5 files changed, 147 insertions, 145 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.h b/src/plugins/platforms/cocoa/qcocoabackingstore.h
index 5ed455fd71..bf6766beaa 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.h
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.h
@@ -53,6 +53,7 @@ public:
     void flush(QWindow *, const QRegion &, const QPoint &) Q_DECL_OVERRIDE;
 
 private:
+    bool windowHasUnifiedToolbar() const;
     QImage::Format format() const Q_DECL_OVERRIDE;
 };
 
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.mm b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index 1d7ad772dc..e0f7f7f57a 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -44,6 +44,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_LOGGING_CATEGORY(lcCocoaBackingStore, "qt.qpa.cocoa.backingstore");
+
 QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
     : QRasterBackingStore(window)
 {
@@ -51,26 +53,157 @@ QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
 
 QCocoaBackingStore::~QCocoaBackingStore()
 {
-    if (QCocoaWindow *cocoaWindow = static_cast<QCocoaWindow *>(window()->handle()))
-        [qnsview_cast(cocoaWindow->view()) clearBackingStore:this];
+}
+
+bool QCocoaBackingStore::windowHasUnifiedToolbar() const
+{
+    Q_ASSERT(window()->handle());
+    return static_cast<QCocoaWindow *>(window()->handle())->m_drawContentBorderGradient;
 }
 
 QImage::Format QCocoaBackingStore::format() const
 {
-    QCocoaWindow *cocoaWindow = static_cast<QCocoaWindow *>(window()->handle());
-    if (cocoaWindow && cocoaWindow->m_drawContentBorderGradient)
+    if (windowHasUnifiedToolbar())
         return QImage::Format_ARGB32_Premultiplied;
 
     return QRasterBackingStore::format();
 }
 
+#if !QT_MACOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__MAC_10_12)
+static const NSCompositingOperation NSCompositingOperationCopy = NSCompositeCopy;
+static const NSCompositingOperation NSCompositingOperationSourceOver = NSCompositeSourceOver;
+#endif
+
+/*!
+    Flushes the given \a region from the specified \a window onto the
+    screen.
+
+    The \a window is the top level window represented by this backingstore,
+    or a non-transient child of that window.
+
+    If the \a window is a child window, the \a region will be in child window
+    coordinates, and the \a offset will be the child window's offset in relation
+    to the backingstore's top level window.
+*/
 void QCocoaBackingStore::flush(QWindow *window, const QRegion &region, const QPoint &offset)
 {
     if (m_image.isNull())
         return;
 
-    if (QCocoaWindow *cocoaWindow = static_cast<QCocoaWindow *>(window->handle()))
-        [qnsview_cast(cocoaWindow->view()) flushBackingStore:this region:region offset:offset];
+    const QWindow *topLevelWindow = this->window();
+
+    Q_ASSERT(topLevelWindow->handle() && window->handle());
+    Q_ASSERT(!topLevelWindow->handle()->isForeignWindow() && !window->handle()->isForeignWindow());
+
+    QNSView *topLevelView = qnsview_cast(static_cast<QCocoaWindow *>(topLevelWindow->handle())->view());
+    QNSView *view = qnsview_cast(static_cast<QCocoaWindow *>(window->handle())->view());
+
+    if (lcCocoaBackingStore().isDebugEnabled()) {
+        QString targetViewDescription;
+        if (view != topLevelView) {
+            QDebug targetDebug(&targetViewDescription);
+            targetDebug << "onto" << topLevelView << "at" << offset;
+        }
+        qCDebug(lcCocoaBackingStore) << "Flushing" << region << "of" << view << targetViewDescription;
+    }
+
+    // Normally a NSView is drawn via drawRect, as part of the display cycle in the
+    // main runloop, via setNeedsDisplay and friends. AppKit will lock focus on each
+    // individual view, starting with the top level and then traversing any subviews,
+    // calling drawRect for each of them. This pull model results in expose events
+    // sent to Qt, which result in drawing to the backingstore and flushing it.
+    // Qt may also decide to paint and flush the backingstore via e.g. timers,
+    // or other events such as mouse events, in which case we're in a push model.
+    // If there is no focused view, it means we're in the latter case, and need
+    // to manually flush the NSWindow after drawing to its graphic context.
+    const bool drawingOutsideOfDisplayCycle = ![NSView focusView];
+
+    // We also need to ensure the flushed view has focus, so that the graphics
+    // context is set up correctly (coordinate system, clipping, etc). Outside
+    // of the normal display cycle there is no focused view, as explained above,
+    // so we have to handle it manually. There's also a corner case inside the
+    // normal display cycle due to way QWidgetBackingStore composits native child
+    // widgets, where we'll get a flush of a native child during the drawRect of
+    // its parent/ancestor, and the parent/ancestor being the one locked by AppKit.
+    // In this case we also need to lock and unlock focus manually.
+    const bool shouldHandleViewLockManually = [NSView focusView] != view;
+    if (shouldHandleViewLockManually && ![view lockFocusIfCanDraw]) {
+        qWarning() << "failed to lock focus of" << view;
+        return;
+    }
+
+    const qreal devicePixelRatio = m_image.devicePixelRatio();
+
+    // If the flushed window is a content view, and not in unified toolbar mode,
+    // we can get away with copying the backingstore instead of blending.
+    const NSCompositingOperation compositingOperation = static_cast<QCocoaWindow *>(
+        window->handle())->isContentView() && !windowHasUnifiedToolbar() ?
+            NSCompositingOperationCopy : NSCompositingOperationSourceOver;
+
+#ifdef QT_DEBUG
+    static bool debugBackingStoreFlush = [[NSUserDefaults standardUserDefaults]
+        boolForKey:@"QtCocoaDebugBackingStoreFlush"];
+#endif
+
+    // -------------------------------------------------------------------------
+
+    // The current contexts is typically a NSWindowGraphicsContext, but can be
+    // NSBitmapGraphicsContext e.g. when debugging the view hierarchy in Xcode.
+    // If we need to distinguish things here in the future, we can use e.g.
+    // [NSGraphicsContext drawingToScreen], or the attributes of the context.
+    NSGraphicsContext *graphicsContext = [NSGraphicsContext currentContext];
+    Q_ASSERT_X(graphicsContext, "QCocoaBackingStore",
+        "Focusing the view should give us a current graphics context");
+
+    // Create temporary image to use for blitting, without copying image data
+    NSImage *backingStoreImage = [[[NSImage alloc]
+        initWithCGImage:QCFType<CGImageRef>(m_image.toCGImage()) size:NSZeroSize] autorelease];
+
+    if ([topLevelView hasMask]) {
+        // FIXME: Implement via NSBezierPath and addClip
+        CGRect boundingRect = region.boundingRect().toCGRect();
+        QCFType<CGImageRef> subMask = CGImageCreateWithImageInRect([topLevelView maskImage], boundingRect);
+        CGContextClipToMask(graphicsContext.CGContext, boundingRect, subMask);
+    }
+
+    for (const QRect &viewLocalRect : region) {
+        QPoint backingStoreOffset = viewLocalRect.topLeft() + offset;
+        QRect backingStoreRect(backingStoreOffset * devicePixelRatio, viewLocalRect.size() * devicePixelRatio);
+        if (graphicsContext.flipped) // Flip backingStoreRect to match graphics context
+            backingStoreRect.moveTop(m_image.height() - (backingStoreRect.y() + backingStoreRect.height()));
+
+        CGRect viewRect = viewLocalRect.toCGRect();
+
+        if (windowHasUnifiedToolbar())
+            NSDrawWindowBackground(viewRect);
+
+        [backingStoreImage drawInRect:viewRect fromRect:backingStoreRect.toCGRect()
+            operation:compositingOperation fraction:1.0 respectFlipped:YES hints:nil];
+
+#ifdef QT_DEBUG
+        if (Q_UNLIKELY(debugBackingStoreFlush)) {
+            [[NSColor colorWithCalibratedRed:drand48() green:drand48() blue:drand48() alpha:0.3] set];
+            [NSBezierPath fillRect:viewRect];
+
+            if (drawingOutsideOfDisplayCycle) {
+                [[[NSColor magentaColor] colorWithAlphaComponent:0.5] set];
+                [NSBezierPath strokeLineFromPoint:viewLocalRect.topLeft().toCGPoint()
+                    toPoint:viewLocalRect.bottomRight().toCGPoint()];
+            }
+        }
+#endif
+    }
+
+    // -------------------------------------------------------------------------
+
+    if (shouldHandleViewLockManually)
+        [view unlockFocus];
+
+    if (drawingOutsideOfDisplayCycle)
+        [view.window flushWindow];
+
+    // FIXME: Tie to changing window flags and/or mask instead
+    [view invalidateWindowShadowIfNeeded];
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 86599a2529..9f98ad56de 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -1059,8 +1059,6 @@ void QCocoaWindow::handleGeometryChange()
     // calls, which Qt and Qt applications do not expect.
     if (!m_inSetGeometry)
         QWindowSystemInterface::flushWindowSystemEvents();
-    else if (newGeometry.size() != geometry().size())
-        [qnsview_cast(m_view) clearBackingStore];
 }
 
 void QCocoaWindow::handleExposeEvent(const QRegion &region)
diff --git a/src/plugins/platforms/cocoa/qnsview.h b/src/plugins/platforms/cocoa/qnsview.h
index 770aae240e..414c6b7fe7 100644
--- a/src/plugins/platforms/cocoa/qnsview.h
+++ b/src/plugins/platforms/cocoa/qnsview.h
@@ -51,15 +51,12 @@
 
