ensure empty containment emit uiReady()

Containments with no applets will emit uiReady now

It adds a test as well that checks if this is the case.

There is still a case where the corona doesn't emit startupCompleted()
that's when there is more than one activity, but that, as well the test
will be adressed by another patch on a different part.

Change-Id: I4d83aa612c29fb0f441d11681bc5aba241370bc3

autotests/coronatest.cpp

@@ -129,7 +129,7 @@ void CoronaTest::cleanupTestCase()
 void CoronaTest::restore()
 {
     m_corona->loadLayout("plasma-test-appletsrc");
-    QCOMPARE(m_corona->containments().count(), 1);
+    QCOMPARE(m_corona->containments().count(), 2);
     QCOMPARE(m_corona->containments().first()->applets().count(), 2);
 }
 

autotests/plasma-test-appletsrc

@@ -14,5 +14,13 @@ plugin=invalid
 immutability=1
 plugin=simpleapplet
 
+#empty panel: should emit complete even if empty
+[Containments][4]
+formfactor=2
+immutability=1
+lastScreen=0
+location=4
+plugin=simplecontainment
+
 [General]
 immutability=1

src/plasma/corona.cpp

@@ -563,7 +563,6 @@ QList<Plasma::Containment *> CoronaPrivate::importLayout(const KConfigGroup &con
                     if (!ready) {
                         return;
                     }
-
                     --containmentsStarting;
                     if (containmentsStarting <= 0) {
                         emit q->startupCompleted();

src/plasma/private/containment_p.cpp

@@ -246,7 +246,7 @@ void ContainmentPrivate::setUiReady()
     //if we are the containment and there is still some uncomplete applet, we're still incomplete
     if (!uiReady) {
         uiReady = true;
-        if (q->Applet::d->started && appletsUiReady && loadingApplets.isEmpty()) {
+        if (q->Applet::d->started && (appletsUiReady || applets.isEmpty()) && loadingApplets.isEmpty()) {
             emit q->uiReadyChanged(true);
         }
     }