Implement NativeWidgetMac::ReorderNativeViews

ui/views/cocoa/bridged_native_widget.mm

Index: ui/views/cocoa/bridged_native_widget.mm
diff --git a/ui/views/cocoa/bridged_native_widget.mm b/ui/views/cocoa/bridged_native_widget.mm
index 6f5dec0f96864ede56c8a7cf940de5ebf964aa92..cf2cc00edd6eae412b48f7c403fc52866fc0ecbb 100644
--- a/ui/views/cocoa/bridged_native_widget.mm
+++ b/ui/views/cocoa/bridged_native_widget.mm
@@ -83,6 +83,8 @@ CGError CGSSetWindowBackgroundBlurRadius(CGSConnection connection,
 
 namespace {
 
+using RankMap = std::map<NSView*, int>;
+
 const CGFloat kMavericksMenuOpacity = 251.0 / 255.0;
 const CGFloat kYosemiteMenuOpacity = 194.0 / 255.0;
 const int kYosemiteMenuBlur = 80;
@@ -263,6 +265,38 @@ scoped_refptr<base::SingleThreadTaskRunner> GetCompositorTaskRunner() {
   return task_runner ? task_runner : base::ThreadTaskRunnerHandle::Get();
 }
 
+void RankNSViews(views::View* view,
+                 const views::BridgedNativeWidget::AssociatedViews& hosts,
+                 RankMap* rank) {
+  auto it = hosts.find(view);
+  if (it != hosts.end())
+    rank->emplace(it->second, rank->size());
+  for (int i = 0; i < view->child_count(); ++i)
+    RankNSViews(view->child_at(i), hosts, rank);
+}
+
+NSComparisonResult SubviewSorter(id lhs, id rhs, void* rank_as_void) {

[tapted, 2016/03/17 23:51:27]

Make sure you do a build with xcode 7 too. I had to change this method signature
to

NSComparisonResult SubviewSorter(__kindof NSView* lhs, __kindof NSView* rhs,
void* rank_as_void) 

to avoid

../../ui/views/cocoa/bridged_native_widget.mm:941:54: error: incompatible
pointer types sending 'NSComparisonResult (*)(id, id, void *)' to parameter of
type 'NSComparisonResult (* _Nonnull)(__kindof NSView * _Nonnull, __kindof
NSView * _Nonnull, void * _Nullable)' (aka 'NSComparisonResult (*)(__kindof
NSView * _Nonnull, __kindof NSView * _Nonnull, void * _Nullable)')
[-Werror,-Wincompatible-pointer-types]


However, I think the bots are still xcode 6, and that probably doesn't have
__kindof, so we might need some other way to fix this, or have a #if xcode < 7
check that #defines it to something empty.


Sadly, if you break developer's compiles on xcode 7, that's probably enough to
have the patch quickly reverted, even if no bots break.

+  DCHECK_NE(lhs, rhs);
+
+  const RankMap* rank = static_cast<const RankMap*>(rank_as_void);
+  auto left_rank = rank->find(lhs);
+  auto right_rank = rank->find(rhs);
+  bool left_found = left_rank != rank->end();
+  bool right_found = right_rank != rank->end();
+
+  // Sort unassociated views above associated views.
+  if (left_found != right_found)
+    return left_found ? NSOrderedAscending : NSOrderedDescending;
+
+  if (left_found) {
+    return left_rank->second < right_rank->second ? NSOrderedAscending
+                                                  : NSOrderedDescending;
+  }
+
+  // If both are unassociated, consider that order is not important
+  return NSOrderedSame;
+}
+
 }  // namespace
 
 namespace views {
@@ -884,6 +918,30 @@ void BridgedNativeWidget::CreateLayer(ui::LayerType layer_type,
   UpdateLayerProperties();
 }
 
+void BridgedNativeWidget::SetAssociationForView(const views::View* view,
+                                                NSView* native_view) {
+  DCHECK_EQ(0u, associated_views_.count(view));
+  associated_views_[view] = native_view;
+  native_widget_mac_->GetWidget()->ReorderNativeViews();
+}
+
+void BridgedNativeWidget::ClearAssociationForView(const views::View* view) {
+  auto it = associated_views_.find(view);
+  DCHECK(it != associated_views_.end());
+  associated_views_.erase(it);
+}
+
+void BridgedNativeWidget::ReorderChildViews() {
+  RankMap rank;
+  Widget* widget = native_widget_mac_->GetWidget();
+  RankNSViews(widget->GetRootView(), associated_views_, &rank);
+  // Set compositor view below

[tapted, 2016/03/17 23:04:15]

Yep - this makes sense, but the comment should explain a bit more. E.g.

  // Unassociated NSViews should be ordered above associated ones. The exception
  // is the UI compositor's superview, which should always be on the very
  // bottom, so give it an explicit negative rank.

+  if (compositor_superview_)
+    rank[compositor_superview_.get()] = -1;

[tapted, 2016/03/17 23:04:15]

The .get() shouldn't be required -- scoped_nsobject auto-converts usually

+  [widget->GetNativeView() sortSubviewsUsingFunction:&SubviewSorter

[tapted, 2016/03/17 23:04:15]

widget->GetNativeView() --> bridged_view_ 

+                                             context:&rank];
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BridgedNativeWidget, internal::InputMethodDelegate: