MacViews: Implement Tab Dragging

ui/views/cocoa/bridged_native_widget.mm

 // Copyright 2014 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/bridged_native_widget.h"
 
 #import <objc/runtime.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 19 matching lines @@
 #import "ui/views/cocoa/widget_owner_nswindow_adapter.h"
 #include "ui/views/view.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/native_widget_mac.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_aura_utils.h"
 #include "ui/views/widget/widget_delegate.h"
 
 extern "C" {
 
+typedef int32_t CGSWindow;
 typedef int32_t CGSConnection;
 CGSConnection _CGSDefaultConnection();
+OSStatus CGSGetWindowBounds(CGSConnection connection,
+                            CGSWindow window,
+                            CGRect* bounds);
 CGError CGSSetWindowBackgroundBlurRadius(CGSConnection connection,
                                          NSInteger windowNumber,
                                          int radius);
 
 }
 
 // The NSView that hosts the composited CALayer drawing the UI. It fills the
 // window but is not hittable so that accessibility hit tests always go to the
 // BridgedContentView.
 @interface ViewsCompositorSuperview : NSView
@@ skipping 144 matching lines @@
   NSInteger event_number = [ns_event eventNumber];
 
   // The logic here is a bit convoluted because we want to mitigate race
   // conditions if somehow a different mouse-down occurs between reposts.
   // Specifically, we want to avoid:
   // - BridgedNativeWidget's draggability getting out of sync (e.g. if it is
   //   draggable outside of a repost cycle),
   // - any repost loop.
 
   if (repost_state == NONE) {
+    if (CGEventGetIntegerValueField([ns_event CGEvent],
+                                    kCGEventSourceUserData) ==
+        views::CocoaWindowMoveLoop::
+            kCocoaWindowMoveLoopSimulatedEventUserData) {
+      return ns_event;
+    }
+
     if (WindowWantsMouseDownReposted(ns_event)) {
       repost_state = EXPECTING_REPOST;
       reposted_event_number = event_number;
       CGEventPost(kCGSessionEventTap, [ns_event CGEvent]);
       return nil;
     }
 
     return ns_event;
   }
 
@@ skipping 392 matching lines @@
 }
 
 void BridgedNativeWidget::ReleaseCapture() {
   mouse_capture_.reset();
 }
 
 bool BridgedNativeWidget::HasCapture() {
   return mouse_capture_ && mouse_capture_->IsActive();
 }
 
+Widget::MoveLoopResult BridgedNativeWidget::RunMoveLoop(
+      const gfx::Vector2d& drag_offset) {
+  DCHECK(!HasCapture());
+  DCHECK(!window_move_loop_);
+
+  // First, position the window in the right place. The point |drag_offset|
+  // away from the top-left corner needs to be positioned under the mouse.
+  // TODO(tapted): Figure out why the toolkit-views drag controller doesn't get
+  // this right when it first initializes the Widget.
+  gfx::Point mouse_in_screen = gfx::Screen::GetScreen()->GetCursorScreenPoint();
+
+  // A window can't be moved vertically up out of the work area. Treat this case
+  // as if the mouse location is at the point it would be when the window first
+  // stopped moving. That is, vertically down such that the top edge of the
+  // window touches the menubar (or top of the screen in a dual-screen setup).
+  // Note on Mac we can assume that the y-coordinate of the work area origin is
+  // the bottom of the menu bar and not the Dock which doesn't affect window
+  // movement, but can reduce the work area on the bottom, left and right.
+  const gfx::Display display =
+      gfx::Screen::GetScreen()->GetDisplayNearestPoint(mouse_in_screen);
+  const int min_y = display.work_area().y() + drag_offset.y();
+  if (mouse_in_screen.y() < min_y)
+    mouse_in_screen.set_y(min_y);
+
+  gfx::Rect frame = gfx::ScreenRectFromNSRect([window_ frame]);
+  frame.set_x(mouse_in_screen.x() - drag_offset.x());
+  frame.set_y(mouse_in_screen.y() - drag_offset.y());
+  DCHECK_GE(frame.y(), display.work_area().y());
+
+  // After setting the frame to correct the initial offset, the drag controller
+  // may immediately want to quit when it's notified of the new bounds. So the
+  // MoveLoop must be set up before the call to setFrame.
+  window_move_loop_.reset(new CocoaWindowMoveLoop(this, mouse_in_screen));
+
+  const NSRect ns_frame = gfx::ScreenRectToNSRect(frame);
+  [window_ setFrame:ns_frame display:YES animate:NO];
+
+  // Setting the frame will call OnWidgetBoundsChanged(), which could result in
+  // a call to EndMoveLoop().
+  if (!window_move_loop_)
+    return Widget::MOVE_LOOP_SUCCESSFUL;
+
+  // Make sure WindowServer has caught up with moving the window, this is
+  // required in order to send the MouseDown click to the intended position.
+  // El Capitan would always replicate the old window coordinates when calling
+  // CGSGetWindowBounds().
+  // DetachToBrowserTabDragControllerTest.MacDetachesAndReattachesSecondTab will
+  // fail without the following NSRunLoop pass.
+  [[NSRunLoop currentRunLoop]
+      runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0]];
+  DCHECK(NSEqualRects(ns_frame, WindowServerFrame()));
+
+  return window_move_loop_->Run();
+
+  // |this| may be destroyed during the RunLoop, causing it to exit early.
+  // Even if that doesn't happen, CocoaWindowMoveLoop will clean itself up by
+  // calling EndMoveLoop(). So window_move_loop_ will always be null before the
+  // function returns. But don't DCHECK since |this| might not be valid.
+}
+
+void BridgedNativeWidget::EndMoveLoop() {
+  DCHECK(window_move_loop_);
+  window_move_loop_->End();
+  window_move_loop_.reset();
+}
+
+bool BridgedNativeWidget::IsRunMoveLoopActive() const {
+  return window_move_loop_.get();
+}
+
 void BridgedNativeWidget::SetNativeWindowProperty(const char* name,
                                                   void* value) {
   NSString* key = [NSString stringWithUTF8String:name];
   if (value) {
     [GetWindowProperties() setObject:[NSValue valueWithPointer:value]
                               forKey:key];
   } else {
     [GetWindowProperties() removeObjectForKey:key];
   }
 }
 
