Reland: mus: Enable system modal windows

components/mus/ws/server_window.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 "components/mus/ws/server_window.h"
 
 #include <inttypes.h>
 #include <stddef.h>
 
 #include "base/strings/stringprintf.h"
 #include "components/mus/common/transient_window_utils.h"
 #include "components/mus/ws/server_window_delegate.h"
 #include "components/mus/ws/server_window_observer.h"
 #include "components/mus/ws/server_window_surface_manager.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
 
 namespace mus {
 
 namespace ws {
 
-namespace {
-
-const ServerWindow* GetModalChildForWindowAncestor(const ServerWindow* window) {
-  for (const ServerWindow* ancestor = window; ancestor;
-       ancestor = ancestor->parent()) {
-    for (const auto& transient_child : ancestor->transient_children()) {
-      if (transient_child->is_modal() && transient_child->IsDrawn())
-        return transient_child;
-    }
-  }
-  return nullptr;
-}
-
-const ServerWindow* GetModalTargetForWindow(const ServerWindow* window) {
-  const ServerWindow* modal_window = GetModalChildForWindowAncestor(window);
-  if (!modal_window)
-    return window;
-  return GetModalTargetForWindow(modal_window);
-}
-
-}  // namespace
-
 ServerWindow::ServerWindow(ServerWindowDelegate* delegate, const WindowId& id)
     : ServerWindow(delegate, id, Properties()) {}
 
 ServerWindow::ServerWindow(ServerWindowDelegate* delegate,
                            const WindowId& id,
                            const Properties& properties)
     : delegate_(delegate),
       id_(id),
       parent_(nullptr),
       stacking_target_(nullptr),
@@ skipping 169 matching lines @@
 
   for (ServerWindow* child : children_) {
     ServerWindow* window = child->GetChildWindow(window_id);
     if (window)
       return window;
   }
 
   return nullptr;
 }
 
-void ServerWindow::AddTransientWindow(ServerWindow* child) {
+bool ServerWindow::AddTransientWindow(ServerWindow* child) {
+  // A system modal window cannot become a transient child.
+  if (child->is_modal() && !child->transient_parent())
+    return false;
+
   if (child->transient_parent())
     child->transient_parent()->RemoveTransientWindow(child);
 
   DCHECK(std::find(transient_children_.begin(), transient_children_.end(),
                    child) == transient_children_.end());
   transient_children_.push_back(child);
   child->transient_parent_ = this;
 
   // Restack |child| properly above its transient parent, if they share the same
   // parent.
   if (child->parent() == parent())
     RestackTransientDescendants(this, &GetStackingTarget, &ReorderImpl);
 
   FOR_EACH_OBSERVER(ServerWindowObserver, observers_,
                     OnTransientWindowAdded(this, child));
+  return true;
 }
 
 void ServerWindow::RemoveTransientWindow(ServerWindow* child) {
   Windows::iterator i =
       std::find(transient_children_.begin(), transient_children_.end(), child);
   DCHECK(i != transient_children_.end());
   transient_children_.erase(i);
   DCHECK_EQ(this, child->transient_parent());
   child->transient_parent_ = nullptr;
 
   // If |child| and its former transient parent share the same parent, |child|
   // should be restacked properly so it is not among transient children of its
   // former parent, anymore.
   if (parent() == child->parent())
     RestackTransientDescendants(this, &GetStackingTarget, &ReorderImpl);
 
   FOR_EACH_OBSERVER(ServerWindowObserver, observers_,
                     OnTransientWindowRemoved(this, child));
 }
 
 void ServerWindow::SetModal() {
   is_modal_ = true;
 }
 
-bool ServerWindow::IsBlockedByModalWindow() const {
-  return !!GetModalChildForWindowAncestor(this);
-}
-
-const ServerWindow* ServerWindow::GetModalTarget() const {
-  return GetModalTargetForWindow(this);
-}
-
 bool ServerWindow::Contains(const ServerWindow* window) const {
   for (const ServerWindow* parent = window; parent; parent = parent->parent_) {
     if (parent == this)
       return true;
   }
   return false;
 }
 
 void ServerWindow::SetVisible(bool value) {
   if (visible_ == value)
@@ skipping 170 matching lines @@
 }
 
 // static
 ServerWindow** ServerWindow::GetStackingTarget(ServerWindow* window) {
   return &window->stacking_target_;
 }
 
 }  // namespace ws
 
 }  // namespace mus