aura-mus: Implement stacking in DesktopWindowTreeHostMus.

services/ui/ws/window_tree.cc

 // 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.
 
 #include "services/ui/ws/window_tree.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1587 matching lines @@
     // The window isn't parented. There's nothing to do.
     DVLOG(1) << "DeactivateWindow failed (window unparented)";
     return;
   }
 
   WindowTree* wm_tree = display_root->window_manager_state()->window_tree();
   wm_tree->window_manager_internal_->WmDeactivateWindow(
       wm_tree->ClientWindowIdForWindow(window).id);
 }
 
+void WindowTree::StackAtTop(uint32_t change_id, Id window_id) {
+  ServerWindow* window =
+      GetWindowByClientId(ClientWindowId(window_id));
+  if (!window) {
+    DVLOG(1) << "StackAtTop failed (invalid id)";
+    client()->OnChangeCompleted(change_id, false);
+    return;
+  }
+
+  ServerWindow* parent = window->parent();
+  if (!parent) {
+    DVLOG(1) << "StackAtTop failed (window unparented)";
+    client()->OnChangeCompleted(change_id, false);
+    return;
+  }
+
+  DCHECK(!parent->children().empty());
+  if (parent->children().back() == window) {
+    // Ignore this call; the client didn't know they were already at the top.
+    DVLOG(1) << "StackAtTop ignored (already at top)";

[sky, 2017/01/19 22:20:59]

As this isn't a failure (response is true), how about changing to 3. 3 better
matches similar places in this file.

[Elliot Glaysher, 2017/01/20 01:03:44]

Done.

+    client()->OnChangeCompleted(change_id, true);
+    return;
+  }
+
+  ServerWindow* relative_window = parent->children().back();

[sky, 2017/01/19 22:20:59]

Please call through to the accesspolicy. See line 1579 for an example. The
access policy should only allow this if the client doesn't own the window, but
the windowmanager does, and the implementation should redirect to the window
manager. Ash will then handle the reorder.

[Elliot Glaysher, 2017/01/20 01:03:44]

I've added an access policy check, though per discussion, it isn't forwarding to
the window manager.

+  Operation op(this, window_server_, OperationType::REORDER_WINDOW);
+  window->Reorder(relative_window, mojom::OrderDirection::ABOVE);
+  window_server_->ProcessWindowReorder(window, relative_window,
+                                       mojom::OrderDirection::ABOVE);
+
+  client()->OnChangeCompleted(change_id, true);
+}
+
 void WindowTree::GetWindowManagerClient(
     mojo::AssociatedInterfaceRequest<mojom::WindowManagerClient> internal) {
   if (!access_policy_->CanSetWindowManager() || !window_manager_internal_ ||
       window_manager_internal_client_binding_) {
     return;
   }
   window_manager_internal_client_binding_.reset(
       new mojo::AssociatedBinding<mojom::WindowManagerClient>(
           this, std::move(internal)));
 }
@@ skipping 412 matching lines @@
   client()->OnCompleteDrop(client_window_id.id, event_flags, cursor_offset,
                            effect_bitmask, callback);
 }
 
 void WindowTree::PerformOnDragDropDone() {
   client()->OnDragDropDone();
 }
 
 }  // namespace ws
 }  // namespace ui