diff --git a/src/plugins/platforms/cocoa/cocoa.pro b/src/plugins/platforms/cocoa/cocoa.pro
index 5e3703a674..02d8b16110 100644
--- a/src/plugins/platforms/cocoa/cocoa.pro
+++ b/src/plugins/platforms/cocoa/cocoa.pro
@@ -105,8 +105,6 @@ OTHER_FILES += cocoa.json
 # DEFINES += QT_COCOA_ENABLE_ACCESSIBILITY_INSPECTOR
 # include ($$PWD/../../../../util/accessibilityinspector/accessibilityinspector.pri)
 
-# Window debug support
-#DEFINES += QT_COCOA_ENABLE_WINDOW_DEBUG
 
 PLUGIN_TYPE = platforms
 PLUGIN_CLASS_NAME = QCocoaIntegrationPlugin
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.h b/src/plugins/platforms/cocoa/qcocoahelpers.h
index 766561a264..ec2f7f8cf1 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.h
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.h
@@ -57,6 +57,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_DECLARE_LOGGING_CATEGORY(lcQpaCocoaWindow)
+
 class QPixmap;
 class QString;
 
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.mm b/src/plugins/platforms/cocoa/qcocoahelpers.mm
index 204f2440d9..7480d99d19 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.mm
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.mm
@@ -77,6 +77,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_LOGGING_CATEGORY(lcQpaCocoaWindow, "qt.qpa.cocoa.window");
+
 //
 // Conversion Functions
 //
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index b501358acc..29cc4130ed 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -374,9 +374,8 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     , m_bottomContentBorderThickness(0)
     , m_normalGeometry(QRect(0,0,-1,-1))
 {
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::QCocoaWindow" << this;
-#endif
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::QCocoaWindow" << window();
+
     QMacAutoReleasePool pool;
 
     if (tlw->type() == Qt::ForeignWindow) {
@@ -409,9 +408,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
 
 QCocoaWindow::~QCocoaWindow()
 {
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::~QCocoaWindow" << this;
-#endif
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::~QCocoaWindow" << window();
 
     QMacAutoReleasePool pool;
     [m_nsWindow makeFirstResponder:nil];
@@ -469,6 +466,8 @@ QSurfaceFormat QCocoaWindow::format() const
 
 void QCocoaWindow::setGeometry(const QRect &rectIn)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setGeometry" << window() << rectIn;
+
     QBoolBlocker inSetGeometry(m_inSetGeometry, true);
 
     QRect rect = rectIn;
@@ -481,9 +480,7 @@ void QCocoaWindow::setGeometry(const QRect &rectIn)
     }
     if (geometry() == rect)
         return;
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::setGeometry" << this << rect;
-#endif
+
     setCocoaGeometry(rect);
 }
 
@@ -506,6 +503,7 @@ QRect QCocoaWindow::geometry() const
 
 void QCocoaWindow::setCocoaGeometry(const QRect &rect)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setCocoaGeometry" << window() << rect;
     QMacAutoReleasePool pool;
 
     if (m_contentViewIsEmbedded) {
@@ -629,6 +627,8 @@ void QCocoaWindow::show(bool becauseOfAncestor)
 
 void QCocoaWindow::setVisible(bool visible)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setVisible" << window() << visible;
+
     if (m_isNSWindowChild && m_hiddenByClipping)
         return;
 
@@ -638,9 +638,7 @@ void QCocoaWindow::setVisible(bool visible)
     QCocoaWindow *parentCocoaWindow = 0;
     if (window()->transientParent())
         parentCocoaWindow = static_cast<QCocoaWindow *>(window()->transientParent()->handle());
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::setVisible" << window() << visible;
-#endif
+
     if (visible) {
         // We need to recreate if the modality has changed as the style mask will need updating
         if (m_windowModality != window()->modality())
@@ -861,9 +859,6 @@ NSUInteger QCocoaWindow::windowStyleMask(Qt::WindowFlags flags)
     if (m_drawContentBorderGradient)
         styleMask |= NSTexturedBackgroundWindowMask;
 
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug("windowStyleMask of '%s': flags %X -> styleMask %lX", qPrintable(window()->title()), (int)flags, styleMask);
-#endif
     return styleMask;
 }
 
