Don't load components until the Loader component itself is completed

Previously components were loaded as soon as setSource() or
setSourceComponent() were called, even if the Loader component was not
complete. If a source component had been set, the itemChanged(),
statusChanged() etc. signals would be emitted before the Loader would
be complete and before the internal item had been sized. If a source
had been set via url, these signals were not emitted at all. It also
caused loaded() to be emitted twice for components set by
setSourceComponent().

Task-number: QTBUG-16319
Reviewed-by: Martin Jones

3 files changed, 86 insertions, 66 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativeloader.cpp b/src/declarative/graphicsitems/qdeclarativeloader.cpp
index 242435c..871850d 100644
--- a/src/declarative/graphicsitems/qdeclarativeloader.cpp
+++ b/src/declarative/graphicsitems/qdeclarativeloader.cpp
@@ -262,6 +262,7 @@ void QDeclarativeLoader::setSource(const QUrl &url)
     d->clear();
 
     d->source = url;
+
     if (d->source.isEmpty()) {
         emit sourceChanged();
         emit statusChanged();
@@ -272,18 +273,9 @@ void QDeclarativeLoader::setSource(const QUrl &url)
 
     d->component = new QDeclarativeComponent(qmlEngine(this), d->source, this);
     d->ownComponent = true;
-    if (!d->component->isLoading()) {
-        d->_q_sourceLoaded();
-    } else {
-        connect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)),
-                this, SLOT(_q_sourceLoaded()));
-        connect(d->component, SIGNAL(progressChanged(qreal)),
-                this, SIGNAL(progressChanged()));
-        emit statusChanged();
-        emit progressChanged();
-        emit sourceChanged();
-        emit itemChanged();
-    }
+
+    if (isComponentComplete())
+        d->load();
 }
 
 /*!
@@ -324,6 +316,7 @@ void QDeclarativeLoader::setSourceComponent(QDeclarativeComponent *comp)
 
     d->component = comp;
     d->ownComponent = false;
+
     if (!d->component) {
         emit sourceChanged();
         emit statusChanged();
@@ -332,18 +325,8 @@ void QDeclarativeLoader::setSourceComponent(QDeclarativeComponent *comp)
         return;
     }
 
-    if (!d->component->isLoading()) {
-        d->_q_sourceLoaded();
-    } else {
-        connect(d->component, SIGNAL(statusChanged(QDeclarativeComponent::Status)),
-                this, SLOT(_q_sourceLoaded()));
-        connect(d->component, SIGNAL(progressChanged(qreal)),
-                this, SIGNAL(progressChanged()));
-        emit progressChanged();
-        emit sourceChanged();
-        emit statusChanged();
-        emit itemChanged();
-    }
+    if (isComponentComplete())
+        d->load();
 }
 
 void QDeclarativeLoader::resetSourceComponent()
@@ -351,6 +334,27 @@ void QDeclarativeLoader::resetSourceComponent()
     setSourceComponent(0);
 }
 
+void QDeclarativeLoaderPrivate::load()
+{
+    Q_Q(QDeclarativeLoader);
+
+    if (!q->isComponentComplete() || !component)
+        return;
+
+    if (!component->isLoading()) {
+        _q_sourceLoaded();
+    } else {
+        QObject::connect(component, SIGNAL(statusChanged(QDeclarativeComponent::Status)),
+                q, SLOT(_q_sourceLoaded()));
+        QObject::connect(component, SIGNAL(progressChanged(qreal)),
+                q, SIGNAL(progressChanged()));
+        emit q->statusChanged();
+        emit q->progressChanged();
+        emit q->sourceChanged();
+        emit q->itemChanged();
+    }
+}
+
 void QDeclarativeLoaderPrivate::_q_sourceLoaded()
 {
     Q_Q(QDeclarativeLoader);
@@ -465,9 +469,10 @@ QDeclarativeLoader::Status QDeclarativeLoader::status() const
 
 void QDeclarativeLoader::componentComplete()
 {
+    Q_D(QDeclarativeLoader);
+
     QDeclarativeItem::componentComplete();
-    if (status() == Ready)
-        emit loaded();
+    d->load();
 }
 
 
diff --git a/src/declarative/graphicsitems/qdeclarativeloader_p_p.h b/src/declarative/graphicsitems/qdeclarativeloader_p_p.h
index 2239b16..e366a14 100644
--- a/src/declarative/graphicsitems/qdeclarativeloader_p_p.h
+++ b/src/declarative/graphicsitems/qdeclarativeloader_p_p.h
@@ -72,6 +72,7 @@ public:
     void itemGeometryChanged(QDeclarativeItem *item, const QRectF &newGeometry, const QRectF &oldGeometry);
     void clear();
     void initResize();
+    void load();
 
