativexmllistmodel.cpp
@@ -57,6 +57,7 @@
 #include <QBuffer>
 #include <QNetworkRequest>
 #include <QNetworkReply>
+#include <QTimer>
 
 #include <private/qobject_p.h>
 
@@ -67,6 +68,8 @@ QT_BEGIN_NAMESPACE
 
 typedef QPair<int, int> QDeclarativeXmlListRange;
 
+#define XMLLISTMODEL_CLEAR_ID 0
+
 /*!
     \qmlclass XmlRole QDeclarativeXmlListModelRole
   \since 4.7
@@ -127,9 +130,10 @@ class QDeclarativeXmlQuery : public QThread
     Q_OBJECT
 public:
     QDeclarativeXmlQuery(QObject *parent=0)
-        : QThread(parent), m_quit(false), m_abortQueryId(-1), m_queryIds(0) {
+        : QThread(parent), m_quit(false), m_abortQueryId(-1), m_queryIds(XMLLISTMODEL_CLEAR_ID + 1) {
         qRegisterMetaType<QDeclarativeXmlQueryResult>("QDeclarativeXmlQueryResult");
     }
+
     ~QDeclarativeXmlQuery() {
         m_mutex.lock();
         m_quit = true;
@@ -586,7 +590,8 @@ void QDeclarativeXmlListModel::setSource(const QUrl &src)
     Q_D(QDeclarativeXmlListModel);
     if (d->src != src) {
         d->src = src;
-        reload();
+        if (d->xml.isEmpty())   // src is only used if d->xml is not set
+            reload();
         emit sourceChanged();
    }
 }
@@ -663,23 +668,13 @@ void QDeclarativeXmlListModel::setNamespaceDeclarations(const QString &declarati
 
 /*!
     \qmlproperty enum XmlListModel::status
+    Specifies the model loading status, which can be one of the following:
 
-    This property holds the status of data source loading.  It can be one of:
     \list
-    \o Null - no data source has been set
-    \o Ready - the data source has been loaded
-    \o Loading - the data source is currently being loaded
-    \o Error - an error occurred while loading the data source
-    \endlist
-
-    Note that a change in the status property does not cause anything to happen
-    (although it reflects what has happened to the XmlListModel internally). If you wish
-    to react to the change in status you need to do it yourself, for example in one
-    of the following ways:
-    \list
-    \o Create a state, so that a state change occurs, e.g. State{name: 'loaded'; when: xmlListModel.status = XmlListModel.Ready;}
-    \o Do something inside the onStatusChanged signal handler, e.g. XmlListModel{id: xmlListModel; onStatusChanged: if(xmlListModel.status == XmlListModel.Ready) console.log('Loaded');}
-    \o Bind to the status variable somewhere, e.g. Text{text: if(xmlListModel.status!=XmlListModel.Ready){'Not Loaded';}else{'Loaded';}}
+    \o Null - No XML data has been set for this model.
+    \o Ready - The XML data has been loaded into the model.
+    \o Loading - The model is in the process of reading and loading XML data.
+    \o Error - An error occurred while the model was loading.
     \endlist
 
     \sa progress
@@ -694,10 +689,17 @@ QDeclarativeXmlListModel::Status QDeclarativeXmlListModel::status() const
 /*!
     \qmlproperty real XmlListModel::progress
 
-    This property holds the progress of data source loading, from 0.0 (nothing loaded)
-    to 1.0 (finished).
+    This indicates the current progress of the downloading of the XML data
+    source. This value ranges from 0.0 (no data downloaded) to
+    1.0 (all data downloaded). If the XML data is not from a remote source,
+    the progress becomes 1.0 as soon as the data is read.
+
+    Note that when the progress is 1.0, the XML data has been downloaded, but 
+    it is yet to be loaded into the model at this point. Use the status
+    property to find out when the XML data has been read and loaded into
+    the model.
 
-    \sa status
+    \sa status, source
 */
 qreal QDeclarativeXmlListModel::progress() const
 {
@@ -741,27 +743,8 @@ void QDeclarativeXmlListModel::reload()
     globalXmlQuery()->abort(d->queryId);
     d->queryId = -1;
 
-    int count = d->size;
-    if (count < 0)
-        d->size = 0;
-    bool hasKeys = false;
-    for (int i=0; i<d->roleObjects.count(); i++) {
-        if (d->roleObjects[i]->isKey()) {
-            hasKeys = true;
-            break;
-        }
-    }
-    if (!hasKeys) {
-        d->data.clear();
+    if (d->size < 0)
         d->size = 0;
-        if (count > 0) {
-            emit itemsRemoved(0, count);
-            emit countChanged();
-        }
-    }
-
-    if (d->src.isEmpty() && d->xml.isEmpty())
-        return;
 
     if (d->reply) {
         d->reply->abort();
@@ -772,12 +755,22 @@ void QDeclarativeXmlListModel::reload()
     if (!d->xml.isEmpty()) {
         d->queryId = globalXmlQuery()->doQuery(d->query, d->namespaces, d->xml.toUtf8(), &d->roleObjects, d->keyRoleResultsCache);
         d->progress = 1.0;
-        d->status = Ready;
+        d->status = Loading;
         emit progressChanged(d->progress);
         emit statusChanged(d->status);
         return;
     }
 
