Pulls display related changes from mojo to chrome

mojo/services/view_manager/gesture_manager.cc

Index: mojo/services/view_manager/gesture_manager.cc
diff --git a/mojo/services/view_manager/gesture_manager.cc b/mojo/services/view_manager/gesture_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1b312bd6b0e4d9c1567df0aff3b6f20fdaa4e26d
--- /dev/null
+++ b/mojo/services/view_manager/gesture_manager.cc
@@ -0,0 +1,701 @@
+// 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.
+
+#include "mojo/services/view_manager/gesture_manager.h"
+
+#include <algorithm>
+
+#include "mojo/services/view_manager/gesture_manager_delegate.h"
+#include "mojo/services/view_manager/server_view.h"
+#include "mojo/services/view_manager/view_coordinate_conversions.h"
+#include "mojo/services/view_manager/view_locator.h"
+#include "third_party/mojo_services/src/input_events/public/interfaces/input_events.mojom.h"
+#include "third_party/mojo_services/src/view_manager/public/cpp/keys.h"
+#include "ui/gfx/geometry/point_f.h"
+
+namespace view_manager {
+
+using Views = std::vector<const ServerView*>;
+
+namespace {
+
+GestureManager::GestureAndConnectionId MakeGestureAndConnectionId(
+    const ServerView* view,
+    uint32_t gesture_id) {
+  return (static_cast<GestureManager::GestureAndConnectionId>(
+              view->id().connection_id)
+          << 32) |
+         gesture_id;
+}
+
+// Returns the views (deepest first) that should receive touch events. This only
+// returns one view per connection. If multiple views from the same connection
+// are interested in touch events the shallowest view is returned.
+Views GetTouchTargets(const ServerView* deepest) {
+  Views result;
+  const ServerView* view = deepest;
+  while (view) {
+    if (view->properties().count(mojo::kViewManagerKeyWantsTouchEvents)) {
+      if (!result.empty() &&
+          result.back()->id().connection_id == view->id().connection_id) {
+        result.pop_back();
+      }
+      result.push_back(view);
+    }
+    view = view->parent();
+  }
+  // TODO(sky): I'm doing this until things are converted. Seems as though we
+  // shouldn't do this long term.
+  if (result.empty())
+    result.push_back(deepest);
+  return result;
+}
+
+mojo::EventPtr CloneEventForView(const mojo::Event& event,
+                                 const ServerView* view) {
+  mojo::EventPtr result(event.Clone());
+  const gfx::PointF location(event.pointer_data->x, event.pointer_data->y);
+  const gfx::PointF target_location(
+      ConvertPointFBetweenViews(view->GetRoot(), view, location));
+  result->pointer_data->x = target_location.x();
+  result->pointer_data->y = target_location.y();
+  return result.Pass();
+}
+
+}  // namespace
+
+// GestureStateChange ----------------------------------------------------------
+
+GestureStateChange::GestureStateChange()
+    : chosen_gesture(GestureManager::kInvalidGestureId) {
+}
+
+GestureStateChange::~GestureStateChange() {
+}
+
+// ViewIterator ----------------------------------------------------------------
+
+// Used to iterate over a set of views.
+class ViewIterator {
+ public:
+  explicit ViewIterator(const Views& views)
+      : views_(views), current_(views_.begin()) {}
+
+  // Advances to the next view. Returns true if there are no more views (at
+  // the end).
+  bool advance() { return ++current_ != views_.end(); }
+
+  bool at_end() const { return current_ == views_.end(); }
+
+  bool empty() const { return views_.empty(); }
+
+  const ServerView* current() const { return *current_; }
+
+  void reset_to_beginning() { current_ = views_.begin(); }
+
+  void remove(const ServerView* view) {
+    Views::iterator iter = std::find(views_.begin(), views_.end(), view);
+    DCHECK(iter != views_.end());
+    if (iter == current_) {
+      current_ = views_.erase(current_);
+    } else if (!at_end()) {
+      size_t index = current_ - views_.begin();
+      if (current_ > iter)
+        index--;
+      views_.erase(iter);
+      current_ = views_.begin() + index;
+    } else {
+      views_.erase(iter);
+      current_ = views_.end();
+    }
+  }
+
+  bool contains(const ServerView* view) const {
+    return std::find(views_.begin(), views_.end(), view) != views_.end();
+  }
+
+ private:
+  Views views_;
+  Views::iterator current_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViewIterator);
+};
+
+// PointerAndView --------------------------------------------------------------
+
+struct GestureManager::PointerAndView {
+  PointerAndView();
+  PointerAndView(Pointer* pointer, const ServerView* view);
+
+  // Compares two PointerAndView instances based on pointer id, then view id.
