[libinput] Bind libinput support to VirtualTerminal

This change is motivated by the fact that we need to suspend libinput
before switching the virtual terminal. Also we don't want to take over
libinput if we do not have a VirtualTerminal created - in windowed mode
we don't want libinput to be started. So binding it to the backends which
create the VirtualTerminal makes sense.

The KWin::Application gains a new signal virtualTerminalCreated which is
emitted from VirtualTerminal once it's properly setup. This is used by
Input to create Libinput integration instead of binding it to logind.

Furthermore Libinput gets suspended when the VirtualTerminal reports that
it is no longer active. For re-activation we still just use logind's
session active property.

input.cpp

@@ -202,19 +202,10 @@ InputRedirection::InputRedirection(QObject *parent)
 {
 #if HAVE_INPUT
     if (Application::usesLibinput()) {
-        LogindIntegration *logind = LogindIntegration::self();
-        auto takeControl = [logind, this]() {
-            if (logind->hasSessionControl()) {
-                setupLibInput();
-            } else {
-                logind->takeControl();
-                m_sessionControlConnection = connect(logind, &LogindIntegration::hasSessionControlChanged, this, &InputRedirection::setupLibInput);
-            }
-        };
-        if (logind->isConnected()) {
-            takeControl();
+        if (VirtualTerminal::self()) {
+            setupLibInput();
         } else {
-            connect(logind, &LogindIntegration::connectedChanged, this, takeControl);
+            connect(kwinApp(), &Application::virtualTerminalCreated, this, &InputRedirection::setupLibInput);
         }
     }
 #endif
@@ -242,10 +233,6 @@ void InputRedirection::setupLibInput()
     if (!Application::usesLibinput()) {
         return;
     }
-    if (m_sessionControlConnection) {
-        disconnect(m_sessionControlConnection);
-        m_sessionControlConnection = QMetaObject::Connection();
-    }
     if (m_libInput) {
         return;
     }
@@ -307,6 +294,13 @@ void InputRedirection::setupLibInput()
                 }
             );
         }
+        connect(VirtualTerminal::self(), &VirtualTerminal::activeChanged, m_libInput,
+            [this] (bool active) {
+                if (!active) {
+                    m_libInput->deactivate();
+                }
+            }
+        );
 #endif
     }
 #endif

input.h

@@ -203,8 +203,6 @@ private:
 
     GlobalShortcutsManager *m_shortcuts;
 
-    QMetaObject::Connection m_sessionControlConnection;
-
     LibInput::Connection *m_libInput = nullptr;
 
     KWIN_SINGLETON(InputRedirection)

libinput/connection.cpp

@@ -96,6 +96,9 @@ void Connection::setup()
     connect(logind, &LogindIntegration::sessionActiveChanged, this,
         [this](bool active) {
             if (active) {
+                if (!m_input->isSuspended()) {
+                    return;
+                }
                 m_input->resume();
                 handleEvent();
                 if (m_keyboardBeforeSuspend && !m_keyboard) {
@@ -108,17 +111,25 @@ void Connection::setup()
                     emit hasTouchChanged(false);
                 }
             } else {
-                m_keyboardBeforeSuspend = hasKeyboard();
-                m_pointerBeforeSuspend = hasPointer();
-                m_touchBeforeSuspend = hasTouch();
-                m_input->suspend();
-                handleEvent();
+                deactivate();
             }
         }
     );
     handleEvent();
 }
 
+void Connection::deactivate()
+{
+    if (m_input->isSuspended()) {
+        return;
+    }
+    m_keyboardBeforeSuspend = hasKeyboard();
+    m_pointerBeforeSuspend = hasPointer();
+    m_touchBeforeSuspend = hasTouch();
+    m_input->suspend();
+    handleEvent();
+}
+
 void Connection::handleEvent()
 {
     do {

libinput/connection.h

@@ -60,6 +60,8 @@ public:
 
     bool isSuspended() const;
 
+    void deactivate();
+
 Q_SIGNALS:
     void keyChanged(uint32_t key, InputRedirection::KeyboardKeyState, uint32_t time);
     void pointerButtonChanged(uint32_t button, InputRedirection::PointerButtonState state, uint32_t time);

main.h

@@ -152,6 +152,7 @@ Q_SIGNALS:
     void x11ConnectionChanged();
     void workspaceCreated();
     void screensCreated();
+    void virtualTerminalCreated();
 
 protected:
     Application(OperationMode mode, int &argc, char **argv);

virtual_terminal.cpp

@@ -20,6 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "virtual_terminal.h"
 // kwin
 #include "logind.h"
+#include "main.h"
 #include "utils.h"
 // Qt
 #include <QDebug>
@@ -126,6 +127,7 @@ void VirtualTerminal::setup(int vtNr)
         return;
     }
     setActive(true);
+    emit kwinApp()->virtualTerminalCreated();
 }
 
 void VirtualTerminal::closeFd()