Implement QDesktopWidget::screenCountChanged signal on desktop platforms,

and add manual testcase.

Provide replacement "screenCount" for numScreens and document numScreens
as obsolete to be more consistent with other APIs.

6 files changed, 80 insertions, 47 deletions

diff --git a/src/gui/kernel/qapplication_x11.cpp b/src/gui/kernel/qapplication_x11.cpp
index cc41299..a07ccdd 100644
--- a/src/gui/kernel/qapplication_x11.cpp
+++ b/src/gui/kernel/qapplication_x11.cpp
@@ -3441,19 +3441,10 @@ int QApplication::x11ProcessEvent(XEvent* event)
         QSize oldSize(w->size());
         w->data->crect.setWidth(DisplayWidth(X11->display, scr));
         w->data->crect.setHeight(DisplayHeight(X11->display, scr));
-        QVarLengthArray<QRect> oldSizes(desktop->numScreens());
-        for (int i = 0; i < desktop->numScreens(); ++i)
-            oldSizes[i] = desktop->screenGeometry(i);
         QResizeEvent e(w->size(), oldSize);
         QApplication::sendEvent(w, &e);
-        for (int i = 0; i < qMin(oldSizes.count(), desktop->numScreens()); ++i) {
-            if (oldSizes[i] != desktop->screenGeometry(i))
-                emit desktop->resized(i);
-        }
-        for (int i = oldSizes.count(); i < desktop->numScreens(); ++i)
-            emit desktop->resized(i); // added
-        for (int i = desktop->numScreens(); i < oldSizes.count(); ++i)
-            emit desktop->resized(i); // removed
+        if (w != desktop)
+            QApplication::sendEvent(desktop, &e);
     }
 #endif // QT_NO_XRANDR
 
diff --git a/src/gui/kernel/qdesktopwidget.h b/src/gui/kernel/qdesktopwidget.h
index 470f10a..5ac953c 100644
--- a/src/gui/kernel/qdesktopwidget.h
+++ b/src/gui/kernel/qdesktopwidget.h
@@ -85,6 +85,7 @@ public:
 Q_SIGNALS:
     void resized(int);
     void workAreaResized(int);
+    void screenCountChanged(int);
 
 protected:
     void resizeEvent(QResizeEvent *e);
@@ -97,6 +98,9 @@ private:
     friend class QApplicationPrivate;
 };
 
+inline int QDesktopWidget::screenCount() const
+{ return numScreens(); }
+
 QT_END_NAMESPACE
 
 QT_END_HEADER
diff --git a/src/gui/kernel/qdesktopwidget_mac.mm b/src/gui/kernel/qdesktopwidget_mac.mm
index 2489fe4..7dd74da 100644
--- a/src/gui/kernel/qdesktopwidget_mac.mm
+++ b/src/gui/kernel/qdesktopwidget_mac.mm
@@ -97,15 +97,13 @@ QT_USE_NAMESPACE
 Q_GLOBAL_STATIC(QDesktopWidgetImplementation, qdesktopWidgetImplementation)
 
 QDesktopWidgetImplementation::QDesktopWidgetImplementation()
-    : appScreen(0), displays(0)
+    : appScreen(0)
 {
     onResize();
 }
 
 QDesktopWidgetImplementation::~QDesktopWidgetImplementation()
 {
-    if (displays)
-        [displays release];
 }
 
 QDesktopWidgetImplementation *QDesktopWidgetImplementation::instance()
@@ -118,13 +116,7 @@ QRect QDesktopWidgetImplementation::availableRect(int screenIndex) const
     if (screenIndex < 0 || screenIndex >= screenCount)
         screenIndex = appScreen;
 
-    NSRect r = [[displays objectAtIndex:screenIndex] visibleFrame];
-    NSRect primaryRect = [[displays objectAtIndex:0] frame];
-
-    const int flippedY = - r.origin.y +                // account for position offset and
-              primaryRect.size.height - r.size.height; // height difference.
-    return QRectF(r.origin.x, flippedY,
-            r.size.width, r.size.height).toRect();
+	return availableRects[screenIndex].toRect(); 
 }
 
