Ensure the layoutChanged DBus signal gets emitted when changing layouts through DBus

Summary:
Unfortunately Xkb does not emit a signal when the keyboard layout
changes. Due to that we need to manually check in KeyboardLayout after
each action which could change the layout whether the layout changed.

This was not yet done for the case when the layout got changed through
the DBus interface. Resulting in the DBus signal not emitted.

This change addresses the issue by invoking the check for change after
changing the keyboard layout.

Test Plan: Added test case

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D4387

autotests/integration/keyboard_layout_test.cpp

@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #include "kwin_wayland_test.h"
 #include "keyboard_input.h"
+#include "keyboard_layout.h"
 #include "platform.h"
 #include "wayland_server.h"
 
@@ -78,6 +79,20 @@ void KeyboardLayoutTest::cleanup()
 {
 }
 
+class LayoutChangedSignalWrapper : public QObject
+{
+    Q_OBJECT
+public:
+    LayoutChangedSignalWrapper()
+        : QObject()
+    {
+        QDBusConnection::sessionBus().connect(QStringLiteral("org.kde.keyboard"), QStringLiteral("/Layouts"), QStringLiteral("org.kde.KeyboardLayouts"), QStringLiteral("currentLayoutChanged"), this, SIGNAL(layoutChanged(QString)));
+    }
+
+Q_SIGNALS:
+    void layoutChanged(const QString &name);
+};
+
 void KeyboardLayoutTest::testReconfigure()
 {
     // verifies that we can change the keymap
@@ -124,6 +139,10 @@ void KeyboardLayoutTest::testChangeLayoutThroughDBus()
     xkb->switchToLayout(0);
     QCOMPARE(xkb->layoutName(), QStringLiteral("German"));
 
+    LayoutChangedSignalWrapper wrapper;
+    QSignalSpy layoutChangedSpy(&wrapper, &LayoutChangedSignalWrapper::layoutChanged);
+    QVERIFY(layoutChangedSpy.isValid());
+
     // now change through DBus to english
     auto changeLayout = [] (const QString &layoutName) {
         QDBusMessage msg = QDBusMessage::createMethodCall(QStringLiteral("org.kde.keyboard"), QStringLiteral("/Layouts"), QStringLiteral("org.kde.KeyboardLayouts"), QStringLiteral("setLayout"));
@@ -135,24 +154,34 @@ void KeyboardLayoutTest::testChangeLayoutThroughDBus()
     QVERIFY(!reply.isError());
     QCOMPARE(reply.reply().arguments().first().toBool(), true);
     QCOMPARE(xkb->layoutName(), QStringLiteral("English (US)"));
+    QVERIFY(layoutChangedSpy.wait());
+    QCOMPARE(layoutChangedSpy.count(), 1);
+    layoutChangedSpy.clear();
 
     // switch to a layout which does not exist
     reply = changeLayout(QStringLiteral("French"));
     QVERIFY(!reply.isError());
     QCOMPARE(reply.reply().arguments().first().toBool(), false);
     QCOMPARE(xkb->layoutName(), QStringLiteral("English (US)"));
+    QVERIFY(!layoutChangedSpy.wait());
+    QVERIFY(layoutChangedSpy.isEmpty());
 
     // switch to another layout should work
     reply = changeLayout(QStringLiteral("German"));
     QVERIFY(!reply.isError());
     QCOMPARE(reply.reply().arguments().first().toBool(), true);
     QCOMPARE(xkb->layoutName(), QStringLiteral("German"));
+    QVERIFY(layoutChangedSpy.wait());
+    QCOMPARE(layoutChangedSpy.count(), 1);
+    layoutChangedSpy.clear();
 
     // switching to same layout should also work
     reply = changeLayout(QStringLiteral("German"));
     QVERIFY(!reply.isError());
     QCOMPARE(reply.reply().arguments().first().toBool(), true);
     QCOMPARE(xkb->layoutName(), QStringLiteral("German"));
+    QVERIFY(!layoutChangedSpy.wait());
+    QVERIFY(layoutChangedSpy.isEmpty());
 }
 
 WAYLANDTEST_MAIN(KeyboardLayoutTest)

keyboard_layout.cpp

@@ -274,9 +274,10 @@ void KeyboardLayout::reinitNotifierMenu()
 static const QString s_keyboardService = QStringLiteral("org.kde.keyboard");
 static const QString s_keyboardObject = QStringLiteral("/Layouts");
 
-KeyboardLayoutDBusInterface::KeyboardLayoutDBusInterface(Xkb *xkb, QObject *parent)
+KeyboardLayoutDBusInterface::KeyboardLayoutDBusInterface(Xkb *xkb, KeyboardLayout *parent)
     : QObject(parent)
     , m_xkb(xkb)
+    , m_keyboardLayout(parent)
 {
     QDBusConnection::sessionBus().registerService(s_keyboardService);
     QDBusConnection::sessionBus().registerObject(s_keyboardObject, this, QDBusConnection::ExportAllSlots | QDBusConnection::ExportAllSignals);
@@ -300,6 +301,7 @@ bool KeyboardLayoutDBusInterface::setLayout(const QString &layout)
         return false;
     }
     m_xkb->switchToLayout(it.key());
+    m_keyboardLayout->checkLayoutChange();
     return true;
 }
 

keyboard_layout.h

@@ -82,7 +82,7 @@ class KeyboardLayoutDBusInterface : public QObject
     Q_CLASSINFO("D-Bus Interface", "org.kde.KeyboardLayouts")
 
 public:
-    explicit KeyboardLayoutDBusInterface(Xkb *xkb, QObject *parent);
+    explicit KeyboardLayoutDBusInterface(Xkb *xkb, KeyboardLayout *parent);
     ~KeyboardLayoutDBusInterface() override;
 
 public Q_SLOTS:
@@ -97,6 +97,7 @@ Q_SIGNALS:
 
 private:
     Xkb *m_xkb;
+    KeyboardLayout *m_keyboardLayout;
 };
 
 }