Split QPlatformWindow::isEmbedded into isAncestorOf to separate concerns

The function was doing two things, both checking window ancestry and
whether or the window was a direct child of non-Qt window. The former
has now been split of in a QPlatformWindow::isAncestorOf(), which
simplifies the code in e.g. QApplicationPrivate::isWindowBlocked().

Change-Id: I259a190e03ef8def23356005474eeeee74c9ae89
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

3 files changed, 30 insertions, 9 deletions

diff --git a/src/gui/kernel/qplatformwindow.cpp b/src/gui/kernel/qplatformwindow.cpp
index bcd3e830dd..70e2c22ee1 100644
--- a/src/gui/kernel/qplatformwindow.cpp
+++ b/src/gui/kernel/qplatformwindow.cpp
@@ -192,15 +192,30 @@ bool QPlatformWindow::isActive() const
 }
 
 /*!
-    Returns \c true if the window is a descendant of an embedded non-Qt window.
-    Example of an embedded non-Qt window is the parent window of an in-process QAxServer.
+    Returns \c true if the window is an ancestor of the given \a child.
 
-    If \a parentWindow is nonzero, only check if the window is embedded in the
-    specified \a parentWindow.
+    Platform overrides should iterate the native window hierarchy of the child,
+    to ensure that ancestary is reflected even with native windows in the window
+    hierarchy.
 */
-bool QPlatformWindow::isEmbedded(const QPlatformWindow *parentWindow) const
+bool QPlatformWindow::isAncestorOf(const QPlatformWindow *child) const
+{
+    for (const QPlatformWindow *parent = child->parent(); parent; parent = child->parent()) {
+        if (parent == this)
+            return true;
+    }
+
+    return false;
+}
+
+/*!
+    Returns \c true if the window is a child of a non-Qt window.
+
+    A embedded window has no parent platform window as reflected
+    though parent(), but will have a native parent window.
+*/
+bool QPlatformWindow::isEmbedded() const
 {
-    Q_UNUSED(parentWindow);
     return false;
 }
 
diff --git a/src/gui/kernel/qplatformwindow.h b/src/gui/kernel/qplatformwindow.h
index dcee4d2d84..d7fdbb156e 100644
--- a/src/gui/kernel/qplatformwindow.h
+++ b/src/gui/kernel/qplatformwindow.h
@@ -102,7 +102,8 @@ public:
 
     virtual bool isExposed() const;
     virtual bool isActive() const;
-    virtual bool isEmbedded(const QPlatformWindow *parentWindow = 0) const;
+    virtual bool isAncestorOf(const QPlatformWindow *child) const;
+    virtual bool isEmbedded() const;
     virtual QPoint mapToGlobal(const QPoint &pos) const;
     virtual QPoint mapFromGlobal(const QPoint &pos) const;
 
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 93edfe6331..5a27b19101 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -1300,8 +1300,13 @@ bool QWindow::isAncestorOf(const QWindow *child, AncestorMode mode) const
     if (child->parent() == this || (mode == IncludeTransients && child->transientParent() == this))
         return true;
 
-    if (child->parent(mode) && isAncestorOf(child->parent(mode), mode))
-        return true;
+    if (QWindow *parent = child->parent(mode)) {
+        if (isAncestorOf(parent, mode))
+            return true;
+    } else if (handle() && child->handle()) {
+        if (handle()->isAncestorOf(child->handle()))
+            return true;
+    }
 
     return false;
 }