 QT_BEGIN_NAMESPACE
 class QCocoaWindow;
-class QCocoaBackingStore;
 class QCocoaGLContext;
 QT_END_NAMESPACE
 
 Q_FORWARD_DECLARE_OBJC_CLASS(QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper));
 
 @interface QT_MANGLE_NAMESPACE(QNSView) : NSView <NSTextInputClient> {
-    QCocoaBackingStore* m_backingStore;
-    QPoint m_backingStoreOffset;
     QRegion m_maskRegion;
     CGImageRef m_maskImage;
     bool m_shouldInvalidateWindowShadow;
@@ -93,13 +90,10 @@ Q_FORWARD_DECLARE_OBJC_CLASS(QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper));
 #ifndef QT_NO_OPENGL
 - (void)setQCocoaGLContext:(QCocoaGLContext *)context;
 #endif
-- (void)flushBackingStore:(QCocoaBackingStore *)backingStore region:(const QRegion &)region offset:(QPoint)offset;
-- (void)clearBackingStore;
-- (void)clearBackingStore:(QCocoaBackingStore *)backingStore;
 - (void)setMaskRegion:(const QRegion *)region;
+- (CGImageRef)maskImage;
 - (void)invalidateWindowShadowIfNeeded;
 - (void)drawRect:(NSRect)dirtyRect;
-- (void)drawBackingStoreUsingCoreGraphics:(NSRect)dirtyRect;
 - (void)textInputContextKeyboardSelectionDidChangeNotification : (NSNotification *) textInputContextKeyboardSelectionDidChangeNotification;
 - (void)viewDidHide;
 - (void)removeFromSuperview;
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 73d308213d..e531e79c8f 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -134,7 +134,6 @@ static QTouchDevice *touchDevice = 0;
 - (id) init
 {
     if (self = [super initWithFrame:NSZeroRect]) {
-        m_backingStore = 0;
         m_maskImage = 0;
         m_shouldInvalidateWindowShadow = false;
         m_buttons = Qt::NoButton;
@@ -267,11 +266,6 @@ static QTouchDevice *touchDevice = 0;
     }
 }
 
-- (void)viewDidMoveToWindow
-{
-    m_backingStore = Q_NULLPTR;
-}
-
 - (QWindow *)topLevelWindow
 {
     if (!m_platformWindow)
@@ -316,67 +310,6 @@ static QTouchDevice *touchDevice = 0;
     [super removeFromSuperview];
 }
 
-- (void)flushBackingStore:(QCocoaBackingStore *)backingStore region:(const QRegion &)region offset:(QPoint)offset
-{
-    qCDebug(lcQpaCocoaWindow) << "[QNSView flushBackingStore:]" << m_platformWindow->window() << region.rectCount() << region.boundingRect() << offset;
-
-    m_backingStore = backingStore;
-    m_backingStoreOffset = offset * m_backingStore->paintDevice()->devicePixelRatio();
-
-    // FIXME: Clean up this method now that the drawRect logic has been merged into it
-
-    const NSRect dirtyRect = region.boundingRect().toCGRect();
-
-    // Normally a NSView is drawn via drawRect, as part of the display cycle in the
-    // main runloop, via setNeedsDisplay and friends. AppKit will lock focus on each
-    // individual view, starting with the top level and then traversing any subviews,
-    // calling drawRect for each of them. This pull model results in expose events
-    // sent to Qt, which result in drawing to the backingstore and flushing it.
-    // Qt may also decide to paint and flush the backingstore via e.g. timers,
-    // or other events such as mouse events, in which case we're in a push model.
-    // If there is no focused view, it means we're in the latter case, and need
-    // to manually flush the NSWindow after drawing to its graphic context.
-    const bool drawingOutsideOfDisplayCycle = ![NSView focusView];
-
-    // We also need to ensure the flushed view has focus, so that the graphics
-    // context is set up correctly (coordinate system, clipping, etc). Outside
-    // of the normal display cycle there is no focused view, as explained above,
-    // so we have to handle it manually. There's also a corner case inside the
-    // normal display cycle due to way QWidgetBackingStore composits native child
-    // widgets, where we'll get a flush of a native child during the drawRect of
-    // its parent/ancestor, and the parent/ancestor being the one locked by AppKit.
-    // In this case we also need to lock and unlock focus manually.
-    const bool shouldHandleViewLockManually = [NSView focusView] != self;
-    if (shouldHandleViewLockManually && ![self lockFocusIfCanDraw]) {
-        qWarning() << "failed to lock focus of" << self;
-        return;
-    }
-
-    if (m_platformWindow->m_drawContentBorderGradient)
-        NSDrawWindowBackground(dirtyRect);
-
-    [self drawBackingStoreUsingCoreGraphics:dirtyRect];
-
-    if (shouldHandleViewLockManually)
-        [self unlockFocus];
-
-    if (drawingOutsideOfDisplayCycle)
-        [self.window flushWindow];
-
-    [self invalidateWindowShadowIfNeeded];
-}
-
-- (void)clearBackingStore
-{
-    m_backingStore = nullptr;
-}
-
-- (void)clearBackingStore:(QCocoaBackingStore *)backingStore
-{
-    if (backingStore == m_backingStore)
-        m_backingStore = 0;
-}
-
 - (BOOL) hasMask
 {
     return !m_maskRegion.isEmpty();
@@ -418,6 +351,11 @@ static QTouchDevice *touchDevice = 0;
     m_maskImage = qt_mac_toCGImageMask(maskImage);
 }
 
