eglfs: Support virtual desktops in the OpenGL cursor

The GBM-based hardware cursor already has this. Let's implement it
in the commonly used OpenGL cursor too. The main user will be the
EGLDevice backend which does not currently have a hardware cursor
but supports multiple screens.

This also means QEglFSCursor must be capable of operating on different
contexts (and what's more, non-sharing contexts).

Task-number: QTBUG-55161
Change-Id: Ie23bba1e6aab34b04d689f26a84c19a2bde518da
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

6 files changed, 78 insertions, 3 deletions

diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
index 743f714cf0..f45b947fa6 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.cpp
@@ -40,11 +40,15 @@
 #include "qeglfskmsegldevice.h"
 #include "qeglfskmsegldevicescreen.h"
 #include "qeglfskmsegldeviceintegration.h"
+#include "private/qeglfscursor_p.h"
 
 #include <QtCore/private/qcore_unix_p.h>
 
+QT_BEGIN_NAMESPACE
+
 QEglFSKmsEglDevice::QEglFSKmsEglDevice(QEglFSKmsIntegration *integration, const QString &path)
-    : QEglFSKmsDevice(integration, path)
+    : QEglFSKmsDevice(integration, path),
+      m_globalCursor(nullptr)
 {
 }
 
@@ -52,6 +56,8 @@ bool QEglFSKmsEglDevice::open()
 {
     Q_ASSERT(fd() == -1);
 
+    qCDebug(qLcEglfsKmsDebug, "Opening DRM device %s", qPrintable(devicePath()));
+
     int fd = drmOpen(devicePath().toLocal8Bit().constData(), Q_NULLPTR);
     if (Q_UNLIKELY(fd < 0))
         qFatal("Could not open DRM device");
@@ -63,6 +69,8 @@ bool QEglFSKmsEglDevice::open()
 
 void QEglFSKmsEglDevice::close()
 {
+    qCDebug(qLcEglfsKmsDebug, "Closing DRM device");
+
     if (qt_safe_close(fd()) == -1)
         qErrnoWarning("Could not close DRM device");
 
@@ -74,7 +82,26 @@ EGLNativeDisplayType QEglFSKmsEglDevice::nativeDisplay() const
     return static_cast<QEglFSKmsEglDeviceIntegration *>(m_integration)->eglDevice();
 }
 
-QEglFSKmsScreen *QEglFSKmsEglDevice::createScreen(QEglFSKmsIntegration *integration, QEglFSKmsDevice *device, QEglFSKmsOutput output, QPoint position)
+QEglFSKmsScreen *QEglFSKmsEglDevice::createScreen(QEglFSKmsIntegration *integration, QEglFSKmsDevice *device,
+                                                  QEglFSKmsOutput output, QPoint position)
 {
-    return new QEglFSKmsEglDeviceScreen(integration, device, output, position);
+    QEglFSKmsScreen *screen = new QEglFSKmsEglDeviceScreen(integration, device, output, position);
+
+    if (!m_globalCursor && !integration->separateScreens()) {
+        qCDebug(qLcEglfsKmsDebug, "Creating new global mouse cursor");
+        m_globalCursor = new QEglFSCursor(screen);
+    }
+
+    return screen;
 }
+
+void QEglFSKmsEglDevice::destroyGlobalCursor()
+{
+    if (m_globalCursor) {
+        qCDebug(qLcEglfsKmsDebug, "Destroying global mouse cursor");
+        delete m_globalCursor;
+        m_globalCursor = nullptr;
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.h
index b1c98f3fe6..a27112fb4f 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevice.h
@@ -42,6 +42,10 @@
 
 #include <qeglfskmsdevice.h>
 
+QT_BEGIN_NAMESPACE
+
+class QPlatformCursor;
+
 class QEglFSKmsEglDevice: public QEglFSKmsDevice
 {
 public:
@@ -56,6 +60,14 @@ public:
                                           QEglFSKmsDevice *device,
                                           QEglFSKmsOutput output,
                                           QPoint position) Q_DECL_OVERRIDE;
+
+    QPlatformCursor *globalCursor() { return m_globalCursor; }
+    void destroyGlobalCursor();
+
+private:
+    QPlatformCursor *m_globalCursor;
 };
 
