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>
 
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #import "base/mac/sdk_forward_declarations.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
 #import "ui/base/cocoa/constrained_window/constrained_window_animation.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/input_method_factory.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/geometry/dip_util.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 #import "ui/gfx/mac/nswindow_frame_controls.h"
 #import "ui/views/cocoa/bridged_content_view.h"
 #import "ui/views/cocoa/cocoa_mouse_capture.h"
+#import "ui/views/cocoa/cocoa_window_move_loop.h"
 #include "ui/views/cocoa/tooltip_manager_mac.h"
 #import "ui/views/cocoa/views_nswindow_delegate.h"
 #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"
 
@@ skipping 570 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.
+  gfx::Point mouse_in_screen =
+      display::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 display::Display display =
+      display::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:NO 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;
+
+  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();
+}
+
 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];
   }
 }
@@ skipping 98 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 557 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