Allow menus to stay open during a child view's drag and drop

chrome/browser/ui/views/toolbar/browser_actions_container.cc

 // Copyright 2013 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.
 
 #include "chrome/browser/ui/views/toolbar/browser_actions_container.h"
 
 #include "base/compiler_specific.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 24 matching lines @@
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/dragdrop/drag_utils.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/nine_image_painter_factory.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/views/controls/button/label_button_border.h"
+#include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/controls/resize_area.h"
 #include "ui/views/metrics.h"
 #include "ui/views/painter.h"
 #include "ui/views/widget/widget.h"
 
 using extensions::Extension;
 
 namespace {
 
 // Horizontal spacing between most items in the container, as well as after the
@@ skipping 402 matching lines @@
   // the center of the drop indicator at the midpoint of the space before our
   // chosen icon.
   SetDropIndicator(width_before_icons + (before_icon * IconWidth(true)) -
       (kItemSpacing / 2));
 
   return ui::DragDropTypes::DRAG_MOVE;
 }
 
 void BrowserActionsContainer::OnDragExited() {
   StopShowFolderDropMenuTimer();
+  if (in_overflow_mode()) {

[sky, 2014/07/09 16:09:16]

This is too fragile. The menu code should change so that you don't have to do
anything special here, dnd from a view on the menu just works.

I'm not sure of the ideal route to make that happen, I would have to do a bit
more investigation. I'm just getting back from vacation and so rather behind. I
can take a look later in the week or next week if you get stuck.

[Devlin, 2014/07/09 18:03:41]

Okay - let's try this approach.  It seems to fit the requirement of "just
working" from the view's perspective. :)
I'll keep plugging away for a bit, and see what I can come up with.  If nothing
else, the background will be useful.  If you can keep sparing a few minutes here
and there to lemme know if I'm on the right track, that'd be great. :)

+    views::MenuController* controller =
+        views::MenuController::GetActiveInstance();
+    // Notify the controller that we finished our drag.
+    if (controller)
+      controller->set_drag_in_progress(false);
+    // During the drag, the widget lost mouse capture (even though it
+    // conceptually retained it). Reset the capture to this so that future
+    // capture losses (like clicking outside of the menu) register again.
+    GetWidget()->SetCapture(this);
+  }
   drop_indicator_position_ = -1;
   SchedulePaint();
 }
 
 int BrowserActionsContainer::OnPerformDrop(
     const ui::DropTargetEvent& event) {
   BrowserActionDragData data;
   if (!data.Read(event.data()))
     return ui::DragDropTypes::DRAG_NONE;
 
@@ skipping 47 matching lines @@
     overflow_menu_->set_observer(this);
     overflow_menu_->RunMenu(GetWidget(), false);
   }
 }
 
 void BrowserActionsContainer::WriteDragDataForView(View* sender,
                                                    const gfx::Point& press_pt,
                                                    OSExchangeData* data) {
   DCHECK(data);
 
+  if (in_overflow_mode()) {
+    views::MenuController* controller =
+        views::MenuController::GetActiveInstance();
+    // Notify the controller that a drag is in progress so that reported
+    // capture losses are ignored appropriately.
+    if (controller)
+      controller->set_drag_in_progress(true);
+  }
   for (size_t i = 0; i < browser_action_views_.size(); ++i) {
     BrowserActionButton* button = browser_action_views_[i]->button();
     if (button == sender) {
       // Set the dragging image for the icon.
       gfx::ImageSkia badge(browser_action_views_[i]->GetIconWithBadge());
       drag_utils::SetDragImageOnDataObject(badge,
                                            press_pt.OffsetFromOrigin(),
                                            data);
 
       // Fill in the remaining info.
@@ skipping 509 matching lines @@
                                      views::BubbleBorder::TOP_RIGHT,
                                      show_action);
   popup_->GetWidget()->AddObserver(this);
   popup_button_ = button;
 
   // Only set button as pushed if it was triggered by a user click.
   if (should_grant)
     popup_button_->SetButtonPushed();
   return true;
 }