Add function QPlatformScreen::platformScreenForWidget

This so there is some logical connection between what screen a widget
belongs to

6 files changed, 36 insertions, 39 deletions

diff --git a/src/gui/kernel/qdesktopwidget_qpa_p.h b/src/gui/kernel/qdesktopwidget_qpa_p.h
index 8bed09d5fd..47ccca2f14 100644
--- a/src/gui/kernel/qdesktopwidget_qpa_p.h
+++ b/src/gui/kernel/qdesktopwidget_qpa_p.h
@@ -59,7 +59,13 @@
 class QDesktopScreenWidget : public QWidget {
     Q_OBJECT
 public:
-    QDesktopScreenWidget(int screenNumber = -1) { setWindowFlags(Qt::Desktop); setVisible(false); d_func()->screenNumber = screenNumber; }
+    QDesktopScreenWidget(int screenNumber = -1)
+    {
+        setWindowFlags(Qt::Desktop);
+        setVisible(false);
+        QTLWExtra *topData = d_func()->topData();
+        topData->screenIndex = screenNumber;
+    }
 };
 
 class QDesktopWidgetPrivate : public QWidgetPrivate {
diff --git a/src/gui/kernel/qplatformscreen_qpa.cpp b/src/gui/kernel/qplatformscreen_qpa.cpp
index 5e80ba8d06..118835ff99 100644
--- a/src/gui/kernel/qplatformscreen_qpa.cpp
+++ b/src/gui/kernel/qplatformscreen_qpa.cpp
@@ -41,7 +41,11 @@
 
 #include "qplatformscreen_qpa.h"
 #include <QtGui/qapplication.h>
+#include <QtGui/private/qapplication_p.h>
 #include <QtGui/qdesktopwidget.h>
+#include <QtGui/qplatformintegration_qpa.h>
+#include <QtGui/qwidget.h>
+#include <QtGui/private/qwidget_p.h>
 
 /*!
     Return the given top level widget for a given position.
@@ -77,6 +81,17 @@ QSize QPlatformScreen::physicalSize() const
     return QSize(width,height);
 }
 
+Q_GUI_EXPORT extern QWidgetPrivate *qt_widget_private(QWidget *widget);
+QPlatformScreen * QPlatformScreen::platformScreenForWidget(const QWidget *widget)
+{
+    QWidget *window = widget->window();
+    QWidgetPrivate *windowPrivate = qt_widget_private(window);
+    QTLWExtra * topData = windowPrivate->topData();
+    QPlatformIntegration *integration =
+            QApplicationPrivate::platformIntegration();
+    return integration->screens()[topData->screenIndex];
+}
+
 /*!
     \class QPlatformScreen
     \since 4.8
diff --git a/src/gui/kernel/qplatformscreen_qpa.h b/src/gui/kernel/qplatformscreen_qpa.h
index 908048950e..1f52764cac 100644
--- a/src/gui/kernel/qplatformscreen_qpa.h
+++ b/src/gui/kernel/qplatformscreen_qpa.h
@@ -73,6 +73,10 @@ public:
     //jl: should setDirty be removed.
     virtual void setDirty(const QRect &) {}
     virtual QWidget *topLevelAt(const QPoint &point) const;
+
+    //jl: should this function be in QPlatformIntegration
+    //jl: maybe screenForWidget is a better name?
+    static QPlatformScreen *platformScreenForWidget(const QWidget *widget);
 };
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 16f64fffbc..6a6a218d8d 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -303,8 +303,6 @@ QWidgetPrivate::QWidgetPrivate(int version)
       , hasAlienChildren(0)
       , window_event(0)
       , qd_hd(0)
-#elif defined (Q_WS_QPA)
-      , screenNumber(0)
 #endif
 {
     if (!qApp) {
@@ -1277,7 +1275,7 @@ void QWidgetPrivate::init(QWidget *parentWidget, Qt::WindowFlags f)
     }
 #elif defined(Q_WS_QPA)
     if (desktopWidget) {
-        int screen = desktopWidget->d_func()->screenNumber;
+        int screen = desktopWidget->d_func()->topData()->screenIndex;
         QPlatformIntegration *platform = QApplicationPrivate::platformIntegration();
         platform->moveToScreen(q, screen);
     }
@@ -1729,6 +1727,7 @@ void QWidgetPrivate::createTLExtra()
 #if defined(Q_WS_QPA)
         x->platformWindow = 0;
         x->platformWindowFormat = QPlatformWindowFormat::defaultFormat();
+        x->screenIndex = 0;
 #endif
     }
 }
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index 6b85391414..a0f0ec812c 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -233,6 +233,7 @@ struct QTLWExtra {
 #elif defined(Q_WS_QPA)
     QPlatformWindow *platformWindow;
     QPlatformWindowFormat platformWindowFormat;
+    quint32 screenIndex; // index in qplatformscreenlist
 #endif
 };
 
