input: Synchronize multiple mice handled through evdevmouse plugin

EvdevMouseManager now receives relative pointer coordinates from each
connected mouse and is then responsible for clamping and forwarding them
to the QWindowSystemInterface. This avoids jumping cursors when multiple
pointer devices are connected. This does not change behavior together
with devices handled through the evdevtouch plugin.

Change-Id: I7feb358f68c3b3ebd138116224b4747c88c6761f
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>

src/plugins/generic/evdevmouse/qevdevmousehandler.cpp

@@ -73,8 +73,6 @@ QEvdevMouseHandler *QEvdevMouseHandler::createLinuxInputMouseHandler(const QStri
     QString device = "/dev/input/event0";
     bool compression = true;
     int jitterLimit = 0;
-    int xoffset = 0;
-    int yoffset = 0;
 
     QStringList args = specification.split(QLatin1Char(':'));
     foreach (const QString &arg, args) {
@@ -82,10 +80,6 @@ QEvdevMouseHandler *QEvdevMouseHandler::createLinuxInputMouseHandler(const QStri
             compression = false;
         else if (arg.startsWith("dejitter="))
             jitterLimit = arg.mid(9).toInt();
-        else if (arg.startsWith("xoffset="))
-            xoffset = arg.mid(8).toInt();
-        else if (arg.startsWith("yoffset="))
-            yoffset = arg.mid(8).toInt();
         else if (arg.startsWith(QLatin1String("/dev/")))
             device = arg;
     }
@@ -97,17 +91,17 @@ QEvdevMouseHandler *QEvdevMouseHandler::createLinuxInputMouseHandler(const QStri
     int fd;
     fd = qt_safe_open(device.toLocal8Bit().constData(), O_RDONLY | O_NDELAY, 0);
     if (fd >= 0) {
-        return new QEvdevMouseHandler(fd, compression, jitterLimit, xoffset, yoffset);
+        return new QEvdevMouseHandler(fd, compression, jitterLimit);
     } else {
         qWarning("Cannot open mouse input device '%s': %s", qPrintable(device), strerror(errno));
         return 0;
     }
 }
 
-QEvdevMouseHandler::QEvdevMouseHandler(int deviceDescriptor, bool compression, int jitterLimit, int xoffset, int yoffset)
+QEvdevMouseHandler::QEvdevMouseHandler(int deviceDescriptor, bool compression, int jitterLimit)
     : m_notify(0), m_x(0), m_y(0), m_prevx(0), m_prevy(0),
       m_fd(deviceDescriptor), m_compression(compression),
-      m_xoffset(xoffset), m_yoffset(yoffset), m_buttons(0)
+      m_buttons(0)
 {
     setObjectName(QLatin1String("Evdev Mouse Handler"));
 
@@ -127,24 +121,8 @@ QEvdevMouseHandler::~QEvdevMouseHandler()
 
 void QEvdevMouseHandler::sendMouseEvent()
 {
-    QRect g = QGuiApplication::primaryScreen()->virtualGeometry();
-    if (m_x + m_xoffset < g.left())
-        m_x = g.left() - m_xoffset;
-    else if (m_x + m_xoffset > g.right())
-        m_x = g.right() - m_xoffset;
+    emit handleMouseEvent(m_x - m_prevx, m_y - m_prevy, m_buttons);
 
-    if (m_y + m_yoffset < g.top())
-        m_y = g.top() - m_yoffset;
-    else if (m_y + m_yoffset > g.bottom())
-        m_y = g.bottom() - m_yoffset;
-
-    QPoint pos(m_x + m_xoffset, m_y + m_yoffset);
-
-#ifdef QT_QPA_MOUSE_HANDLER_DEBUG
-    qDebug("mouse event %d %d %d", pos.x(), pos.y(), int(m_buttons));
-#endif
-
-    QWindowSystemInterface::handleMouseEvent(0, pos, pos, m_buttons);
     m_prevx = m_x;
     m_prevy = m_y;
 }

src/plugins/generic/evdevmouse/qevdevmousehandler.h

@@ -58,11 +58,14 @@ public:
     static QEvdevMouseHandler *createLinuxInputMouseHandler(const QString &key, const QString &specification);
     ~QEvdevMouseHandler();
 
+signals:
+    void handleMouseEvent(int x, int y, Qt::MouseButtons buttons);
+
 private slots:
     void readMouseData();
 
 private:
-    QEvdevMouseHandler(int deviceDescriptor, bool compression, int jitterLimit, int xoffset, int yoffset);
+    QEvdevMouseHandler(int deviceDescriptor, bool compression, int jitterLimit);
 
     void sendMouseEvent();
 