+  // This is really only interesting for unit tests so that they get a known
+  // order of events.
+  bool operator<(const PointerAndView& other) const;
+
+  Pointer* pointer;
+  const ServerView* view;
+};
+
+// Gesture ---------------------------------------------------------------------
+
+// Gesture maintains the set of pointers and views it is attached to.
+class GestureManager::Gesture {
+ public:
+  enum State { STATE_INITIAL, STATE_CANCELED, STATE_CHOSEN };
+
+  explicit Gesture(uint32_t id);
+  ~Gesture();
+
+  uint32_t id() const { return id_; }
+
+  void Attach(Pointer* pointer, const ServerView* view);
+  void Detach(Pointer* pointer, const ServerView* view);
+
+  void set_state(State state) { state_ = state; }
+  State state() const { return state_; }
+
+  const std::set<PointerAndView>& pointers_and_views() const {
+    return pointers_and_views_;
+  }
+
+ private:
+  const uint32_t id_;
+  State state_;
+  std::set<PointerAndView> pointers_and_views_;
+
+  DISALLOW_COPY_AND_ASSIGN(Gesture);
+};
+
+GestureManager::Gesture::Gesture(uint32_t id) : id_(id), state_(STATE_INITIAL) {
+}
+
+GestureManager::Gesture::~Gesture() {
+}
+
+void GestureManager::Gesture::Attach(Pointer* pointer, const ServerView* view) {
+  pointers_and_views_.insert(PointerAndView(pointer, view));
+}
+
+void GestureManager::Gesture::Detach(Pointer* pointer, const ServerView* view) {
+  pointers_and_views_.erase(PointerAndView(pointer, view));
+}
+
+// Pointer ---------------------------------------------------------------------
+
+// Pointer manages the state associated with a particular pointer from the time
+// of the POINTER_DOWN to the time of the POINTER_UP (or POINTER_CANCEL). This
+// state includes a mapping from view to the set of gestures the view is
+// interested in. It also manages choosing gestures at the appropriate point as
+// well as which view to dispatch to and the events to dispatch.
+// See description in GestureManager for more.
+class GestureManager::Pointer {
+ public:
+  Pointer(GestureManager* gesture_manager,
+          int32_t pointer_id,
+          const mojo::Event& event,
+          const Views& views);
+  ~Pointer();
+
+  int32_t pointer_id() const { return pointer_id_; }
+  bool was_chosen_or_canceled() const { return was_chosen_or_canceled_; }
+
+  // Sets the set of gestures for this pointer.
+  void SetGestures(const ServerView* view,
+                   uint32_t chosen_gesture_id,
+                   const std::set<uint32_t>& possible_gesture_ids,
+                   const std::set<uint32_t>& canceled_ids);
+
+  // Called when a Gesture we contain has been canceled.
+  void GestureCanceled(Gesture* gesture);
+
+  // Called when a Gesture we contain has been chosen.
+  void GestureChosen(Gesture* gesture, const ServerView* view);
+
+  // Process a move or up event. This may delay processing if we're waiting for
+  // previous results.
+  void ProcessEvent(const mojo::Event& event);
+
+ private:
+  // Corresponds to the type of event we're dispatching.
+  enum Phase {
+    // We're dispatching the initial down.
+    PHASE_DOWN,
+
+    // We're dispatching a move.
+    PHASE_MOVE,
+  };
+
+  // Sends the event for the current phase to the delegate.
+  void ForwardCurrentEvent();
+
+  // Moves |pending_event_| to |current_event_| and notifies the delegate.
+  void MovePendingToCurrentAndProcess();
+
+  // If |was_chosen_or_canceled_| is false and there is only one possible
+  // gesture and it is in the initial state, choose it. Otherwise do nothing.
+  void ChooseGestureIfPossible();
+
+  bool ScheduleDeleteIfNecessary();
+
+  GestureManager* gesture_manager_;
+  const int32_t pointer_id_;
+  Phase phase_;
+
+  // Used to iterate over the set of views that potentially have gestures.
+  ViewIterator view_iter_;
+
+  // Maps from the view to the set of possible gestures for the view.
