MacViews: Allow views::Widgets to be parented off NSWindows

ui/views/cocoa/widget_owner_nswindow_adapter.mm

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ui/views/cocoa/widget_owner_nswindow_adapter.h"
+
+#import <Cocoa/Cocoa.h>
+
+#include "base/logging.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/vector2d.h"
+#import "ui/gfx/mac/coordinate_conversion.h"
+#import "ui/views/cocoa/bridged_native_widget.h"
+
+// Bridges an AppKit observer to observe when the (non-views) NSWindow owning a
+// views::Widget will close.
+@interface WidgetOwnerNSWindowAdapterBridge : NSObject {
+ @private
+  views::WidgetOwnerNSWindowAdapter* adapter_;  // Weak. Owns us.
+}
+- (instancetype)initWithAdapter:(views::WidgetOwnerNSWindowAdapter*)adapter;
+- (void)windowWillClose:(NSNotification*)notification;
+@end
+
+@implementation WidgetOwnerNSWindowAdapterBridge
+
+- (instancetype)initWithAdapter:(views::WidgetOwnerNSWindowAdapter*)adapter {
+  if ((self = [super init]))
+    adapter_ = adapter;
+  return self;
+}
+
+- (void)windowWillClose:(NSNotification*)notification {
+  adapter_->OnWindowWillClose();
+}
+
+@end
+
+namespace views {
+
+WidgetOwnerNSWindowAdapter::WidgetOwnerNSWindowAdapter(
+    BridgedNativeWidget* child,
+    NSView* anchor_view)
+    : child_(child),
+      anchor_view_([anchor_view retain]),
+      observer_bridge_(
+          [[WidgetOwnerNSWindowAdapterBridge alloc] initWithAdapter:this]) {
+  DCHECK([anchor_view_ window]);
+  [[NSNotificationCenter defaultCenter]
+      addObserver:observer_bridge_
+         selector:@selector(windowWillClose:)
+             name:NSWindowWillCloseNotification
+           object:[anchor_view_ window]];
+}
+
+void WidgetOwnerNSWindowAdapter::OnWindowWillClose() {
+  [child_->ns_window() close];
+  // Note: |this| will be deleted here.
+}
+
+NSWindow* WidgetOwnerNSWindowAdapter::GetNSWindow() {
+  return [anchor_view_ window];
+}
+
+gfx::Vector2d WidgetOwnerNSWindowAdapter::GetChildWindowOffset() const {
+  NSWindow* window = [anchor_view_ window];
+  NSRect rect_in_window =
+      [anchor_view_ convertRect:[anchor_view_ bounds] toView:nil];
+  // Ensure we anchor off the top-left of |anchor_view_| (rect_in_window.origin
+  // is the bottom-left of the view).
+  // TODO(tapted): Use -[NSWindow convertRectToScreen:] when we ditch 10.6.
+  NSRect rect_in_screen = NSZeroRect;
+  rect_in_screen.origin =
+      [window convertBaseToScreen:NSMakePoint(NSMinX(rect_in_window),
+                                              NSMaxY(rect_in_window))];
+  return gfx::ScreenRectFromNSRect(rect_in_screen).OffsetFromOrigin();
+}
+
+bool WidgetOwnerNSWindowAdapter::IsVisibleParent() const {
+  return [[anchor_view_ window] isVisible];
+}
+
+void WidgetOwnerNSWindowAdapter::RemoveChildWindow(BridgedNativeWidget* child) {
+  DCHECK_EQ(child, child_);
+  [GetNSWindow() removeChildWindow:child->ns_window()];
+  delete this;
+}
+
+WidgetOwnerNSWindowAdapter::~WidgetOwnerNSWindowAdapter() {
+  [[NSNotificationCenter defaultCenter] removeObserver:observer_bridge_];
+}
+
+}  // namespace views