Support QCursor::setPos() properly for eglfs

The internal state of the input handlers need updating too. This was not possible
in the past due to the one way communication from the input handlers (that are
potentially loaded as interface-less generic plugins), but using our new private
QInputDeviceManager in QtGui we can now easily implement "talking back" from QtGui
to the input handlers, regardless of them being plugins or compiled in.

The rest of setPos() is in place already for eglfs.

linuxfb will be handled in follow-up patches.

Task-number: QTBUG-44856
Change-Id: Id72fdb8b1ea176ddfe082e466e7a538a2a98a005
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

9 files changed, 74 insertions, 10 deletions

diff --git a/src/gui/kernel/qinputdevicemanager.cpp b/src/gui/kernel/qinputdevicemanager.cpp
index 1a3e6b8119..d0dd8a4e7c 100644
--- a/src/gui/kernel/qinputdevicemanager.cpp
+++ b/src/gui/kernel/qinputdevicemanager.cpp
@@ -36,6 +36,25 @@
 
 QT_BEGIN_NAMESPACE
 
+/*!
+  \class QInputDeviceManager
+  \internal
+
+  \brief QInputDeviceManager acts as a communication hub between QtGui and the input handlers.
+
+  On embedded platforms the input handling code is either compiled into the platform
+  plugin or is loaded dynamically as a generic plugin without any interface. The input
+  handler in use may also change between each run (e.g. evdevmouse/keyboard/touch
+  vs. libinput). QWindowSystemInterface is too limiting when Qt (the platform plugin) is
+  acting as a windowing system, and is one way only.
+
+  QInputDeviceManager solves this by providing a global object that is used to communicate
+  from the input handlers to the rest of Qt (e.g. the number of connected mice, which may
+  be important information for the cursor drawing code), and vice-versa (e.g. to indicate
+  to the input handler that a manual cursor position change was requested by the
+  application via QCursor::setPos and thus any internal state has to be updated accordingly).
+*/
+
 QInputDeviceManager::QInputDeviceManager(QObject *parent)
     : QObject(*new QInputDeviceManagerPrivate, parent)
 {
@@ -61,4 +80,9 @@ void QInputDeviceManagerPrivate::setDeviceCount(QInputDeviceManager::DeviceType
     }
 }
 
+void QInputDeviceManager::setCursorPos(const QPoint &pos)
+{
+    emit cursorPositionChangeRequested(pos);
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qinputdevicemanager_p.h b/src/gui/kernel/qinputdevicemanager_p.h
index cc55c8b4e5..15c84d1a82 100644
--- a/src/gui/kernel/qinputdevicemanager_p.h
+++ b/src/gui/kernel/qinputdevicemanager_p.h
@@ -68,8 +68,11 @@ public:
 
     int deviceCount(DeviceType type) const;
 
+    void setCursorPos(const QPoint &pos);
+
 signals:
     void deviceListChanged(DeviceType type);
+    void cursorPositionChangeRequested(const QPoint &pos);
 };
 
 QT_END_NAMESPACE
diff --git a/src/platformsupport/eglconvenience/qeglplatformcursor.cpp b/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
index 5023efbaf6..09243487c7 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
@@ -298,6 +298,7 @@ QPoint QEGLPlatformCursor::pos() const
 
 void QEGLPlatformCursor::setPos(const QPoint &pos)
 {
+    QGuiApplicationPrivate::inputDeviceManager()->setCursorPos(pos);
     const QRect oldCursorRect = cursorRect();
     m_cursor.pos = pos;
     update(oldCursorRect | cursorRect());
diff --git a/src/platformsupport/input/evdevmouse/qevdevmousemanager.cpp b/src/platformsupport/input/evdevmouse/qevdevmousemanager.cpp
index 6eb1fccba0..805397f021 100644
--- a/src/platformsupport/input/evdevmouse/qevdevmousemanager.cpp
+++ b/src/platformsupport/input/evdevmouse/qevdevmousemanager.cpp
@@ -92,6 +92,9 @@ QEvdevMouseManager::QEvdevMouseManager(const QString &key, const QString &specif
             connect(m_deviceDiscovery, SIGNAL(deviceRemoved(QString)), this, SLOT(removeMouse(QString)));
         }
     }
+
+    connect(QGuiApplicationPrivate::inputDeviceManager(), SIGNAL(cursorPositionChangeRequested(QPoint)),
+            this, SLOT(handleCursorPositionChange(QPoint)));
 }
 
 QEvdevMouseManager::~QEvdevMouseManager()
@@ -100,17 +103,8 @@ QEvdevMouseManager::~QEvdevMouseManager()
     m_mice.clear();
 }
 
-void QEvdevMouseManager::handleMouseEvent(int x, int y, bool abs, Qt::MouseButtons buttons)
+void QEvdevMouseManager::clampPosition()
 {
-    // update current absolute coordinates
-    if (!abs) {
-        m_x += x;
-        m_y += y;
-    } else {
-        m_x = x;
-        m_y = y;
-    }
-
     // clamp to screen geometry
     QRect g = QGuiApplication::primaryScreen()->virtualGeometry();
     if (m_x + m_xoffset < g.left())
@@ -122,6 +116,20 @@ void QEvdevMouseManager::handleMouseEvent(int x, int y, bool abs, Qt::MouseButto
         m_y = g.top() - m_yoffset;
     else if (m_y + m_yoffset > g.bottom())
         m_y = g.bottom() - m_yoffset;
+}
+
+void QEvdevMouseManager::handleMouseEvent(int x, int y, bool abs, Qt::MouseButtons buttons)
+{
+    // update current absolute coordinates
+    if (!abs) {
+        m_x += x;
+        m_y += y;
+    } else {
+        m_x = x;
+        m_y = y;
+    }
+
+    clampPosition();
 
