Move mus to //services/ui

components/mus/common/transient_window_utils.h

-// Copyright 2015 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.
-
-#ifndef COMPONENTS_MUS_COMMON_TRANSIENT_WINDOW_UTILS_H_
-#define COMPONENTS_MUS_COMMON_TRANSIENT_WINDOW_UTILS_H_
-
-#include <stddef.h>
-
-#include <vector>
-
-#include "components/mus/public/interfaces/mus_constants.mojom.h"
-
-namespace mus {
-
-// Returns true if |window| has |ancestor| as a transient ancestor. A transient
-// ancestor is found by following the transient parent chain of the window.
-template <class T>
-bool HasTransientAncestor(const T* window, const T* ancestor) {
-  const T* transient_parent = window->transient_parent();
-  if (transient_parent == ancestor)
-    return true;
-  return transient_parent ? HasTransientAncestor(transient_parent, ancestor)
-                          : false;
-}
-
-// Populates |ancestors| with all transient ancestors of |window| that are
-// siblings of |window|. Returns true if any ancestors were found, false if not.
-template <class T>
-bool GetAllTransientAncestors(T* window, std::vector<T*>* ancestors) {
-  T* parent = window->parent();
-  for (; window; window = window->transient_parent()) {
-    if (window->parent() == parent)
-      ancestors->push_back(window);
-  }
-  return !ancestors->empty();
-}
-
-// Replaces |window1| and |window2| with their possible transient ancestors that
-// are still siblings (have a common transient parent).  |window1| and |window2|
-// are not modified if such ancestors cannot be found.
-template <class T>
-void FindCommonTransientAncestor(T** window1, T** window2) {
-  DCHECK(window1);
-  DCHECK(window2);
-  DCHECK(*window1);
-  DCHECK(*window2);
-  // Assemble chains of ancestors of both windows.
-  std::vector<T*> ancestors1;
-  std::vector<T*> ancestors2;
-  if (!GetAllTransientAncestors(*window1, &ancestors1) ||
-      !GetAllTransientAncestors(*window2, &ancestors2)) {
-    return;
-  }
-  // Walk the two chains backwards and look for the first difference.
-  auto it1 = ancestors1.rbegin();
-  auto it2 = ancestors2.rbegin();
-  for (; it1 != ancestors1.rend() && it2 != ancestors2.rend(); ++it1, ++it2) {
-    if (*it1 != *it2) {
-      *window1 = *it1;
-      *window2 = *it2;
-      break;
-    }
-  }
-}
-
-template <class T>
-bool AdjustStackingForTransientWindows(T** child,
-                                       T** target,
-                                       mojom::OrderDirection* direction,
-                                       T* stacking_target) {
-  if (stacking_target == *target)
-    return true;
-
-  // For windows that have transient children stack the transient ancestors that
-  // are siblings. This prevents one transient group from being inserted in the
-  // middle of another.
-  FindCommonTransientAncestor(child, target);
-
-  // When stacking above skip to the topmost transient descendant of the target.
-  if (*direction == mojom::OrderDirection::ABOVE &&
-      !HasTransientAncestor(*child, *target)) {
-    const std::vector<T*>& siblings((*child)->parent()->children());
-    size_t target_i =
-        std::find(siblings.begin(), siblings.end(), *target) - siblings.begin();
-    while (target_i + 1 < siblings.size() &&
-           HasTransientAncestor(siblings[target_i + 1], *target)) {
-      ++target_i;
-    }
-    *target = siblings[target_i];
-  }
-
-  return *child != *target;
-}
-
-// Stacks transient descendants of |window| that are its siblings just above it.
-// |GetStackingTarget| is a function that returns a marker associated with a
-// Window that indicates the current Window being stacked.
-// |Reorder| is a function that takes in two windows and orders the first
-// relative to the second based on the provided OrderDirection.
-template <class T>
-void RestackTransientDescendants(T* window,
-                                 T** (*GetStackingTarget)(T*),
-                                 void (*Reorder)(T*,
-                                                 T*,
-                                                 mojom::OrderDirection)) {
-  T* parent = window->parent();
-  if (!parent)
-    return;
-
-  // stack any transient children that share the same parent to be in front of
-  // |window_|. the existing stacking order is preserved by iterating backwards
-  // and always stacking on top.
-  std::vector<T*> children(parent->children());
-  for (auto it = children.rbegin(); it != children.rend(); ++it) {
-    if ((*it) != window && HasTransientAncestor(*it, window)) {
-      T* old_stacking_target = *GetStackingTarget(*it);
-      *GetStackingTarget(*it) = window;
-      Reorder(*it, window, mojom::OrderDirection::ABOVE);
-      *GetStackingTarget(*it) = old_stacking_target;
-    }
-  }
-}
-}  // namespace mus
-
-#endif  // COMPONENTS_MUS_COMMON_TRANSIENT_WINDOW_UTILS_H_