     QUrl source;
     QGraphicsObject *item;
diff --git a/tests/auto/declarative/qdeclarativeloader/tst_qdeclarativeloader.cpp b/tests/auto/declarative/qdeclarativeloader/tst_qdeclarativeloader.cpp
index bfa81ed..358822e 100644
--- a/tests/auto/declarative/qdeclarativeloader/tst_qdeclarativeloader.cpp
+++ b/tests/auto/declarative/qdeclarativeloader/tst_qdeclarativeloader.cpp
@@ -69,9 +69,8 @@ public:
     tst_QDeclarativeLoader();
 
 private slots:
-    void url();
-    void invalidUrl();
-    void component();
+    void sourceOrComponent();
+    void sourceOrComponent_data();
     void clear();
     void urlToComponent();
     void componentToUrl();
@@ -100,56 +99,71 @@ tst_QDeclarativeLoader::tst_QDeclarativeLoader()
 {
 }
 
-void tst_QDeclarativeLoader::url()
+void tst_QDeclarativeLoader::sourceOrComponent()
 {
+    QFETCH(QString, sourceDefinition);
+    QFETCH(QUrl, sourceUrl);
+    QFETCH(QString, errorString);
+
+    bool error = !errorString.isEmpty();
+    if (error)
+        QTest::ignoreMessage(QtWarningMsg, errorString.toUtf8().constData());
+
     QDeclarativeComponent component(&engine);
-    component.setData(QByteArray("import QtQuick 1.0\nLoader { property int did_load: 0; onLoaded: did_load=123; source: \"Rect120x60.qml\" }"), TEST_FILE(""));
+    component.setData(QByteArray(
+            "import QtQuick 1.0\n"
+            "Loader {\n"
+            "   property int onItemChangedCount: 0\n"
+            "   property int onSourceChangedCount: 0\n"
+            "   property int onStatusChangedCount: 0\n"
+            "   property int onProgressChangedCount: 0\n"
+            "   property int onLoadedCount: 0\n")
+            + sourceDefinition.toUtf8()
+            + QByteArray(
+            "   onItemChanged: onItemChangedCount += 1\n"
+            "   onSourceChanged: onSourceChangedCount += 1\n"
+            "   onStatusChanged: onStatusChangedCount += 1\n"
+            "   onProgressChanged: onProgressChangedCount += 1\n"
+            "   onLoaded: onLoadedCount += 1\n"
+            "}")
+        , TEST_FILE(""));
+
     QDeclarativeLoader *loader = qobject_cast<QDeclarativeLoader*>(component.create());
     QVERIFY(loader != 0);
-    QVERIFY(loader->item());
-    QVERIFY(loader->source() == QUrl::fromLocalFile(SRCDIR "/data/Rect120x60.qml"));
+    QCOMPARE(loader->item() == 0, error);
+    QCOMPARE(loader->source(), sourceUrl);
     QCOMPARE(loader->progress(), 1.0);
-    QCOMPARE(loader->status(), QDeclarativeLoader::Ready);
-    QCOMPARE(loader->property("did_load").toInt(), 123);
-    QCOMPARE(static_cast<QGraphicsItem*>(loader)->children().count(), 1);
 
-    delete loader;
-}
+    QCOMPARE(loader->status(), error ? QDeclarativeLoader::Error : QDeclarativeLoader::Ready);
+    QCOMPARE(static_cast<QGraphicsItem*>(loader)->children().count(), error ? 0: 1);
 
-void tst_QDeclarativeLoader::component()
-{
-    QDeclarativeComponent component(&engine, TEST_FILE("/SetSourceComponent.qml"));
-    QDeclarativeItem *item = qobject_cast<QDeclarativeItem*>(component.create());
-    QVERIFY(item);
+    if (!error) {
+        QDeclarativeComponent *c = qobject_cast<QDeclarativeComponent*>(loader->QGraphicsObject::children().at(0));
+        QVERIFY(c);
+        QCOMPARE(loader->sourceComponent(), c);
+    }
 