     QPoint pos(m_x + m_xoffset, m_y + m_yoffset);
     // Cannot track the keyboard modifiers ourselves here. Instead, report the
@@ -163,4 +171,11 @@ void QEvdevMouseManager::removeMouse(const QString &deviceNode)
     }
 }
 
+void QEvdevMouseManager::handleCursorPositionChange(const QPoint &pos)
+{
+    m_x = pos.x();
+    m_y = pos.y();
+    clampPosition();
+}
+
 QT_END_NAMESPACE
diff --git a/src/platformsupport/input/evdevmouse/qevdevmousemanager_p.h b/src/platformsupport/input/evdevmouse/qevdevmousemanager_p.h
index 944effd80b..e1b24b807d 100644
--- a/src/platformsupport/input/evdevmouse/qevdevmousemanager_p.h
+++ b/src/platformsupport/input/evdevmouse/qevdevmousemanager_p.h
@@ -69,8 +69,11 @@ public slots:
 private slots:
     void addMouse(const QString &deviceNode = QString());
     void removeMouse(const QString &deviceNode);
+    void handleCursorPositionChange(const QPoint &pos);
 
 private:
+    void clampPosition();
+
     QString m_spec;
     QHash<QString,QEvdevMouseHandler*> m_mice;
     QDeviceDiscovery *m_deviceDiscovery;
diff --git a/src/platformsupport/input/libinput/qlibinputhandler.cpp b/src/platformsupport/input/libinput/qlibinputhandler.cpp
index 22b08960df..1a64ad5a30 100644
--- a/src/platformsupport/input/libinput/qlibinputhandler.cpp
+++ b/src/platformsupport/input/libinput/qlibinputhandler.cpp
@@ -107,6 +107,9 @@ QLibInputHandler::QLibInputHandler(const QString &key, const QString &spec)
     m_keyboard.reset(new QLibInputKeyboard);
     m_touch.reset(new QLibInputTouch);
 
+    connect(QGuiApplicationPrivate::inputDeviceManager(), SIGNAL(cursorPositionChangeRequested(QPoint)),
+            this, SLOT(onCursorPositionChangeRequested(QPoint)));
+
     // Process the initial burst of DEVICE_ADDED events.
     onReadyRead();
 }
@@ -227,4 +230,9 @@ void QLibInputHandler::processEvent(libinput_event *ev)
     }
 }
 
+void QLibInputHandler::onCursorPositionChangeRequested(const QPoint &pos)
+{
+    m_pointer->setPos(pos);
+}
+
 QT_END_NAMESPACE
diff --git a/src/platformsupport/input/libinput/qlibinputhandler_p.h b/src/platformsupport/input/libinput/qlibinputhandler_p.h
index 5d54f984de..de04d71f93 100644
--- a/src/platformsupport/input/libinput/qlibinputhandler_p.h
+++ b/src/platformsupport/input/libinput/qlibinputhandler_p.h
@@ -74,6 +74,7 @@ signals:
 
 private slots:
     void onReadyRead();
+    void onCursorPositionChangeRequested(const QPoint &pos);
 
 private:
     void processEvent(libinput_event *ev);
diff --git a/src/platformsupport/input/libinput/qlibinputpointer.cpp b/src/platformsupport/input/libinput/qlibinputpointer.cpp
index 794ac54e8e..48e5a6cf1c 100644
--- a/src/platformsupport/input/libinput/qlibinputpointer.cpp
+++ b/src/platformsupport/input/libinput/qlibinputpointer.cpp
@@ -108,4 +108,11 @@ void QLibInputPointer::processAxis(libinput_event_pointer *e)
 #endif
 }
 
+void QLibInputPointer::setPos(const QPoint &pos)
+{
+    const QRect g = QGuiApplication::primaryScreen()->virtualGeometry();
+    m_pos.setX(qBound(g.left(), pos.x(), g.right()));
+    m_pos.setY(qBound(g.top(), pos.y(), g.bottom()));
+}
+
 QT_END_NAMESPACE
diff --git a/src/platformsupport/input/libinput/qlibinputpointer_p.h b/src/platformsupport/input/libinput/qlibinputpointer_p.h
index 3b0c5df1c6..a8ba19c7ec 100644
--- a/src/platformsupport/input/libinput/qlibinputpointer_p.h
+++ b/src/platformsupport/input/libinput/qlibinputpointer_p.h
@@ -60,6 +60,8 @@ public:
     void processMotion(libinput_event_pointer *e);
     void processAxis(libinput_event_pointer *e);
 
+    void setPos(const QPoint &pos);
+
 private:
     QPoint m_pos;
     Qt::MouseButtons m_buttons;