 QRect QDesktopWidgetImplementation::screenRect(int screenIndex) const
@@ -132,22 +124,28 @@ QRect QDesktopWidgetImplementation::screenRect(int screenIndex) const
     if (screenIndex < 0 || screenIndex >= screenCount)
         screenIndex = appScreen;
 
-    NSRect r = [[displays objectAtIndex:screenIndex] frame];
-    NSRect primaryRect = [[displays objectAtIndex:0] frame];
-
-    const int flippedY = - r.origin.y +                // account for position offset and
-              primaryRect.size.height - r.size.height; // height difference.
-    return QRectF(r.origin.x, flippedY,
-            r.size.width, r.size.height).toRect();
+    return screenRects[screenIndex].toRect();
 }
 
 void QDesktopWidgetImplementation::onResize()
 {
-    if (displays)
-        [displays release];
-
-    displays = [[NSScreen screens] retain];
-    screenCount = [displays count];
+    QMacCocoaAutoReleasePool pool; 
+    NSArray *displays = [NSScreen screens]; 
+    screenCount = [displays count]; 
+ 
+    screenRects.clear(); 
+    availableRects.clear(); 
+    NSRect primaryRect = [[displays objectAtIndex:0] frame]; 
+    for (int i = 0; i<screenCount; i++) { 
+        NSRect r = [[displays objectAtIndex:i] frame]; 
+        const int flippedY = - r.origin.y +            // account for position offset and 
+              primaryRect.size.height - r.size.height; // height difference. 
+        screenRects.append(QRectF(r.origin.x, flippedY, 
+            r.size.width, r.size.height)); 
+        r = [[displays objectAtIndex:i] visibleFrame]; 
+        availableRects.append(QRectF(r.origin.x, flippedY, 
+                r.size.width, r.size.height)); 
+    } 
 }
 
 
@@ -195,7 +193,7 @@ const QRect QDesktopWidget::screenGeometry(int screen) const
 
 int QDesktopWidget::screenNumber(const QWidget *widget) const
 {
-   QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
+    QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
     if (!widget)
         return d->appScreen;
     QRect frame = widget->frameGeometry();
@@ -216,7 +214,7 @@ int QDesktopWidget::screenNumber(const QWidget *widget) const
 
 int QDesktopWidget::screenNumber(const QPoint &point) const
 {
-   QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
+    QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
     int closestScreen = -1;
     int shortestDistance = INT_MAX;
     for (int i = 0; i < d->screenCount; ++i) {
@@ -232,13 +230,25 @@ int QDesktopWidget::screenNumber(const QPoint &point) const
 
 void QDesktopWidget::resizeEvent(QResizeEvent *)
 {
-   QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
+    QDesktopWidgetImplementation *d = qdesktopWidgetImplementation();
+
+    const int oldScreenCount = d->screenCount;
+    const QVector<QRect> oldRects(d->screenRects);
+    const QVector<QRect> oldWorks(d->availableRects);
 
     d->onResize();
 
-    for (int i = 0; i < d->screenCount; ++i) {
-        emit resized(i);
+    for (int i = 0; i < qMin(oldScreenCount, d->screenCount); ++i) {
+        if (oldRects.at(i) != d->screenRects.at(i))
+            emit resized(i);
+    }
+    for (int i = 0; i < qMin(oldScreenCount, d->screenCount); ++i) {
+        if (oldWorks.at(i) != d->availableRects.at(i))
+            emit workAreaResized(i);
     }
+
+    if (oldscreencount != d->screenCount)
+        emit screenCountChanged(d->screenCount);
 }
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qdesktopwidget_mac_p.h b/src/gui/kernel/qdesktopwidget_mac_p.h
index 0fdc455..e9d5d9f 100644
--- a/src/gui/kernel/qdesktopwidget_mac_p.h
+++ b/src/gui/kernel/qdesktopwidget_mac_p.h
@@ -64,7 +64,8 @@ public:
     int appScreen;
     int screenCount;
 