 void* BridgedNativeWidget::GetNativeWindowProperty(const char* name) const {
   NSString* key = [NSString stringWithUTF8String:name];
   return [[GetWindowProperties() objectForKey:key] pointerValue];
 }
 
 void BridgedNativeWidget::SetCursor(NSCursor* cursor) {
   [window_delegate_ setCursor:cursor];
 }
 
 void BridgedNativeWidget::OnWindowWillClose() {
+  DCHECK(!drag_run_loop_);
   if (parent_) {
     parent_->RemoveChildWindow(this);
     parent_ = nullptr;
   }
   [window_ setDelegate:nil];
   [[NSNotificationCenter defaultCenter] removeObserver:window_delegate_];
   native_widget_mac_->OnWindowWillClose();
 }
 
 void BridgedNativeWidget::OnFullscreenTransitionStart(
@@ skipping 77 matching lines @@
 
   // 10.9 is unable to generate a window shadow from the composited CALayer, so
   // use Quartz.
   // We don't update the window mask during a live resize, instead it is done
   // after the resize is completed in viewDidEndLiveResize: in
   // BridgedContentView.
   if (base::mac::IsOSMavericksOrEarlier() && ![window_ inLiveResize])
     [bridged_view_ updateWindowMask];
 }
 
+void BridgedNativeWidget::OnPositionChanged() {
+  native_widget_mac_->GetWidget()->OnNativeWidgetMove();
+}
+
 void BridgedNativeWidget::OnVisibilityChanged() {
   OnVisibilityChangedTo([window_ isVisible]);
 }
 
 void BridgedNativeWidget::OnVisibilityChangedTo(bool new_visibility) {
   if (window_visible_ == new_visibility)
     return;
 
   window_visible_ = new_visibility;
 
@@ skipping 133 matching lines @@
   return input_method_.get();
 }
 
 gfx::Rect BridgedNativeWidget::GetRestoredBounds() const {
   if (target_fullscreen_state_ || in_fullscreen_transition_)
     return bounds_before_fullscreen_;
 
   return gfx::ScreenRectFromNSRect([window_ frame]);
 }
 
+NSRect BridgedNativeWidget::WindowServerFrame() const {
+  CGRect bounds = NSZeroRect;
+  CGSGetWindowBounds(_CGSDefaultConnection(), [window_ windowNumber],
+                     &bounds);
+  NSRect rect = ScreenRectToNSRect(gfx::Rect(bounds));
+  rect.size = [window_ frame].size;
+  return rect;
+}
+
 void BridgedNativeWidget::CreateLayer(ui::LayerType layer_type,
                                       bool translucent) {
   DCHECK(bridged_view_);
   DCHECK(!layer());
 
   CreateCompositor();
   DCHECK(compositor_);
 
   SetLayer(new ui::Layer(layer_type));
   // Note, except for controls, this will set the layer to be hidden, since it
@@ skipping 401 matching lines @@
   [bridged_view_ setMouseDownCanMoveWindow:draggable];
   // AppKit will not update its cache of mouseDownCanMoveWindow unless something
   // changes. Previously we tried adding an NSView and removing it, but for some
   // reason it required reposting the mouse-down event, and didn't always work.
   // Calling the below seems to be an effective solution.
   [window_ setMovableByWindowBackground:NO];
   [window_ setMovableByWindowBackground:YES];
 }
 
 }  // namespace views