Multiple screen support for Symbian in QDeskopWidget.

When using TV-out, the TV display can be used as an independent screen.
By default the content shown there is a clone of the device screen,
however from now on parenting a widget to QDesktopWidget::screen(1)
and calling show() will turn off cloning and have the widget shown
instead. screenCount() and the screenCountChanged signal can be used
to detect the availability of the secondary display, just like on other
platforms.

Task-number: QT-830

Reviewed-by: Sami Merila
Reviewed-by: Jani Hautakangas

1 files changed, 132 insertions, 28 deletions

diff --git a/src/gui/kernel/qdesktopwidget_s60.cpp b/src/gui/kernel/qdesktopwidget_s60.cpp
index 3653ae2..9d48b64 100644
--- a/src/gui/kernel/qdesktopwidget_s60.cpp
+++ b/src/gui/kernel/qdesktopwidget_s60.cpp
@@ -44,36 +44,67 @@
 #include "qwidget_p.h"
 #include "qt_s60_p.h"
 #include <w32std.h>
-
-#include "hal.h"
-#include "hal_data.h"
+#if defined(Q_SYMBIAN_SUPPORTS_MULTIPLE_SCREENS)
+#include <graphics/displaycontrol.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
-class QDesktopWidgetPrivate : public QWidgetPrivate
+extern int qt_symbian_create_desktop_on_screen;
+
+class QSingleDesktopWidget : public QWidget
+{
+public:
+    QSingleDesktopWidget();
+    ~QSingleDesktopWidget();
+};
+
+QSingleDesktopWidget::QSingleDesktopWidget()
+    : QWidget(0, Qt::Desktop)
+{
+}
+
+QSingleDesktopWidget::~QSingleDesktopWidget()
 {
+    const QObjectList &childList = children();
+    for (int i = childList.size(); i > 0 ;) {
+        --i;
+        childList.at(i)->setParent(0);
+    }
+}
 
+class QDesktopWidgetPrivate : public QWidgetPrivate
+{
 public:
     QDesktopWidgetPrivate();
     ~QDesktopWidgetPrivate();
-
     static void init(QDesktopWidget *that);
     static void cleanup();
+    static void init_sys();
 
     static int screenCount;
     static int primaryScreen;
 
     static QVector<QRect> *rects;
     static QVector<QRect> *workrects;
+    static QVector<QWidget *> *screens;
 
     static int refcount;
+
+#if defined(Q_SYMBIAN_SUPPORTS_MULTIPLE_SCREENS)
+    static MDisplayControl *displayControl;
+#endif
 };
 
 int QDesktopWidgetPrivate::screenCount = 1;
 int QDesktopWidgetPrivate::primaryScreen = 0;
 QVector<QRect> *QDesktopWidgetPrivate::rects = 0;
 QVector<QRect> *QDesktopWidgetPrivate::workrects = 0;
+QVector<QWidget *> *QDesktopWidgetPrivate::screens = 0;
 int QDesktopWidgetPrivate::refcount = 0;
+#if defined(Q_SYMBIAN_SUPPORTS_MULTIPLE_SCREENS)
+MDisplayControl *QDesktopWidgetPrivate::displayControl = 0;
+#endif
 
 QDesktopWidgetPrivate::QDesktopWidgetPrivate()
 {
@@ -88,25 +119,53 @@ QDesktopWidgetPrivate::~QDesktopWidgetPrivate()
 
 void QDesktopWidgetPrivate::init(QDesktopWidget *that)
 {
-    Q_UNUSED(that);
-//    int screenCount=0;
-
-    // ### TODO: Implement proper multi-display support
-	QDesktopWidgetPrivate::screenCount = 1;
-//    if (HAL::Get(0, HALData::EDisplayNumberOfScreens, screenCount) == KErrNone)
-//        QDesktopWidgetPrivate::screenCount = screenCount;
-//    else
-//        QDesktopWidgetPrivate::screenCount = 0;
+    // Note that on S^3 devices the screen count retrieved via RWsSession
+    // will always be 2 but the width and height for screen number 1 will
+    // be 0 as long as TV-out is not connected.
+    //
+    // On the other hand a valid size for screen 1 will be reported even
+    // after the cable is disconnected. In order to overcome this, we use
+    // MDisplayControl::NumberOfResolutions() to check if the display is
+    // valid or not.
+
+    screenCount = S60->screenCount();
+    if (displayControl) {
+        if (displayControl->NumberOfResolutions() < 1)
+            screenCount = 1;
+    }
+    if (screenCount < 1) {
+        qWarning("No screen available");
+        screenCount = 1;
+    }
 
