macOS: Gather QNSView draw callbacks together

Change-Id: I29881b379481287b4938e47fc06405c918aa39a3
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 51 insertions, 39 deletions

diff --git a/src/plugins/platforms/cocoa/qnsview_drawing.mm b/src/plugins/platforms/cocoa/qnsview_drawing.mm
index e72142466b..6f9c72513d 100644
--- a/src/plugins/platforms/cocoa/qnsview_drawing.mm
+++ b/src/plugins/platforms/cocoa/qnsview_drawing.mm
@@ -71,24 +71,6 @@
     return YES;
 }
 
-- (void)drawRect:(NSRect)dirtyRect
-{
-    Q_UNUSED(dirtyRect);
-
-    if (!m_platformWindow)
-        return;
-
-    QRegion exposedRegion;
-    const NSRect *dirtyRects;
-    NSInteger numDirtyRects;
-    [self getRectsBeingDrawn:&dirtyRects count:&numDirtyRects];
-    for (int i = 0; i < numDirtyRects; ++i)
-        exposedRegion += QRectF::fromCGRect(dirtyRects[i]).toRect();
-
-    qCDebug(lcQpaDrawing) << "[QNSView drawRect:]" << m_platformWindow->window() << exposedRegion;
-    m_platformWindow->handleExposeEvent(exposedRegion);
-}
-
 - (BOOL)layerEnabledByMacOS
 {
     // AppKit has its own logic for this, but if we rely on that, our layers are created
@@ -173,8 +155,59 @@
 }
 #endif
 
+- (void)viewDidChangeBackingProperties
+{
+    qCDebug(lcQpaDrawing) << "Backing properties changed for" << self;
+
+    if (self.layer)
+        self.layer.contentsScale = self.window.backingScaleFactor;
+
+    // Ideally we would plumb this situation through QPA in a way that lets
+    // clients invalidate their own caches, recreate QBackingStore, etc.
+    // For now we trigger an expose, and let QCocoaBackingStore deal with
+    // buffer invalidation internally.
+    [self setNeedsDisplay:YES];
+}
+
+// ----------------------- Draw callbacks -----------------------
+
+/*
+    This method is called by AppKit for the non-layer case, where we are
+    drawing into the NSWindow's surface.
+*/
+- (void)drawRect:(NSRect)dirtyRect
+{
+    Q_UNUSED(dirtyRect);
+
+    Q_ASSERT_X(!self.layer, "QNSView",
+        "The drawRect code path should not be hit when we are layer backed");
+
+    if (!m_platformWindow)
+        return;
+
+    QRegion exposedRegion;
+    const NSRect *dirtyRects;
+    NSInteger numDirtyRects;
+    [self getRectsBeingDrawn:&dirtyRects count:&numDirtyRects];
+    for (int i = 0; i < numDirtyRects; ++i)
+        exposedRegion += QRectF::fromCGRect(dirtyRects[i]).toRect();
+
+    qCDebug(lcQpaDrawing) << "[QNSView drawRect:]" << m_platformWindow->window() << exposedRegion;
+    m_platformWindow->handleExposeEvent(exposedRegion);
+}
+
+/*
+    This method is called by AppKit when we are layer-backed, where
+    we are drawing into the layer.
+*/
 - (void)displayLayer:(CALayer *)layer
 {
+    Q_ASSERT_X(self.layer && layer == self.layer, "QNSView",
+        "The displayLayer code path should only be hit for our own layer");
+
+    if (!m_platformWindow)
+        return;
+
     if (!NSThread.isMainThread) {
         // Qt is calling AppKit APIs such as -[NSOpenGLContext setView:] on secondary threads,
         // which we shouldn't do. This may result in AppKit (wrongly) triggering a display on
@@ -184,29 +217,8 @@
         return;
     }
 
-    Q_ASSERT(layer == self.layer);
-
-    if (!m_platformWindow)
-        return;
-
     qCDebug(lcQpaDrawing) << "[QNSView displayLayer]" << m_platformWindow->window();
-
-    // FIXME: Find out if there's a way to resolve the dirty rect like in drawRect:
     m_platformWindow->handleExposeEvent(QRectF::fromCGRect(self.bounds).toRect());
 }
 
-- (void)viewDidChangeBackingProperties
-{
-    qCDebug(lcQpaDrawing) << "Backing properties changed for" << self;
-
-    if (self.layer)
-        self.layer.contentsScale = self.window.backingScaleFactor;
-
-    // Ideally we would plumb this situation through QPA in a way that lets
-    // clients invalidate their own caches, recreate QBackingStore, etc.
-    // For now we trigger an expose, and let QCocoaBackingStore deal with
-    // buffer invalidation internally.
-    [self setNeedsDisplay:YES];
-}
-
 @end