Wires up drag/drop for aura-mus

ui/aura/mus/drag_drop_controller_mus.cc

+// Copyright 2016 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 "ui/aura/mus/drag_drop_controller_mus.h"
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/auto_reset.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "services/ui/public/interfaces/window_tree.mojom.h"
+#include "services/ui/public/interfaces/window_tree_constants.mojom.h"
+#include "ui/aura/client/drag_drop_delegate.h"
+#include "ui/aura/mus/drag_drop_controller_host.h"
+#include "ui/aura/mus/mus_types.h"
+#include "ui/aura/mus/os_exchange_data_provider_mus.h"
+#include "ui/aura/mus/window_mus.h"
+#include "ui/aura/window.h"
+#include "ui/aura/window_tree_host.h"
+#include "ui/base/dragdrop/drop_target_event.h"
+
+// Interaction with DragDropDelegate assumes constants are the same.
+static_assert(ui::DragDropTypes::DRAG_NONE == ui::mojom::kDropEffectNone,
+              "Drag constants must be the same");
+static_assert(ui::DragDropTypes::DRAG_MOVE == ui::mojom::kDropEffectMove,
+              "Drag constants must be the same");
+static_assert(ui::DragDropTypes::DRAG_COPY == ui::mojom::kDropEffectCopy,
+              "Drag constants must be the same");
+static_assert(ui::DragDropTypes::DRAG_LINK == ui::mojom::kDropEffectLink,
+              "Drag constants must be the same");
+
+namespace aura {
+
+// State related to a drag initiated by this client.
+struct DragDropControllerMus::CurrentDragState {
+  Id window_id;
+
+  // The change id of the drag. Used to identify the drag on the server.
+  uint32_t change_id;
+
+  // The result of the drag. This is set on completion and returned to the
+  // caller.
+  uint32_t completed_action;
+
+  // OSExchangeData supplied to StartDragAndDrop().
+  const ui::OSExchangeData& drag_data;
+
+  // StartDragDrop() runs a nested message loop. This closure is used to quit
+  // the run loop when the drag completes.
+  base::Closure runloop_quit_closure;
+};
+
+DragDropControllerMus::DragDropControllerMus(
+    DragDropControllerHost* drag_drop_controller_host,
+    ui::mojom::WindowTree* window_tree)
+    : drag_drop_controller_host_(drag_drop_controller_host),
+      window_tree_(window_tree) {}
+
+DragDropControllerMus::~DragDropControllerMus() {}
+
+bool DragDropControllerMus::DoesChangeIdMatchDragChangeId(uint32_t id) const {
+  return current_drag_state_ && current_drag_state_->change_id == id;
+}
+
+void DragDropControllerMus::OnDragDropStart(
+    std::map<std::string, std::vector<uint8_t>> data) {
+  os_exchange_data_ = base::MakeUnique<ui::OSExchangeData>(
+      base::MakeUnique<aura::OSExchangeDataProviderMus>(std::move(data)));
+}
+
+uint32_t DragDropControllerMus::OnDragEnter(WindowMus* window,
+                                            uint32_t event_flags,
+                                            const gfx::Point& screen_location,
+                                            uint32_t effect_bitmask) {
+  return HandleDragEnterOrOver(window, event_flags, screen_location,
+                               effect_bitmask, true);
+}
+
+uint32_t DragDropControllerMus::OnDragOver(WindowMus* window,
+                                           uint32_t event_flags,
+                                           const gfx::Point& screen_location,
+                                           uint32_t effect_bitmask) {
+  return HandleDragEnterOrOver(window, event_flags, screen_location,
+                               effect_bitmask, false);
+}
+
+void DragDropControllerMus::OnDragLeave(WindowMus* window) {
+  if (drop_target_window_tracker_.windows().empty())
+    return;
+  DCHECK(window);
+  Window* current_target = drop_target_window_tracker_.Pop();
+  DCHECK_EQ(window->GetWindow(), current_target);
+  client::GetDragDropDelegate(current_target)->OnDragExited();
+}
+
+uint32_t DragDropControllerMus::OnCompleteDrop(
+    WindowMus* window,
+    uint32_t event_flags,
+    const gfx::Point& screen_location,
+    uint32_t effect_bitmask) {
+  if (drop_target_window_tracker_.windows().empty())
+    return ui::mojom::kDropEffectNone;
+
+  DCHECK(window);
+  Window* current_target = drop_target_window_tracker_.Pop();
+  DCHECK_EQ(window->GetWindow(), current_target);
+  std::unique_ptr<ui::DropTargetEvent> event = CreateDropTargetEvent(
+      window->GetWindow(), event_flags, screen_location, effect_bitmask);
+  return client::GetDragDropDelegate(current_target)->OnPerformDrop(*event);
+}
+
+void DragDropControllerMus::OnPerformDragDropCompleted(uint32_t action_taken) {
+  DCHECK(current_drag_state_);
+  current_drag_state_->completed_action = action_taken;
+  current_drag_state_->runloop_quit_closure.Run();
+}
+
+void DragDropControllerMus::OnDragDropDone() {
+  os_exchange_data_.reset();
+}
+
+int DragDropControllerMus::StartDragAndDrop(
+    const ui::OSExchangeData& data,
+    Window* root_window,
+    Window* source_window,
+    const gfx::Point& screen_location,
+    int drag_operations,
+    ui::DragDropTypes::DragEventSource source) {
+  DCHECK(!current_drag_state_);
+
+  // TODO(erg): Pass |cursor_location| and |bitmap| in PerformDragDrop() when
+  // we start showing an image representation of the drag under he cursor.