@@ -885,11 +886,9 @@ public:
     void updateCursor() const;
 #endif
     QScreen* getScreen() const;
-#elif defined(Q_WS_QPA)
+#elif defined(Q_WS_QPA) // <--------------------------------------------------------- QPA
     void setMaxWindowState_helper();
     void setFullScreenSize_helper();
-
-    int screenNumber; // screen the widget should be displayed on
 #ifndef QT_NO_CURSOR
     void updateCursor() const;
 #endif
diff --git a/src/gui/kernel/qwidget_qpa.cpp b/src/gui/kernel/qwidget_qpa.cpp
index 1279e0a856..24ab8f7999 100644
--- a/src/gui/kernel/qwidget_qpa.cpp
+++ b/src/gui/kernel/qwidget_qpa.cpp
@@ -53,7 +53,6 @@
 #include <QtGui/QPlatformCursor>
 
 QT_BEGIN_NAMESPACE
-static QPlatformScreen *qt_screenForWidget(const QWidget *w);
 
 void q_createNativeChildrenAndSetParent(QPlatformWindow *parentWindow, const QWidget *parentWidget)
 {
@@ -122,7 +121,7 @@ void QWidgetPrivate::create_sys(WId window, bool initializeWindow, bool destroyO
         }
     }
 
-    QApplicationPrivate::platformIntegration()->moveToScreen(q, screenNumber);
+    QApplicationPrivate::platformIntegration()->moveToScreen(q, topData()->screenIndex);
 //    qDebug() << "create_sys" << q << q->internalWinId();
 }
 
@@ -173,7 +172,7 @@ void QWidgetPrivate::setParent_sys(QWidget *newparent, Qt::WindowFlags f)
         // programmer specified desktop widget
 
         // get the desktop's screen number
-        targetScreen = newparent->d_func()->screenNumber;
+        targetScreen = newparent->window()->d_func()->topData()->screenIndex;
         newparent = 0;
     }
 
@@ -192,7 +191,7 @@ void QWidgetPrivate::setParent_sys(QWidget *newparent, Qt::WindowFlags f)
         f |= Qt::Window;
         if (targetScreen == -1) {
             if (parent)
-                targetScreen = qobject_cast<QWidget *>(parent)->d_func()->screenNumber;
+                targetScreen = q->parentWidget()->window()->d_func()->topData()->screenIndex;
         }
     }
 
@@ -228,7 +227,8 @@ void QWidgetPrivate::setParent_sys(QWidget *newparent, Qt::WindowFlags f)
 
     // move the window to the selected screen
     if (!newparent && targetScreen != -1) {
-        screenNumber = targetScreen;
+        if (maybeTopData())
+            maybeTopData()->screenIndex = targetScreen;
         // only if it is already created
         if (q->testAttribute(Qt::WA_WState_Created)) {
             QPlatformIntegration *platform = QApplicationPrivate::platformIntegration();
@@ -643,37 +643,11 @@ void QWidgetPrivate::scroll_sys(int dx, int dy, const QRect &r)
     scrollRect(r, dx, dy);
 }
 
-static QPlatformScreen *qt_screenForWidget(const QWidget *w)
-{
-    if (!w)
-        return 0;
-    QRect frame = w->frameGeometry();
-    if (!w->isWindow())
-        frame.moveTopLeft(w->mapToGlobal(QPoint(0, 0)));
-    const QPoint p = (frame.topLeft() + frame.bottomRight()) / 2;
-
-    QPlatformIntegration *pi = QApplicationPrivate::platformIntegration();
-    QList<QPlatformScreen *> screens = pi->screens();
-
-    for (int i = 0; i < screens.size(); ++i) {
-        if (screens[i]->geometry().contains(p))
-            return screens[i];
-    }
-
-    // Assume screen zero if we have it.
-    if (!screens.isEmpty())
-        return screens[0];
-    else
-        qWarning("qt_screenForWidget: no screens");
-
-    return 0;
-}
-
 int QWidget::metric(PaintDeviceMetric m) const
 {
     Q_D(const QWidget);
 
-    QPlatformScreen *screen = qt_screenForWidget(this);
+    QPlatformScreen *screen = QPlatformScreen::platformScreenForWidget(this);
     if (!screen) {
         if (m == PdmDpiX || m == PdmDpiY)
               return 72;