+  std::map<const ServerView*, std::set<Gesture*>> view_to_gestures_;
+
+  Gesture* chosen_gesture_;
+
+  bool was_chosen_or_canceled_;
+
+  // The event we're processing. When initially created this is the supplied
+  // down event. When in PHASE_MOVE this is a move event.
+  mojo::EventPtr current_event_;
+
+  // Incoming events (move or up) are added here while while waiting for
+  // responses.
+  mojo::EventPtr pending_event_;
+
+  DISALLOW_COPY_AND_ASSIGN(Pointer);
+};
+
+GestureManager::Pointer::Pointer(GestureManager* gesture_manager,
+                                 int32_t pointer_id,
+                                 const mojo::Event& event,
+                                 const Views& views)
+    : gesture_manager_(gesture_manager),
+      pointer_id_(pointer_id),
+      phase_(PHASE_DOWN),
+      view_iter_(views),
+      chosen_gesture_(nullptr),
+      was_chosen_or_canceled_(false),
+      current_event_(event.Clone()) {
+  ForwardCurrentEvent();
+}
+
+GestureManager::Pointer::~Pointer() {
+  for (auto& pair : view_to_gestures_) {
+    for (Gesture* gesture : pair.second)
+      gesture_manager_->DetachGesture(gesture, this, pair.first);
+  }
+}
+
+void GestureManager::Pointer::SetGestures(
+    const ServerView* view,
+    uint32_t chosen_gesture_id,
+    const std::set<uint32_t>& possible_gesture_ids,
+    const std::set<uint32_t>& canceled_gesture_ids) {
+  if (!view_iter_.contains(view)) {
+    // We don't know about this view.
+    return;
+  }
+
+  // True if this is the view we're waiting for a response from.
+  const bool was_waiting_on =
+      (!was_chosen_or_canceled_ &&
+       (!view_iter_.at_end() && view_iter_.current() == view));
+
+  if (possible_gesture_ids.empty()) {
+    // The view no longer wants to be notified.
+    for (Gesture* gesture : view_to_gestures_[view])
+      gesture_manager_->DetachGesture(gesture, this, view);
+    view_to_gestures_.erase(view);
+    view_iter_.remove(view);
+    if (view_iter_.empty()) {
+      gesture_manager_->PointerHasNoGestures(this);
+      // WARNING: we've been deleted.
+      return;
+    }
+  } else {
+    if (was_waiting_on)
+      view_iter_.advance();
+
+    Gesture* to_choose = nullptr;
+    std::set<Gesture*> gestures;
+    for (auto gesture_id : possible_gesture_ids) {
+      Gesture* gesture = gesture_manager_->GetGesture(view, gesture_id);
+      gesture_manager_->AttachGesture(gesture, this, view);
+      gestures.insert(gesture);
+      if (gesture->state() == Gesture::STATE_CHOSEN &&
+          !was_chosen_or_canceled_) {
+        to_choose = gesture;
+      }
+    }
+
+    // Give preference to the supplied |chosen_gesture_id|.
+    if (!was_chosen_or_canceled_ && chosen_gesture_id != kInvalidGestureId) {
+      Gesture* gesture = gesture_manager_->GetGesture(view, chosen_gesture_id);
+      if (gesture->state() != Gesture::STATE_CANCELED)
+        to_choose = gesture;
+
+      DCHECK(possible_gesture_ids.count(gesture->id()));
+      gesture_manager_->AttachGesture(gesture, this, view);
+    }
+
+    // Tell GestureManager of any Gestures we're no longer associated with.
+    std::set<Gesture*> removed_gestures;
+    std::set_difference(
+        view_to_gestures_[view].begin(), view_to_gestures_[view].end(),
+        gestures.begin(), gestures.end(),
+        std::inserter(removed_gestures, removed_gestures.begin()));
+    view_to_gestures_[view].swap(gestures);
+    for (Gesture* gesture : removed_gestures)
+      gesture_manager_->DetachGesture(gesture, this, view);
+
+    if (chosen_gesture_ && removed_gestures.count(chosen_gesture_))
+      chosen_gesture_ = nullptr;
+
+    if (to_choose) {
+      gesture_manager_->ChooseGesture(to_choose, this, view);
+    } else {
+      // Choosing a gesture implicitly cancels all other gestures. If we didn't
+      // choose a gesture we need to update the state of any newly added
+      // gestures.
