QCursor: Associate cursor with screen.

- Introduce cursor() accessor to QPlatformScreen.
- Remove screen member of QPlatformCursor (a
  cursor can be shared by multiple screens
  of a virtual desktop).
- Add QCursor::pos()/ QCursor::setPos() taking
  a QScreen-parameter, use primaryScreen() for
  old overloads.  QCursor::pos() can then query
  the platform cursor for the position and return
  the position even if the mouse position is outside
  the windows owned by the Qt application.
- Fix tests

Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

Task-number: QTBUG-22457
Task-number: QTBUG-22565
Task-number: QTBUG-20753
Change-Id: Ia69f37343f95772e934eab1cd806bd54cbdbbe51
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

8 files changed, 103 insertions, 47 deletions

diff --git a/src/gui/kernel/qcursor.cpp b/src/gui/kernel/qcursor.cpp
index f16e5c85de..95b2b4a28e 100644
--- a/src/gui/kernel/qcursor.cpp
+++ b/src/gui/kernel/qcursor.cpp
@@ -185,10 +185,10 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn QPoint QCursor::pos()
+    \fn QPoint QCursor::pos(const QScreen *screen)
 
-    Returns the position of the cursor (hot spot) in global screen
-    coordinates.
+    Returns the position of the cursor (hot spot) of the \a screen
+    in global screen coordinates.
 
     You can call QWidget::mapFromGlobal() to translate it to widget
     coordinates.
@@ -197,10 +197,23 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn void QCursor::setPos(int x, int y)
+    \fn QPoint QCursor::pos()
+
+    Returns the position of the cursor (hot spot) of
+    the primary screen in global screen coordinates.
+
+    You can call QWidget::mapFromGlobal() to translate it to widget
+    coordinates.
+
+    \sa setPos(), QWidget::mapFromGlobal(), QWidget::mapToGlobal(), QGuiApplication::primaryScreen()
+*/
 
-    Moves the cursor (hot spot) to the global screen position (\a x,
-    \a y).
+
+/*!
+    \fn void QCursor::setPos(QScreen *screen, int x, int y)
+
+    Moves the cursor (hot spot) of the \a screen to the global
+    screen position (\a x, \a y).
 
     You can call QWidget::mapToGlobal() to translate widget
     coordinates to global screen coordinates.
@@ -209,6 +222,18 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn void QCursor::setPos(int x, int y)
+
+    Moves the cursor (hot spot) of the primary screen
+    to the global screen position (\a x, \a y).
+
+    You can call QWidget::mapToGlobal() to translate widget
+    coordinates to global screen coordinates.
+
+    \sa pos(), QWidget::mapFromGlobal(), QWidget::mapToGlobal(), QGuiApplication::primaryScreen()
+*/
+
+/*!
     \fn void QCursor::setPos (const QPoint &p)
 
     \overload
@@ -217,6 +242,15 @@ QT_BEGIN_NAMESPACE
     \a p.
 */
 
+/*!
+    \fn void QCursor::setPos (QScreen *screen,const QPoint &p)
+
+    \overload
+
+    Moves the cursor (hot spot) to the global screen position of the
+    \a screen at point \a p.
+*/
+
 /*****************************************************************************
   QCursor stream functions
  *****************************************************************************/
diff --git a/src/gui/kernel/qcursor.h b/src/gui/kernel/qcursor.h
index 00b709b308..4820bcee9b 100644
--- a/src/gui/kernel/qcursor.h
+++ b/src/gui/kernel/qcursor.h
@@ -51,6 +51,7 @@ QT_BEGIN_NAMESPACE
 
 
 class QVariant;
+class QScreen;
 
 /*
   ### The fake cursor has to go first with old qdoc.
@@ -101,8 +102,11 @@ public:
     QPoint hotSpot() const;
 
     static QPoint pos();
+    static QPoint pos(const QScreen *screen);
     static void setPos(int x, int y);
+    static void setPos(QScreen *screen, int x, int y);
     inline static void setPos(const QPoint &p) { setPos(p.x(), p.y()); }
+    inline static void setPos(QScreen *screen, const QPoint &p) { setPos(screen, p.x(), p.y()); }
     
 #ifdef qdoc
     HCURSOR_or_HANDLE handle() const;
diff --git a/src/gui/kernel/qcursor_qpa.cpp b/src/gui/kernel/qcursor_qpa.cpp
index 7ba2e1c580..1c719c839e 100644
--- a/src/gui/kernel/qcursor_qpa.cpp
+++ b/src/gui/kernel/qcursor_qpa.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include <qcursor.h>
+#include <qscreen.h>
 #include <private/qcursor_p.h>
 #include <qplatformcursor_qpa.h>
 #include <private/qguiapplication_p.h>
@@ -110,27 +111,34 @@ void QCursorData::update()
 
 QPoint QCursor::pos()
 {
+    return QCursor::pos(QGuiApplication::primaryScreen());
+}
+
+QPoint QCursor::pos(const QScreen *screen)
+{
+    if (screen)
+        if (const QPlatformCursor *cursor = screen->handle()->cursor())
+            return cursor->pos();
     return QGuiApplicationPrivate::lastCursorPosition.toPoint();
 }
 
-void QCursor::setPos(int x, int y)
+void QCursor::setPos(QScreen *screen, int x, int y)
 {
-    QPoint target(x, y);
-
-    // Need to check, since some X servers generate null mouse move
-    // events, causing looping in applications which call setPos() on
-    // every mouse move event.
-    //
-    if (pos() == target)
-        return;
-
-    QList<QWeakPointer<QPlatformCursor> > cursors = QPlatformCursorPrivate::getInstances();
-    int cursorCount = cursors.count();
-    for (int i = 0; i < cursorCount; ++i) {
-        const QWeakPointer<QPlatformCursor> &cursor(cursors.at(i));
-        if (cursor)
-            cursor.data()->setPos(target);
+    if (screen) {
+        if (QPlatformCursor *cursor = screen->handle()->cursor()) {
+            const QPoint pos = QPoint(x, y);
+            // Need to check, since some X servers generate null mouse move
+            // events, causing looping in applications which call setPos() on
+            // every mouse move event.
+            if (pos != cursor->pos())
+                cursor->setPos(pos);
+        }
     }
 }
 
+void QCursor::setPos(int x, int y)
+{
+    QCursor::setPos(QGuiApplication::primaryScreen(), x, y);
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index f5aea654fc..42ce3745de 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -978,10 +978,9 @@ void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::Mo
         QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, buttons, e->modifiers);
         ev.setTimestamp(e->timestamp);
 #ifndef QT_NO_CURSOR
-        QList<QWeakPointer<QPlatformCursor> > cursors = QPlatformCursorPrivate::getInstances();
-        for (int i = 0; i < cursors.count(); ++i)
-            if (cursors.at(i))
-                cursors.at(i).data()->pointerEvent(ev);
+        if (const QScreen *screen = window->screen())
+            if (QPlatformCursor *cursor = screen->handle()->cursor())
+                cursor->pointerEvent(ev);
 #endif
         QGuiApplication::sendSpontaneousEvent(window, &ev);
         if (!e->synthetic && !ev.isAccepted() && qApp->testAttribute(Qt::AA_SynthesizeTouchForUnhandledMouseEvents)) {
@@ -1814,16 +1813,11 @@ void QGuiApplication::changeOverrideCursor(const QCursor &cursor)
 
 
 #ifndef QT_NO_CURSOR
-static void applyCursor(QWindow *w, const QCursor &c)
-{
-    QCursor cc = c;
-    QList<QWeakPointer<QPlatformCursor> > cursors = QPlatformCursorPrivate::getInstances();
-    int cursorCount = cursors.count();
-    for (int i = 0; i < cursorCount; ++i) {
-        const QWeakPointer<QPlatformCursor> &cursor(cursors.at(i));
-        if (cursor)
-            cursor.data()->changeCursor(&cc, w);
-    }
+static inline void applyCursor(QWindow *w, QCursor c)
+{
+    if (const QScreen *screen = w->screen())
+        if (QPlatformCursor *cursor = screen->handle()->cursor())
+            cursor->changeCursor(&c, w);
 }
 
 static inline void applyCursor(const QList<QWindow *> &l, const QCursor &c)
diff --git a/src/gui/kernel/qplatformcursor_qpa.cpp b/src/gui/kernel/qplatformcursor_qpa.cpp
index fd7bcdcf18..a4e998ddbc 100644
--- a/src/gui/kernel/qplatformcursor_qpa.cpp
+++ b/src/gui/kernel/qplatformcursor_qpa.cpp
@@ -43,13 +43,22 @@
 #include <QPainter>
 #include <QBitmap>
 #include <QGuiApplication>
+#include <QScreen>
+#include <QPlatformScreen>
 #include <private/qguiapplication_p.h>
 