+    if (d->src.isEmpty()) {
+        d->queryId = XMLLISTMODEL_CLEAR_ID;
+        d->progress = 1.0;
+        d->status = Loading;
+        emit progressChanged(d->progress);
+        emit statusChanged(d->status);
+        QTimer::singleShot(0, this, SLOT(dataCleared()));
+        return;
+    }
+
     d->progress = 0.0;
     d->status = Loading;
     emit progressChanged(d->progress);
@@ -813,18 +806,33 @@ void QDeclarativeXmlListModel::requestFinished()
         disconnect(d->reply, 0, this, 0);
         d->reply->deleteLater();
         d->reply = 0;
+
+        int count = this->count();
+        d->data.clear();
+        d->size = 0;
+        if (count > 0) {
+            emit itemsRemoved(0, count);
+            emit countChanged();
+        }
+
         d->status = Error;
+        d->queryId = -1;
+        emit statusChanged(d->status);
     } else {
-        d->status = Ready;
         QByteArray data = d->reply->readAll();
-        d->queryId = globalXmlQuery()->doQuery(d->query, d->namespaces, data, &d->roleObjects, d->keyRoleResultsCache);
+        if (data.isEmpty()) {
+            d->queryId = XMLLISTMODEL_CLEAR_ID;
+            QTimer::singleShot(0, this, SLOT(dataCleared()));
+        } else {
+            d->queryId = globalXmlQuery()->doQuery(d->query, d->namespaces, data, &d->roleObjects, d->keyRoleResultsCache);
+        }
         disconnect(d->reply, 0, this, 0);
         d->reply->deleteLater();
         d->reply = 0;
+
+        d->progress = 1.0;
+        emit progressChanged(d->progress);
     }
-    d->progress = 1.0;
-    emit progressChanged(d->progress);
-    emit statusChanged(d->status);
 }
 
 void QDeclarativeXmlListModel::requestProgress(qint64 received, qint64 total)
@@ -836,23 +844,58 @@ void QDeclarativeXmlListModel::requestProgress(qint64 received, qint64 total)
     }
 }
 
+void QDeclarativeXmlListModel::dataCleared()
+{
+    Q_D(QDeclarativeXmlListModel);
+    QDeclarativeXmlQueryResult r;
+    r.queryId = XMLLISTMODEL_CLEAR_ID;
+    r.size = 0;
+    r.removed << qMakePair(0, count());
+    r.keyRoleResultsCache = d->keyRoleResultsCache;
+    queryCompleted(r);
+}
+
 void QDeclarativeXmlListModel::queryCompleted(const QDeclarativeXmlQueryResult &result)
 {
     Q_D(QDeclarativeXmlListModel);
     if (result.queryId != d->queryId)
         return;
+
+    int origCount = d->size;
     bool sizeChanged = result.size != d->size;
+
     d->size = result.size;
     d->data = result.data;
     d->keyRoleResultsCache = result.keyRoleResultsCache;
+    d->status = Ready;
+    d->queryId = -1;
 
-    for (int i=0; i<result.removed.count(); i++)
-        emit itemsRemoved(result.removed[i].first, result.removed[i].second);
-    for (int i=0; i<result.inserted.count(); i++)
-        emit itemsInserted(result.inserted[i].first, result.inserted[i].second);
+    bool hasKeys = false;
+    for (int i=0; i<d->roleObjects.count(); i++) {
+        if (d->roleObjects[i]->isKey()) {
+            hasKeys = true;
+            break;
+        }
+    }
+    if (!hasKeys) {
+        if (!(origCount == 0 && d->size == 0)) {
+            emit itemsRemoved(0, origCount);
+            emit itemsInserted(0, d->size);
+            emit countChanged();
+        }
+
+    } else {
+
+        for (int i=0; i<result.removed.count(); i++)
+            emit itemsRemoved(result.removed[i].first, result.removed[i].second);
+        for (int i=0; i<result.inserted.count(); i++)
+            emit itemsInserted(result.inserted[i].first, result.inserted[i].second);
 
-    if (sizeChanged)
-        emit countChanged();
+        if (sizeChanged)
+            emit countChanged();
+    }
+
+    emit statusChanged(d->status);
 }
 
 QT_END_NAMESPACE
diff --git a/src/declarative/util/qdeclarativexmllistmodel_p.h b/src/declarative/util/qdeclarativexmllistmodel_p.h
index 7bb0f0e..7b85476 100644
--- a/src/declarative/util/qdeclarativexmllistmodel_p.h
+++ b/src/declarative/util/qdeclarativexmllistmodel_p.h
@@ -117,7 +117,7 @@ public:
     virtual void componentComplete();
 
 Q_SIGNALS:
-    void statusChanged(Status);
+    void statusChanged(QDeclarativeXmlListModel::Status);
     void progressChanged(qreal progress);
     void countChanged();
     void sourceChanged();
@@ -135,6 +135,7 @@ public Q_SLOTS:
 private Q_SLOTS:
     void requestFinished();
     void requestProgress(qint64,qint64);
+    void dataCleared();
     void queryCompleted(const QDeclarativeXmlQueryResult &);
 
 private: