base on screen() to see what containment is loading

if a containment's lastScreen is not -1 (and a valid screen)
*and* its activity() is not the current one, its QML
will *not* be loaded, therefore it would dangle blocking
corona::startupCompleted until the activity is selected

Change-Id: I6757d29240a012377e9ff0a22fe16541ea712ee6

autotests/coronatest.cpp

@@ -31,6 +31,8 @@ Plasma::Applet *SimpleLoader::internalLoadApplet(const QString &name, uint apple
         return new SimpleApplet(0, QString(), appletId);
     } else if (name == "simplecontainment") {
         return new SimpleContainment(0, QString(), appletId);
+    } else if (name == "simplenoscreencontainment") {
+        return new SimpleNoScreenContainment(0, QString(), appletId);
     } else {
         return 0;
     }
@@ -52,6 +54,14 @@ QRect SimpleCorona::screenGeometry(int screen) const
     return QRect(100*screen, 100, 100, 100);
 }
 
+int SimpleCorona::screenForContainment(const Plasma::Containment *c) const
+{
+    if (qobject_cast<const SimpleNoScreenContainment *>(c)) {
+        return -1;
+    }
+    return 0;
+}
+
 SimpleApplet::SimpleApplet(QObject *parent , const QString &serviceId, uint appletId)
     : Plasma::Applet(parent, serviceId, appletId)
 {
@@ -83,7 +93,11 @@ SimpleContainment::SimpleContainment(QObject *parent , const QString &serviceId,
     });
 }
 
-
+SimpleNoScreenContainment::SimpleNoScreenContainment(QObject *parent , const QString &serviceId, uint appletId)
+    : Plasma::Containment(parent, serviceId, appletId)
+{
+    //This containment will *never* be isUiReady()
+}
 
 static void runKBuildSycoca()
 {
@@ -129,8 +143,20 @@ void CoronaTest::cleanupTestCase()
 void CoronaTest::restore()
 {
     m_corona->loadLayout("plasma-test-appletsrc");
-    QCOMPARE(m_corona->containments().count(), 2);
+    QCOMPARE(m_corona->containments().count(), 3);
-    QCOMPARE(m_corona->containments().first()->applets().count(), 2);
+    //TODO: check the order of m_corona->containments() is stable:
+    //at the moment the ordering seems pretty random
+    //same thing for the order of containment->applets()
+    for (auto cont : m_corona->containments()) {
+        switch (cont->id()) {
+        case 1:
+            QCOMPARE(cont->applets().count(), 2);
+            break;
+        default:
+            QCOMPARE(cont->applets().count(), 0);
+            break;
+        }
+    }
 }
 
 void CoronaTest::startupCompletion()

autotests/coronatest.h

@@ -43,6 +43,7 @@ public:
     ~SimpleCorona();
 
     QRect screenGeometry(int) const;
+    int screenForContainment(const Plasma::Containment *) const;
 };
 
 class SimpleApplet : public Plasma::Applet
@@ -65,6 +66,14 @@ private:
     QTimer m_timer;
 };
 
+class SimpleNoScreenContainment : public Plasma::Containment
+{
+    Q_OBJECT
+
+public:
+    explicit SimpleNoScreenContainment(QObject *parent = 0, const QString &serviceId = QString(), uint appletId = 0);
+};
+
 class CoronaTest : public QObject
 {
     Q_OBJECT

autotests/plasma-test-appletsrc

@@ -22,5 +22,15 @@ lastScreen=0
 location=4
 plugin=simplecontainment
 
+#this is a desktop containment that even if has lastScreen=0
+#its screen will be -1: this is the case of a containment of
+#another activity, not the current one
+[Containments][5]
+formfactor=0
+immutability=1
+lastScreen=0
+location=0
+plugin=simplenoscreencontainment
+
 [General]
 immutability=1

src/plasma/corona.cpp

@@ -557,7 +557,7 @@ QList<Plasma::Containment *> CoronaPrivate::importLayout(const KConfigGroup &con
     if (!mergeConfig) {
         containmentsStarting = 0;
         foreach (Containment *containment, containments) {
-            if (!containment->isUiReady() && containment->lastScreen() < q->numScreens()) {
+            if (!containment->isUiReady() && containment->screen() < q->numScreens() && containment->screen() >= 0) {
                 ++containmentsStarting;
                 QObject::connect(containment, &Plasma::Containment::uiReadyChanged, [=](bool ready) {
                     if (!ready) {