+      for (Gesture* gesture : gestures) {
+        if (gesture != chosen_gesture_ &&
+            (was_chosen_or_canceled_ ||
+             canceled_gesture_ids.count(gesture->id()))) {
+          gesture_manager_->CancelGesture(gesture, this, view);
+        }
+      }
+    }
+  }
+
+  if (was_waiting_on && !was_chosen_or_canceled_) {
+    if (view_iter_.at_end()) {
+      if (ScheduleDeleteIfNecessary())
+        return;
+      // If we're got all the responses, check if there is only one valid
+      // gesture.
+      ChooseGestureIfPossible();
+      if (!was_chosen_or_canceled_) {
+        // There is more than one valid gesture and none chosen. Continue
+        // synchronous dispatch of move events.
+        phase_ = PHASE_MOVE;
+        MovePendingToCurrentAndProcess();
+      }
+    } else {
+      ForwardCurrentEvent();
+    }
+  } else if (!was_chosen_or_canceled_ && phase_ != PHASE_DOWN) {
+    // We weren't waiting on this view but we're in the move phase. The set of
+    // gestures may have changed such that we only have one valid gesture. Check
+    // for that.
+    ChooseGestureIfPossible();
+  }
+}
+
+void GestureManager::Pointer::GestureCanceled(Gesture* gesture) {
+  if (was_chosen_or_canceled_ && gesture == chosen_gesture_) {
+    chosen_gesture_ = nullptr;
+    // No need to cancel other gestures as they are already canceled by virtue
+    // of us having been chosen.
+  } else if (!was_chosen_or_canceled_ && phase_ == PHASE_MOVE) {
+    ChooseGestureIfPossible();
+  }
+}
+
+void GestureManager::Pointer::GestureChosen(Gesture* gesture,
+                                            const ServerView* view) {
+  DCHECK(!was_chosen_or_canceled_);
+  was_chosen_or_canceled_ = true;
+  chosen_gesture_ = gesture;
+  for (auto& pair : view_to_gestures_) {
+    for (Gesture* g : pair.second) {
+      if (g != gesture)
+        gesture_manager_->CancelGesture(g, this, pair.first);
+    }
+  }
+
+  while (!view_iter_.at_end()) {
+    ForwardCurrentEvent();
+    view_iter_.advance();
+  }
+  if (ScheduleDeleteIfNecessary())
+    return;
+  phase_ = PHASE_MOVE;
+  MovePendingToCurrentAndProcess();
+}
+
+void GestureManager::Pointer::ProcessEvent(const mojo::Event& event) {
+  // |event| is either a move or up. In either case it has the new coordinates
+  // and is safe to replace the existing one with.
+  pending_event_ = event.Clone();
+  if (was_chosen_or_canceled_) {
+    MovePendingToCurrentAndProcess();
+  } else if (view_iter_.at_end()) {
+    view_iter_.reset_to_beginning();
+    MovePendingToCurrentAndProcess();
+  }
+  // The else case is we are waiting on a response from a view before we
+  // continue dispatching. When we get the response for the last view in the
+  // stack we'll move pending to current and start dispatching it.
+}
+
+void GestureManager::Pointer::ForwardCurrentEvent() {
+  DCHECK(!view_iter_.at_end());
+  const ServerView* view = view_iter_.current();
+  gesture_manager_->delegate_->ProcessEvent(
+      view, CloneEventForView(*current_event_, view), was_chosen_or_canceled_);
+}
+
+void GestureManager::Pointer::MovePendingToCurrentAndProcess() {
+  if (!pending_event_.get()) {
+    current_event_ = nullptr;
+    return;
+  }
+  current_event_ = pending_event_.Pass();
+  view_iter_.reset_to_beginning();
+  ForwardCurrentEvent();
+  if (was_chosen_or_canceled_) {
+    while (view_iter_.advance())
+      ForwardCurrentEvent();
+    if (ScheduleDeleteIfNecessary())
+      return;
+    current_event_ = nullptr;
+  }
+}
+
+void GestureManager::Pointer::ChooseGestureIfPossible() {
+  if (was_chosen_or_canceled_)
+    return;
+
+  Gesture* gesture_to_choose = nullptr;
+  const ServerView* view = nullptr;
+  for (auto& pair : view_to_gestures_) {
+    for (Gesture* gesture : pair.second) {
+      if (gesture->state() == Gesture::STATE_INITIAL) {
+        if (gesture_to_choose)
+          return;
+        view = pair.first;
+        gesture_to_choose = gesture;