@@ -985,7 +980,8 @@ bool QCocoaWindow::isAlertState() const
 
 void QCocoaWindow::raise()
 {
-    //qDebug() << "raise" << this;
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::raise" << window();
+
     // ### handle spaces (see Qt 4 raise_sys in qwidget_mac.mm)
     if (!m_nsWindow)
         return;
@@ -1026,6 +1022,7 @@ void QCocoaWindow::raise()
 
 void QCocoaWindow::lower()
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::lower" << window();
     if (!m_nsWindow)
         return;
     if (m_isNSWindowChild) {
@@ -1078,13 +1075,11 @@ void QCocoaWindow::propagateSizeHints()
     if (!m_nsWindow)
         return;
 
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::propagateSizeHints" << this;
-    qDebug() << "       min/max" << windowMinimumSize() << windowMaximumSize();
-    qDebug() << "size increment" << windowSizeIncrement();
-    qDebug() << "      basesize" << windowBaseSize();
-    qDebug() << "      geometry" << windowGeometry();
-#endif
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::propagateSizeHints" << window() << "\n"
+                              << "       min/max" << windowMinimumSize() << windowMaximumSize()
+                              << "size increment" << windowSizeIncrement()
+                              << "      basesize" << windowBaseSize()
+                              << "      geometry" << windowGeometry();
 
     // Set the minimum content size.
     const QSize minimumSize = windowMinimumSize();
@@ -1116,6 +1111,7 @@ void QCocoaWindow::propagateSizeHints()
 
 void QCocoaWindow::setOpacity(qreal level)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setOpacity" << level;
     if (m_nsWindow) {
         [m_nsWindow setAlphaValue:level];
         [m_nsWindow setOpaque: isOpaque()];
@@ -1124,6 +1120,7 @@ void QCocoaWindow::setOpacity(qreal level)
 
 void QCocoaWindow::setMask(const QRegion &region)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setMask" << window() << region;
     if (m_nsWindow)
         [m_nsWindow setBackgroundColor:[NSColor clearColor]];
 
@@ -1133,6 +1130,7 @@ void QCocoaWindow::setMask(const QRegion &region)
 
 bool QCocoaWindow::setKeyboardGrabEnabled(bool grab)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setKeyboardGrabEnabled" << window() << grab;
     if (!m_nsWindow)
         return false;
 
@@ -1145,6 +1143,7 @@ bool QCocoaWindow::setKeyboardGrabEnabled(bool grab)
 
 bool QCocoaWindow::setMouseGrabEnabled(bool grab)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setMouseGrabEnabled" << window() << grab;
     if (!m_nsWindow)
         return false;
 
@@ -1162,6 +1161,8 @@ WId QCocoaWindow::winId() const
 
 void QCocoaWindow::setParent(const QPlatformWindow *parentWindow)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::setParent" << window() << (parentWindow ? parentWindow->window() : 0);
+
     // recreate the window for compatibility
     bool unhideAfterRecreate = parentWindow && !m_contentViewIsToBeEmbedded && ![m_contentView isHidden];
     recreateWindow(parentWindow);
@@ -1245,6 +1246,7 @@ void QCocoaWindow::windowDidEndLiveResize()
 
 bool QCocoaWindow::windowShouldClose()
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::windowShouldClose" << window();
    // This callback should technically only determine if the window
    // should (be allowed to) close, but since our QPA API to determine
    // that also involves actually closing the window we do both at the
@@ -1285,6 +1287,9 @@ QCocoaGLContext *QCocoaWindow::currentContext() const
 
 void QCocoaWindow::recreateWindow(const QPlatformWindow *parentWindow)
 {
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::recreateWindow" << window()
+                              << "parent" << (parentWindow ? parentWindow->window() : 0);
+
     bool wasNSWindowChild = m_isNSWindowChild;
     BOOL requestNSWindowChild = qt_mac_resolveOption(NO, window(), "_q_platform_MacUseNSWindow",
                                                                    "QT_MAC_USE_NSWINDOW");
@@ -1621,10 +1626,6 @@ void QCocoaWindow::syncWindowState(Qt::WindowState newState)
         }
     }
 