+
+  base::RunLoop run_loop;
+  WindowMus* source_window_mus = WindowMus::Get(source_window);
+  const uint32_t change_id =
+      drag_drop_controller_host_->CreateChangeIdForDrag(source_window_mus);
+  CurrentDragState current_drag_state = {source_window_mus->server_id(),
+                                         change_id, ui::mojom::kDropEffectNone,
+                                         data, run_loop.QuitClosure()};
+  base::AutoReset<CurrentDragState*> resetter(&current_drag_state_,
+                                              &current_drag_state);
+  std::map<std::string, std::vector<uint8_t>> drag_data =
+      static_cast<const aura::OSExchangeDataProviderMus&>(data.provider())
+          .GetData();
+  window_tree_->PerformDragDrop(
+      change_id, source_window_mus->server_id(),
+      mojo::Map<mojo::String, mojo::Array<uint8_t>>::From(drag_data),
+      drag_operations);
+
+  base::MessageLoop* loop = base::MessageLoop::current();
+  base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
+  run_loop.Run();
+
+  return current_drag_state.completed_action;
+}
+
+void DragDropControllerMus::DragCancel() {
+  DCHECK(current_drag_state_);
+  // Server will clean up drag and fail the in-flight change.
+  window_tree_->CancelDragDrop(current_drag_state_->window_id);
+}
+
+bool DragDropControllerMus::IsDragDropInProgress() {
+  return current_drag_state_ != nullptr;
+}
+
+uint32_t DragDropControllerMus::HandleDragEnterOrOver(
+    WindowMus* window,
+    uint32_t event_flags,
+    const gfx::Point& screen_location,
+    uint32_t effect_bitmask,
+    bool is_enter) {
+  client::DragDropDelegate* drag_drop_delegate =
+      window ? client::GetDragDropDelegate(window->GetWindow()) : nullptr;
+  WindowTreeHost* window_tree_host =
+      window ? window->GetWindow()->GetHost() : nullptr;
+  if ((!is_enter && drop_target_window_tracker_.windows().empty()) ||
+      !drag_drop_delegate || !window_tree_host) {
+    drop_target_window_tracker_.RemoveAll();
+    return ui::mojom::kDropEffectNone;
+  }
+  drop_target_window_tracker_.Add(window->GetWindow());
+
+  std::unique_ptr<ui::DropTargetEvent> event = CreateDropTargetEvent(
+      window->GetWindow(), event_flags, screen_location, effect_bitmask);
+  if (is_enter)
+    drag_drop_delegate->OnDragEntered(*event);
+  return drag_drop_delegate->OnDragUpdated(*event);
+}
+
+std::unique_ptr<ui::DropTargetEvent>
+DragDropControllerMus::CreateDropTargetEvent(Window* window,
+                                             uint32_t event_flags,
+                                             const gfx::Point& screen_location,
+                                             uint32_t effect_bitmask) {
+  DCHECK(window->GetHost());
+  gfx::Point root_location = screen_location;
+  window->GetHost()->ConvertPointFromNativeScreen(&root_location);
+  gfx::Point location = root_location;
+  Window::ConvertPointToTarget(window->GetRootWindow(), window, &location);
+  std::unique_ptr<ui::DropTargetEvent> event =
+      base::MakeUnique<ui::DropTargetEvent>(
+          current_drag_state_ ? current_drag_state_->drag_data
+                              : *(os_exchange_data_.get()),
+          location, root_location, effect_bitmask);
+  event->set_flags(event_flags);
+  return event;
+}
+
+}  // namespace aura