[plasma/plasma-workspace] shell: ScreenPool: unsigned int for idForName as std::optional

Git commit 1b547c5736c50b6f05acfeb221ec37c8cd9826b8 by Nate Graham, on behalf of Marco Martin.
Committed on 21/07/2026 at 13:45.
Pushed by ngraham into branch 'master'.

ScreenPool: unsigned int for idForName as std::optional

finish the unsigned migration having this also for ScreenPool.

since we can always pass invalid names to idForName, make it a std::optional

checking at every usage the optional has actually a value

M  +5    -1    shell/panelview.cpp
M  +14   -9    shell/screenpool.cpp
M  +3    -3    shell/screenpool.h
M  +1    -1    shell/scripting/scriptengine_v1.cpp
M  +29   -15   shell/shellcorona.cpp
M  +14   -5    shell/strutmanager.cpp

https://invent.kde.org/plasma/plasma-workspace/-/commit/1b547c5736c50b6f05acfeb221ec37c8cd9826b8

diff --git a/shell/panelview.cpp b/shell/panelview.cpp
index dd8c367693..013538ab42 100644
--- a/shell/panelview.cpp
+++ b/shell/panelview.cpp
@@ -1080,7 +1080,11 @@ void PanelView::showEvent(QShowEvent *event)
 void PanelView::moveToScreen(QScreen *screen)
 {
     if (containment()) {
-        const int screenId = m_corona->screenPool()->idForScreen(screen);
+        const auto screenOpt = m_corona->screenPool()->idForScreen(screen);
+        if (!screenOpt.has_value()) {
+            return;
+        }
+        const int screenId = screenOpt.value();
         containment()->setScreen(screenId);
     }
     setScreenToFollow(screen);
diff --git a/shell/screenpool.cpp b/shell/screenpool.cpp
index 16a7d55c72..757f817a88 100644
--- a/shell/screenpool.cpp
+++ b/shell/screenpool.cpp
@@ -35,16 +35,16 @@ ScreenPool::ScreenPool(QObject *parent)
 
 ScreenPool::~ScreenPool() = default;
 
-int ScreenPool::idForName(const QString &connector) const
+std::optional<uint> ScreenPool::idForName(const QString &connector) const
 {
-    int i = 0;
+    uint i = 0;
     for (auto *s : m_availableScreens) {
         if (s->name() == connector) {
             return i;
         }
         ++i;
     }
-    return -1;
+    return {};
 }
 
 QList<QScreen *> ScreenPool::screenOrder() const
@@ -89,9 +89,9 @@ void ScreenPool::handleUpdate()
         return;
     }
 
-    QHash<QString, int> order;
+    QHash<QString, uint> order;
     order.reserve(outputOrder.count());
-    for (int i = 0; i < outputOrder.count(); i++) {
+    for (uint i = 0; i < outputOrder.count(); i++) {
         order.insert(outputOrder[i], i);
     }
 
@@ -109,18 +109,23 @@ void ScreenPool::handleUpdate()
     }
 }
 
-QScreen *ScreenPool::screenForId(int id) const
+QScreen *ScreenPool::screenForId(uint id) const
 {
-    if (id < 0 || m_availableScreens.size() <= id) {
+    if (m_availableScreens.size() <= id) {
         return nullptr;
     }
 
     return m_availableScreens[id];
 }
 
-int ScreenPool::idForScreen(const QScreen *screen) const
+std::optional<uint> ScreenPool::idForScreen(const QScreen *screen) const
 {
-    return m_availableScreens.indexOf(screen);
+    const int idx = m_availableScreens.indexOf(screen);
+    if (idx >= 0) {
+        return uint(idx);
+    }
+
+    return {};
 }
 
 QDebug operator<<(QDebug debug, const ScreenPool *pool)
diff --git a/shell/screenpool.h b/shell/screenpool.h
index 7d9aa32006..339fe654c9 100644
--- a/shell/screenpool.h
+++ b/shell/screenpool.h
@@ -34,10 +34,10 @@ public:
     explicit ScreenPool(QObject *parent = nullptr);
     ~ScreenPool() override;
 
-    int idForName(const QString &connector) const;
-    int idForScreen(const QScreen *screen) const;
+    std::optional<uint> idForName(const QString &connector) const;
+    std::optional<uint> idForScreen(const QScreen *screen) const;
 
-    QScreen *screenForId(int id) const;
+    QScreen *screenForId(uint id) const;
 
