Add "Configure Displays" action to desktop context menu

With a multi-screen setup, it's possible to get into a situation where
all of your means to launch apps have gone missing because a screen
forgot its containmewt or moved the only panel onto a disabled output,
or any number of other issues that unfortunately have not yet been
resolved. In such a situation, it is common for people to try to fix it
by visiting the KScreen KCM to switch around their primary screens,
enable disabled outputs, turn it off and on again, etc.

However if your only visible means to launch apps has gone missing, you
may have a hard time accessing the KScreen KCM. In such a circumstance,
it can be helpful to have the action in the desktop context menu so that
people can right-click on the wallpaper of any screen that *is* working
and make System Settings launch with the KScreen KCM on that screen.

Co-authored-by: Nate Graham <nate@kde.org>

BUG: 355679
FIXED-IN: 5.24

containmentactions/contextmenu/CMakeLists.txt

@@ -20,4 +20,5 @@ target_link_libraries(plasma_containmentactions_contextmenu
                       KF5::Plasma
                       KF5::XmlGui
                       KF5::KIOCore
+                      KF5::KIOGui
                       PW::KWorkspace)

containmentactions/contextmenu/menu.cpp

@@ -14,6 +14,7 @@
 #include <KActionCollection>
 #include <KAuthorized>
 #include <KGlobalAccel>
+#include <KIO/CommandLauncherJob>
 #include <KLocalizedString>
 #include <QDebug>
 #include <QIcon>
@@ -30,6 +31,7 @@ ContextMenu::ContextMenu(QObject *parent, const QVariantList &args)
     , m_runCommandAction(nullptr)
     , m_lockScreenAction(nullptr)
     , m_logoutAction(nullptr)
+    , m_configureDisplaysAction(nullptr)
     , m_separator1(nullptr)
     , m_separator2(nullptr)
     , m_separator3(nullptr)
@@ -52,6 +54,8 @@ void ContextMenu::restore(const KConfigGroup &config)
     QHash<QString, bool> actions;
     QSet<QString> disabled;
 
+    // clang-format off
+    // because it really wants to mangle this nice aligned list
     if (c->containmentType() == Plasma::Types::PanelContainment || c->containmentType() == Plasma::Types::CustomPanelContainment) {
         m_actionOrder << QStringLiteral("add widgets")
                       << QStringLiteral("_add panel")
@@ -61,6 +65,7 @@ void ContextMenu::restore(const KConfigGroup &config)
     } else {
         actions.insert(QStringLiteral("configure shortcuts"), false);
         m_actionOrder << QStringLiteral("configure")
+                      << QStringLiteral("_display_settings")
                       << QStringLiteral("run associated application")
                       << QStringLiteral("configure shortcuts")
                       << QStringLiteral("_sep1")
@@ -79,6 +84,7 @@ void ContextMenu::restore(const KConfigGroup &config)
         disabled.insert(QStringLiteral("configure shortcuts"));
         disabled.insert(QStringLiteral("_run_command"));
     }
+    // clang-format on
 
     for (const QString &name : qAsConst(m_actionOrder)) {
         actions.insert(name, !disabled.contains(name));
@@ -115,6 +121,10 @@ void ContextMenu::restore(const KConfigGroup &config)
         });
         connect(m_logoutAction, &QAction::triggered, this, &ContextMenu::startLogout);
 
+        m_configureDisplaysAction = new QAction(i18nc("plasma_containmentactions_contextmenu", "Configure Display Settings…"), this);
+        m_configureDisplaysAction->setIcon(QIcon::fromTheme(QStringLiteral("preferences-desktop-display")));
+        connect(m_configureDisplaysAction, &QAction::triggered, this, &ContextMenu::configureDisplays);
+
         m_separator1 = new QAction(this);
         m_separator1->setSeparator(true);
         m_separator2 = new QAction(this);
@@ -183,6 +193,10 @@ QAction *ContextMenu::action(const QString &name)
         if (KAuthorized::authorize(QStringLiteral("logout"))) {
             return m_logoutAction;
         }
+    } else if (name == QLatin1String("_display_settings")) {
+        if (KAuthorized::authorizeControlModule(QStringLiteral("kcm_kscreen.desktop")) && KService::serviceByStorageId(QStringLiteral("kcm_kscreen"))) {
+            return m_configureDisplaysAction;
+        }
     } else if (name == QLatin1String("edit mode")) {
         if (c->corona()) {
             return c->corona()->actions()->action(QStringLiteral("edit mode"));
@@ -226,6 +240,27 @@ void ContextMenu::startLogout()
     }
 }
 
+// FIXME: this function contains some code copied from KCMShell::openSystemSettings()
+// which is not publicly available to C++ code right now. Eventually we should
+// move that code into KIO so it's accessible to everyone, and then call that
+// function instead of this one
+void ContextMenu::configureDisplays()
+{
+    const QString systemSettings = QStringLiteral("systemsettings");
+    const QString kscreenKCM = QStringLiteral("kcm_kscreen");
+
+    KIO::CommandLauncherJob *job = nullptr;
+
+    // Open in System Settings if it's available
+    if (KService::serviceByDesktopName(systemSettings)) {
+        job = new KIO::CommandLauncherJob(QStringLiteral("systemsettings5"), {kscreenKCM});
+        job->setDesktopName(systemSettings);
+    } else {
+        job = new KIO::CommandLauncherJob(QStringLiteral("kcmshell5"), {kscreenKCM});
+    }
+    job->start();
+}
+
 QWidget *ContextMenu::createConfigurationInterface(QWidget *parent)
 {
     QWidget *widget = new QWidget(parent);

containmentactions/contextmenu/menu.h

@@ -30,11 +30,13 @@ public:
 public Q_SLOTS:
     void runCommand();
     void startLogout();
+    void configureDisplays();
 
 private:
     QAction *m_runCommandAction;
     QAction *m_lockScreenAction;
     QAction *m_logoutAction;
+    QAction *m_configureDisplaysAction;
     QAction *m_separator1;
     QAction *m_separator2;
     QAction *m_separator3;