-    NSArray *displays;
+    QVector<QRectF> availableRects; 
+    QVector<QRectF> screenRects; 
 
     QRect availableRect(int screenIndex) const;
     QRect screenRect(int screenIndex) const;
diff --git a/src/gui/kernel/qdesktopwidget_win.cpp b/src/gui/kernel/qdesktopwidget_win.cpp
index fb176b7..a89e08f 100644
--- a/src/gui/kernel/qdesktopwidget_win.cpp
+++ b/src/gui/kernel/qdesktopwidget_win.cpp
@@ -354,10 +354,8 @@ int QDesktopWidget::screenNumber(const QPoint &point) const
 void QDesktopWidget::resizeEvent(QResizeEvent *)
 {
     Q_D(QDesktopWidget);
-    QVector<QRect> oldrects;
-    oldrects = *d->rects;
-    QVector<QRect> oldworkrects;
-    oldworkrects = *d->workrects;
+    const QVector<QRect> oldrects(*d->rects);
+    const QVector<QRect> oldworkrects(*d->workrects);
     int oldscreencount = d->screenCount;
 
     QDesktopWidgetPrivate::cleanup();
@@ -368,18 +366,22 @@ void QDesktopWidget::resizeEvent(QResizeEvent *)
 #endif
 
     for (int i = 0; i < qMin(oldscreencount, d->screenCount); ++i) {
-        QRect oldrect = oldrects[i];
-        QRect newrect = d->rects->at(i);
+        const QRect oldrect = oldrects[i];
+        const QRect newrect = d->rects->at(i);
         if (oldrect != newrect)
             emit resized(i);
     }
 
     for (int j = 0; j < qMin(oldscreencount, d->screenCount); ++j) {
-        QRect oldrect = oldworkrects[j];
-        QRect newrect = d->workrects->at(j);
+        const QRect oldrect = oldworkrects[j];
+        const QRect newrect = d->workrects->at(j);
         if (oldrect != newrect)
             emit workAreaResized(j);
     }
+
+    if (oldscreencount != d->screenCount) {
+        emit screenCountChanged(d->screenCount);
+    }
 }
 
 #ifdef Q_CC_MSVC
diff --git a/src/gui/kernel/qdesktopwidget_x11.cpp b/src/gui/kernel/qdesktopwidget_x11.cpp
index 59d3239..1555fc0 100644
--- a/src/gui/kernel/qdesktopwidget_x11.cpp
+++ b/src/gui/kernel/qdesktopwidget_x11.cpp
@@ -372,7 +372,32 @@ int QDesktopWidget::screenNumber(const QPoint &point) const
 void QDesktopWidget::resizeEvent(QResizeEvent *event)
 {
     Q_D(QDesktopWidget);
+    int oldScreenCount = d->screenCount;
+    QVector<QRect> oldRects(oldScreenCount);
+    QVector<QRect> oldWorks(oldScreenCount);
+    for (int i = 0; i < oldScreenCount; ++i) {
+        oldRects[i] = d->rects[i];
+        oldWorks[i] = d->workareas[i];
+    }
+
     d->init();
+
+    for (int i = 0; i < qMin(oldScreenCount, d->screenCount); ++i) {
+        if (oldRects.at(i) != d->rects[i])
+            emit resized(i);
+    }
+
+    // ### workareas are just reset by init, not filled with new values
+    // ### so this will not work correctly
+    for (int j = 0; j < qMin(oldScreenCount, d->screenCount); ++j) {
+        if (oldWorks.at(j) != d->workareas[j])
+            emit workAreaResized(j);
+    }
+
+    if (oldScreenCount != d->screenCount) {
+        emit screenCountChanged(d->screenCount);
+    }
+
     qt_desktopwidget_workarea_dirty = true;
     QWidget::resizeEvent(event);
 }