-    QDeclarativeLoader *loader = qobject_cast<QDeclarativeLoader*>(item->QGraphicsObject::children().at(1)); 
-    QVERIFY(loader);
-    QVERIFY(loader->item());
-    QCOMPARE(loader->progress(), 1.0);
-    QCOMPARE(loader->status(), QDeclarativeLoader::Ready);
-    QCOMPARE(static_cast<QGraphicsItem*>(loader)->children().count(), 1);
+    QCOMPARE(loader->property("onSourceChangedCount").toInt(), 1);
+    QCOMPARE(loader->property("onStatusChangedCount").toInt(), 1);
+    QCOMPARE(loader->property("onProgressChangedCount").toInt(), 1);
 
-    QDeclarativeComponent *c = qobject_cast<QDeclarativeComponent*>(item->QGraphicsObject::children().at(0));
-    QVERIFY(c);
-    QCOMPARE(loader->sourceComponent(), c);
+    QCOMPARE(loader->property("onItemChangedCount").toInt(), error ? 0 : 1);
+    QCOMPARE(loader->property("onLoadedCount").toInt(), error ? 0 : 1);
 
-    delete item;
+    delete loader;
 }
 
-void tst_QDeclarativeLoader::invalidUrl()
+void tst_QDeclarativeLoader::sourceOrComponent_data()
 {
-    QTest::ignoreMessage(QtWarningMsg, QString(QUrl::fromLocalFile(SRCDIR "/data/IDontExist.qml").toString() + ": File not found").toUtf8().constData());
+    QTest::addColumn<QString>("sourceDefinition");
+    QTest::addColumn<QUrl>("sourceUrl");
+    QTest::addColumn<QString>("errorString");
 
-    QDeclarativeComponent component(&engine);
-    component.setData(QByteArray("import QtQuick 1.0\nLoader { source: \"IDontExist.qml\" }"), TEST_FILE(""));
-    QDeclarativeLoader *loader = qobject_cast<QDeclarativeLoader*>(component.create());
-    QVERIFY(loader != 0);
-    QVERIFY(loader->item() == 0);
-    QCOMPARE(loader->progress(), 1.0);
-    QCOMPARE(loader->status(), QDeclarativeLoader::Error);
-    QCOMPARE(static_cast<QGraphicsItem*>(loader)->children().count(), 0);
+    QTest::newRow("source") << "source: 'Rect120x60.qml'\n" << QUrl::fromLocalFile(SRCDIR "/data/Rect120x60.qml") << "";
+    QTest::newRow("sourceComponent") << "Component { id: comp; Rectangle { width: 100; height: 50 } }\n sourceComponent: comp\n" << QUrl() << "";
 
-    delete loader;
+    QTest::newRow("invalid source") << "source: 'IDontExist.qml'\n" << QUrl::fromLocalFile(SRCDIR "/data/IDontExist.qml")
+            << QString(QUrl::fromLocalFile(SRCDIR "/data/IDontExist.qml").toString() + ": File not found");
 }
 
 void tst_QDeclarativeLoader::clear()
@@ -446,7 +460,7 @@ void tst_QDeclarativeLoader::networkRequestUrl()
     server.serveDirectory(SRCDIR "/data");
 
     QDeclarativeComponent component(&engine);
-    component.setData(QByteArray("import QtQuick 1.0\nLoader { property int did_load : 0; source: \"http://127.0.0.1:14450/Rect120x60.qml\"; onLoaded: did_load=123 }"), QUrl::fromLocalFile(SRCDIR "/dummy.qml"));
+    component.setData(QByteArray("import QtQuick 1.0\nLoader { property int signalCount : 0; source: \"http://127.0.0.1:14450/Rect120x60.qml\"; onLoaded: signalCount += 1 }"), QUrl::fromLocalFile(SRCDIR "/dummy.qml"));
     if (component.isError())
         qDebug() << component.errors();
     QDeclarativeLoader *loader = qobject_cast<QDeclarativeLoader*>(component.create());
@@ -456,7 +470,7 @@ void tst_QDeclarativeLoader::networkRequestUrl()
 
     QVERIFY(loader->item());
     QCOMPARE(loader->progress(), 1.0);
-    QCOMPARE(loader->property("did_load").toInt(), 123);
+    QCOMPARE(loader->property("signalCount").toInt(), 1);
     QCOMPARE(static_cast<QGraphicsItem*>(loader)->children().count(), 1);
 
     delete loader;