+      }
+    }
+  }
+  if (view)
+    gesture_manager_->ChooseGesture(gesture_to_choose, this, view);
+}
+
+bool GestureManager::Pointer::ScheduleDeleteIfNecessary() {
+  if (current_event_ &&
+      (current_event_->action == mojo::EVENT_TYPE_POINTER_UP ||
+       current_event_->action == mojo::EVENT_TYPE_POINTER_CANCEL)) {
+    gesture_manager_->ScheduleDelete(this);
+    return true;
+  }
+  return false;
+}
+
+// ScheduledDeleteProcessor ---------------------------------------------------
+
+class GestureManager::ScheduledDeleteProcessor {
+ public:
+  explicit ScheduledDeleteProcessor(GestureManager* manager)
+      : manager_(manager) {}
+
+  ~ScheduledDeleteProcessor() { manager_->pointers_to_delete_.clear(); }
+
+ private:
+  GestureManager* manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScheduledDeleteProcessor);
+};
+
+// PointerAndView --------------------------------------------------------------
+
+GestureManager::PointerAndView::PointerAndView()
+    : pointer(nullptr), view(nullptr) {
+}
+
+GestureManager::PointerAndView::PointerAndView(Pointer* pointer,
+                                               const ServerView* view)
+    : pointer(pointer), view(view) {
+}
+
+bool GestureManager::PointerAndView::operator<(
+    const PointerAndView& other) const {
+  if (other.pointer->pointer_id() == pointer->pointer_id())
+    return view->id().connection_id < other.view->id().connection_id;
+  return pointer->pointer_id() < other.pointer->pointer_id();
+}
+
+// GestureManager --------------------------------------------------------------
+
+// static
+const uint32_t GestureManager::kInvalidGestureId = 0u;
+
+GestureManager::GestureManager(GestureManagerDelegate* delegate,
+                               const ServerView* root)
+    : delegate_(delegate), root_view_(root) {
+}
+
+GestureManager::~GestureManager() {
+  // Explicitly delete the pointers first as this may result in calling back to
+  // us to cleanup and delete gestures.
+  active_pointers_.clear();
+}
+
+bool GestureManager::ProcessEvent(const mojo::Event& event) {
+  if (!event.pointer_data)
+    return false;
+
+  ScheduledDeleteProcessor delete_processor(this);
+  const gfx::Point location(static_cast<int>(event.pointer_data->x),
+                            static_cast<int>(event.pointer_data->y));
+  switch (event.action) {
+    case mojo::EVENT_TYPE_POINTER_DOWN: {
+      if (GetPointerById(event.pointer_data->pointer_id)) {
+        DVLOG(1) << "received more than one down for a pointer without a "
+                 << "corresponding up, id=" << event.pointer_data->pointer_id;
+        NOTREACHED();
+        return true;
+      }
+
+      const ServerView* deepest = FindDeepestVisibleView(root_view_, location);
+      Views targets(GetTouchTargets(deepest));
+      if (targets.empty())
+        return true;
+
+      scoped_ptr<Pointer> pointer(
+          new Pointer(this, event.pointer_data->pointer_id, event, targets));
+      active_pointers_.push_back(pointer.Pass());
+      return true;
+    }
+
+    case mojo::EVENT_TYPE_POINTER_CANCEL:
+    case mojo::EVENT_TYPE_POINTER_MOVE:
+    case mojo::EVENT_TYPE_POINTER_UP: {
+      Pointer* pointer = GetPointerById(event.pointer_data->pointer_id);
+      // We delete a pointer when it has no gestures, so it's possible to get
+      // here with no gestures. Additionally there is no need to explicitly
+      // delete |pointer| as it'll tell us when it's ready to be deleted.
+      if (pointer)
+        pointer->ProcessEvent(event);
+      return true;
+    }
+
+    default:
+      break;
+  }
+  return false;
+}
+
+scoped_ptr<ChangeMap> GestureManager::SetGestures(
+    const ServerView* view,
+    int32_t pointer_id,
+    uint32_t chosen_gesture_id,
+    const std::set<uint32_t>& possible_gesture_ids,
+    const std::set<uint32_t>& canceled_gesture_ids) {
+  // TODO(sky): caller should validate ids and make sure possible contains
+  // canceled and chosen.