 #include <QDebug>
 
 QT_BEGIN_NAMESPACE
 
-QList <QWeakPointer<QPlatformCursor> > QPlatformCursorPrivate::instances;
+QList<QPlatformCursor *> QPlatformCursorPrivate::getInstances()
+{
+    QList<QPlatformCursor *> result;
+    foreach (const QScreen *screen, QGuiApplicationPrivate::screen_list)
+        if (QPlatformCursor *cursor = screen->handle()->cursor())
+            result.push_back(cursor);
+    return result;
+}
 
 /*!
     \class QPlatformCursor
@@ -93,10 +102,8 @@ QList <QWeakPointer<QPlatformCursor> > QPlatformCursorPrivate::instances;
 
     Constructs a QPlatformCursor for the given \a screen.
 */
-QPlatformCursor::QPlatformCursor(QPlatformScreen *scr )
-        : screen(scr)
+QPlatformCursor::QPlatformCursor()
 {
-    QPlatformCursorPrivate::instances.append(this);
 }
 
 QPoint QPlatformCursor::pos() const
diff --git a/src/gui/kernel/qplatformcursor_qpa.h b/src/gui/kernel/qplatformcursor_qpa.h
index a8cbb282fa..e29cf87d03 100644
--- a/src/gui/kernel/qplatformcursor_qpa.h
+++ b/src/gui/kernel/qplatformcursor_qpa.h
@@ -74,13 +74,12 @@ class QPlatformCursor;
 
 class Q_GUI_EXPORT QPlatformCursorPrivate {
 public:
-    static QList<QWeakPointer<QPlatformCursor> > getInstances() { return instances; }
-    static QList<QWeakPointer<QPlatformCursor> > instances;
+    static QList<QPlatformCursor *> getInstances();
 };
 
 class Q_GUI_EXPORT QPlatformCursor : public QObject {
 public:
-    QPlatformCursor(QPlatformScreen *);
+    QPlatformCursor();
 
     // input methods
     virtual void pointerEvent(const QMouseEvent & event) { Q_UNUSED(event); }
@@ -88,11 +87,8 @@ public:
     virtual QPoint pos() const;
     virtual void setPos(const QPoint &pos);
 
-protected:
-    QPlatformScreen* screen;  // Where to request an update
-
 private:
-    Q_DECLARE_PRIVATE(QPlatformCursor);
+    Q_DECLARE_PRIVATE(QPlatformCursor)
     friend void qt_qpa_set_cursor(QWidget * w, bool force);
     friend class QApplicationPrivate;
 };
diff --git a/src/gui/kernel/qplatformscreen_qpa.cpp b/src/gui/kernel/qplatformscreen_qpa.cpp
index c832d853f4..022f198073 100644
--- a/src/gui/kernel/qplatformscreen_qpa.cpp
+++ b/src/gui/kernel/qplatformscreen_qpa.cpp
@@ -41,6 +41,7 @@
 
 #include "qplatformscreen_qpa.h"
 #include <QtGui/qguiapplication.h>
+#include <QtGui/qplatformcursor_qpa.h>
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtGui/private/qplatformscreen_qpa_p.h>
 #include <QtGui/qplatformintegration_qpa.h>
@@ -250,4 +251,14 @@ QPlatformScreenPageFlipper *QPlatformScreen::pageFlipper() const
     return 0;
 }
 
+/*!
+    Reimplement this function in subclass to return the cursor of the screen.
+
+    The default implementation returns 0.
+*/
+QPlatformCursor *QPlatformScreen::cursor() const
+{
+    return 0;
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformscreen_qpa.h b/src/gui/kernel/qplatformscreen_qpa.h
index 7d74698074..b6eb91f9b2 100644
--- a/src/gui/kernel/qplatformscreen_qpa.h
+++ b/src/gui/kernel/qplatformscreen_qpa.h
@@ -63,6 +63,7 @@ class QPlatformBackingStore;
 class QPlatformOpenGLContext;
 class QPlatformScreenPrivate;
 class QPlatformWindow;
+class QPlatformCursor;
 class QPlatformScreenPageFlipper;
 class QScreen;
 class QSurfaceFormat;
@@ -103,6 +104,7 @@ public:
     virtual QString name() const { return QString(); }
 
     virtual QPlatformScreenPageFlipper *pageFlipper() const;
+    virtual QPlatformCursor *cursor() const;
 
 protected:
     QScopedPointer<QPlatformScreenPrivate> d_ptr;