+QT_END_NAMESPACE
+
 #endif // QEGLFSKMSEGLDEVICE_H
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
index cbf7cfe7d0..0120c0726d 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
@@ -41,6 +41,7 @@
 #include "qeglfskmsegldeviceintegration.h"
 #include <QtPlatformSupport/private/qeglconvenience_p.h>
 #include "private/qeglfswindow_p.h"
+#include "private/qeglfscursor_p.h"
 #include "qeglfskmsegldevice.h"
 #include "qeglfskmsscreen.h"
 #include <QLoggingCategory>
@@ -258,4 +259,9 @@ bool QEglFSKmsEglDeviceIntegration::query_egl_device()
     return true;
 }
 
+QPlatformCursor *QEglFSKmsEglDeviceIntegration::createCursor(QPlatformScreen *screen) const
+{
+    return separateScreens() ? new QEglFSCursor(screen) : nullptr;
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.h
index af6b3f81ce..375c388548 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.h
@@ -65,6 +65,7 @@ public:
 
 protected:
     QEglFSKmsDevice *createDevice(const QString &devicePath) Q_DECL_OVERRIDE;
+    QPlatformCursor *createCursor(QPlatformScreen *screen) const Q_DECL_OVERRIDE;
 
 private:
     bool setup_kms();
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
index da1b577801..b0deabe834 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
@@ -39,12 +39,32 @@
 
 #include "qeglfskmsegldevicescreen.h"
 #include "qeglfskmsegldevice.h"
+#include <QGuiApplication>
+
+QT_BEGIN_NAMESPACE
 
 QEglFSKmsEglDeviceScreen::QEglFSKmsEglDeviceScreen(QEglFSKmsIntegration *integration, QEglFSKmsDevice *device, QEglFSKmsOutput output, QPoint position)
     : QEglFSKmsScreen(integration, device, output, position)
 {
 }
 
+QEglFSKmsEglDeviceScreen::~QEglFSKmsEglDeviceScreen()
+{
+    const int remainingScreenCount = qGuiApp->screens().count();
+    qCDebug(qLcEglfsKmsDebug, "Screen dtor. Remaining screens: %d", remainingScreenCount);
+    if (!remainingScreenCount && !m_integration->separateScreens())
+        static_cast<QEglFSKmsEglDevice *>(device())->destroyGlobalCursor();
+}
+
+QPlatformCursor *QEglFSKmsEglDeviceScreen::cursor() const
+{
+    // The base class creates a cursor via integration->createCursor()
+    // in its ctor. With separateScreens just use that. Otherwise
+    // there's a virtual desktop and the device has a global cursor
+    // and the base class has no dedicated cursor at all.
+    return m_integration->separateScreens() ? QEglFSScreen::cursor() : static_cast<QEglFSKmsEglDevice *>(device())->globalCursor();
+}
+
 void QEglFSKmsEglDeviceScreen::waitForFlip()
 {
     if (!output().mode_set) {
@@ -76,3 +96,5 @@ void QEglFSKmsEglDeviceScreen::waitForFlip()
     }
 
 }
+
+QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
index 0cd46e9f9d..7fceae4978 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
@@ -42,6 +42,8 @@
 
 #include <qeglfskmsscreen.h>
 
+QT_BEGIN_NAMESPACE
+
 class QEglFSKmsEglDeviceScreen : public QEglFSKmsScreen
 {
 public:
@@ -49,8 +51,13 @@ public:
                              QEglFSKmsDevice *device,
                              QEglFSKmsOutput output,
                              QPoint position);
+    ~QEglFSKmsEglDeviceScreen();
+
+    QPlatformCursor *cursor() const Q_DECL_OVERRIDE;
 
     void waitForFlip() Q_DECL_OVERRIDE;
 };
 
+QT_END_NAMESPACE
+
 #endif // QEGLFSKMSEGLDEVICESCREEN_H