Restore active client after ending showing desktop

Summary:
Showing desktop requests focus on the desktop window. This means the
active window is reset. When ending showing desktop the state was not
restored.

This change addresses this problem by requesting focus to the best
window.

BUG: 375993
FIXED-IN: 5.10.4

Test Plan: New autotest and manual testing

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D6420

autotests/integration/CMakeLists.txt

@@ -44,6 +44,7 @@ integrationTest(NAME testWindowSelection SRCS window_selection_test.cpp)
 integrationTest(NAME testPointerConstraints SRCS pointer_constraints_test.cpp)
 integrationTest(NAME testKeyboardLayout SRCS keyboard_layout_test.cpp)
 integrationTest(NAME testKeymapCreationFailure SRCS keymap_creation_failure_test.cpp)
+integrationTest(NAME testShowingDesktop SRCS showing_desktop_test.cpp)
 
 if (XCB_ICCCM_FOUND)
     integrationTest(NAME testMoveResize SRCS move_resize_window_test.cpp LIBS XCB::ICCCM)

autotests/integration/showing_desktop_test.cpp

@@ -0,0 +1,128 @@
+/********************************************************************
+KWin - the KDE window manager
+This file is part of the KDE project.
+
+Copyright (C) 2017 Martin Flöser <mgraesslin@kde.org>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+#include "kwin_wayland_test.h"
+#include "platform.h"
+#include "shell_client.h"
+#include "wayland_server.h"
+#include "workspace.h"
+
+#include <KWayland/Client/plasmashell.h>
+#include <KWayland/Client/surface.h>
+#include <KWayland/Client/shell.h>
+
+using namespace KWin;
+using namespace KWayland::Client;
+
+static const QString s_socketName = QStringLiteral("wayland_test_kwin_showing_desktop-0");
+
+class ShowingDesktopTest : public QObject
+{
+    Q_OBJECT
+private Q_SLOTS:
+    void initTestCase();
+    void init();
+    void cleanup();
+
+    void testRestoreFocus();
+    void testRestoreFocusWithDesktopWindow();
+};
+
+void ShowingDesktopTest::initTestCase()
+{
+    qRegisterMetaType<KWin::ShellClient*>();
+    qRegisterMetaType<KWin::AbstractClient*>();
+    QSignalSpy workspaceCreatedSpy(kwinApp(), &Application::workspaceCreated);
+    QVERIFY(workspaceCreatedSpy.isValid());
+    kwinApp()->platform()->setInitialWindowSize(QSize(1280, 1024));
+    QVERIFY(waylandServer()->init(s_socketName.toLocal8Bit()));
+
+    kwinApp()->start();
+    QVERIFY(workspaceCreatedSpy.wait());
+    waylandServer()->initWorkspace();
+}
+
+void ShowingDesktopTest::init()
+{
+    QVERIFY(Test::setupWaylandConnection(Test::AdditionalWaylandInterface::PlasmaShell));
+}
+
+void ShowingDesktopTest::cleanup()
+{
+    Test::destroyWaylandConnection();
+}
+
+void ShowingDesktopTest::testRestoreFocus()
+{
+    QScopedPointer<Surface> surface1(Test::createSurface());
+    QScopedPointer<ShellSurface> shellSurface1(Test::createShellSurface(surface1.data()));
+    auto client1 = Test::renderAndWaitForShown(surface1.data(), QSize(100, 50), Qt::blue);
+    QScopedPointer<Surface> surface2(Test::createSurface());
+    QScopedPointer<ShellSurface> shellSurface2(Test::createShellSurface(surface2.data()));
+    auto client2 = Test::renderAndWaitForShown(surface2.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(client1 != client2);
+
+    QCOMPARE(workspace()->activeClient(), client2);
+    workspace()->slotToggleShowDesktop();
+    QVERIFY(workspace()->showingDesktop());
+    workspace()->slotToggleShowDesktop();
+    QVERIFY(!workspace()->showingDesktop());
+
+    QVERIFY(workspace()->activeClient());
+    QCOMPARE(workspace()->activeClient(), client2);
+}
+
+void ShowingDesktopTest::testRestoreFocusWithDesktopWindow()
+{
+    // first create a desktop window
+
+    QScopedPointer<Surface> desktopSurface(Test::createSurface());
+    QVERIFY(!desktopSurface.isNull());
+    QScopedPointer<ShellSurface> desktopShellSurface(Test::createShellSurface(desktopSurface.data()));
+    QVERIFY(!desktopSurface.isNull());
+    QScopedPointer<PlasmaShellSurface> plasmaSurface(Test::waylandPlasmaShell()->createSurface(desktopSurface.data()));
+    QVERIFY(!plasmaSurface.isNull());
+    plasmaSurface->setRole(PlasmaShellSurface::Role::Desktop);
+
+    auto desktop = Test::renderAndWaitForShown(desktopSurface.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(desktop);
+    QVERIFY(desktop->isDesktop());
+
+    // now create some windows
+    QScopedPointer<Surface> surface1(Test::createSurface());
+    QScopedPointer<ShellSurface> shellSurface1(Test::createShellSurface(surface1.data()));
+    auto client1 = Test::renderAndWaitForShown(surface1.data(), QSize(100, 50), Qt::blue);
+    QScopedPointer<Surface> surface2(Test::createSurface());
+    QScopedPointer<ShellSurface> shellSurface2(Test::createShellSurface(surface2.data()));
+    auto client2 = Test::renderAndWaitForShown(surface2.data(), QSize(100, 50), Qt::blue);
+    QVERIFY(client1 != client2);
+
+    QCOMPARE(workspace()->activeClient(), client2);
+    workspace()->slotToggleShowDesktop();
+    QVERIFY(workspace()->showingDesktop());
+    QCOMPARE(workspace()->activeClient(), desktop);
+    workspace()->slotToggleShowDesktop();
+    QVERIFY(!workspace()->showingDesktop());
+
+    QVERIFY(workspace()->activeClient());
+    QCOMPARE(workspace()->activeClient(), client2);
+}
+
+WAYLANDTEST_MAIN(ShowingDesktopTest)
+#include "showing_desktop_test.moc"

workspace.cpp

@@ -1307,8 +1307,14 @@ void Workspace::setShowingDesktop(bool showing)
     }
     } // ~StackingUpdatesBlocker
 
-    if (showing_desktop && topDesk)
+    if (showing_desktop && topDesk) {
         requestFocus(topDesk);
+    } else if (!showing_desktop && changed) {
+        const auto client = FocusChain::self()->getForActivation(VirtualDesktopManager::self()->current());
+        if (client) {
+            activateClient(client);
+        }
+    }
     if (changed)
         emit showingDesktopChanged(showing);
 }