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.

1 files changed, 25 insertions, 0 deletions

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);
 }