mozart: Initial commit of the view manager.

services/ui/view_manager/view_tree_state.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 SERVICES_UI_VIEW_MANAGER_VIEW_TREE_STATE_H_
+#define SERVICES_UI_VIEW_MANAGER_VIEW_TREE_STATE_H_
+
+#include <memory>
+#include <set>
+#include <unordered_map>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/services/ui/views/interfaces/view_trees.mojom.h"
+#include "services/ui/view_manager/view_state.h"
+
+namespace view_manager {
+
+// Describes the state of a particular view tree.
+// This object is owned by the ViewRegistry that created it.
+class ViewTreeState : public base::SupportsWeakPtr<ViewTreeState> {
+ public:
+  ViewTreeState(mojo::ui::ViewTreePtr view_tree);
+  ~ViewTreeState();
+
+  // Gets the view tree interface, never null.
+  // Caller does not obtain ownership of the view.
+  mojo::ui::ViewTree* view_tree() const { return view_tree_.get(); }
+
+  // Sets the associated host implementation and takes ownership of it.
+  void set_view_tree_host(mojo::ui::ViewTreeHost* host) {
+    view_tree_host_.reset(host);
+  }
+
+  // Sets the connection error handler for the view.
+  void set_view_tree_connection_error_handler(const base::Closure& handler) {
+    view_tree_.set_connection_error_handler(handler);
+  }
+
+  // Gets the root of the view tree, or null if it is unavailable.
+  ViewState* root() const { return root_; }
+
+  // Sets the root of the view tree.  Must not be null.
+  // The view specified as the new root must not have any parents.
+  void SetRoot(ViewState* root, uint32_t key);
+
+  // Resets the root view to null.
+  void ResetRoot();
+
+  // True if the client previously set but has not yet explicitly unset
+  // the root, independent of whether it is currently available.
+  bool root_was_set;
+
+  // True if there is a pending layout request.
+  bool layout_request_pending;
+
+  // True if a layout request has been issued.
+  bool layout_request_issued;
+
+ private:
+  mojo::ui::ViewTreePtr view_tree_;
+  std::unique_ptr<mojo::ui::ViewTreeHost> view_tree_host_;
+
+  ViewState* root_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViewTreeState);
+};
+
+}  // namespace view_manager
+
+#endif  // SERVICES_UI_VIEW_MANAGER_VIEW_TREE_STATE_H_