+  DCHECK(!canceled_gesture_ids.count(kInvalidGestureId));
+  DCHECK(!possible_gesture_ids.count(kInvalidGestureId));
+  DCHECK(chosen_gesture_id == kInvalidGestureId ||
+         possible_gesture_ids.count(chosen_gesture_id));
+  DCHECK(chosen_gesture_id == kInvalidGestureId ||
+         !canceled_gesture_ids.count(chosen_gesture_id));
+  ScheduledDeleteProcessor delete_processor(this);
+  Pointer* pointer = GetPointerById(pointer_id);
+  current_change_.reset(new ChangeMap);
+  if (pointer) {
+    pointer->SetGestures(view, chosen_gesture_id, possible_gesture_ids,
+                         canceled_gesture_ids);
+  }
+  return current_change_.Pass();
+}
+
+GestureManager::Pointer* GestureManager::GetPointerById(int32_t pointer_id) {
+  for (Pointer* pointer : active_pointers_) {
+    if (pointer->pointer_id() == pointer_id)
+      return pointer;
+  }
+  return nullptr;
+}
+
+void GestureManager::PointerHasNoGestures(Pointer* pointer) {
+  auto iter =
+      std::find(active_pointers_.begin(), active_pointers_.end(), pointer);
+  CHECK(iter != active_pointers_.end());
+  active_pointers_.erase(iter);
+}
+
+GestureManager::Gesture* GestureManager::GetGesture(const ServerView* view,
+                                                    uint32_t gesture_id) {
+  GestureAndConnectionId gesture_and_connection_id =
+      MakeGestureAndConnectionId(view, gesture_id);
+  Gesture* gesture = gesture_map_[gesture_and_connection_id];
+  if (!gesture) {
+    gesture = new Gesture(gesture_id);
+    gesture_map_[gesture_and_connection_id] = gesture;
+  }
+  return gesture;
+}
+
+void GestureManager::AttachGesture(Gesture* gesture,
+                                   Pointer* pointer,
+                                   const ServerView* view) {
+  gesture->Attach(pointer, view);
+}
+
+void GestureManager::DetachGesture(Gesture* gesture,
+                                   Pointer* pointer,
+                                   const ServerView* view) {
+  gesture->Detach(pointer, view);
+  if (gesture->pointers_and_views().empty()) {
+    gesture_map_.erase(MakeGestureAndConnectionId(view, gesture->id()));
+    delete gesture;
+  }
+}
+
+void GestureManager::CancelGesture(Gesture* gesture,
+                                   Pointer* pointer,
+                                   const ServerView* view) {
+  if (gesture->state() == Gesture::STATE_CANCELED)
+    return;
+
+  gesture->set_state(Gesture::STATE_CANCELED);
+  for (auto& pointer_and_view : gesture->pointers_and_views()) {
+    (*current_change_)[pointer_and_view.view].canceled_gestures.insert(
+        gesture->id());
+    if (pointer_and_view.pointer != pointer)
+      pointer_and_view.pointer->GestureCanceled(gesture);
+  }
+}
+
+void GestureManager::ChooseGesture(Gesture* gesture,
+                                   Pointer* pointer,
+                                   const ServerView* view) {
+  if (gesture->state() == Gesture::STATE_CHOSEN) {
+    // This happens when |pointer| is supplied a gesture that is already
+    // chosen.
+    DCHECK((*current_change_)[view].chosen_gesture == kInvalidGestureId ||
+           (*current_change_)[view].chosen_gesture == gesture->id());
+    (*current_change_)[view].chosen_gesture = gesture->id();
+    pointer->GestureChosen(gesture, view);
+  } else {
+    gesture->set_state(Gesture::STATE_CHOSEN);
+    for (auto& pointer_and_view : gesture->pointers_and_views()) {
+      DCHECK((*current_change_)[pointer_and_view.view].chosen_gesture ==
+                 kInvalidGestureId ||
+             (*current_change_)[pointer_and_view.view].chosen_gesture ==
+                 gesture->id());
+      (*current_change_)[pointer_and_view.view].chosen_gesture = gesture->id();
+      pointer_and_view.pointer->GestureChosen(gesture, view);
+    }
+  }
+}
+
+void GestureManager::ScheduleDelete(Pointer* pointer) {
+  auto iter =
+      std::find(active_pointers_.begin(), active_pointers_.end(), pointer);
+  if (iter != active_pointers_.end()) {
+    active_pointers_.weak_erase(iter);
+    pointers_to_delete_.push_back(pointer);
+  }
+}
+
+}  // namespace view_manager