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QCocoaWindow::syncWindowState" << newState << "actual" << predictedState << "was" << m_synchedWindowState << "effectively maximized" << m_effectivelyMaximized;
-#endif
-
     // New state is now the current synched state
     m_synchedWindowState = predictedState;
 }
@@ -1817,7 +1818,9 @@ void QCocoaWindow::exposeWindow()
         m_isExposed = true;
         m_exposedGeometry = geometry();
         m_exposedDevicePixelRatio = devicePixelRatio();
-        QWindowSystemInterface::handleExposeEvent(window(), QRect(QPoint(0, 0), m_exposedGeometry.size()));
+        QRect geometry(QPoint(0, 0), m_exposedGeometry.size());
+        qCDebug(lcQpaCocoaWindow) << "QCocoaWindow: exposeWindow" << window() << geometry;
+        QWindowSystemInterface::handleExposeEvent(window(), geometry);
     }
 }
 
@@ -1827,6 +1830,8 @@ void QCocoaWindow::obscureWindow()
     if (m_isExposed) {
         m_geometryUpdateExposeAllowed = false;
         m_isExposed = false;
+
+        qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::obscureWindow" << window();
         QWindowSystemInterface::handleExposeEvent(window(), QRegion());
     }
 }
@@ -1853,7 +1858,10 @@ void QCocoaWindow::updateExposedGeometry()
     m_isExposed = true;
     m_exposedGeometry = geometry();
     m_exposedDevicePixelRatio = devicePixelRatio();
-    QWindowSystemInterface::handleExposeEvent(window(), QRect(QPoint(0, 0), m_exposedGeometry.size()));
+
+    QRect geometry(QPoint(0, 0), m_exposedGeometry.size());
+    qCDebug(lcQpaCocoaWindow) << "QCocoaWindow::updateExposedGeometry" << window() << geometry;
+    QWindowSystemInterface::handleExposeEvent(window(), geometry);
 }
 
 QWindow *QCocoaWindow::childWindowAt(QPoint windowPoint)
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 169844fcbc..0733ac3092 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -369,9 +369,8 @@ static NSString *_q_NSWindowDidChangeOcclusionStateNotification = nil;
     if (m_platformWindow->m_inSetStyleMask && !self.window)
         return;
 
-#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
-    qDebug() << "QNSView::udpateGeometry" << m_platformWindow << geometry;
-#endif
+     qCDebug(lcQpaCocoaWindow) << "[QNSView udpateGeometry:]" << m_window
+                               << "current" << m_platformWindow->geometry() << "new" << geometry;
 
     // Call setGeometry on QPlatformWindow. (not on QCocoaWindow,
     // doing that will initiate a geometry change it and possibly create
@@ -514,6 +513,8 @@ QT_WARNING_POP
 
 - (void) flushBackingStore:(QCocoaBackingStore *)backingStore region:(const QRegion &)region offset:(QPoint)offset
 {
+    qCDebug(lcQpaCocoaWindow) << "[QNSView flushBackingStore:]" << m_window << region.rectCount() << region.boundingRect() << offset;
+
     m_backingStore = backingStore;
     m_backingStoreOffset = offset * m_backingStore->getBackingStoreDevicePixelRatio();
     foreach (QRect rect, region.rects())
@@ -576,6 +577,8 @@ QT_WARNING_POP
 
 - (void) drawRect:(NSRect)dirtyRect
 {
+    qCDebug(lcQpaCocoaWindow) << "[QNSView drawRect:]" << m_window << qt_mac_toQRect(dirtyRect);
+
 #ifndef QT_NO_OPENGL
     if (m_glContext && m_shouldSetGLContextinDrawRect) {
         [m_glContext->nsOpenGLContext() setView:self];
diff --git a/src/plugins/platforms/cocoa/qt_mac_p.h b/src/plugins/platforms/cocoa/qt_mac_p.h
index 18a3d1b3e5..03eae1b2e7 100644
--- a/src/plugins/platforms/cocoa/qt_mac_p.h
+++ b/src/plugins/platforms/cocoa/qt_mac_p.h
@@ -64,6 +64,7 @@
 #include "QtCore/qvariant.h"
 #include "QtCore/qmimedata.h"
 #include "QtCore/qpointer.h"
+#include "QtCore/qloggingcategory.h"
 #include "private/qcore_mac_p.h"