@@ -71,7 +74,6 @@ private:
     int m_prevx, m_prevy;
     int m_fd;
     bool m_compression;
-    int m_xoffset, m_yoffset;
     Qt::MouseButtons m_buttons;
     int m_jitterLimitSquared;
 };

src/plugins/generic/evdevmouse/qevdevmousemanager.cpp

@@ -42,9 +42,11 @@
 #include "qevdevmousemanager.h"
 
 #include <QStringList>
-#include <QCoreApplication>
+#include <QGuiApplication>
+#include <QScreen>
+#include <QWindowSystemInterface>
 
-//#define QT_QPA_MOUSEMANAGER_DEBUG
+#define QT_QPA_MOUSEMANAGER_DEBUG
 
 #ifdef QT_QPA_MOUSEMANAGER_DEBUG
 #include <QDebug>
@@ -53,6 +55,7 @@
 QT_BEGIN_NAMESPACE
 
 QEvdevMouseManager::QEvdevMouseManager(const QString &key, const QString &specification)
+    : m_x(0), m_y(0), m_xoffset(0), m_yoffset(0)
 {
     Q_UNUSED(key);
 
@@ -70,6 +73,10 @@ QEvdevMouseManager::QEvdevMouseManager(const QString &key, const QString &specif
             devices.append(arg);
             args.removeAll(arg);
             useUDev = false;
+        } else if (arg.startsWith("xoffset=")) {
+            m_xoffset = arg.mid(8).toInt();
+        } else if (arg.startsWith("yoffset=")) {
+            m_yoffset = arg.mid(8).toInt();
         }
     }
 
@@ -109,6 +116,32 @@ QEvdevMouseManager::~QEvdevMouseManager()
     m_mice.clear();
 }
 
+void QEvdevMouseManager::handleMouseEvent(int x, int y, Qt::MouseButtons buttons)
+{
+    // update current absolute coordinates
+    m_x += x;
+    m_y += y;
+
+    // clamp to screen geometry
+    QRect g = QGuiApplication::primaryScreen()->virtualGeometry();
+    if (m_x + m_xoffset < g.left())
+        m_x = g.left() - m_xoffset;
+    else if (m_x + m_xoffset > g.right())
+        m_x = g.right() - m_xoffset;
+
+    if (m_y + m_yoffset < g.top())
+        m_y = g.top() - m_yoffset;
+    else if (m_y + m_yoffset > g.bottom())
+        m_y = g.bottom() - m_yoffset;
+
+    QPoint pos(m_x + m_xoffset, m_y + m_yoffset);
+    QWindowSystemInterface::handleMouseEvent(0, pos, pos, buttons);
+
+#ifdef QT_QPA_MOUSEMANAGER_DEBUG
+    qDebug("mouse event %d %d %d", pos.x(), pos.y(), int(buttons));
+#endif
+}
+
 void QEvdevMouseManager::addMouse(const QString &deviceNode)
 {
 #ifdef QT_QPA_MOUSEMANAGER_DEBUG
@@ -124,10 +157,12 @@ void QEvdevMouseManager::addMouse(const QString &deviceNode)
 
     QEvdevMouseHandler *handler;
     handler = QEvdevMouseHandler::createLinuxInputMouseHandler("EvdevMouse", specification);
-    if (handler)
+    if (handler) {
+        connect(handler, SIGNAL(handleMouseEvent(int, int, Qt::MouseButtons)), this, SLOT(handleMouseEvent(int, int, Qt::MouseButtons)));
         m_mice.insert(deviceNode, handler);
-    else
+    } else {
         qWarning("Failed to open mouse");
+    }
 }
 
 void QEvdevMouseManager::removeMouse(const QString &deviceNode)

src/plugins/generic/evdevmouse/qevdevmousemanager.h

@@ -63,6 +63,9 @@ public:
     explicit QEvdevMouseManager(const QString &key, const QString &specification);
     ~QEvdevMouseManager();
 
+public slots:
+    void handleMouseEvent(int x, int y, Qt::MouseButtons buttons);
+
 private slots:
     void addMouse(const QString &deviceNode = QString());
     void removeMouse(const QString &deviceNode);
@@ -73,6 +76,10 @@ private:
 #ifndef QT_NO_LIBUDEV
     QUDeviceHelper *m_udeviceHelper;
 #endif // QT_NO_LIBUDEV
+    int m_x;
+    int m_y;
+    int m_xoffset;
+    int m_yoffset;
 };
 
 QT_END_HEADER