     rects = new QVector<QRect>();
     workrects = new QVector<QRect>();
-
-    rects->resize(QDesktopWidgetPrivate::screenCount);
-    workrects->resize(QDesktopWidgetPrivate::screenCount);
-
-    (*rects)[0].setRect(0, 0, S60->screenWidthInPixels, S60->screenHeightInPixels);
-    QRect wr = qt_TRect2QRect(static_cast<CEikAppUi*>(S60->appUi())->ClientRect());
-    (*workrects)[0].setRect(wr.x(), wr.y(), wr.width(), wr.height());
+    screens = new QVector<QWidget *>();
+
+    rects->resize(screenCount);
+    workrects->resize(screenCount);
+    screens->resize(screenCount);
+
+    for (int i = 0; i < screenCount; ++i) {
+        // All screens will share the same geometry as there is no true virtual desktop
+        // or pointer event support for multiple screens on Symbian.
+        QRect r(0, 0,
+            S60->screenWidthInPixelsForScreen[i], S60->screenHeightInPixelsForScreen[i]);
+        // Stop here if empty and ignore this screen.
+        if (r.isEmpty()) {
+            screenCount = i;
+            break;
+        }
+        (*rects)[i] = r;
+        QRect wr;
+        if (i == 0)
+            wr = qt_TRect2QRect(static_cast<CEikAppUi*>(S60->appUi())->ClientRect());
+        else
+            wr = rects->at(i);
+        (*workrects)[i].setRect(wr.x(), wr.y(), wr.width(), wr.height());
+        (*screens)[i] = 0;
+    }
+    (*screens)[0] = that;
 }
 
 void QDesktopWidgetPrivate::cleanup()
@@ -115,6 +174,27 @@ void QDesktopWidgetPrivate::cleanup()
     rects = 0;
     delete workrects;
     workrects = 0;
+    if (screens) {
+        // First item is the QDesktopWidget so skip it.
+        for (int i = 1; i < screens->count(); ++i)
+            delete screens->at(i);
+    }
+    delete screens;
+    screens = 0;
+}
+
+void QDesktopWidgetPrivate::init_sys()
+{
+#if defined(Q_SYMBIAN_SUPPORTS_MULTIPLE_SCREENS)
+    CWsScreenDevice *dev = S60->screenDevice(1);
+    if (dev) {
+        displayControl = static_cast<MDisplayControl *>(
+                    dev->GetInterface(MDisplayControl::ETypeId));
+        if (displayControl) {
+            displayControl->EnableDisplayChangeEvents(ETrue);
+        }
+    }
+#endif
 }
 
 
@@ -122,6 +202,7 @@ QDesktopWidget::QDesktopWidget()
     : QWidget(*new QDesktopWidgetPrivate, 0, Qt::Desktop)
 {
     setObjectName(QLatin1String("desktop"));
+    QDesktopWidgetPrivate::init_sys();
     QDesktopWidgetPrivate::init(this);
 }
 
@@ -131,7 +212,7 @@ QDesktopWidget::~QDesktopWidget()
 
 bool QDesktopWidget::isVirtualDesktop() const
 {
-    return true;
+    return false;
 }
 
 int QDesktopWidget::primaryScreen() const
@@ -145,9 +226,23 @@ int QDesktopWidget::numScreens() const
     return QDesktopWidgetPrivate::screenCount;
 }
 
-QWidget *QDesktopWidget::screen(int /* screen */)
+static inline QWidget *newSingleDesktopWidget(int screen)
 {
-    return this;
+    qt_symbian_create_desktop_on_screen = screen;
+    QWidget *w = new QSingleDesktopWidget;
+    qt_symbian_create_desktop_on_screen = -1;
+    return w;
+}
+
+QWidget *QDesktopWidget::screen(int screen)
+{
+    Q_D(QDesktopWidget);
+    if (screen < 0 || screen >= d->screenCount)
+        screen = d->primaryScreen;
+    if (!d->screens->at(screen)
+        || d->screens->at(screen)->windowType() != Qt::Desktop)
+        (*d->screens)[screen] = newSingleDesktopWidget(screen);
+    return (*d->screens)[screen];
 }
 
 const QRect QDesktopWidget::availableGeometry(int screen) const
@@ -168,14 +263,19 @@ const QRect QDesktopWidget::screenGeometry(int screen) const
     return d->rects->at(screen);
 }
 
-int QDesktopWidget::screenNumber(const QWidget * /* widget */) const
+int QDesktopWidget::screenNumber(const QWidget *widget) const
 {
-    return QDesktopWidgetPrivate::primaryScreen;
+    Q_D(const QDesktopWidget);
+    return widget
+        ? S60->screenNumberForWidget(widget)
+        : d->primaryScreen;
 }
 
-int QDesktopWidget::screenNumber(const QPoint & /* point */) const
+int QDesktopWidget::screenNumber(const QPoint &point) const
 {
-    return QDesktopWidgetPrivate::primaryScreen;
+    Q_UNUSED(point);
+    Q_D(const QDesktopWidget);
+    return d->primaryScreen;
 }
 
 void QDesktopWidget::resizeEvent(QResizeEvent *)
@@ -203,6 +303,10 @@ void QDesktopWidget::resizeEvent(QResizeEvent *)
         if (oldrect != newrect)
             emit workAreaResized(j);
     }
+
+    if (oldscreencount != d->screenCount) {
+        emit screenCountChanged(d->screenCount);
+    }
 }
 
 QT_END_NAMESPACE