Use Ash's ShelfWindowWatcher for app panel windows.

ash/common/shelf/shelf_window_watcher_item_delegate.cc

Index: ash/common/shelf/shelf_window_watcher_item_delegate.cc
diff --git a/ash/common/shelf/shelf_window_watcher_item_delegate.cc b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
index a1450e171d42059cb1f0af117e2f9180ea446c36..3a18d68a98922cda7d01e54519843713dffa5ae0 100644
--- a/ash/common/shelf/shelf_window_watcher_item_delegate.cc
+++ b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
@@ -4,18 +4,61 @@
 
 #include "ash/common/shelf/shelf_window_watcher_item_delegate.h"
 
+#include "ash/common/shelf/shelf_controller.h"
+#include "ash/common/shelf/shelf_model.h"
+#include "ash/common/wm/window_state.h"
+#include "ash/common/wm_lookup.h"
+#include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ui/events/event.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
 
 namespace ash {
 
-ShelfWindowWatcherItemDelegate::ShelfWindowWatcherItemDelegate(WmWindow* window)
-    : window_(window) {}
+namespace {
+
+ShelfItemType GetShelfItemType(ShelfID id) {
+  ShelfModel* model = WmShell::Get()->shelf_controller()->model();
+  ShelfItems::const_iterator item = model->ItemByID(id);
+  return item == model->items().end() ? TYPE_UNDEFINED : item->type;
+}
+
+// Moves |window| to the display where |event| occurred; returns true if moved.
+// Note: This was forked from ash/wm/window_util.h's wm::MoveWindowToEventRoot.
+// TODO(msw): Reduce function copies once aura-as-a-mus-client is resolved.
+bool MoveWindowToEventRoot(WmWindow* window, const ui::Event& event) {

[James Cook, 2016/11/02 17:53:44]

I think there's another copy of this in TestShelfItemDelegate. I'm OK with one
forked copy for mustash, but not two. Can you refactor this to share the code?
Maybe just make it a public static method?

[msw, 2016/11/10 21:07:46]

Done (moved to WmWindow in a prior CL).

+  views::View* target = static_cast<views::View*>(event.target());
+  if (!target)
+    return false;
+  WmWindow* target_root =
+      WmLookup::Get()->GetWindowForWidget(target->GetWidget())->GetRootWindow();
+  if (!target_root || target_root == window->GetRootWindow())
+    return false;
+  WmWindow* window_container = target_root->GetChildByShellWindowId(
+      window->GetParent()->GetShellWindowId());
+  window_container->AddChild(window);
+  return true;
+}
+
+}  // namespace
+
+ShelfWindowWatcherItemDelegate::ShelfWindowWatcherItemDelegate(ShelfID id,
+                                                               WmWindow* window)
+    : id_(id), window_(window) {}
 
 ShelfWindowWatcherItemDelegate::~ShelfWindowWatcherItemDelegate() {}
 
 ShelfItemDelegate::PerformedAction ShelfWindowWatcherItemDelegate::ItemSelected(
     const ui::Event& event) {
+  // Move panels attached on another display to the current display.
+  if (GetShelfItemType(id_) == TYPE_APP_PANEL &&
+      window_->GetWindowState()->panel_attached() &&
+      MoveWindowToEventRoot(window_, event)) {
+    window_->Activate();
+    return kExistingWindowActivated;
+  }
+
   if (window_->IsActive()) {
     if (event.type() & ui::ET_KEY_RELEASED) {
       window_->Animate(::wm::WINDOW_ANIMATION_TYPE_BOUNCE);
@@ -42,10 +85,16 @@ bool ShelfWindowWatcherItemDelegate::IsDraggable() {
 }
 
 bool ShelfWindowWatcherItemDelegate::CanPin() const {
-  return true;
+  return GetShelfItemType(id_) != TYPE_APP_PANEL;
 }
 
 bool ShelfWindowWatcherItemDelegate::ShouldShowTooltip() {
+  // Do not show tooltips for visible attached app panel windows.
+  return GetShelfItemType(id_) != TYPE_APP_PANEL || !window_->IsVisible() ||
+         !window_->GetWindowState()->panel_attached();
+}
+
+bool ShelfWindowWatcherItemDelegate::IsOpen() const {
   return true;
 }