Unify input device hotplugging support for embedded

On embedded the mouse cursor will now appear and reappear regardless of
how the input handling code is loaded (via a generic plugin or compiled-in
to the platform plugin).

Instead of passing around QDeviceDiscovery instances that only works
when compiling-in the code into the platform plugin, introduce a new
internal central QInputDeviceManager. The single instance of this
provides a place to store any future input device related signals and
properties.

Also introduce mouse hotplugging support to linuxfb.

[ChangeLog][QtGui] The mouse cursor on Embedded Linux is now handling
hotplugging correctly with eglfs and linuxfb regardless of how the input
handling code is loaded (via a generic plugin or built in to the platform
plugin).

Change-Id: I147c1b04a193baf216598015264f2c06e1b20f84
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

3 files changed, 15 insertions, 40 deletions

diff --git a/src/platformsupport/eglconvenience/qeglplatformcursor.cpp b/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
index cf41bd2f1b..b07f8cd470 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformcursor.cpp
@@ -39,7 +39,7 @@
 #include <QtCore/QJsonObject>
 #include <QtDebug>
 
-#include <QtPlatformSupport/private/qdevicediscovery_p.h>
+#include <QtGui/private/qguiapplication_p.h>
 
 #include "qeglplatformcursor_p.h"
 #include "qeglplatformintegration_p.h"
@@ -79,6 +79,11 @@ QEGLPlatformCursor::QEGLPlatformCursor(QPlatformScreen *screen)
     QCursor cursor(Qt::ArrowCursor);
     setCurrentCursor(&cursor);
 #endif
+
+    m_deviceListener = new QEGLPlatformCursorDeviceListener(this);
+    connect(QGuiApplicationPrivate::inputDeviceManager(), &QInputDeviceManager::deviceListChanged,
+            m_deviceListener, &QEGLPlatformCursorDeviceListener::onDeviceListChanged);
+    updateMouseStatus();
 }
 
 QEGLPlatformCursor::~QEGLPlatformCursor()
@@ -87,42 +92,20 @@ QEGLPlatformCursor::~QEGLPlatformCursor()
     delete m_deviceListener;
 }
 
-void QEGLPlatformCursor::setMouseDeviceDiscovery(QDeviceDiscovery *dd)
-{
-    if (m_visible && dd) {
-        m_deviceListener = new QEGLPlatformCursorDeviceListener(dd, this);
-        updateMouseStatus();
-    }
-}
-
 void QEGLPlatformCursor::updateMouseStatus()
 {
     m_visible = m_deviceListener->hasMouse();
 }
 
-QEGLPlatformCursorDeviceListener::QEGLPlatformCursorDeviceListener(QDeviceDiscovery *dd, QEGLPlatformCursor *cursor)
-    : m_cursor(cursor)
-{
-    m_mouseCount = dd->scanConnectedDevices().count();
-    connect(dd, SIGNAL(deviceDetected(QString)), SLOT(onDeviceAdded()));
-    connect(dd, SIGNAL(deviceRemoved(QString)), SLOT(onDeviceRemoved()));
-}
-
 bool QEGLPlatformCursorDeviceListener::hasMouse() const
 {
-    return m_mouseCount > 0;
-}
-
-void QEGLPlatformCursorDeviceListener::onDeviceAdded()
-{
-    ++m_mouseCount;
-    m_cursor->updateMouseStatus();
+    return QGuiApplicationPrivate::inputDeviceManager()->deviceCount(QInputDeviceManager::DeviceTypePointer) > 0;
 }
 
-void QEGLPlatformCursorDeviceListener::onDeviceRemoved()
+void QEGLPlatformCursorDeviceListener::onDeviceListChanged(QInputDeviceManager::DeviceType type)
 {
-    --m_mouseCount;
-    m_cursor->updateMouseStatus();
+    if (type == QInputDeviceManager::DeviceTypePointer)
+        m_cursor->updateMouseStatus();
 }
 
 void QEGLPlatformCursor::resetResources()
diff --git a/src/platformsupport/eglconvenience/qeglplatformcursor_p.h b/src/platformsupport/eglconvenience/qeglplatformcursor_p.h
index bf2aeef378..8d111e26ed 100644
--- a/src/platformsupport/eglconvenience/qeglplatformcursor_p.h
+++ b/src/platformsupport/eglconvenience/qeglplatformcursor_p.h
@@ -48,11 +48,11 @@
 #include <qpa/qplatformcursor.h>
 #include <qpa/qplatformscreen.h>
 #include <QtGui/QOpenGLFunctions>
+#include <QtGui/private/qinputdevicemanager_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class QOpenGLShaderProgram;
-class QDeviceDiscovery;
 class QEGLPlatformCursor;
 
 class QEGLPlatformCursorDeviceListener : public QObject
@@ -60,16 +60,14 @@ class QEGLPlatformCursorDeviceListener : public QObject
     Q_OBJECT
 
 public:
-    QEGLPlatformCursorDeviceListener(QDeviceDiscovery *dd, QEGLPlatformCursor *cursor);
+    QEGLPlatformCursorDeviceListener(QEGLPlatformCursor *cursor) : m_cursor(cursor) { }
     bool hasMouse() const;
 
-private slots:
-    void onDeviceAdded();
-    void onDeviceRemoved();
+public slots:
+    void onDeviceListChanged(QInputDeviceManager::DeviceType type);
 
 private:
     QEGLPlatformCursor *m_cursor;
-    int m_mouseCount;
 };
 
 class QEGLPlatformCursorUpdater : public QObject
@@ -108,7 +106,6 @@ public:
     void paintOnScreen();
     void resetResources();
 
-    void setMouseDeviceDiscovery(QDeviceDiscovery *dd);
     void updateMouseStatus();
 
 private:
diff --git a/src/platformsupport/eglconvenience/qeglplatformintegration.cpp b/src/platformsupport/eglconvenience/qeglplatformintegration.cpp
index e2a215d35f..ef794f0e1b 100644
--- a/src/platformsupport/eglconvenience/qeglplatformintegration.cpp
+++ b/src/platformsupport/eglconvenience/qeglplatformintegration.cpp
@@ -352,12 +352,7 @@ void QEGLPlatformIntegration::createInputHandlers()
 {
 #if !defined(QT_NO_EVDEV) && (!defined(Q_OS_ANDROID) || defined(Q_OS_ANDROID_NO_SDK))
     m_kbdMgr = new QEvdevKeyboardManager(QLatin1String("EvdevKeyboard"), QString() /* spec */, this);
-    QEvdevMouseManager *mouseMgr = new QEvdevMouseManager(QLatin1String("EvdevMouse"), QString() /* spec */, this);
-    Q_FOREACH (QScreen *screen, QGuiApplication::screens()) {
-        QEGLPlatformCursor *cursor = qobject_cast<QEGLPlatformCursor *>(screen->handle()->cursor());
-        if (cursor)
-            cursor->setMouseDeviceDiscovery(mouseMgr->deviceDiscovery());
-    }
+    new QEvdevMouseManager(QLatin1String("EvdevMouse"), QString() /* spec */, this);
 #ifndef QT_NO_TSLIB
     const bool useTslib = qEnvironmentVariableIntValue("QT_QPA_EGLFS_TSLIB");
     if (useTslib)