     QList<QScreen *> screenOrder() const;
     QScreen *primaryScreen() const;
diff --git a/shell/scripting/scriptengine_v1.cpp b/shell/scripting/scriptengine_v1.cpp
index 9455429822..4ddbc9f1dd 100644
--- a/shell/scripting/scriptengine_v1.cpp
+++ b/shell/scripting/scriptengine_v1.cpp
@@ -208,7 +208,7 @@ QJSValue ScriptEngine::V1::screenForConnector(const QJSValue &param) const
     const QString connector = param.toString();
     auto *sc = qobject_cast<ShellCorona *>(m_engine->m_corona);
     if (sc) {
-        return m_engine->toScriptValue<int>(sc->screenPool()->idForName(connector));
+        return m_engine->toScriptValue<int>(sc->screenPool()->idForName(connector).value_or(-1));
     }
     return m_engine->toScriptValue<int>(-1);
 }
diff --git a/shell/shellcorona.cpp b/shell/shellcorona.cpp
index 867c787cc4..82a550a58b 100644
--- a/shell/shellcorona.cpp
+++ b/shell/shellcorona.cpp
@@ -881,7 +881,9 @@ void ShellCorona::screenInvariants() const
 
     QSet<QScreen *> screens;
     for (QScreen *knownScreen : managedScreens) {
-        const uint id = m_screenPool->idForScreen(knownScreen);
+        const auto idOpt = m_screenPool->idForScreen(knownScreen);
+        Q_ASSERT_X(idOpt.has_value(), Q_FUNC_INFO, qUtf8Printable(debugMessage()));
+        const uint id = idOpt.value();
         const DesktopView *view = desktopForScreen(knownScreen);
         Q_ASSERT_X(view->isVisible(), Q_FUNC_INFO, qUtf8Printable(debugMessage()));
         QScreen *screen = view->screenToFollow();
@@ -1380,7 +1382,11 @@ DesktopView *ShellCorona::desktopForScreen(QScreen *screen) const
     if (!screen) {
         return nullptr;
     }
-    if (auto *v = m_desktopViewForScreen.value(m_screenPool->idForScreen(screen))) {
+    const auto id = m_screenPool->idForScreen(screen);
+    if (!id.has_value()) {
+        return nullptr;
+    }
+    if (auto *v = m_desktopViewForScreen.value(id.value())) {
         return v;
     }
 
@@ -1462,23 +1468,29 @@ void ShellCorona::handleScreenOrderChanged(QList<QScreen *> screens)
 void ShellCorona::addOutput(QScreen *screen)
 {
     Q_ASSERT(screen);
+    if (!m_screenPool->idForScreen(screen).has_value()) {
+        return;
+    }
+    uint insertPosition = m_screenPool->idForScreen(screen).value();
+
     if (desktopForScreen(screen)) {
-        Q_EMIT screenAdded(m_screenPool->idForScreen(screen));
+        Q_EMIT screenAdded(insertPosition);
         return;
     }
     Q_ASSERT(!screen->geometry().isNull());
 
-    int insertPosition = m_screenPool->idForScreen(screen);
-    Q_ASSERT(insertPosition >= 0);
-
     auto *view = new DesktopView(this, screen);
 
     if (view->rendererInterface()->graphicsApi() != QSGRendererInterface::Software) {
         connect(view, &QQuickWindow::sceneGraphError, this, &ShellCorona::glInitializationFailed);
     }
     connect(view, &DesktopView::geometryChanged, this, [this, view]() {
-        const int id = m_screenPool->idForScreen(view->screen());
-        if (id >= 0 && !m_screenReorderInProgress) {
+        const auto idOpt = m_screenPool->idForScreen(view->screen());
+        if (!idOpt.has_value()) {
+            return;
+        }
+        const uint id = m_screenPool->idForScreen(view->screen()).value();
+        if (!m_screenReorderInProgress) {
             Q_EMIT screenGeometryChanged(id);
             Q_EMIT availableScreenRectChanged(id);
         }
@@ -1502,9 +1514,9 @@ void ShellCorona::addOutput(QScreen *screen)
     connect(containment, &Plasma::Containment::uiReadyChanged, this, &ShellCorona::checkAllDesktopsUiReady);
 
     if (!m_screenReorderInProgress) {
-        Q_EMIT availableScreenRectChanged(m_screenPool->idForScreen(screen));
+        Q_EMIT availableScreenRectChanged(insertPosition);
     }
-    Q_EMIT screenAdded(m_screenPool->idForScreen(screen));
+    Q_EMIT screenAdded(insertPosition);
 }
 
 void ShellCorona::checkAllDesktopsUiReady()
@@ -2581,7 +2593,7 @@ Plasma::Containment *ShellCorona::addPanel(const QString &plugin)
     }
 
