Expose if the tablet mode switch is available

Summary:
expose in the libinput wrapper a property that tells whether
a tablet mode switch input device is present on the machine,
expose it trough dbus

Test Plan:
still not complete, I need a way to either access the connection
from TabletModeManager or setting to TabletModeManager from input.cpp

Reviewers: #kwin, #plasma, graesslin

Reviewed By: #kwin, #plasma, graesslin

Subscribers: graesslin, ngraham, davidedmundson, plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D9944

input.cpp

@@ -1807,6 +1807,14 @@ void InputRedirection::setupLibInput()
                     emit hasAlphaNumericKeyboardChanged(set);
                 }
             );
+            connect(conn, &LibInput::Connection::hasTabletModeSwitchChanged, this,
+                [this] (bool set) {
+                    if (m_libInput->isSuspended()) {
+                        return;
+                    }
+                    emit hasTabletModeSwitchChanged(set);
+                }
+            );
             connect(conn, &LibInput::Connection::hasPointerChanged, this,
                 [this, s] (bool set) {
                     if (m_libInput->isSuspended()) {
@@ -1879,6 +1887,16 @@ bool InputRedirection::hasAlphaNumericKeyboard()
     return true;
 }
 
+bool InputRedirection::hasTabletModeSwitch()
+{
+#if HAVE_INPUT
+    if (m_libInput) {
+        return m_libInput->hasTabletModeSwitch();
+    }
+#endif
+    return false;
+}
+
 void InputRedirection::setupLibInputWithScreens()
 {
 #if HAVE_INPUT

input.h

@@ -218,6 +218,7 @@ public:
     }
 
     bool hasAlphaNumericKeyboard();
+    bool hasTabletModeSwitch();
 
     void startInteractiveWindowSelection(std::function<void(KWin::Toplevel*)> callback, const QByteArray &cursorName);
     void startInteractivePositionSelection(std::function<void(const QPoint &)> callback);
@@ -265,6 +266,7 @@ Q_SIGNALS:
     void keyStateChanged(quint32 keyCode, InputRedirection::KeyboardKeyState state);
 
     void hasAlphaNumericKeyboardChanged(bool set);
+    void hasTabletModeSwitchChanged(bool set);
 
 private:
     void setupLibInput();

libinput/connection.cpp

@@ -225,6 +225,7 @@ void Connection::deactivate()
     m_alphaNumericKeyboardBeforeSuspend = hasAlphaNumericKeyboard();
     m_pointerBeforeSuspend = hasPointer();
     m_touchBeforeSuspend = hasTouch();
+    m_tabletModeSwitchBeforeSuspend = hasTabletModeSwitch();
     m_input->suspend();
     handleEvent();
 }
@@ -280,6 +281,12 @@ void Connection::processEvents()
                         emit hasTouchChanged(true);
                     }
                 }
+                if (device->isTabletModeSwitch()) {
+                    m_tabletModeSwitch++;
+                    if (m_tabletModeSwitch == 1) {
+                        emit hasTabletModeSwitchChanged(true);
+                    }
+                }
                 applyDeviceConfig(device);
                 applyScreenToDevice(device);
 
@@ -323,6 +330,12 @@ void Connection::processEvents()
                         emit hasTouchChanged(false);
                     }
                 }
+                if (device->isTabletModeSwitch()) {
+                    m_tabletModeSwitch--;
+                    if (m_tabletModeSwitch == 0) {
+                        emit hasTabletModeSwitchChanged(false);
+                    }
+                }
                 device->deleteLater();
                 break;
             }
@@ -492,6 +505,9 @@ void Connection::processEvents()
         if (m_touchBeforeSuspend && !m_touch) {
             emit hasTouchChanged(false);
         }
+        if (m_tabletModeSwitchBeforeSuspend && !m_tabletModeSwitch) {
+            emit hasTabletModeSwitchChanged(false);
+        }
         wasSuspended = false;
     }
 }

libinput/connection.h

@@ -75,6 +75,9 @@ public:
     bool hasPointer() const {
         return m_pointer > 0;
     }
+    bool hasTabletModeSwitch() const {
+        return m_tabletModeSwitch > 0;
+    }
 
     bool isSuspended() const;
 
@@ -111,6 +114,7 @@ Q_SIGNALS:
     void hasAlphaNumericKeyboardChanged(bool);
     void hasPointerChanged(bool);
     void hasTouchChanged(bool);
+    void hasTabletModeSwitchChanged(bool);
     void deviceAdded(KWin::LibInput::Device *);
     void deviceRemoved(KWin::LibInput::Device *);
     void deviceAddedSysName(QString);
@@ -144,10 +148,12 @@ private:
     int m_alphaNumericKeyboard = 0;
     int m_pointer = 0;
     int m_touch = 0;
+    int m_tabletModeSwitch = 0;
     bool m_keyboardBeforeSuspend = false;
     bool m_alphaNumericKeyboardBeforeSuspend = false;
     bool m_pointerBeforeSuspend = false;
     bool m_touchBeforeSuspend = false;
+    bool m_tabletModeSwitchBeforeSuspend = false;
     QMutex m_mutex;
     QVector<Event*> m_eventQueue;
     bool wasSuspended = false;

tabletmodemanager.cpp

@@ -80,6 +80,13 @@ TabletModeManager::TabletModeManager(QObject *parent)
                                                  this,
                                                  QDBusConnection::ExportAllProperties | QDBusConnection::ExportAllSignals
     );
+
+    connect(input(), &InputRedirection::hasTabletModeSwitchChanged, this, &TabletModeManager::tabletModeAvailableChanged);
+}
+
+bool TabletModeManager::isTabletModeAvailable() const
+{
+    return input()->hasTabletModeSwitch();
 }
 
 bool TabletModeManager::isTablet() const

tabletmodemanager.h

@@ -33,17 +33,24 @@ class TabletModeManager : public QObject
 {
     Q_OBJECT
     Q_CLASSINFO("D-Bus Interface", "org.kde.KWin.TabletModeManager")
+    //assuming such a switch is not pluggable for now
+    Q_PROPERTY(bool tabletModeAvailable READ isTabletModeAvailable NOTIFY tabletModeAvailableChanged)
     Q_PROPERTY(bool tabletMode READ isTablet NOTIFY tabletModeChanged)
 
 public:
     ~TabletModeManager() = default;
+
+    bool isTabletModeAvailable() const;
+
     bool isTablet() const;
     void setIsTablet(bool tablet);
 
 Q_SIGNALS:
+    void tabletModeAvailableChanged(bool available);
     void tabletModeChanged(bool tabletMode);
 
 private:
+    bool m_tabletModeAvailable = false;
     bool m_isTabletMode = false;
     TabletModeInputEventSpy *m_spy;
     KWIN_SINGLETON_VARIABLE(TabletModeManager, s_manager)