+- (CGImageRef)maskImage
+{
+    return m_maskImage;
+}
+
 - (void)invalidateWindowShadowIfNeeded
 {
     if (m_shouldInvalidateWindowShadow && m_platformWindow->isContentView()) {
@@ -452,69 +390,7 @@ static QTouchDevice *touchDevice = 0;
     m_platformWindow->handleExposeEvent(exposedRegion);
 }
 
-// Draws the backing store content to the QNSView using Core Graphics.
-// This function assumes that the QNSView is in a configuration that
-// supports Core Graphics, such as "classic" mode or layer mode with
-// the default layer.
-- (void)drawBackingStoreUsingCoreGraphics:(NSRect)dirtyRect
-{
-    if (!m_backingStore)
-        return;
-
-    // Calculate source and target rects. The target rect is the dirtyRect:
-    CGRect dirtyWindowRect = NSRectToCGRect(dirtyRect);
-
-    // The backing store source rect will be larger on retina displays.
-    // Scale dirtyRect by the device pixel ratio:
-    const qreal devicePixelRatio = m_backingStore->paintDevice()->devicePixelRatio();
-    CGRect dirtyBackingRect = CGRectMake(dirtyRect.origin.x * devicePixelRatio,
-                                         dirtyRect.origin.y * devicePixelRatio,
-                                         dirtyRect.size.width * devicePixelRatio,
-                                         dirtyRect.size.height * devicePixelRatio);
-
-    NSGraphicsContext *nsGraphicsContext = [NSGraphicsContext currentContext];
-    CGContextRef cgContext = (CGContextRef) [nsGraphicsContext graphicsPort];
-
-    // Translate coordiate system from CoreGraphics (bottom-left) to NSView (top-left):
-    CGContextSaveGState(cgContext);
-    int dy = dirtyWindowRect.origin.y + CGRectGetMaxY(dirtyWindowRect);
-
-    CGContextTranslateCTM(cgContext, 0, dy);
-    CGContextScaleCTM(cgContext, 1, -1);
-
-    // If a mask is set, modify the sub image accordingly:
-    CGImageRef subMask = 0;
-    if (m_maskImage) {
-        subMask = CGImageCreateWithImageInRect(m_maskImage, dirtyWindowRect);
-        CGContextClipToMask(cgContext, dirtyWindowRect, subMask);
-    }
-
-    // Clip out and draw the correct sub image from the (shared) backingstore:
-    CGRect backingStoreRect = CGRectMake(
-        dirtyBackingRect.origin.x + m_backingStoreOffset.x(),
-        dirtyBackingRect.origin.y + m_backingStoreOffset.y(),
-        dirtyBackingRect.size.width,
-        dirtyBackingRect.size.height
-    );
-    CGImageRef bsCGImage = qt_mac_toCGImage(m_backingStore->toImage());
-    CGImageRef cleanImg = CGImageCreateWithImageInRect(bsCGImage, backingStoreRect);
-
-    // Optimization: Copy frame buffer content instead of blending for
-    // top-level windows where Qt fills the entire window content area.
-    // (But don't overpaint the title-bar gradient)
-    if (m_platformWindow->isContentView() && !m_platformWindow->m_drawContentBorderGradient)
-        CGContextSetBlendMode(cgContext, kCGBlendModeCopy);
-
-    CGContextDrawImage(cgContext, dirtyWindowRect, cleanImg);
-
-    // Clean-up:
-    CGContextRestoreGState(cgContext);
-    CGImageRelease(cleanImg);
-    CGImageRelease(subMask);
-    CGImageRelease(bsCGImage);
-}
-
-- (BOOL) isFlipped
+- (BOOL)isFlipped
 {
     return YES;
 }