Merge lp:~jonas-drange/ubuntu-ui-extras/printerloader-thread-affinity into lp:~phablet-team/ubuntu-ui-extras/printer-staging

[Jonas G. Drange]

corrects thread affinity for printerloaded printers, as well as any qobject children it might have

corrects thread affinity for printerloaded printers, as well as any qobject children it might have

[Andrew Hayzen (ahayzen)]

LGTM, fixes the issue when applying the patch [0], to the examples and the tests still pass :-)

0 - http://pastebin.ubuntu.com/24214888/

review: Approve

=== modified file 'modules/Ubuntu/Components/Extras/Printers/cups/printerloader.cpp'
--- modules/Ubuntu/Components/Extras/Printers/cups/printerloader.cpp	2017-02-21 10:46:29 +0000
+++ modules/Ubuntu/Components/Extras/Printers/cups/printerloader.cpp	2017-03-20 13:33:08 +0000
@@ -18,6 +18,7 @@
 #include "backend/backend_cups.h"
 #include "printerloader.h"
 
+#include <QApplication>
 #include <QPrinterInfo>
 
 class PrinterCupsBackend;
@@ -48,6 +49,8 @@
 
     auto p = QSharedPointer<Printer>(new Printer(backend));
 
+    p->moveToThread(QApplication::instance()->thread());
+
     Q_EMIT loaded(p);
     Q_EMIT finished();
 }

=== modified file 'modules/Ubuntu/Components/Extras/Printers/printer/printer.cpp'
--- modules/Ubuntu/Components/Extras/Printers/printer/printer.cpp	2017-03-14 14:47:54 +0000
+++ modules/Ubuntu/Components/Extras/Printers/printer/printer.cpp	2017-03-20 13:33:08 +0000
@@ -29,6 +29,7 @@
 {
     loadAttributes();
 
+    m_jobs.setParent(this);
     m_jobs.filterOnPrinterName(name());
 
     QObject::connect(m_backend, &PrinterBackend::printerStateChanged,

=== modified file 'tests/unittests/Printers/tst_printer.cpp'
--- tests/unittests/Printers/tst_printer.cpp	2017-03-10 13:15:27 +0000
+++ tests/unittests/Printers/tst_printer.cpp	2017-03-20 13:33:08 +0000
@@ -348,6 +348,28 @@
         );
         QCOMPARE(proxy->sourceModel()->objectName(), jobs.objectName());
     }
+
+    /* There was a bug causing QML thread assertion to fail. The assertion
+    requires all QObjects accessed from QML to be in the same thread as QML.
+    For newly loaded non-proxy printers, this was not the case. This test
+    serves as a regression test, as well as a place where we can make sure
+    every QObject of the Printer API moves thread when the printer itself
+    moves.
+
+    For POD, this is inconsequential. */
+    void testPrinterMovesProperlyFromThread()
+    {
+        MockPrinterBackend *backend = new MockPrinterBackend(m_printerName);
+
+        Printer p(backend);
+        QThread thread;
+        p.moveToThread(&thread);
+
+        QCOMPARE(p.thread(), &thread);
+
+        // Ideally, all QObjects in the Printer API needs to be tested here.
+        QCOMPARE(p.jobs()->thread(), &thread);
+    }
 private:
     QString m_printerName = "my-printer";
     MockPrinterBackend *m_backend = nullptr;