Make QWindow::setVisible() work for widgets

QWidget has its own setVisible() code that needs to
be run in order to correctly transition widget visibility.

It is desirable to be able to show and hide (native)
widgets also from the QWindow side, for example from
the platform plugin, or from generic QWindow handling
code in QtGui.

Add a new virtual QWindowPrivate::setVisible() and
move the QWindow visibility implementation there.
Subclasses can now override this function to add custom
code.

Make QWidgetPrivate::show/hide_sys() call the QWindowPrivate
setVisible implementation instead of the QWindow setVisible
public API.

Change-Id: I082f174b100659e1221d5898b490f8a9f498abdf
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

2 files changed, 79 insertions, 65 deletions

diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 796a552bcb..34d35ef2d1 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -317,6 +317,83 @@ void QWindow::setVisibility(Visibility v)
     }
 }
 
+/*
+    Subclasses may override this function to run custom setVisible
+    logic. Subclasses that do so must call the base class implementation
+    at some point to make the native window visible, and must not
+    call QWindow::setVisble() since that will recurse back here.
+*/
+void QWindowPrivate::setVisible(bool visible)
+{
+    Q_Q(QWindow);
+
+    if (this->visible != visible) {
+        this->visible = visible;
+        emit q->visibleChanged(visible);
+        updateVisibility();
+    } else if (platformWindow) {
+        // Visibility hasn't changed, and the platform window is in sync
+        return;
+    }
+
+    if (!platformWindow) {
+        // If we have a parent window, but the parent hasn't been created yet, we
+        // can defer creation until the parent is created or we're re-parented.
+        if (parentWindow && !parentWindow->handle())
+            return;
+
+        // We only need to create the window if it's being shown
+        if (visible)
+            q->create();
+    }
+
+    if (visible) {
+        // remove posted quit events when showing a new window
+        QCoreApplication::removePostedEvents(qApp, QEvent::Quit);
+
+        if (q->type() == Qt::Window) {
+            QGuiApplicationPrivate *app_priv = QGuiApplicationPrivate::instance();
+            QString &firstWindowTitle = app_priv->firstWindowTitle;
+            if (!firstWindowTitle.isEmpty()) {
+                q->setTitle(firstWindowTitle);
+                firstWindowTitle = QString();
+            }
+            if (!app_priv->forcedWindowIcon.isNull())
+                q->setIcon(app_priv->forcedWindowIcon);
+
+            // Handling of the -qwindowgeometry, -geometry command line arguments
+            static bool geometryApplied = false;
+            if (!geometryApplied) {
+                geometryApplied = true;
+                QGuiApplicationPrivate::applyWindowGeometrySpecificationTo(q);
+            }
+        }
+
+        QShowEvent showEvent;
+        QGuiApplication::sendEvent(q, &showEvent);
+    }
+
+    if (q->isModal()) {
+        if (visible)
+            QGuiApplicationPrivate::showModalWindow(q);
+        else
+            QGuiApplicationPrivate::hideModalWindow(q);
+    }
+
+#ifndef QT_NO_CURSOR
+    if (visible && (hasCursor || QGuiApplication::overrideCursor()))
+        applyCursor();
+#endif
+
+    if (platformWindow)
+        platformWindow->setVisible(visible);
+
+    if (!visible) {
+        QHideEvent hideEvent;
+        QGuiApplication::sendEvent(q, &hideEvent);
+    }
+}
+
 void QWindowPrivate::updateVisibility()
 {
     Q_Q(QWindow);
@@ -514,71 +591,7 @@ void QWindow::setVisible(bool visible)
 {
     Q_D(QWindow);
 
-    if (d->visible != visible) {
-        d->visible = visible;
-        emit visibleChanged(visible);
-        d->updateVisibility();
-    } else if (d->platformWindow) {
-        // Visibility hasn't changed, and the platform window is in sync
-        return;
-    }
-
-    if (!d->platformWindow) {
-        // If we have a parent window, but the parent hasn't been created yet, we
-        // can defer creation until the parent is created or we're re-parented.
-        if (parent() && !parent()->handle())
-            return;
-
-        // We only need to create the window if it's being shown
-        if (visible)
-            create();
-    }
-
-    if (visible) {
-        // remove posted quit events when showing a new window
-        QCoreApplication::removePostedEvents(qApp, QEvent::Quit);
-
-        if (type() == Qt::Window) {
-            QGuiApplicationPrivate *app_priv = QGuiApplicationPrivate::instance();
-            QString &firstWindowTitle = app_priv->firstWindowTitle;
-            if (!firstWindowTitle.isEmpty()) {
-                setTitle(firstWindowTitle);
-                firstWindowTitle = QString();
-            }
-            if (!app_priv->forcedWindowIcon.isNull())
-                setIcon(app_priv->forcedWindowIcon);
-
-            // Handling of the -qwindowgeometry, -geometry command line arguments
-            static bool geometryApplied = false;
-            if (!geometryApplied) {
-                geometryApplied = true;
-                QGuiApplicationPrivate::applyWindowGeometrySpecificationTo(this);
-            }
-        }
-
-        QShowEvent showEvent;
-        QGuiApplication::sendEvent(this, &showEvent);
-    }
-
-    if (isModal()) {
-        if (visible)
-            QGuiApplicationPrivate::showModalWindow(this);
-        else
-            QGuiApplicationPrivate::hideModalWindow(this);
-    }
-
-#ifndef QT_NO_CURSOR
-    if (visible && (d->hasCursor || QGuiApplication::overrideCursor()))
-        d->applyCursor();
-#endif
-
-    if (d->platformWindow)
-        d->platformWindow->setVisible(visible);
-
-    if (!visible) {
-        QHideEvent hideEvent;
-        QGuiApplication::sendEvent(this, &hideEvent);
-    }
+    d->setVisible(visible);
 }
 
 bool QWindow::isVisible() const
diff --git a/src/gui/kernel/qwindow_p.h b/src/gui/kernel/qwindow_p.h
index cffe5b4125..9b8e2c47e4 100644
--- a/src/gui/kernel/qwindow_p.h
+++ b/src/gui/kernel/qwindow_p.h
@@ -132,6 +132,7 @@ public:
 
     virtual QWindow *eventReceiver() { Q_Q(QWindow); return q; }
 
+    virtual void setVisible(bool visible);
     void updateVisibility();
     void _q_clearAlert();