     Q_ASSERT(panel);
-    const int screen = std::max(0, m_screenPool->idForScreen(wantedScreen));
+    const int screen = m_screenPool->idForScreen(wantedScreen).value_or(0);
     panel->setScreen(screen);
     m_waitingPanels << panel;
     if (m_screensWithUiReady.contains(screen)) {
@@ -2943,8 +2955,8 @@ void ShellCorona::activateLauncherMenu(const QString &screenName)
         return false;
     };
 
-    const int rawId = m_screenPool->idForName(screenName);
-    const uint screenId = rawId >= 0 ? uint(rawId) : 0;
+    const auto screenOpt = m_screenPool->idForName(screenName);
+    const uint screenId = screenOpt.value_or(0);
 
     QList<Plasma::Containment *> conts = containments();
 
@@ -2998,13 +3010,15 @@ bool ShellCorona::grabContainmentImage(const QString &name, int width, int heigh
 {
     Q_ASSERT(calledFromDBus());
 
-    auto screenId = m_screenPool->idForName(name);
-    if (screenId < 0) {
+    const auto screenIdOpt = m_screenPool->idForName(name);
+    if (!screenIdOpt.has_value()) {
         qCWarning(PLASMASHELL) << "grabContainmentImage: unknown screen name" << name;
         sendErrorReply(QDBusError::InvalidArgs, QStringLiteral("Unknown screen name"));
         return false;
     }
 
+    const uint screenId = screenIdOpt.value();
+
     auto currentActivity = m_activityController->currentActivity();
     currentActivity = QUuid::fromString(currentActivity).isNull() ? QString() : currentActivity;
 
diff --git a/shell/strutmanager.cpp b/shell/strutmanager.cpp
index 128559e96a..cf710c9f9f 100644
--- a/shell/strutmanager.cpp
+++ b/shell/strutmanager.cpp
@@ -51,7 +51,7 @@ QRect StrutManager::availableScreenRect(int id) const
 
 QRect StrutManager::availableScreenRect(const QString &screenName) const
 {
-    return availableScreenRect(m_plasmashellCorona->screenPool()->idForName(screenName));
+    return availableScreenRect(m_plasmashellCorona->screenPool()->idForName(screenName).value_or(0));
 }
 
 QRegion StrutManager::availableScreenRegion(int id) const
@@ -67,8 +67,12 @@ QRegion StrutManager::availableScreenRegion(int id) const
 
 void StrutManager::setAvailableScreenRect(const QString &service, const QString &screenName, const QRect &rect)
 {
-    int id = m_plasmashellCorona->screenPool()->idForName(screenName);
-    if (id == -1 || m_availableScreenRects.value(service).value(id) == rect || !addWatchedService(service)) {
+    const auto idOpt = m_plasmashellCorona->screenPool()->idForName(screenName);
+    if (!idOpt.has_value()) {
+        return;
+    }
+    const uint id = idOpt.value();
+    if (m_availableScreenRects.value(service).value(id) == rect || !addWatchedService(service)) {
         return;
     }
     m_availableScreenRects[service][id] = rect;
@@ -77,13 +81,18 @@ void StrutManager::setAvailableScreenRect(const QString &service, const QString
 
 void StrutManager::setAvailableScreenRegion(const QString &service, const QString &screenName, const QList<QRect> &rects)
 {
-    int id = m_plasmashellCorona->screenPool()->idForName(screenName);
+    const auto idOpt = m_plasmashellCorona->screenPool()->idForName(screenName);
+    if (!idOpt.has_value()) {
+        return;
+    }
+    const uint id = idOpt.value();
+
     QRegion region;
     for (const QRect &rect : rects) {
         region += rect;
     }
 
-    if (id == -1 || m_availableScreenRegions.value(service).value(id) == region || !addWatchedService(service)) {
+    if (m_availableScreenRegions.value(service).value(id) == region || !addWatchedService(service)) {
         return;
     }
     m_availableScreenRegions[service][id] = region;